CN115831784A - Preparation method of composite semiconductor substrate and device system thereof - Google Patents

Abstract

The invention provides a preparation method of a composite semiconductor substrate and a device system thereof, wherein the preparation method comprises the following steps: (1) Performing first reduction on the substrate by adopting formic acid steam to remove an oxide layer on the surface of the copper pillar on the substrate; (2) Sequentially treating the substrate by adopting plasma and water vapor to activate the surface of the polyimide film on the substrate; (3) Performing second reduction on the substrate by adopting formic acid steam to remove an oxide layer on the surface of the copper cylinder on the substrate, which is generated by plasma and water vapor treatment; (4) And (3) obtaining at least 2 substrates through the steps (1) to (3), aligning the at least 2 substrates, and carrying out hot-press bonding to obtain the composite semiconductor substrate. The preparation method provided by the invention realizes the rapid bonding of the cured polyimide-copper mixed surface in a low-temperature environment, gives consideration to the bonding strength and the bonding efficiency, finally obtains the high-quality composite semiconductor substrate or device stack, and is beneficial to large-scale popularization and application.

Description

Preparation method of composite semiconductor substrate and device system thereof

Technical Field

The invention belongs to the technical field of semiconductors, relates to a preparation method of a semiconductor substrate, and particularly relates to a preparation method of a composite semiconductor substrate and a device system thereof.

Background

Since transistor size approaches physical limits, process cost increases, and reliance on high-precision lithographic equipment, moore's law is difficult to persist in traditional two-dimensional integration, and three-dimensional integration techniques provide another avenue for continuation of moore's law. By this technique, chips or wafers having different functions can be manufactured separately and vertically stacked by a hybrid bonding process. Therefore, the hybrid bonding technology has very important research significance and application value.

In conventional hybrid bonding, siO₂ Is commonly used for filling the gap between metal interconnection lines to prevent the metal from being oxidized during the bonding process, thereby effectively increasing the bonding area. However, due to SiO₂ High hardness, poor deformation characteristics, siO₂ The surface needs to have high flatness and surface cleanliness to avoid electrical interconnection failures. Furthermore, siO₂ The mismatch in thermal expansion coefficient with the metal may create residual stress during bonding, which may lead to reliability problems. In contrast, the adhesive has the advantages of low hardness, low surface roughness and flatness tolerance and the like, and can replace oxide as a buffer layer to release residual stress after bonding. Thus, adhesive/metal hybrid bonding is a promising three-dimensional integration solution. Typical adhesive/metal hybrid bonds include metal/metal and adhesive/adhesive bonds, the former providing electrical interconnection and the latter providing passivation protection and mechanical support.

Among them, the "adhesive-first" method has advantages of void-free and highly reliable bonding, but is liable to cause severe misalignment of metal interconnections due to fluidity and volume shrinkage of the adhesive; the "metal first" approach avoids the problem of dislocation of the metal patterns after bonding, however, the curing process releases gas after bonding of the adhesive, which reduces the reliability of bonding. Both "adhesive-first" and "metal-first" methods must achieve curing of the adhesive during bonding, not only creating various reliability problems, but also increasing the time required for the bonding process. Among various adhesive materials, polyimide is a promising adhesive for metal deposition, photolithography, and wet etching processes due to its advantages in flexibility, chemical inertness, mechanical toughness, and high temperature thermal stability.

However, the temperature required for full curing of polyimide is high, and the bonding temperature is high, which is not suitable for some advanced process fields such as dram and led. Therefore, there is a need for developing a fast and low-temperature (250 ℃ or lower) cured polyimide-copper hybrid surface bonding method to achieve high-efficiency and high-reliability bonding and further to obtain a high-quality composite semiconductor substrate.

Disclosure of Invention

The invention aims to provide a preparation method of a composite semiconductor substrate and a device system thereof, wherein the preparation method realizes the rapid bonding of a polyimide-copper mixed surface solidified in a low-temperature environment (less than or equal to 250 ℃), gives consideration to the bonding strength and the bonding efficiency, finally obtains the high-quality composite semiconductor substrate, and is beneficial to large-scale popularization and application.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a method for manufacturing a composite semiconductor substrate, the method comprising the steps of:

(1) Performing first reduction on the substrate by adopting formic acid steam to remove an oxide layer on the surface of a copper column on the substrate;

(2) Treating the substrate obtained in the step (1) by adopting plasma and water vapor in sequence to activate the surface of the polyimide film on the substrate;

(3) Carrying out second reduction on the substrate obtained in the step (2) by adopting formic acid steam, and removing an oxide layer on the surface of the copper column on the substrate, which is generated by plasma and water vapor treatment;

(4) And (3) obtaining at least 2 substrates through the steps (1) to (3), aligning the at least 2 substrates, and carrying out hot-press bonding to obtain the composite semiconductor substrate.

The substrate comprises a silicon substrate and a bonding structure arranged on the surface of the silicon substrate; the bonding structure comprises copper columns and polyimide films, the copper columns are arranged periodically, and the polyimide films fill all gaps among the copper columns to play an insulating protection role.

