CN1700427A - Device and method for plasma processing, and slow-wave plate - Google Patents

Abstract

In a microwave plasma processing apparatus that uses a radial line slot antenna, a slot plate (16) is formed by a material having a thermal expansion rate close to the wave retardation plate (18), or depositing a metal on a dielectric plate constituting the wave retardation plate (18). An intimate contact between the wave retardation plate and a slot plate constituting a microwave radiation surface is improved so as to prevent an abnormal electric discharge.

Description

Plasma processing apparatus, method of plasma processing and slow-wave plate

This case be the application number submitted on March 28th, 2002 be 02800921.5 (PCT/JP02/03112), denomination of invention leads dividing an application of the identical patent application of this case.

Technical field

The present invention relates generally to a kind of plasma processing apparatus, relate in particular to a kind of microwave plasma processing apparatus.

Plasma treatment operation and plasma processing apparatus for have in recent years what is called be called super sub-micro element (deep submicron) or super inferior 1/4th microcomponents (deep subquartermicron) near 0.1 μ m or less than the manufacturing of the superfine semiconductor device of 0.1 μ m grid length or to comprise for the manufacturing of high definition flat display apparatus of liquid crystal indicator be indispensable technology.

As being used for producing the semiconductor devices or the plasma processing apparatus of liquid crystal indicator, used various plasma exciatiaon modes in the past, but especially general be parallel plate-type high frequency excitation plasma processing apparatus or induction coupled mode plasma processing apparatus.But the plasma of these existing plasma processing apparatus forms inhomogeneous, limits electron-dense zone, also is the problem of under the output the whole surface of processed substrate evenly being processed so existence is difficult in big processing speed.This problem is particularly more deep under the situation of handling the major diameter substrate.In addition, in these existing plasma processing apparatus, the semiconductor element that forms in the processed substrate is produced infringement, in addition, also have several essential problems such as metallic pollution that the sputter of process chamber wall causes is big because electron temperature is high.Therefore, by existing plasma processing apparatus, be difficult to more granular and the more corresponding strict demand of high production rate satisfied and semiconductor device or liquid crystal indicator.

On the other hand, proposal is not in the past used D.C. magnetic field and is used the microwave plasma processing apparatus of the high-density plasma that is excited by microwave electric field.For example, propose the plasma processing apparatus of following structure:, utilize the gas in this microwave electric field electric vacuum container to come activated plasma from having plane antenna (radioactive ray slot antenna) microwave radiation in container handling of a plurality of grooves of arranging according to even microwave can be produced.(for example open flat 9-63793 communique with reference to the spy.) microwave plasma that excited by this method can realize high plasma density in the wide zone under antenna, can carry out uniform plasma treatment at short notice.In addition, because the microwave plasma that forms through this method does not use the stimulating frequency height and used the resonance phenomenon of the electronics in magnetic field,, can avoid the infringement or the metallic pollution of processed substrate so electron temperature is low.And owing on large-area substrates, excite uniform plasma easily, so also can be easily corresponding to the manufacturing process of the semiconductor element that uses the heavy caliber semiconductor substrate or the manufacturing of large-scale liquid crystal indicator.

Background technology

Figure 1A, 1B represent to use the structure of the existing microwaveplasma processing apparatus 100 of this radioactive ray slot antenna.Figure 1A is the sectional view of expression microwaveplasma processing apparatus 100, and Figure 1B is the figure of expression radioactive ray slot antenna structure.

With reference to Figure 1A, microwaveplasma processing apparatus 100 has from theprocess chamber 101 of a plurality ofexhaust passages 116 exhausts, forms themaintenance platform 115 that keeps processedsubstrate 114 in above-mentioned process chamber 101.In order to realize the even exhaust of above-mentionedprocess chamber 101, around above-mentionedmaintenance platform 115, form thespace 101A of annular, by equally spaced, promptly form above-mentioned a plurality ofexhaust passage 116 symmetrically and be communicated with above-mentionedspace 101A for processed substrate axis, thereby above-mentionedprocess chamber 101 can be by above-mentionedspace 101A andexhaust passage 116 even exhausts.

Above above-mentionedprocess chamber 101, on position corresponding to the processedsubstrate 114 on the above-mentionedmaintenance platform 115, form as above-mentionedprocess chamber 101 part outer walls, constitute, be formed with the plateshape shower plate 103 of a plurality ofperistomes 107 byseal 109, and byother seal 108 cover plate 102 that is made of the low-dielectric loss dielectric is set too in the outside of above-mentionedshower plate 103 by the low-dielectric loss dielectric.

In above-mentionedshower plate 103, form thepath 104 of plasma gas in the above, form above-mentioned a plurality ofperistome 107 according to each mode that all is communicated with above-mentioned plasma gas path 104.And, the inside of above-mentionedshower plate 103 form be arranged on above-mentioned container handling 101 outer walls on plasma gas plasma exciatiaon gas that port one 05 is communicated with is providedpath 106 is provided, providepath 106 to carry to above-mentionedperistome 107 to offer the plasma exciatiaon gas that above-mentioned plasma exciatiaon gas provides the Ar of port one 05 or Kr etc., discharge from thespace 101B of above-mentionedperistome 107 under the above-mentionedshower plate 103 of above-mentioned container handling 101 inside from above-mentioned with the same in fact concentration by above-mentionedpath 104.

On above-mentionedcontainer handling 101,, has the radioactive ray slot antenna 110 that the setting of 4-5mm part has radiating surface shown in Figure 1B apart from above-mentioned cover plate 102 also in the outside of above-mentioned cover plate 102.Above-mentioned radioactive ray slot antenna 110 is connected in external microwave source (not shown) bycoaxial waveguide 110A, by the microwave from above-mentioned microwave source, excites the plasma exciatiaon gas to above-mentionedspace 101B discharging.Fill the gap between the radiating surface of above-mentioned cover plate 102 and radioactive ray slot antenna 110 by atmosphere.

Above-mentioned radioactive ray slot antenna 110 is by the flat disk shaped radial lineback metal plate 110B on the outer conductor that is connected in above-mentionedcoaxial waveguide 110A and be formed in the peristome of above-mentioned radial lineback metal plate 110B, theradiant panel 110C that forms a plurality ofgroove 110a shown in Figure 1B and perpendicular a plurality ofgroove 110b constitutes, and inserts the slow-wave plate 110D that is made of certain thickness dielectric film between above-mentioned radial lineback metal plate 110B and above-mentionedradiant panel 110C.

