CN115831784B

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Info

Publication number: CN115831784B
Application number: CN202310044366.8A
Authority: CN
Inventors: 母凤文; 田野
Original assignee: Tianjin Zhongke Jinghe Electronic Technology Co ltd
Current assignee: Tianjin Zhongke Jinghe Electronic Technology Co ltd
Priority date: 2023-01-30
Filing date: 2023-01-30
Publication date: 2023-04-21
Anticipated expiration: 2043-01-30
Also published as: CN115831784A

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) Carrying out first reduction on the substrate by adopting formic acid vapor, and removing an oxide layer on the surface of a copper column on the substrate; (2) Sequentially adopting plasma and water vapor to process the substrate and activate the surface of the polyimide film on the substrate; (3) Carrying out second reduction on the substrate by adopting formic acid vapor, and removing an oxide layer on the surface of a copper column on the substrate, which is generated by plasma and vapor treatment; (4) And (3) obtaining at least 2 substrates through the steps (1) - (3), aligning the at least 2 substrates, and performing thermocompression 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, combines bonding strength and bonding efficiency, finally obtains high-quality composite semiconductor substrates or device stacks, 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

Because transistor size approaches physical limits, process costs increase, and reliance on high precision lithographic equipment, moore's law is difficult to sustain in conventional two-dimensional integration, and three-dimensional integration techniques provide another approach to continuation of moore's law. By this technique, chips or wafers having different functions can be manufactured separately, and vertical stacking can be achieved by a hybrid bonding process. Therefore, the hybrid bonding technology has very important research significance and application value.

In conventional hybrid bonding, siO₂ The metal filling material is commonly used for filling gaps among metal interconnection lines and preventing metal from being oxidized in the bonding process, so that the bonding area is effectively increased. However, due to SiO₂ Higher hardness, poorer deformation characteristics, siO₂ The surface needs to have high flatness and surface cleanliness to avoid electrical interconnection failure. Furthermore, siO₂ Mismatch of thermal expansion coefficients with metals can create residual stresses during bonding, which can lead to reliability problems. In contrast, the adhesive has the advantages of low hardness, low surface roughness, low flatness tolerance and the like, and can replace oxide as a buffer layer to release residual stress after bondingForce. Thus, adhesive/metal hybrid bonding is a very promising three-dimensional integration solution. Typical adhesive/metal hybrid bonds include metal/metal and adhesive/adhesive bonds, the former to provide electrical interconnection and the latter to provide passivation protection and mechanical support.

Among them, the "adhesive-first" method has the advantages of void-free and high-reliability bonding, but is liable to cause serious dislocation of metal interconnections due to fluidity and volume shrinkage of the adhesive; the metal priority method avoids the problem of dislocation of metal patterns after bonding, however, the curing process releases gas after bonding of the adhesive, and the bonding reliability is reduced. Both "adhesive first" and "metal first" methods must effect 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 because of its advantages in terms of flexibility, chemical inertness, mechanical toughness, thermal stability, etc., so that it can withstand the manufacturing processes of metal deposition, photolithography, wet etching, etc.

However, the higher temperatures required for complete curing of polyimide and higher bonding temperatures are not suitable for applications in certain advanced process areas such as dynamic random access memory and light emitting diodes. Therefore, those skilled in the art are highly required to develop a rapid, low temperature (250 ℃ C. Or less) curing polyimide-copper hybrid surface bonding method to achieve high efficiency and high reliability bonding, thereby producing high quality composite semiconductor substrates.

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 the cured polyimide-copper mixed surface in a low-temperature environment (less than or equal to 250 ℃), combines bonding strength and bonding efficiency, finally obtains the high-quality composite semiconductor substrate, and is beneficial to large-scale popularization and application.

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

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

(1) Carrying out first reduction on the substrate by adopting formic acid vapor, and removing an oxide layer on the surface of a copper column on the substrate;

(2) Sequentially adopting plasma and water vapor to treat the substrate obtained in the step (1) and activating 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 a copper column on the substrate, which is generated by plasma and steam treatment;

(4) And (3) obtaining at least 2 substrates through the steps (1) - (3), aligning the at least 2 substrates, and performing thermocompression 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 a role in insulation protection.