According to the invention, through sequentially carrying out first reduction, activation, second reduction and hot-press bonding, volatile formic acid steam with good reducibility is adopted in the first reduction stage and the second reduction stage respectively, and plasma and water vapor are adopted in the activation stage, a water molecule bridging layer is formed on the surface of the polyimide film on the substrate, so that the rapid bonding of the polyimide-copper mixed surface solidified in a low-temperature environment (less than or equal to 250 ℃) is finally realized, the bonding strength and the bonding efficiency are considered, and the high-quality composite semiconductor substrate is obtained, and is beneficial to large-scale popularization and application.

Preferably, the diameter of individual ones of the copper pillars is 1 to 50 μm, and may be, for example, 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm, but is not limited to the recited values, and other values not recited within the range of values are also applicable.

Preferably, the height of individual ones of the copper pillars is 1 to 20 μm, and may be, for example, 1 μm, 2 μm, 4 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm or 20 μm, but is not limited to the recited values, and other values not recited within the range of values are also applicable.

Preferably, the thickness difference between the copper pillar and the polyimide film is not more than. + -. 0.5. Mu.m, and may be, for example,. + -. 0.05. Mu.m,. + -. 0.1. Mu.m,. + -. 0.15. Mu.m,. + -. 0.2. Mu.m,. + -. 0.25. Mu.m,. + -. 0.3. Mu.m,. + -. 0.35. Mu.m,. + -. 0.4. Mu.m,. + -. 0.45. Mu.m, or. + -. 0.5. Mu.m, but is not limited to the enumerated values, and other unrecited values within the numerical range are also applicable.

Preferably, the formic acid vapor in step (1) is introduced with a carrier gas at a flow rate of 10-2000mL/min, such as 10mL/min, 100mL/min, 1000mL/min, 1200mL/min, 1400mL/min, 1600mL/min, 1800mL/min or 2000mL/min, but not limited to the values listed, and other values not listed in the range are equally applicable.

Preferably, the carrier gas comprises any one or a combination of at least two of argon, helium or nitrogen, typical but non-limiting combinations include argon and helium, helium and nitrogen, argon and nitrogen, or argon, helium and nitrogen.

Preferably, the temperature of the first reduction in step (1) is 160-200 ℃, for example 160 ℃, 165 ℃, 170 ℃, 175 ℃, 180 ℃, 185 ℃, 190 ℃, 195 ℃ or 200 ℃, but not limited to the recited values, and other values not recited in the range of values are equally applicable.

Preferably, the time of the first reduction in step (1) is 5-100min, such as 5min, 10min, 15min, 20min, 25min, 30min, 35min, 40min, 45min, 50min, 55min, 60min, 65min, 70min, 75min, 80min, 85min, 90min, 95min or 100min, but is not limited to the recited values, and other values not recited in the range of the recited values are also applicable.

In the present invention, the first reduction in step (1) is carried out under normal pressure, specifically, standard atmospheric pressure, that is, 0.1MPa, or under slight positive pressure, which is 200 to 400Pa higher than the standard atmospheric pressure, and may be, for example, 200Pa, 220Pa, 240Pa, 260Pa, 280Pa, 300Pa, 320Pa, 340Pa, 360Pa, 380Pa, or 400Pa, but is not limited to the values listed, and other values not listed in the range of the values are also applicable.

Preferably, the activation in step (2) is performed under vacuum condition with an absolute vacuum degree of 1 × 10^-2 -9×10⁴ Pa, for example, may be 1X 10^-2 Pa、1×10^-1 Pa、1Pa、10Pa、10² Pa、10³ Pa、10⁴ Pa or 9X 10⁴ Pa, but is not limited to the recited values, and other values within the range are equally applicable.

Preferably, the plasma in step (2) is prepared by the inductive ionization of the process gas by a radio frequency power supply or a microwave power supply.

Preferably, the process gas comprises any one or a combination of at least two of argon, nitrogen or oxygen, typical but non-limiting combinations include a combination of argon and nitrogen, a combination of nitrogen and oxygen, a combination of argon and oxygen, or a combination of argon, nitrogen and oxygen.

Preferably, the process gas is introduced at a flow rate of 5-200mL/min, for example, 5mL/min, 10mL/min, 50mL/min, 100mL/min, 150mL/min or 200mL/min, but not limited to the values listed, and other values not listed in this range are equally applicable.

Preferably, the operating frequency of the radio frequency power supply is 13-14MHz, and may be, for example, 13MHz, 13.1MHz, 13.2MHz, 13.3MHz, 13.4MHz, 13.5MHz, 13.6MHz, 13.7MHz, 13.8MHz, 13.9MHz or 14MHz, but is not limited to the recited values, and other values not recited in this range are equally applicable.

Preferably, the plasma treatment temperature in step (2) is 25-150 deg.C, such as 25 deg.C, 30 deg.C, 35 deg.C, 40 deg.C, 45 deg.C, 50 deg.C, 55 deg.C, 60 deg.C, 65 deg.C, 70 deg.C, 75 deg.C, 80 deg.C, 85 deg.C, 90 deg.C, 95 deg.C, 100 deg.C, 105 deg.C, 110 deg.C, 115 deg.C, 120 deg.C, 125 deg.C, 130 deg.C, 135 deg.C, 140 deg.C, 145 deg.C or 150 deg.C, but not limited to the recited values, and other values in the range are also applicable.