In the radioactive ray slot antenna 110 of this structure, advance from microwave edge radial direction between above-mentioned dish type radial lineback metal plate 110B andradiant panel 110C of above-mentioned coaxial waveguide 110 power supplies limit that broadens, at this moment, owing to wavelength is compressed in the effect of above-mentioned slow-wave plate 110D.Therefore, corresponding to the microwave wavelength of advancing on radial direction, above-mentionedgroove 110a and 110b form circular concentric, and are perpendicular to one another, thereby can have the plane wave of circularly polarized wave along essence perpendicular to the direction radiation of above-mentionedradiant panel 110C.

By using this radioactive ray slot antenna 110, form uniform high-density plasma among thespace 101B under above-mentioned shower plate 103.So the electron temperature of the high-density plasma that forms is low, therefore, can not produce infringement to processedsubstrate 114, in addition, also can not produce the metallic pollution that comes from container handling 101 wall sputters.

Theplasma processing apparatus 100 of Fig. 1 also formsconductor structure thing 111 in above-mentionedcontainer handling 101, form in the diffusion plasma zone of thisconductor structure thing 111 between above-mentionedshower plate 103 and processedsubstrate 114 from external treatment gas source (not shown) and provide a plurality ofnozzles 113 of handling gas by theprocessing gas passage 112 that is formed at the above-mentionedcontainer handling 101, the processing gaseous emission that above-mentioned eachnozzle 113 will provide is in thespace 101C between above-mentionedconductor structure thing 111 and the processed substrate 114.In above-mentionedconductor structure thing 111, between above-mentionedadjacent nozzles 113 and 113, form by be diffused into the big peristome that above-mentionedspace 101C effectively passes through the plasma that forms the above-mentionedspace 101B from above-mentionedspace 101B.

Therefore, passing through saidnozzle 113 under the situation of above-mentionedspace 101C evacuated of process gases from above-mentionedconductor structure thing 111, because in the low plasma gas of electron temperature, can suppress to handle excessively dissociating of gas, so on above-mentioned processedsubstrate 114, can effectively, at a high speed but not damage component structure on substrate and the substrate, also do not pollute substrate ground and carry out same high-quality plasma treatment.On the other hand, utilize thisconductor structure thing 111 to stop the microwave that gives off from above-mentioned radioactive ray slot antenna 110, even before plasma igniting, also can not damage processedsubstrate 114.

In a word, in theplasma processing apparatus 100 that uses this radioactive ray slot antenna 110, because the plasma density that forms among the above-mentionedspace 101B reaches the order of magnitude of 1012/cm3, soshower plate 103 is exposed under a large amount of ions and electronics that constitute the above-specified high density plasma, produces the heating that is caused by these ions and electronics.The hot-fluid that comes from this ion and electronics also reaches 1～2W/cm2.And, in above-mentionedplasma processing apparatus 100, in order to suppress deposit attached on theprocess chamber 101, how the walls ofprocess chamber 101 are remained under the temperature about 150 ℃ and move, but thisprocess chamber 101 add thermal result, heat accumulation in above-mentionedshower plate 103 that constitutes by dielectric substance and cover plate 102, thus very large Temperature Distribution produced.

In order to alleviate heat in this accumulation inshower plate 103 and cover plate 102, though expectation is close on the above-mentioned cover plate 102 above-mentioned radioactive ray slot antenna 110, with antenna 110 as the radiator heat extraction of making a return journey, but in existing radioactive ray slot antenna 110, because above-mentionedradiant panel 110C is screwed in the center conductor of above-mentionedcoaxial waveguide 110A in opposite directions, so must guarantee between above-mentioned cover plate 102 andradiant panel 110C, to leave the gap that head of screw is used, be difficult to adopt this structure.

In addition, in existingplasma processing apparatus 100, by the hot-fluid from above-mentionedshower plate 103 and cover plate 102, even above-mentioned radioactive ray slot antenna 110 does not connect airtight in above-mentioned cover plate 102, in fact also heated, temperature rises.In addition, under the situation that above-mentioned radioactive ray slot antenna 110 is connected airtight, the temperature of antenna rises bigger.

Existing radioactive ray slot antenna designs not use to prerequisite under hot environment, therefore, under the situation that like this antenna temperature rises, because the coefficient of thermal expansion difference, sometimes in antenna, particularly be arranged to produce the gap between thedielectric plate 110D of slow-wave plate and the radiant panel 110C.So, in case when producing the gap between slow-wave plate 110D andradiant panel 110C, the paradoxical discharge of not expecting takes place in the microwave induced impedance disorder of propagating in the slow-wave plate in antenna and reflected wave forms or problems such as standing wave formation.In case the generation paradoxical discharge, then this antenna just can not use afterwards.

Summary of the invention

Therefore, the object of the present invention is to provide a kind of new-type useful plasma processing apparatus that has solved above-mentioned problem.

Problem more specifically of the present invention is using the radioactive ray slot antenna to come the plasma processing apparatus of activated plasma, improves the slow-wave plate in the radioactive ray slot antenna and the adhesiveness of radiant panel.

Other problem of the present invention is to be provided at the structure that also can stablize microwave radiation under the heated situation of antenna to using the radioactive ray slot antenna to come the plasma processing apparatus of activated plasma.

Other problem of the present invention is to provide a kind of plasma processing apparatus, it by:

Surround and possess the container handling of the maintenance platform that keeps processed substrate with outer wall;

Be connected in the gas extraction system on the above-mentioned container handling;

The plasma gas supply unit of plasma gas is provided in above-mentioned container handling; With

The microwave antenna that is provided with, powers by coaxial waveguide on described container handling, corresponding to described plasma gas supply unit constitutes, and it is characterized in that:

Above-mentioned microwave antenna is by the radial line back metal plate with peristome; Be arranged to cover the microwave radiation surface that is positioned at the above-mentioned peristome on the above-mentioned radial line back metal plate and is provided with a plurality of grooves; And the dielectric plate that is arranged between above-mentioned radial line back metal plate and the microwave radiation surface constitutes,

Above-mentioned microwave radiation surface is made of conductive material, the thermal expansion rate variance of this conductive material and above-mentioned dielectric plate with respect to the coefficient of thermal expansion of above-mentioned dielectric plate in 10%.