According to the invention, through sequentially performing first reduction, activation, second reduction and thermocompression bonding, and adopting formic acid steam which is easy to volatilize and has good reducibility in the first reduction stage and the second reduction stage respectively, and adopting plasma and steam 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 cured polyimide-copper mixed surface in a low-temperature environment (less than or equal to 250 ℃) is finally realized, and the bonding strength and the bonding efficiency are both considered, thereby obtaining a high-quality composite semiconductor substrate, and being beneficial to large-scale popularization and application.

Preferably, the diameter of individual ones of the copper pillars is 1-50 μm, 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 non-recited values within the range of values are equally applicable.

Preferably, the height of individual ones of the copper pillars is 1-20 μm, 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 non-recited values within the range of values are equally applicable.

Preferably, the thickness difference between the copper pillar and the polyimide film is not more than.+ -. 0.5. Mu.m, 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 not limited to the values listed, and other values not listed in the range of values are equally applicable.

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

Preferably, the carrier gas comprises any one or a combination of at least two of argon, helium or nitrogen, typically but not limited to combinations of argon and helium, combinations of helium and nitrogen, combinations of argon and nitrogen, or combinations of argon, helium and nitrogen.

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

Preferably, the time of the first reduction in the step (1) is 5-100min, for example, may be 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 non-recited values in the range of values are equally applicable.

In the present invention, the first reduction in the step (1) is performed under normal pressure or micro-positive pressure, and the normal pressure is specifically a standard atmospheric pressure, that is, 0.1MPa, and the micro-positive pressure is 200 to 400Pa higher than the standard atmospheric pressure, for example, 200Pa, 220Pa, 240Pa, 260Pa, 280Pa, 300Pa, 320Pa, 340Pa, 360Pa, 380Pa or 400Pa, but not limited to the recited values, and other non-recited values within the range of the values are equally applicable.

Preferably, the activation of step (2) is performed under vacuum conditions and the absolute vacuum is 1X 10^-2 -9×10⁴ Pa may be, for example, 1×10^-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 non-recited values within this range are equally applicable.

Preferably, the plasma of step (2) is produced from the inductive ionization of a process gas via 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, typically but not limited to combinations comprising argon and nitrogen, nitrogen and oxygen, argon and oxygen, or argon, nitrogen and oxygen.

Preferably, the flow rate of the process gas is 5-200mL/min, for example, 5mL/min, 10mL/min, 50mL/min, 100mL/min, 150mL/min or 200mL/min, but the process gas is not limited to the recited values, and other non-recited values within the range of the recited values are equally applicable.

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

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

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

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

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

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

In the present invention, the second reduction in the step (3) is performed under normal pressure or micro-positive pressure, and the normal pressure is specifically a standard atmospheric pressure, that is, 0.1MPa, and the micro-positive pressure is 200 to 400Pa higher than the standard atmospheric pressure, for example, 200Pa, 220Pa, 240Pa, 260Pa, 280Pa, 300Pa, 320Pa, 340Pa, 360Pa, 380Pa or 400Pa, but not limited to the recited values, and other non-recited values within the range of the values are equally 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 pressure applied to the substrate during the thermocompression bonding in the step (4) is 0.5 to 100MPa, for example, 0.5MPa, 1MPa, 10MPa, 20MPa, 40MPa, 60MPa, 80MPa or 100MPa, but the present invention is not limited to the values listed, and other values not listed in the range are equally applicable.

Preferably, the temperature of the thermocompression bonding in the step (4) is 180 to 400 ℃, for example, 180 ℃, 200 ℃, 220 ℃, 240 ℃, 260 ℃, 280 ℃, 300 ℃, 320 ℃, 340 ℃, 360 ℃, 380 ℃ or 400 ℃, but not limited to the values listed, and other values not listed in the range of the values are equally applicable.

Preferably, the time of thermocompression bonding in the step (4) is 0.1 to 30min, for example, 0.1min, 0.5min, 1min, 5min, 10min, 15min, 20min, 25min or 30min, but not limited to the recited values, and other non-recited values within the range of values are equally applicable.

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

Preferably, the device system is further provided with a vacuum pump and a robotic arm.

Preferably, the plasma activation chamber, the formic acid reduction chamber and the thermocompression bonding chamber are each independently connected to the vacuum pump for creating a vacuum environment for each chamber.

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

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

Preferably, a catalytic component is also provided in the interior of the formic acid reduction chamber or in the intake line.

Preferably, the catalytic member has a self-heating function and has a temperature ranging from 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 non-recited values within the range are equally applicable.

Preferably, the thermocompression bonding chamber is provided with a pressing member and an alignment member inside.