Preferably, the plasma treatment time in step (2) is 1-300s, for example, 1s, 10s, 20s, 40s, 60s, 80s, 100s, 120s, 140s, 160s, 180s, 200s, 220s, 240s, 260s, 280s, or 300s, but is not limited to the recited values, and other values not recited in the range of values are also applicable.

Preferably, the introduction of the water vapor in step (2) is carried out by passing a process gas through a reservoir bottle, and the temperature of the water in the reservoir bottle is 20-100 ℃, for example, 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃ or 100 ℃, but is not limited to the recited values, and other values not recited in the range of the recited values are also applicable.

Preferably, the formic acid vapor in step (3) is introduced with a carrier gas at a flow rate of 10-2000mL/min, such as 10mL/min, 100mL/min, 1000mL/min, 1200mL/min, 1400mL/min, 1600mL/min, 1800mL/min or 2000mL/min, but not limited to the values listed, and other values not listed in the range are equally applicable.

Preferably, the carrier gas comprises any one or a combination of at least two of argon, helium or nitrogen, typical but non-limiting combinations include argon and helium, helium and nitrogen, argon and nitrogen, or argon, helium and nitrogen.

Preferably, the temperature of the second reduction in step (3) is 160-200 ℃, for example 160 ℃, 165 ℃, 170 ℃, 175 ℃, 180 ℃, 185 ℃, 190 ℃, 195 ℃ or 200 ℃, but not limited to the recited values, and other values not recited in the range of values are equally applicable.

Preferably, the time of the second reduction in step (3) is 1-50min, such as 1min, 5min, 10min, 15min, 20min, 25min, 30min, 35min, 40min, 45min or 50min, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

In the present invention, the second reduction in the step (3) is carried out under normal pressure, specifically, standard atmospheric pressure, that is, 0.1MPa, or under slight positive pressure, specifically, 200 to 400Pa, which is higher than the standard atmospheric pressure, and may be, for example, 200Pa, 220Pa, 240Pa, 260Pa, 280Pa, 300Pa, 320Pa, 340Pa, 360Pa, 380Pa, or 400Pa, but is not limited to the values listed, and other values not listed in the range of the values are also applicable.

Preferably, the thermocompression bonding of step (4) is performed in an atmosphere of a protective gas, and the protective gas includes argon and/or nitrogen.

Preferably, the applied pressure to which the substrate is subjected during the thermocompression bonding in step (4) is 0.5 to 100MPa, for example, 0.5MPa, 1MPa, 10MPa, 20MPa, 40MPa, 60MPa, 80MPa or 100MPa, but is not limited to the recited values, and other values not recited in this range are also applicable.

Preferably, the thermal compression bonding temperature in step (4) is 180-400 ℃, and may be, for example, 180 ℃, 200 ℃, 220 ℃, 240 ℃, 260 ℃, 280 ℃, 300 ℃, 320 ℃, 340 ℃, 360 ℃, 380 ℃ or 400 ℃, but is not limited to the recited values, and other values not recited in the range of values are also applicable.

Preferably, the thermal compression bonding time in step (4) is 0.1-30min, such as 0.1min, 0.5min, 1min, 5min, 10min, 15min, 20min, 25min or 30min, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

In a second aspect, the present invention provides an apparatus system for preparing a composite semiconductor substrate by using the preparation method according to the first aspect, the apparatus system comprising a plasma activation chamber, a formic acid reduction chamber and a thermal compression bonding chamber connected in series in sequence, wherein each chamber is internally provided with a heater independently, and a valve is arranged between adjacent chambers.

Preferably, the apparatus system is further provided with a vacuum pump and a robot arm.

Preferably, the plasma activation chamber, the formic acid reduction chamber and the thermocompression bonding chamber are respectively and independently connected to the vacuum pump, and are used for manufacturing vacuum environments for the respective chambers.

Preferably, the robot arm is used to grasp the substrate and transfer the substrate between the respective chambers.

Preferably, the surface of the plasma activation chamber is provided with an air inlet and an air outlet, and the air inlet is provided with an electrode of a radio frequency power supply.

Preferably, a catalytic component is also arranged inside the formic acid reduction chamber or in the air inlet pipeline.

Preferably, the catalytic member has a self-heating function and a temperature range of 100 to 250 ℃, for example, 100 ℃, 120 ℃, 140 ℃, 160 ℃, 180 ℃, 200 ℃, 220 ℃, 240 ℃ or 250 ℃, but is not limited to the recited values, and other values not recited in the range of values are also applicable.

Preferably, the interior of the thermocompression bonding chamber is provided with a pressurizing member and an alignment member.

In a third aspect, the present invention provides an apparatus system for preparing a composite semiconductor substrate by using the preparation method according to the first aspect, wherein the apparatus system comprises a formic acid reduction chamber, a plasma activation chamber, a thermocompression bonding chamber, a loading and unloading chamber and a vacuum transfer chamber.