According to the present invention, because the thermal expansion difference between the frid of slow-wave plate in the radioactive ray slot antenna and formation radiating surface is controlled at below 10%, so promptly use the heated by plasma antenna also can not occur in the problem that produces the gap in the antenna, can avoid the formation of thing followed paradoxical discharge or reflected wave, the problems such as formation of standing wave.

Other problem of the present invention is to provide a kind of plasma processing apparatus, it by:

Surround and possess the container handling of the maintenance platform that keeps processed substrate with outer wall;

Be connected in the gas extraction system of above-mentioned container handling;

The plasma gas supply unit of plasma gas is provided in above-mentioned container handling; With

The microwave antenna that be positioned at described container handling top, is provided with, powers by coaxial waveguide corresponding to described plasma gas supply unit constitutes, and it is characterized in that:

Above-mentioned microwave antenna is by the radial line back metal plate with peristome; Be arranged to cover the microwave radiation surface that is positioned at the above-mentioned peristome on the above-mentioned radial line back metal plate and is provided with a plurality of grooves; And the dielectric plate that is arranged between above-mentioned radial line back metal plate and the microwave radiation surface constitutes,

Above-mentioned microwave radiation surface is made of the coating that is formed at the electric conducting material on the above-mentioned dielectric plate.

In the present invention, on above-mentioned slow-wave plate, form above-mentioned frid, fill trickle concavo-convex on the above-mentioned slow-wave plate, the adhesion that can realize ideal between above-mentioned frid and the slow-wave plate by coating by plating.

Other problem of the present invention is to provide a kind of plasma processing apparatus, possesses:

Inside is provided with the container handling of the mounting table of the processed substrate of mounting;

Produce microwave and offer the microwave generator of above-mentioned container handling;

Be arranged between this microwave generator and the above-mentioned container handling, shorten the slow-wave plate of the microwave wavelength that provides from above-mentioned microwave generator; With

To shorten microwave radiation parts in the space of microwave radiation in the above-mentioned container handling behind wavelength by this slow-wave plate, it is characterized in that:

Above-mentioned slow-wave plate at least above and below the formation metal level,

Above-mentioned microwave radiation parts are made of the above-mentioned metal level that forms on above-mentioned slow-wave plate surface.

In the present invention, by slow-wave plate at least above and below formation coating, make following coating as the microwave radiation part, even by heated by plasma microwave radiation part, can not be created in problems such as the gap takes place between microwave radiation part and the slow-wave plate yet.Therefore, can avoid the problem such as formation, standing wave formation of paradoxical discharge or reflected wave.In addition, by the coating that on slow-wave plate, forms, even in the upper part of slow-wave plate, also can between metal part and slow-wave plate, not produce the gap, so microwave radiation characteristics is stable.In addition, according to foregoing invention, because form the microwave radiation parts by metal level, so but the thickness of reducing thin groove part can suppress to come from the microwave reflection by (cutoff) phenomenon in the slot part, improve radiation efficiency.

Other problem of the present invention is to provide a kind of method of plasma processing, and this method is used microwave plasma processing apparatus, and this device has the container handling that inside is provided with the mounting table of the processed substrate of mounting; Produce microwave and offer the microwave generator of above-mentioned container handling; Be arranged between this microwave generator and the above-mentioned container handling, cover top and following, shortening slow-wave plate by metal level at least from the microwave wavelength of above-mentioned microwave generator; Microwave radiation parts with a part of utilizing the above-mentioned metal level that forms in above-mentioned slow-wave plate surface constitutes is characterized in that:

The treated side of above-mentioned processed substrate is placed on the above-mentioned mounting table according to the mode relative with above-mentioned microwave radiation parts,

Provide microwave to above-mentioned slow-wave plate, and a plurality of grooves from be formed at the part metals layer import microwave in above-mentioned container handling,

Microwave by importing produces plasma in above-mentioned container handling, utilize the plasma that produces that above-mentioned processed substrate is implemented plasma treatment.

Other problem of the present invention is to provide a kind of slow-wave plate, it is used for having the container handling of implementing plasma treatment and produces microwave and offer the microwave plasma processing apparatus of the microwave generator of above-mentioned container handling, the microwave wavelength that shortening is provided by above-mentioned microwave generator, it is characterized in that: cover by metal level with following at least, utilize the part of this metal level to constitute the microwave radiation parts.

In the present invention, because the microwave radiation parts are integrally formed as a part and the slow-wave plate of metal level, so will not make and combine as separate part with the microwave radiation parts by slow-wave plate.Therefore, prevent from because of thermal expansion or change in time between slow-wave plate and microwave radiation parts, to form the gap, can in container handling, import the same microwave.Therefore, can carry out plasma treatment with low uncertainty in time, that reproducibility is good.In addition, because whole substantially slow-wave plate is all covered by the coat of metal, do not import in the container handling, so can generate plasma effectively so offer the microwave of slow-wave plate with leaking.

Description of drawings

Figure 1A, Figure 1B are the figure that the plasma processing apparatus structure of existing radioactive ray slot antenna has been used in expression;

Fig. 2 A, 2B are the figure that expression utilizes the plasma processing apparatus structure of the present invention's the 1st execution mode;

Fig. 3 is the figure of the part of the radioactive ray slot antenna that uses in the plasma processing apparatus that amplifies among presentation graphs 2A, the 2B;

Fig. 4 is the structure chart that the processing gas of the microwave plasma processing apparatus of presentation graphs 2A provides mechanism;

Fig. 5 is a kind of figure that changes example of the plasma processing apparatus of presentation graphs 2A, 2B;

Fig. 6 is the figure that expression utilizes the plasma processing apparatus structure of the present invention's the 2nd execution mode;

Fig. 7 A-7D is the figure that is illustrated in the formation operation of using in the plasma processing apparatus of Fig. 6 radioactive ray slot antenna, frid;

Fig. 8 is the brief configuration figure that utilizes the microwave plasma processing apparatus of the present invention's the 3rd execution mode;

Fig. 9 is the sectional view of slow-wave plate shown in Figure 8;

Figure 10 is the plane graph of the groove of the coat of metal that forms in the slow-wave plate shown in Figure 8 of expression;

Figure 11 is the sectional view of an example being connected between expression coaxial waveguide and the slow-wave plate;

Figure 12 is the sectional view of another example of being connected between expression coaxial waveguide and the slow-wave plate.