In a third aspect, the present invention provides an apparatus system for preparing a composite semiconductor substrate using the preparation method of the first aspect, the apparatus system comprising 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 thermocompression bonding chamber and the loading and unloading chamber are respectively and independently connected with the vacuum conveying chamber through valves.

The formic acid reduction chamber, the plasma activation chamber and the thermocompression bonding chamber are respectively and independently provided with heaters inside.

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

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

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

Drawings

Fig. 1 is a schematic view of an apparatus system for preparing a composite semiconductor substrate provided in example 1;

fig. 2 is a schematic diagram of an apparatus system for preparing a composite semiconductor substrate according to example 4.

Wherein: a 1-formic acid reduction chamber; 1A-formic acid reduction valve; 2-a plasma activation chamber; 2A-a plasma activated valve; 3-thermocompression bonding chamber; 3A-thermocompression bonding the valve; 4-loading and unloading chambers; 4A-feeding and discharging valves; 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-a water vapor inlet; 22-process gas inlet; 23-radio frequency power supply; 24-a second heater; 25-a second support base; 26-a first exhaust port; 31-catalytic gas inlet; 32-a protective gas inlet; 33-a second exhaust port; 34-alignment means; 35-a lower substrate support pedestal; 35A-a lower substrate heater; 36-an upper substrate support pedestal; 36A-upper substrate heater; 37-a pressurizing member; 100A-a lower substrate; 100B-an upper substrate; 1001-copper columns; 1002-polyimide film.

Detailed Description

The technical scheme of the invention is further described by the following specific embodiments. It will be apparent to those skilled in the art that the examples are merely to aid in understanding the invention and are not to be construed as a specific limitation thereof.

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 sequentially connected in series, 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.

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

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

As shown in fig. 1, the formicacid reduction chamber 1 is provided with aformic acid inlet 11 and aformic acid outlet 12 on the surface thereof, and afirst support base 13, afirst heater 14 and acatalytic member 15 inside thereof; a substrate material (hereinafter, asubstrate 100A is exemplified in fig. 1) to be reduced 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 the electrode of the radiofrequency power supply 23 is arranged at theprocess gas inlet 22; a substrate material (hereinafter,substrate 100A in fig. 1 is taken as an example) to be reduced is placed on thesecond heater 24; the process gas is dissociated into plasma by the discharge of therf power supply 23, and the substrate material is surface-treated.

As shown in fig. 1, thethermocompression bonding chamber 3 is provided with acatalytic gas inlet 31, aprotective gas inlet 32, and asecond gas outlet 33 on the surface thereof, and analignment member 34, a lowersubstrate support base 35, alower substrate heater 35A, an uppersubstrate support base 36, anupper substrate heater 36A, a pressurizingmember 37, and an upper substrate adsorption flipping member (not shown) inside; thealignment member 34 is used for observing alignment marks on two pieces of substrate materials (alower substrate 100A and anupper substrate 100B) respectively placed on the surfaces of thelower substrate heater 35A and theupper substrate heater 36A and performing alignment operation; accordingly, the lowersubstrate support pedestal 35 and the uppersubstrate support pedestal 36 are respectively connected to moving parts (not shown) to achieve mutual alignment of two pieces of substrate material; the lowersubstrate supporting base 35 and the matchedlower substrate heater 35A are arranged opposite to the uppersubstrate supporting base 36 and the matchedupper substrate heater 36A in the vertical direction, and can respectively clamp substrate materials; the pressurizingpart 37 is connected with the uppersubstrate supporting base 36, and can mutually attach and press two surface-treated substrate materials, thereby realizing thermocompression bonding;

example 2

The present embodiment provides an apparatus system for preparing a composite semiconductor substrate, which is not described herein, 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, and the other structures and conditions are the same as those ofembodiment 1.

Example 3

The present embodiment provides an apparatus system for preparing a composite semiconductor substrate, and the other structures and conditions are the same as those ofembodiment 1 except that the pressurizingmember 37 in thethermocompression bonding chamber 3 is provided to be connected with the lowersubstrate support base 35, so that the description thereof will be 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 comprises a formicacid reduction chamber 1, aplasma activation chamber 2, athermocompression bonding chamber 3, an upper and lower material chamber 4 and avacuum conveying chamber 5, wherein the formicacid reduction chamber 1, theplasma activation chamber 2, thethermocompression bonding chamber 3 and the upper and lower material chamber 4 are respectively and independently connected with thevacuum conveying chamber 5 through valves; the formicacid reduction chamber 1, theplasma activation chamber 2 and thethermocompression bonding chamber 3 are each independently provided with a heater inside.