The formic acid reduction chamber, the plasma activation chamber, the thermal compression bonding chamber and the feeding and discharging chamber are respectively and independently connected to the vacuum transmission chamber through valves.

Heaters are respectively and independently arranged in the formic acid reduction chamber, the plasma activation chamber and the hot-press bonding chamber.

Preferably, the apparatus system is further provided with a vacuum pump and a robot arm.

Preferably, the feeding and discharging chamber and the vacuum transfer chamber are respectively and independently connected to the vacuum pump.

Preferably, the robot arm is disposed inside the vacuum transfer chamber.

Compared with the prior art, the invention has the following beneficial effects:

according to the invention, through sequentially carrying out first reduction, activation, second reduction and hot-press bonding, volatile formic acid steam with good reducibility is adopted in the first reduction stage and the second reduction stage respectively, and plasma and water vapor are adopted in the activation stage, a water molecule bridging layer is formed on the surface of the polyimide film on the substrate, so that the rapid bonding of the polyimide-copper mixed surface solidified in a low-temperature environment (less than or equal to 250 ℃) is finally realized, the bonding strength and the bonding efficiency are considered, and the high-quality composite semiconductor substrate is obtained, and is beneficial to large-scale popularization and application.

Drawings

FIG. 1 is a schematic view of a system of an apparatus for manufacturing a composite semiconductor substrate according toembodiment 1;

fig. 2 is a schematic view of an apparatus system for manufacturing a composite semiconductor substrate provided in embodiment 4.

Wherein: a 1-formic acid reduction chamber; 1A-formic acid reduction valve; 2-plasma activating chamber; 2A-a plasma activated valve; 3-thermocompression bonding chamber; 3A-a thermocompression bonding valve; 4-a loading and unloading chamber; 4A-a feeding and discharging valve; 5-a vacuum transfer chamber; 6, a mechanical arm; 11-formic acid inlet; a 12-formic acid vent; 12A-a first valve; 13-a first support base; 13A-a second valve; 14-a first heater; 15-a catalytic component; 21-water vapor inlet; 22-process gas inlet; 23-a radio frequency power supply; 24-a second heater; 25-a second support base; 26-a first exhaust port; 31-catalytic gas inlet; 32-protective gas inlet; 33-a second exhaust port; 34-an alignment member; 35-lower substrate support base; 35A-lower substrate heater; 36-an upper substrate support pedestal; 36A-upper substrate heater; 37-a pressing member; 100A-lower substrate; 100B-an upper substrate; 1001-copper column; 1002-polyimide film.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitation of the present invention.

Example 1

The embodiment provides an apparatus system for preparing a composite semiconductor substrate, as shown in fig. 1, the apparatus system includes aplasma activation chamber 2, a formicacid reduction chamber 1 and athermocompression bonding chamber 3, which are connected in series in sequence, afirst valve 12A is disposed between theplasma activation chamber 2 and the formicacid reduction chamber 1, and asecond valve 13A is disposed between the formicacid reduction chamber 1 and thethermocompression bonding chamber 3.

Thefirst valve 12A can be closed to separate the formicacid reduction chamber 1 from theplasma activation chamber 2, so as to prevent formic acid vapor in the formicacid reduction chamber 1 from affecting theplasma activation chamber 2; thefirst valve 12A may also be opened so that substrate material may be transferred between the two chambers, including transferring formic acid vapor-reduced substrate material from the formicacid reduction chamber 1 to theplasma activation chamber 2, or transferring plasma-activated substrate material from theplasma activation chamber 2 to the formicacid reduction chamber 1. Thesecond valve 13A can be closed to separate theplasma activation chamber 2 from thethermocompression bonding chamber 3, so as to avoid the mutual influence between the two; thesecond valve 13A may also be opened so that substrate material may be transferred between the two chambers, i.e., the plasma activated substrate material is transferred from theplasma activation chamber 2 to thethermocompression bonding chamber 3.

In this embodiment, the apparatus system is further provided with a vacuum pump and a robot arm (not shown in the figure); theplasma activation chamber 2, the formicacid reduction chamber 1 and the thermalcompression bonding chamber 3 are respectively and independently connected to the vacuum pump and used for manufacturing a vacuum environment for each chamber; the robot arm is used to grasp and transfer substrates between the chambers.

As shown in fig. 1, aformic acid inlet 11 and aformic acid outlet 12 are arranged on the surface of the formicacid reduction chamber 1, and afirst support base 13, afirst heater 14 and acatalytic component 15 are arranged inside the formic acid reduction chamber; a substrate material to be reduced (thesubstrate 100A in fig. 1 is taken as an example) is placed on thefirst heater 14, and thefirst heater 14 has an air cooling system (not shown); thecatalytic component 15 has a self-heating function and a temperature range of 100-250 ℃.