Embodiment

Exemplify execution mode below and describe the present invention in detail.

(the 1st execution mode)

Fig. 2 A, 2B represent to utilize the structure of the microwaveplasma processing apparatus 10 of the present invention's the 1st execution mode.

With reference to Fig. 2 A, above-mentioned microwaveplasma processing apparatus 10 comprises: container handling 11; Be arranged in the above-mentioned container handling 11, keep processedsubstrate 12 and preferably by the AlN or the Al that utilize hot isostatic pressing method (HIP) to form by electrostatic chuck₂O₃Themaintenance platform 13 that forms, in above-mentioned container handling 11, in surrounding thespace 11A of above-mentionedmaintenance platform 13 equally spaced, promptly in that basic at least two positions that become the axial symmetry relation, best threeform exhaust passage 11a on the upper part with respect to the processed substrate on the above-mentionedmaintenance platform 13 12.Above-mentioned container handling 11 is by thisexhaust passage 11a, do not waited inclination spiral pump etc. and carried out exhaust, decompression by unequal-interval.

Above-mentioned container handling 11 preferably is made of the austenitic stainless steel that contains Al, forms the diaphragm that is made of aluminium oxide (aluminum oxide) through oxidation processes at internal face.In addition, by the fine and close Al that forms by the HIP method₂O₃Constitute and be formed with the dishtype shower plate 14 of a plurality of nozzle opening 14A of portion,, and be formed in the outer wall of above-mentioned container handling 11 in the part corresponding with above-mentioned processedsubstrate 12 as the part of above-mentioned outer wall.Use Y₂O₃Form the Al that forms by this HIP method as sintering adjuvant₂O₃Shower plate 14, because of the porosity below 0.03%, so do not comprise pore or pin hole in fact, have very large pyroconductivity as pottery, reach 30W/mK, but less than AlN.

Above-mentionedshower plate 14 is installed on the above-mentioned container handling 11 by sealingring 11s, and is provided with by handle the fine and close Al that forms through same HIP by sealingring 11t on above-mentioned shower plate 14₂O₃Thecover plate 15 that constitutes.Side that contacts with above-mentionedcover plate 15 at above-mentionedshower plate 14 forms therecess 14B that is communicated with, constitutes the plasma exciatiaon gas flow path with each saidnozzle peristome 14A, and above-mentionedrecess 14B is communicated in other plasmagas flow road 14C that forms and be connected with theplasma gas inlet 11p that forms in the inside of above-mentionedshower plate 14 on above-mentioned container handling 11 outer walls.

Keep above-mentionedshower plate 14 by theextension 11b that is formed at above-mentioned container handling 11 inwalls, in above-mentionedextension 11b, in the part that keeps above-mentionedshower plate 14, form circle, to suppress paradoxical discharge.

In addition, offer plasma gases such as the Ar of above-mentioned plasmaexciatiaon gas access 11p or Kr, equally offer among the space 11B under the above-mentionedshower plate 14 by above-mentionedperistome 14A successively by behind thestream 14C and 14B of above-mentionedshower plate 14 inside.

On above-mentioned cover plate 15 radioactive ray slot antenna 20 is set, this antenna is by connecting airtight in above-mentioned cover plate 15 and forming a plurality of groove 16a shown in Fig. 2 B, the dish type frid 16 of 16b; The metallic disc-shaped plate 17 (radial line back metal plate) that keeps above-mentioned frid 16; And be clamped between above-mentioned frid 16 and the above-mentioned metallic plate 17, by Al₂O₃, SiO₂Or Si₃N₄The slow-wave plate 18 that forms Deng the low-dielectric loss dielectric substance constitutes.The Cu (copper) that above-mentioned frid 16 preferably comprises up to 10wt%W (tungsten) constitutes, and is 7～8 * 10 using coefficient of linear expansion especially^-6/ ℃ Al₂O₃Be used as under the situation of above-mentioned slow-wave plate 18, be about 7 * 10 by using coefficient of linear expansion^-6/ ℃ the Cu-W alloy be used as slow-wave plate 18, can with and above-mentioned slow-wave plate 18 between thermal expansion difference suppress for less than 10%.Because the resistivity of above-mentioned Cu-W alloy is bigger, so under the situation of the frid 16 that is used as the radioactive ray slot antenna, consider the kelvin effect of microwave, shown in the enlarged drawing of Fig. 3, be preferably in and form thickness on the frid 16 approximately greater than the Au (gold) of 3 μ m or the conductive formation 16r of Ag (silver), copper (Cu) etc.For example can easily form this conductive formation 16r by the electrolysis plating.

Above-mentionedfrid 16 can be bonded on the above-mentioned slow-wave plate 18 by the ceramic-like bonding agent.As this ceramic-like bonding agent, be typically on market, circulate aluminium oxide (alumina) particle is dispersed in bonding agent in the solvent.After bonding, make the solvent volatilization, obtain thefirm adhesive linkage 181 of no lossy microwave shown in Figure 3 by annealing down at 200-300 ℃.

Above-mentioned radioactiveray slot antenna 20 is installed on the above-mentioned container handling 11 by sealingring 11u, and providing frequency by external microwave source (not shown) to above-mentioned radioactiveray slot antenna 20 bycoaxial waveguide 21 is the microwave of 2.45GHz or 8.3GHz.Groove 16a, the 16b of the microwave that provides from above-mentionedfrid 16 is radiated the above-mentioned container handling 11 by above-mentionedcover plate 15 andshower plate 14, among the space 11B under above-mentionedshower plate 14, activated plasma the plasma gas that provides from above-mentioned peristome 14A.At this moment, by Al₂O₃Form above-mentionedcover plate 15 andshower plate 14, as effective microwave penetrating window.At this moment, because avoid activated plasma in above-mentioned plasmagas flow road 14A-14C, so above-mentioned plasma gas can be maintained at about the pressure of 6666Pa-13332Pa (about 50-100Torr) in above-mentionedstream 14A-14C.