As shown in fig. 1, the surface of theplasma activation chamber 2 is provided with awater vapor inlet 21, aprocess gas inlet 22 and afirst exhaust port 26, asecond support base 25, asecond heater 24 and a radiofrequency power supply 23 are arranged inside, and an electrode of the radiofrequency power supply 23 is arranged at theprocess gas inlet 22; a substrate material to be reduced is placed on the second heater 24 (thelower substrate 100A in fig. 1 is taken as an example); the process gas is dissociated into plasma by the discharge of therf power supply 23, thereby performing surface treatment on the substrate material.

As shown in fig. 1, the surface of the thermocompression bonding chamber 3 is provided with a catalytic gas inlet 31, a protective gas inlet 32 and a second gas outlet 33, and the interior thereof is provided with an alignment member 34, a lower substrate support base 35, a lower substrate heater 35A, an upper substrate support base 36, an upper substrate heater 36A, a pressurizing member 37 and an upper substrate adsorption reversing member (not shown); the alignment member 34 is used for observing alignment marks on two substrate materials (the lower substrate 100A and the upper substrate 100B) respectively placed on the surfaces of the lower substrate heater 35A and the upper substrate heater 36A and performing an alignment operation; accordingly, the lower substrate support base 35 and the upper substrate support base 36 are respectively connected to a moving member (not shown in the drawings) to achieve mutual alignment of the two substrate materials; the lower substrate support base 35 and the matched lower substrate heater 35A are arranged opposite to the upper substrate support base 36 and the matched upper substrate heater 36A in the vertical direction, and can respectively clamp substrate materials; the pressurizing part 37 is connected with the upper substrate supporting base 36, so that two substrate materials subjected to surface treatment can be mutually attached and pressed, and hot-press bonding is realized;

example 2

The present embodiment provides an apparatus system for manufacturing a composite semiconductor substrate, except that tworf power sources 23 are provided in theplasma activation chamber 2 to simultaneously perform surface treatment on thelower substrate 100B and theupper substrate 100A, the remaining structures and conditions are the same as those ofembodiment 1, and thus are not described herein again.

Example 3

The present embodiment provides an apparatus system for manufacturing a composite semiconductor substrate, except that the pressingmember 37 in thethermocompression bonding chamber 3 is configured to be connected to the lowersubstrate supporting base 35, and the rest of the structure and conditions are the same as those inembodiment 1, and thus the description thereof is omitted.

Example 4

The embodiment provides an apparatus system for preparing a composite semiconductor substrate, as shown in fig. 2, the apparatus system is an integrated structure, and includes a formicacid reduction chamber 1, aplasma activation chamber 2, athermocompression bonding chamber 3, a loading and unloading chamber 4 and avacuum transfer chamber 5, and the formicacid reduction chamber 1, theplasma activation chamber 2, thethermocompression bonding chamber 3 and the loading and unloading chamber 4 are respectively and independently connected to thevacuum transfer chamber 5 through valves; heaters are independently arranged inside the formicacid reduction chamber 1, theplasma activation chamber 2 and the thermalcompression bonding chamber 3 respectively.

In this embodiment, the apparatus system is further provided with a vacuum pump (not shown in the figure) and arobot arm 6; the feeding and discharging chamber 4 and thevacuum transmission chamber 5 are respectively and independently connected to the vacuum pump and used for manufacturing a vacuum environment for each chamber; therobot arm 6 is disposed inside thevacuum transfer chamber 5, and is used to grasp a substrate and transfer the substrate between the respective chambers.

As shown in fig. 2, the formicacid reduction chamber 1 is connected to thevacuum transfer chamber 5 through a formicacid reduction valve 1A, theplasma activation chamber 2 is connected to thevacuum transfer chamber 5 through aplasma activation valve 2A, thethermocompression bonding chamber 3 is connected to thevacuum transfer chamber 5 through athermocompression bonding valve 3A, and the loading and unloading chamber 4 is connected to thevacuum transfer chamber 5 through a loading and unloadingvalve 4A; the arrangement and internal structure of the inlet and outlet of the formicacid reduction chamber 1, theplasma activation chamber 2 and thethermocompression bonding chamber 3 are the same as those ofembodiment 1, and therefore, the detailed description thereof is omitted.

Application example 1

In this application example, the device system provided inembodiment 1 is applied to produce a composite semiconductor substrate, and the specific production method includes the following steps:

(1) Placing thelower substrate 100A and theupper substrate 100B in the formicacid reduction chamber 1, closing thefirst valve 12A and thesecond valve 13A, and starting the vacuum pump to make the interior of the formicacid reduction chamber 1 in a vacuum state; placing thelower substrate 100A on thefirst heater 14 by using a mechanical arm, introducing formic acid steam into the formicacid reduction chamber 1 from theformic acid inlet 11 along with argon gas with the flow of 1000mL/min, starting thefirst heater 14, setting the heating temperature to be 180 ℃, and heating for 50min, and performing sufficient first reduction on thelower substrate 100A to remove an oxide layer on the surface of thecopper column 1001 on thelower substrate 100A; after the reduction is finished, thelower substrate 100A is taken down by using the mechanical arm, theupper substrate 100B is placed on thefirst heater 14, the first reduction process is repeated, theupper substrate 100B is fully reduced, and thefirst heater 14 is closed after the reduction is finished;