In order to improve the adhesiveness of above-mentioned radioactiveray slot antenna 20 and above-mentionedcover plate 15, in the microwaveplasma processing apparatus 10 of present embodiment, with a part above the chimeric above-mentioned container handling 11 of above-mentionedfrid 16 in be formed with thegroove 11g of annular, by theexhaust passage 11G that is communicated with groove to groove 11g exhaust, make the gap decompression that is formed between above-mentionedfrid 16 and thecover plate 15, thereby can above-mentioned radioactiveray slot antenna 20 be crimped on the above-mentionedcover plate 15 securely by atmospheric pressure.Though thegroove 16a, the 16b that form on above-mentionedfrid 16 are included in this gap, and the gap that forms because of other various reasons is also arranged.Seal this gap by the sealingring 11u between above-mentioned radioactiveray slot antenna 20 and the container handling 11.

In addition, by filling the big inert gas of pyroconductivity in the gap between above-mentionedfrid 16 and above-mentionedcover plate 15 by means of above-mentionedexhaust passage 11G andgroove 11g, can promote heat from above-mentionedcover plate 15 to above-mentionedfrid 16 transmission.As this inert gas, preferably use the big and high He of ionization energy of pyroconductivity.In above-mentioned gap, filling under the situation of He, preferably pressure is set in about 0.8 air pressure.In the structure of Fig. 3, fill inert gas for the exhaust of above-mentionedgroove 11g with to groove 11g,vacuum valve 11V is connected on the above-mentionedexhaust passage 11G.

Among the above-mentionedcoaxial waveguide 21A, outsidewaveguide 21A is connected in metallic disc-shaped plate 17 (radial line back metal plate), andcenter conductor 21B is connected with above-mentionedfrid 16 by the peristome that forms in the above-mentioned slow-wave plate 18.Therefore, radially advance between above-mentionedmetallic plate 17 and frid 16 in the microwave limit that offers above-mentionedcoaxial waveguide 21, and the limit is through above-mentionedgroove 16a, 16b radiation.

Fig. 2 B representsgroove 16a, the 16b of formation on the above-mentionedfrid 16.

With reference to Fig. 2 B, above-mentionedgroove 16a is arranged in circular concentric, and corresponding to eachgroove 16a,perpendicular groove 16b forms circular concentric too.Above-mentionedgroove 16a, 16b on the radial direction of above-mentionedfrid 16 forming corresponding to interval by the microwave wavelength after 18 compressions of above-mentioned slow-wave plate, the result, behind the ripple of the basic complanation of microwave from above-mentionedfrid 16 radiation.At this moment, because above-mentionedgroove 16a and 16b form with the relation that is perpendicular to one another, so the microwave that gives off forms the circularly polarized wave that comprises two vertical partial wave components.

In addition, in theplasma processing apparatus 10 of Fig. 2 A, on above-mentionedmetallic plate 17,form cooling device 19 with coolingwater path 19A, by by the above-mentionedcooling device 19 of the water quench among the above-mentionedcooling water path 19A, be absorbed in the heat of accumulation in the above-mentionedshower plate 14 by means of above-mentioned radioactive ray slot antenna 20.Above-mentionedcooling water path 19A forms spirality on above-mentionedcooling device 19, preferably be connected with to utilize oxygen H2 gas is foamed get rid of dissolving and the cooling water of control peroxidating reduction potential.

In addition, in the microwaveplasma processing apparatus 10 of Fig. 2 A, in the above-mentioned container handling 11 between the processedsubstrate 12 on above-mentionedshower plate 14 and the above-mentionedmaintenance platform 13 set handlinggas mechanism 31 is provided, this structure have the processing gas that will provide from the processinggas inlet 11r that is arranged on above-mentioned container handling 11 outer walls from a plurality of processinggas nozzle openings 31B of portion (with reference to Fig. 4) emit clathrate handlegas passage 31A, the uniform processing substrate of in above-mentioned processing gas providesspace 11C betweenmechanism 31 and the above-mentioned processedsubstrate 12, expecting.In this processing substrate, comprise plasma oxidation processing, plasma nitridation process, plasma oxygen nitrogen treatment, plasma CVD processing etc.In addition, providemechanism 31 to provide C from above-mentioned processing gas to above-mentionedspace 11C₄F₈, C₅F₈Or C₄F₆Etc. the fluorohydrocarbon gas and the etching gass such as F series or Cl series of rich carbon,, can carry out reactive ion etching facing to above-mentioned processedsubstrate 12 by providing high frequency voltage to above-mentionedmaintenance platform 13 from high frequencyelectric source 13A.

In the microwaveplasma processing apparatus 10 of present embodiment, be heated to temperature about 150 ℃ by outer wall with above-mentioned container handling 11, avoid reacting secondary product etc. and be bonded on the container handling inwall, the dry-cleaning about being undertaken once by one day can normally stably move.

Fig. 4 handles the upward view that gas provides the structure ofmechanism 31 among the presentation graphs 2A.

With reference to Fig. 4, above-mentioned processing gas provides mechanism 31 to be made of the electric conductors such as stainless steel of Al alloy that for example comprises Mg or interpolation Al, above-mentioned clathrate is handled gas passage 31A provides port 31R to be connected on the above-mentioned processing gas inlet 11r by handling gas, and a plurality of processing gas nozzle openings 31B of portion that form from below are to the even evacuated of process gases of above-mentioned space 11C.In addition, provide in the mechanism 31 to form at above-mentioned processing gas and make the processing gas that comprises in plasma or the plasma by the peristome 31C between the adjacent processing gas passage 31A.Provide under the situation of mechanism 31 forming above-mentioned processing gas, preferably form fluoride films from the teeth outwards by the Al alloy that contains Mg.In addition, forming above-mentioned processing gas at the stainless steel by interpolation Al provides under the situation of mechanism 31, and expectation forms the passive film of aluminium oxide from the teeth outwards.In plasma processing apparatus 10 of the present invention, because the electron temperature in the plasma that is excited is low, so the ion incidence energy in the plasma is little, avoid on processed substrate 12, producing the problem of metallic pollution because of this processing gas provides the sputter of mechanism 31.Above-mentioned processing gas provides mechanism 31 also can be formed by quartz or aluminium oxide dielectrics such as (Alumina).

Above-mentioned clathrate is handledgas passage 31A and is handled thegas nozzle openings 31B of portion and is provided with according to the mode that covers than the big slightly zone of processedsubstrate 12 shown in dotted lines in Figure 4.By being set, this processing gas providesmechanism 31 between above-mentionedshower plate 14 and processedsubstrate 12, the above-mentioned processing gas of plasma exciatiaon, and the processing gas that utilizes this plasma exciatiaon to cross can be handled uniformly.

Provide under the situation ofmechanism 31 forming above-mentioned processing gas by conductors such as metals, shorter than the size of the cut-off waveguide corresponding with above-mentioned microwave wavelength (カ Star ト オ Off Guide wave duct) by above-mentioned clathrateprocessing gas passage 31A interval is each other set for, above-mentioned processing gas providesmechanism 31 to form the branch stream interface (shunting plane) of microwaves.At this moment, only in above-mentioned space 11B, produce the microwave-excitation of plasma, in thespace 11C that comprises above-mentioned processedsubstrate 12 surfaces, utilize the plasma that excites 11B diffusion in space from above-mentioned, activate and handle gas.In addition, when plasma igniting, directly be exposed to microwave, so also prevented the infringement of microwave to substrate because prevent above-mentioned processedsubstrate 12.

In the microwaveplasma processing apparatus 10 of present embodiment, because by using processing gas that providing of mechanism's 31 same control and treatment gases is provided, so can eliminate the problem of handling gas excessive decomposition on processedsubstrate 12 surfaces, even under the situation that forms big aspect-ratio structure on the surface of processedsubstrate 12, the also the inside that the processing substrate of expectation can be carried out this high-aspect-ratio structure.That is, microwaveplasma processing apparatus 10 in different many of design rule make for semiconductor device effectively.

In the microwaveplasma processing apparatus 10 of present embodiment, according to purposes,plasma processing apparatus 10A that also can be as shown in Figure 5 is such, cancels above-mentioned processing gas supply part 31.But in Fig. 5, the part that illustrates in front is marked with identical reference marks, omits explanation.

In the structure of Fig. 5, by import oxidizing gas or NH such as inert gas such as Ar or Kr and O2 from above-mentionedshower plate 14₃Or N₂With H₂Nitriability gases such as mist, can on the surface of above-mentioned processedsubstrate 12, form oxide-film or nitride film or oxynitride film.

In the present embodiment, because the coefficient of thermal expansion difference between above-mentionedfrid 16 and the slow-wave plate 18 is controlled at below 10%, even so because of rising to the temperature that antenna provides a large amount of hot-fluids that caused by high-density plasma to cause above-mentionedfrid 16 and slow-wave plate 18 from container handling 11, can between above-mentionedfrid 16 and slow-wave plate 18, not produce the gap yet, can effectively avoid the formation of paradoxical discharge or reflected wave, or the problems such as formation of standing wave.

(the 2nd execution mode)

Fig. 6 represents to utilize the structure of the plasma processing apparatus 10B of the present invention's the 2nd execution mode.But in Fig. 6, the part that illustrates previously is marked with identical reference marks and omits explanation.

With reference to Fig. 6, in the present embodiment, use microwave antenna 20A to replacemicrowave antenna 20 among Fig. 2 A.In microwave antenna 20A, the leading section 21b of thecenter conductor 21B ofcoaxial waveguide 21 leaves frid 16, is connected in the behind of the slow-wave plate 18 that forms on above-mentioned frid 16.In this structure, make above-mentionedcenter conductor 21 not contact the above-mentionedfrid 16 ground microwave of effectively powering.In above-mentioned microwave antenna 20A, above-mentioned slow-wave plate 18 extends continuously in the behind of above-mentionedfrid 16, does not form the contact hole that above-mentioned center conductor is used.

Fig. 7 A-7D is the figure of slow-wave plate 18 and the formation operation offrid 16 among the radioactive ray slot antenna 20A that uses among the above-mentioned plasma processing apparatus 10B of expression.

With reference to Fig. 7 A, initial, in electroless plating groove Bathl, will be by Al₂O₃And SiO₂Perhaps Si₃N₄The slow-wave plate 18 that constitutes is immersed in the non-electrolysis plating liquid of Cu, forms the no electrolysis Cu coating 161 of monoatomic layer at least from the teeth outwards.

Then, after the electroless plating of Fig. 7 A, on above-mentioned slow-wave plate 18, electroless plating Cu layer is stacked into the thickness of expectation, but from improving adhering viewpoint, preferably shown in Fig. 7 B, in electrolysis coating bath Bath2, the slow-wave plate 18 behind the above-mentioned no electrolysis Cu coating 161 of formation in the prior figures 7A operation is immersed in the electric field plating bath, above-mentioned no electrolysis Cu coating 161 as electrode, is formed the electrolysis Cu coating 162 of expectation thickness on above-mentioned no electrolysis Cu coating 161.Consider the kelvin effect of microwave, the expectation thickness of above-mentionedCu layer 162 is more preferably greater than 6 μ m.

In the operation of Fig. 7 C; cover theCu layer 161 and 162 of formation like this with diaphragm R; in the operation of Fig. 7 D, expose, develop, to above-mentionedCu layer 161 and 162 processing graphic patterns, obtain forming thefrid 16 of above-mentionedgroove 16a, 16b as facial mask by the diaphragm pattern R ' that will form.In addition, also Pasting has the film of desired pattern, and this film as facial mask, is come above-mentionedCu layer 16 processing graphic pattern by wet etching.

Even the frid that forms through thisoperation 16 is formed by Cu, also because of being trickle concavo-convex formation on filling slow-wave plate 18 surfaces, so the adhesion height can effectively suppress to form the gap betweenfrid 16 and the slow-wave plate 18.

Though the front is illustrated, also can form above-mentionedfrid 16 by electroless plating.In addition, in the example of Fig. 7 A-7D, also available Ni coating replaces above-mentioned noelectrolysis Cu coating 161.

In the execution mode of Fig. 6, also can cancel above-mentioned processing gas mechanism is provided according to the concrete purposes of plasma processing apparatus.

The formation method of thefrid 16 of Fig. 7 A-7D operation is also applicable to theplasma processing apparatus 10 of Fig. 2 A, 2B or theplasma processing apparatus 10A of Fig. 5, and applicable to the existingplasma processing apparatus 100 shown in Figure 1A, the 1B.