(2) Opening the first valve 12A, transferring the lower substrate 100A and the upper substrate 100B into the plasma activation chamber 2 by using a robot arm, and placing the two substrates on the second heater 24 together; closing the first valve 12A, and starting a vacuum pump to enable the absolute vacuum degree inside the plasma activation chamber 2 to reach 0.01Pa; introducing nitrogen into the plasma activation chamber 2 from the process gas inlet 22 at a flow rate of 250mL/min, starting the radio frequency power supply 23, setting the working frequency to be 13.54MHz, starting the second heater 24, setting the heating temperature to be 100 ℃, and heating for 120s, and performing surface treatment on the lower substrate 100A and the upper substrate 100B to enhance the hydrophilicity of the surfaces of the polyimide films 1002 on the two substrates; after the surface treatment of the plasma is finished, closing the process gas inlet 22 and the radio frequency power supply 23, opening the water vapor inlet 21, introducing water vapor into the plasma activation chamber 2, wherein the introduction of the water vapor is realized by flowing nitrogen through a water storage bottle, the temperature of the water in the water storage bottle is 60 ℃, so that a water molecule bridging layer is formed on the surfaces of the polyimide films 1002 on the two substrates, and closing the water vapor inlet 21 after the surface treatment of the water vapor is finished;

(3) Opening thefirst valve 12A, transferring thelower substrate 100A and theupper substrate 100B into the formicacid reduction chamber 1 again by using the mechanical arm, closing thefirst valve 12A, and starting the vacuum pump to make the interior of the formicacid reduction chamber 1 in a vacuum state; placing thelower substrate 100A on thefirst heater 14 by using a mechanical arm, introducing formic acid steam into the formicacid reduction chamber 1 from theformic acid inlet 11 along with argon gas with the flow of 1000mL/min, starting thefirst heater 14, setting the heating temperature to be 180 ℃, and heating for 5min, and performing sufficient second reduction on thelower substrate 100A to remove an oxide layer on the surface of thecopper column 1001 on thelower substrate 100A, which is generated due to plasma and water vapor treatment; after the reduction is finished, thelower substrate 100A is taken down by using the mechanical arm, theupper substrate 100B is placed on thefirst heater 14, the second reduction process is repeated, theupper substrate 100B is fully reduced, and thefirst heater 14 is turned off after the reduction is finished;

(4) Opening thesecond valve 13A, transferring thelower substrate 100A and theupper substrate 100B into thethermocompression bonding chamber 3 by using a robot arm, and placing thelower substrate 100A and theupper substrate 100B on thelower substrate heater 35A and theupper substrate heater 36A, respectively, correspondingly; closing thesecond valve 13A, and introducing argon gas into the hot-press bonding chamber 3 from theprotective gas inlet 32 to create a protective gas atmosphere; observing the alignment marks on thelower substrate 100A and theupper substrate 100B by using thealignment component 34 and adjusting the moving component to perform alignment operation, so that the alignment marks on the two substrates are mutually overlapped in the observation visual field of thealignment component 34, starting thelower substrate heater 35A and theupper substrate heater 36A to heat the two substrates, respectively setting the heating temperature to be 250 ℃ and the heating time to be 30min; and starting the pressurizingpart 37 to attach and compress the two substrates, and applying pressure of 50MPa to finally obtain the composite semiconductor substrate.

Application example 2

In this application example, the device system provided inembodiment 1 is applied to prepare a composite semiconductor substrate, and steps (1) and (2) in the preparation method are the same as those inembodiment 1, and thus are not described herein again.

The step (3) is specifically as follows: opening the second valve 13A, transferring the lower substrate 100A and the upper substrate 100B into the thermocompression bonding chamber 3 by using a robot arm, and placing the lower substrate 100A and the upper substrate 100B on the lower substrate heater 35A and the upper substrate heater 36A, respectively, correspondingly; closing the second valve 13A and starting the vacuum pump so that the interior of the thermocompression bonding chamber 3 is in a vacuum state; observing the alignment marks on the lower substrate 100A and the upper substrate 100B by using the alignment member 34 and adjusting the moving member to perform an alignment operation such that the alignment marks on the two substrates coincide with each other within the observation field of view of the alignment member 34; introducing formic acid steam into the thermocompression bonding chamber 3 from the catalytic gas inlet 31 along with argon gas with the flow of 1000mL/min, starting the lower substrate heater 35A and the upper substrate heater 36A to heat the two substrates, respectively setting the heating temperature to be 180 ℃ and the heating time to be 50min, and performing sufficient second reduction on the two substrates to remove an oxide layer on the surfaces of the copper columns 1001 on the two substrates, which is generated by plasma and water vapor treatment; after the reduction is finished, the catalytic gas inlet 31 is closed, argon is introduced into the hot-pressing bonding chamber 3 from the protective gas inlet 32 to create protective gas atmosphere, the heating temperatures of the lower substrate heater 35A and the upper substrate heater 36A are respectively set to 300 ℃, and the heating time is respectively set to 30min; the pressing member 37 is started to bond and press the two substrates, and the applied pressure is 100MPa, so that the composite semiconductor substrate is finally obtained.