(the 3rd execution mode)

Fig. 8 is the brief configuration figure that utilizes the microwave plasma processing apparatus of embodiment of the present invention.

Microwave plasma processing apparatus 40 shown in Figure 8 such as being plasma CVD equipment, is in container handling 42 semiconductor wafer W as processed substrate to be implemented the device that plasma CVD is handled.Container handling 42 is formed by for example aluminium, has the closed structure of vacuum-pumping.In container handling 42, be provided with the mounting table 44 of mounting semiconductor wafer W.

In the bottom of container handling 42 exhaust outlet 42a is set, connects vacuum pump (not shown), can will maintain the low-pressure state of regulation in the container handling 42.

In the courtyard portion of container handling 42 for airtight and dielectric plate 46 is installed.In the present embodiment, on dielectric plate 46, install at least in the above and the following slow-wave plate 48 of implementing plating.In the present embodiment, because form the microwave radiation parts, be provided as the antenna element of microwave radiation parts so needn't be independent of slow-wave plate 48 by the coating of slow-wave plate 48.The slow-wave plate 48 of implementing plating is described below.

Slow-wave plate 48 is installed on the holding components 50.Holding components 50 also has the function of cooling slow-wave plate 48 when supporting slow-wave plate 48.That is, the inside of holdingcomponents 50 forms the path 50a that flows through cooling water, cooling slow-wave plate 48 when plasma treatment.

Middle body at slow-wave plate 48 is connected with the coaxial waveguide 52 that is used to provide microwave.Coaxial waveguide 52 is connected on thewaveguide 56 bycoaxial waveguide converter 54, andwaveguide 56 is connected on the microwave generator 58 that is made of magnetron etc.

In said structure, the microwave of for example 2.45GHz that is produced by microwave generator 28 is propagated inwaveguide 56, offers coaxial waveguide 52 by coaxial waveguide converter 54.The microwave of propagating in coaxial waveguide 52 utilizes the microwave radiation parts that are made of the slow-wave plate 48 surperficial coating that upward form after slow-wave plate 48 shortens wavelength, see through dielectric plate 46 back radiation in the processing space of container handling 52.

In the processing space of container handling 42, provide plasma gas, come plasma plasma gas by microwave.Come the semiconductor wafer W of mounting on the mounting table 44 is implemented plasma treatment by this plasma.

The slow-wave plate 48 of present embodiment is described below with reference to Fig. 9.Fig. 9 is the sectional view of slow-wave plate 48.

Slow-wave plate 48 is by aluminium oxide (Al₂O₃), silicon nitride (Si₃N₄), dielectrics such as aluminium nitride (AlN), quartz form, and have smooth circular plate shape.Middle body at slow-wave plate 48 forms thejut 48a that connects coaxial waveguide 22.Jut 48a has the conicalinclined plane 48b of the part of formation, prevents that the electric field of microwave generation from concentrating.Theouter tube 52a that onjut 48a, connects coaxial waveguide 52.Outer tube 52a both can be connected on the flat top 48c ofjut 48a, also can be connected on the 48b of inclined plane.

Form the throughhole 48d of theinboard cable 52b that inserts coaxial waveguide 52 in the central authorities of jut 48a.End in the container handling side of throughhole 48d forms tapering 48e, embeds the end with theinboard cable 52b that forms with this tapering shape corresponding shape.

Here, on the surface of slow-wave plate 48, form the coats ofmetal 60 such as copper, gold, silver, nickel.Except that theend face 48c of thejut 48a of slow-wave plate 48, on whole, form the coat of metal 60.Particularly be etched in thecoating 60 that slow-wave plate 48 forms on the surface of container handling 42 inside, remove part behind the coating as groove with predetermined pattern.

Fig. 3 is illustrated in the plane graph that forms the face of groove 32 on the coat ofmetal 60 of slow-wave plate 48.As shown in Figure 3, each groove 32 is an elongated oval shape, along three different circumference P1, P2, P3 configurations.Though the complete cycle along each circumference P1, P2, P3 is provided with groove 32, in Fig. 3,, only represent its part in order to simplify.Here, the center (off-centre) of misalignment slow-wave plate 48 profiles of circumference P1, P2, P3, offset direction separately (eccentric direction) difference.

That is, the direction at the center of misalignment slow-wave plate 48 profiles of the direction at the center of misalignment slow-wave plate 48 profiles of central circumference P2 and inside circumference P1 differs 120 degree.In addition, the direction at the center of misalignment slow-wave plate 48 profiles of the direction at the center of misalignment slow-wave plate 48 profiles of outer circumference P3 and central circumference P2 differs 120 degree.Thereby, the center deflection different directions from each other of circumference P1, P2, P3.

Therefore, if along a plurality of non-concentric circles configured slots 32, then in the coat of metal 30, propagate and return to the central part of slow-wave plate 48, but the center that can not concentrate on slow-wave plate 48 a bit by the surface wave of outer peripheral face reflection along radiation direction.That is, the side-play amount according to circumference P1, P2, P3 turns back to the to a certain degree scope of size.Therefore, configuration according to thegroove 62 of present embodiment, with be under the concentrically ringed situation at circumference P1, P2, P3, by surface wave is converged, the existing planar antenna member that produces inhomogeneities in the electron density of plasma space is compared, improved inhomogeneities, to a certain extent the distribution of uniform plasma volume density.

Thoughgroove 62 shown in Figure 3 is configured to a plurality of non-circular concentric, also can be configured to spirality, in addition, also can be configured to a plurality of circular concentric.The shape ofgroove 62 is not limited to elongated oval shown in Figure 3, also can adopt shapes such as circle, triangle, square, rectangle, but under polygonal situation, be preferably in the bight and form circle, concentrates to prevent electric field.In addition, with two grooves near and be arranged in that to be made as groove behind the T font right, also can be with a plurality of grooves to being arranged in a plurality of circular concentric, spirality or a plurality of non-circular concentric.

The skin depth δ that the thickness of coating 60 cans be compared to microwave most is thick, is preferably determined by following formula.

δ＝(2/ωσμ0)^1/2

Wherein, ω is an angular frequency, and σ is a conductance, andμ 0 is the magnetic susceptibility in the vacuum.

Using the microwave of 2.45GHz, forming under the situation of coating 60, because conductivity=6.45 * 10 of copper by copper facing⁷(Ω m)^-1, vacuummagnetic susceptibility μ 0=1.257 * 10^-6Hm^-1, angular frequency is 2 π * 2.45 * 10⁹So Hz is skin depth δ=1.98 * 10^-6M=1.98 μ m (about 2 μ m).Wherein, because owing to the skin depth internal electric field at coating reduces 30% approximately, so surplus rate (margin rate) is considered as 3 times, formed by copper under the situation of coating 60, thickness preferably is about 6 μ m.

As mentioned above, on the slow-wave plate 48 of present embodiment, form the coat ofmetal 60,,, can reduce components number so antenna element needn't be set separately because the coat ofmetal 60 is realized the function of antenna element (microwave radiation parts).In addition, owing to except that the part (groove) of part that microwave is provided and microwave radiation, all cover in the surface of slow-wave plate 48 by the coat ofmetal 60, so can prevent microwave leakage outside slow-wave plate 48, can the microwave that provide be imported in the processing space of container handling losslessly.

In addition, be that thickness is the coat of metal 30 about number μ m because form the metal parts of groove, so reduced the paradoxical discharge in the groove, and to compare in the past, so the power that can have high input is the output of raising plasma treatment.In addition, because the thin thickness of slot part so reduced the microwave reflection that groove causes, has improved radiation efficiency.

Figure 11 is the sectional view of an example being connected between expression coaxial waveguide 52 and the slow-wave plate 48.In structure shown in Figure 11, the front end of coaxial waveguide 52outer tube 52a is formed shape corresponding to theinclined plane 48b of slow-wave plate 48jut 48a, use the soft soldering combination.In addition, the leading section ofinboard cable 52b also is combined on the inner face and tapering 48e of throughhole 48d with soft soldering.

Between slow-wave plate 48 (be actually and be formed at slow-wave plate 48 lip-deep coating 60) and holdingcomponents 50, the good adhesives of heat-transfer character 68 is set, when being securely fixed in slow-wave plate 48 on the holdingcomponents 50, the heat of slow-wave plate 48 is delivered to holding components 50.In addition, holdingcomponents 50 shown in Figure 11 has omitted cooling water path.Bymetallic plate 64, press the fixedly circumferential lateral surface of slow-wave plate 48 by a plurality ofscrews 66 that connect holding components 50.Keep the reliable electrical contact between slow-wave plate 48 and the holding components thus.

Figure 12 is the sectional view of an example being connected between expression coaxial waveguide 52 and the slow-wave plate 48.In Figure 12, the structure member identical with structure member shown in Figure 11 is marked with identical symbol, omit its explanation.In structure shown in Figure 12, according to forming the front end of theouter tube 52a of coaxial waveguide 52 with the mode of the relative contact ofend face 48c of thejut 48a of slow-wave plate 48.In addition, the leading section ofinboard cable 52b is combined on the inner face and tapering 48e of throughhole 48d by soft soldering.Leading section at the inclined plane ofjut 48a 48b is provided with sealingscrew 70, makes the holdingcomponents 50 and the coat ofmetal 60 of slow-wave plate 48 electrically contact more reliable.

Thecoating 60 of present embodiment can use the method identical with the coating of above-mentioned the 2nd execution mode to form.In addition, though be formed with coating below on slow-wave plate, reaching, also can apply coating in the circumferential lateral surface of slow-wave plate.Like this, slow-wave plate integral body is all covered by coating basically, can prevent microwave leakage, prevents the paradoxical discharge in the whole slow-wave plate basically.

In addition, in the above-mentioned the 2nd and the 3rd execution mode,, be not limited to coating though on the slow-wave plate surface, form metal level by plating.For example, also can form metal level at slow-wave plate surface sediment metal by chemical gas phase synthetic method (PVD) or physical vapor synthetic method (PVD).

Utilizability on the industry

According to the present invention, for the microwave plasma processing apparatus that uses the radioactive ray slot antenna, By forming frid by the Cu-W alloy, can minimize and consist of between the dielectric plate of slow-wave plate The thermal expansion rate variance, even can realize being heated also indeclinable antenna of microwave radiation characteristics. In addition, By forming frid by coating, the adhesion that can realize ideal between slow-wave plate and frid can get Even to overheated, microwave radiation characteristics does not also change and prevents the antenna of paradoxical discharge. And, By on slow-wave plate and below the metal level such as formation coating, can prevent above the slow-wave plate and Following paradoxical discharge.

Claims (8)

1. plasma processing apparatus possesses:

Inside is provided with the container handling of the mounting table of the processed substrate of mounting;

Produce microwave and offer the microwave generator of described container handling;

Be arranged between this microwave generator and the described container handling, shorten slow-wave plate by the wavelength of microwave that described microwave generator provides; With

The microwave radiation parts of radiation in the space of microwave in described container handling after wavelength shortened by this slow-wave plate is characterized in that:

Described slow-wave plate at least above and below be formed with metal level,

Described microwave radiation parts are made of the described metal level that forms on the described slow-wave plate surface.

2. microwave plasma processing apparatus according to claim 1 is characterized in that: described microwave radiation parts have a plurality of grooves, and this groove is removed described metal level by etching and formed.

3. plasma processing apparatus according to claim 1 is characterized in that: described metal layer thickness is bigger than the skin depth of the microwave that described microwave generator produces.

4. plasma processing apparatus according to claim 1 is characterized in that: described metal level is the coating that forms with the material that is selected from copper, gold, silver, nickel.

5. plasma processing apparatus according to claim 4 is characterized in that: microwave wavelength is 2.45GHz, and described metal level is made of copper coating, and the thickness of this copper coating is more than 6 μ m.

6. plasma processing apparatus according to claim 1 is characterized in that: described metal level is the metal film of piling up by chemical gas phase synthetic method (CVD).

7. plasma processing apparatus according to claim 1 is characterized in that: described metal level is the metal film of piling up by physical vapor synthetic method (PVD).

8. plasma processing apparatus according to claim 1, it is characterized in that: also have the coaxial waveguide that the microwave that will come from described microwave generator offers described slow-wave plate, the outer tube of this coaxial waveguide and inboard cable are connected in the middle body of described slow-wave plate by soft soldering.

Images