Application example 3

In this application example, the device system provided in embodiment 4 is applied to produce a composite semiconductor substrate, and the specific production method includes the following steps:

(1) Placing alower substrate 100A and anupper substrate 100B in the feeding and discharging chamber 4, and starting a vacuum pump to enable the interior of the feeding and discharging chamber 4 to be in a vacuum state; opening a feeding and dischargingvalve 4A and a formicacid reduction valve 1A, taking out thelower substrate 100A and theupper substrate 100B from the feeding and discharging chamber 4 by using amechanical arm 6, conveying the substrates into the formicacid reduction chamber 1 through avacuum conveying cavity 5, and closing the feeding and dischargingvalve 4A and the formicacid reduction valve 1A; starting thefirst heater 14 and introducing formic acid vapor to perform first reduction on thelower substrate 100A and theupper substrate 100B, wherein the specific reduction process and conditions are the same as those in the step (1) in application example 1, and thus are not described herein again;

(2) Opening a formicacid reduction valve 1A and aplasma activation valve 2A, taking out alower substrate 100A and anupper substrate 100B from the formicacid reduction chamber 1 by using amechanical arm 6, conveying the substrates into theplasma activation chamber 2 through avacuum conveying cavity 5, and closing the formicacid reduction valve 1A and theplasma activation valve 2A; starting thesecond heater 24 and the radiofrequency power supply 23, and introducing nitrogen and water vapor in sequence to respectively perform surface treatment on thelower substrate 100A and theupper substrate 100B, wherein the specific treatment process and conditions are the same as those in the step (2) in the application example 1, and thus the details are not repeated herein;

(3) Opening theplasma activation valve 2A and the formicacid reduction valve 1A, taking thelower substrate 100A and theupper substrate 100B out of theplasma activation chamber 2 by using themechanical arm 6, conveying the substrates into the formicacid reduction chamber 1 through thevacuum conveying cavity 5, and closing theplasma activation valve 2A and the formicacid reduction valve 1A; starting thefirst heater 14 and introducing formic acid vapor to respectively perform second reduction on thelower substrate 100A and theupper substrate 100B, wherein the specific reduction process and conditions are the same as those in the step (3) in the application example 1, and thus the detailed description is omitted;

(4) Opening a formicacid reduction valve 1A and a hot-press bonding valve 3A, taking out thelower substrate 100A and theupper substrate 100B from the formicacid reduction chamber 1 by using amechanical arm 6, conveying the substrates into the hot-press bonding chamber 3 through avacuum conveying cavity 5, and closing the formicacid reduction valve 1A and the hot-press bonding valve 3A; introducing argon gas into thethermocompression bonding chamber 3 to create an atmosphere of protective gas, aligning the two substrates, starting thelower substrate heater 35A and theupper substrate heater 36A to heat the two substrates, and starting the pressurizingpart 37 to attach and compress the two substrates, wherein the specific thermocompression bonding process and conditions are the same as those in the step (4) in the application example 1, and therefore the detailed description is omitted;

(5) Opening the thermalcompression bonding valve 3A and the feeding and dischargingvalve 4A, taking thelower substrate 100A and theupper substrate 100B out of the thermalcompression bonding chamber 3 by using themechanical arm 6, sending the substrates into the feeding and discharging chamber 4 through thevacuum conveying cavity 5, and closing the thermalcompression bonding valve 3A and the feeding and dischargingvalve 4A; and (4) evacuating the loading and unloading chamber 4 to restore the air pressure value to the atmospheric pressure, and taking out the composite semiconductor substrate.

Application example 4

In this application example, the device system provided in embodiment 4 is applied to prepare a composite semiconductor substrate, and the steps (1), (2), and (4) in the preparation method are the same as those inembodiment 3, and thus are not described herein again.

The step (3) is specifically as follows: opening theplasma activation valve 2A and the thermalcompression bonding valve 3A, taking thelower substrate 100A and theupper substrate 100B out of theplasma activation chamber 2 by using themechanical arm 6, conveying the substrates into the thermalcompression bonding chamber 3 through thevacuum conveying cavity 5, and closing theplasma activation valve 2A and the thermalcompression bonding valve 3A; aligning the two substrates, starting the heater and introducing formic acid steam, and respectively performing second reduction on thelower substrate 100A and theupper substrate 100B, wherein the specific reduction process and conditions are the same as those in the step (3) in the application example 1, and thus the detailed description is omitted; after the reduction is finished, the heater and the pressingmember 37 are started to attach and press the two substrates, and the specific thermocompression bonding process and conditions are the same as those in step (4) in application example 1, and therefore are not described herein again.

Therefore, the method has the advantages that through the first reduction, the activation, the second reduction and the hot-press bonding which are sequentially carried out, the volatile formic acid steam with good reducibility is respectively adopted in the first reduction stage and the second reduction stage, the plasma and the water vapor are adopted in the activation stage, the water molecule bridging layer is formed on the surface of the polyimide film on the substrate, the rapid bonding of the polyimide-copper mixed surface solidified in the low-temperature environment (less than or equal to 250 ℃) is finally realized, the bonding strength and the bonding efficiency are considered, and the high-quality composite semiconductor substrate is obtained, so that the large-scale popularization and application are facilitated.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention disclosed herein fall within the scope and disclosure of the present invention.

Claims (10)

1. A method for manufacturing a composite semiconductor substrate, comprising:

(1) Performing first reduction on the substrate by adopting formic acid steam to remove an oxide layer on the surface of the copper pillar on the substrate;

(2) Treating the substrate obtained in the step (1) by adopting plasma and water vapor in sequence to activate the surface of the polyimide film on the substrate;

(3) Carrying out second reduction on the substrate obtained in the step (2) by adopting formic acid steam, and removing an oxide layer on the surface of the copper column on the substrate, which is generated due to plasma and water vapor treatment;

(4) Obtaining at least 2 substrates through the steps (1) - (3), aligning the at least 2 substrates, and performing hot-press bonding to obtain a composite semiconductor substrate;

the substrate comprises a silicon substrate and a bonding structure arranged on the surface of the silicon substrate; the bonding structure comprises copper columns and polyimide films, the copper columns are arranged periodically, and the polyimide films fill all gaps among the copper columns to play an insulating protection role.

2. The method according to claim 1, wherein the diameter of individual ones of the copper pillars is 1 to 50 μm, and the height is 1 to 20 μm;

the thickness difference between the copper column and the polyimide film is not more than +/-0.5 mu m.

3. The preparation method according to claim 1, wherein the formic acid vapor in the step (1) is introduced with a carrier gas, and the carrier gas introduction flow rate is 10-2000mL/min;

the carrier gas comprises any one or combination of at least two of argon, helium or nitrogen;

the temperature of the first reduction in the step (1) is 160-200 ℃, and the time is 5-100min;

the activation in the step (2) is carried out under vacuum condition, and the absolute vacuum degree is 1 × 10^-2 -9×10⁴ Pa；

The plasma in the step (2) is prepared by the inductive ionization of process gas by a radio frequency power supply or a microwave power supply;

the process gas comprises any one or a combination of at least two of argon, nitrogen or oxygen;

the flow rate of the process gas is 5-200mL/min;

the working frequency of the radio frequency power supply is 13-14MHz;

the treatment temperature of the plasma in the step (2) is 25-150 ℃, and the treatment time is 1-300s;

and (3) introducing the water vapor in the step (2) by means of flowing process gas through a water storage bottle, wherein the water temperature in the water storage bottle is 20-100 ℃.

4. The preparation method according to claim 1, wherein the formic acid vapor in the step (3) is introduced with a carrier gas, and the carrier gas introduction flow rate is 10-2000mL/min;

the carrier gas comprises any one or combination of at least two of argon, helium or nitrogen;

the temperature of the second reduction in the step (3) is 160-200 ℃, and the time is 1-50min.

5. The production method according to claim 1, wherein the thermocompression bonding of step (4) is performed in an atmosphere of a protective gas, and the protective gas includes argon and/or nitrogen;

in the step (4), the applied pressure born by the substrate in the hot-pressing bonding process is 0.5-100MPa;

the temperature of the hot-pressing bonding in the step (4) is 180-400 ℃, and the time is 0.1-30min.

6. An apparatus system for manufacturing a composite semiconductor substrate by the manufacturing method according to any one of claims 1 to 5, wherein the apparatus system comprises a plasma activation chamber, a formic acid reduction chamber and a thermal compression bonding chamber which are connected in series in sequence, each chamber is provided with a heater inside independently, and a valve is provided between adjacent chambers.

7. The device system of claim 6, further provided with a vacuum pump and a robotic arm;

the plasma activation chamber, the formic acid reduction chamber and the hot-press bonding chamber are respectively and independently connected to the vacuum pump and used for manufacturing a vacuum environment for each chamber;

the robot arm is used to grasp and transfer substrates between the chambers.

8. The apparatus system of claim 6, wherein the surface of the plasma activation chamber is provided with an air inlet and an air outlet, and the air inlet is provided with an electrode of the radio frequency power supply;

a catalytic component is also arranged in the formic acid reduction chamber or the air inlet pipeline;

the catalytic component has a self-heating function and the temperature range is 100-250 ℃;

and a pressurizing part and an aligning part are arranged in the thermal compression bonding chamber.

9. An apparatus system for preparing a composite semiconductor substrate by the preparation method according to any one of claims 1 to 5, wherein the apparatus system comprises a formic acid reduction chamber, a plasma activation chamber, a thermocompression bonding chamber, a loading and unloading chamber and a vacuum transfer chamber;

the formic acid reduction chamber, the plasma activation chamber, the hot-press bonding chamber and the feeding and discharging chamber are respectively and independently connected to the vacuum transmission chamber through valves;

heaters are respectively and independently arranged in the formic acid reduction chamber, the plasma activation chamber and the hot-press bonding chamber.

10. The device system of claim 9, further provided with a vacuum pump and a robotic arm;

the feeding and discharging chamber and the vacuum transfer chamber are respectively and independently connected to the vacuum pump;

the robot arm is disposed inside the vacuum transfer chamber.

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