In this embodiment, the device system is further provided with a vacuum pump (not shown in the figures) and arobot arm 6; the feeding and discharging chamber 4 and thevacuum conveying chamber 5 are respectively and independently connected with the vacuum pump and are used for manufacturing vacuum environments for the chambers; therobot arm 6 is disposed inside thevacuum transfer chamber 5, and is configured 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 conveying chamber 5 through a formicacid reduction valve 1A, theplasma activation chamber 2 is connected to thevacuum conveying chamber 5 through aplasma activation valve 2A, thethermocompression bonding chamber 3 is connected to thevacuum conveying chamber 5 through athermocompression bonding valve 3A, and the loading and unloading chamber 4 is connected to thevacuum conveying chamber 5 through a loading and unloadingvalve 4A; the inlet and outlet arrangement and the internal structure of the formicacid reduction chamber 1, theplasma activation chamber 2 and thethermocompression bonding chamber 3 are the same as those ofembodiment 1, so that the description thereof will not be repeated here.

Application example 1

The device system provided in example 1 is used in the preparation of a composite semiconductor substrate, and the specific preparation method comprises 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 so that the inside of the formicacid reduction chamber 1 is 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 the formicacid air inlet 11 along with argon with the flow of 1000mL/min, starting thefirst heater 14, setting the heating temperature to be 180 ℃ and the heating time to be 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 removed by using a 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 mechanical arm, and placing the two substrates together on the second heater 24; closing the first valve 12A, and starting a vacuum pump to enable the absolute vacuum degree in 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 performing surface treatment on the lower substrate 100A and the upper substrate 100B for 120s to enhance the hydrophilicity of the surfaces of the polyimide films 1002 on the two substrates; after the plasma surface treatment is finished, closing a process gas inlet 22 and a radio frequency power supply 23, opening a water vapor inlet 21, introducing water vapor into the plasma activation chamber 2, wherein the introducing of the water vapor is realized by flowing nitrogen through a water storage bottle, the water temperature in the water storage bottle is 60 ℃, so that a water molecule bridging layer is formed on the surfaces of polyimide films 1002 on the two substrates, and closing the water vapor inlet 21 after the water vapor surface treatment 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 enable the inside of the formicacid reduction chamber 1 to be 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 the formicacid air inlet 11 along with argon gas with the flow of 1000mL/min, starting thefirst heater 14, setting the heating temperature to 180 ℃ and the heating time to 5min, and performing sufficient second reduction on thelower substrate 100A to remove an oxide layer generated on the surface of thecopper column 1001 on thelower substrate 100A due to plasma and water vapor treatment; after the reduction is finished, thelower substrate 100A is removed by using a 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 closed 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; closing thesecond valve 13A, and introducing argon into thethermocompression bonding chamber 3 from theprotective gas inlet 32 to create a protective gas atmosphere; the alignment marks on thelower substrate 100A and theupper substrate 100B are observed by using thealignment part 34, and the moving part is regulated to perform alignment operation, so that the alignment marks on the two substrates are mutually overlapped in the observation field of thealignment part 34, thelower substrate heater 35A and theupper substrate heater 36A are started to heat the two substrates, and the heating temperature is set to 250 ℃ and the heating time is set to 30min respectively; the pressurizingmember 37 was activated to bond and press the two substrates, and the pressure was set at 50MPa, thereby obtaining a composite semiconductor substrate.

Application example 2

The device system provided in application example 1 is used for preparing a composite semiconductor substrate, and steps (1) and (2) in the preparation method are the same as those in application example 1, so that description thereof will not be repeated here.

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; closing the second valve 13A, and starting the vacuum pump to enable the interior of the thermocompression bonding chamber 3 to be in a vacuum state; the alignment parts 34 are utilized to observe the alignment marks on the lower substrate 100A and the upper substrate 100B and adjust the moving parts to perform alignment operation, so that the alignment marks on the two substrates are mutually overlapped in the observation field of the alignment parts 34; introducing formic acid vapor into the hot-press bonding chamber 3 from a catalytic gas inlet 31 along with argon with the flow of 1000mL/min, starting a lower substrate heater 35A and an upper substrate heater 36A to heat two substrates, respectively setting the heating temperature to 180 ℃ and the heating time to 50min, and performing sufficient second reduction on the two substrates to remove an oxide layer generated on the surfaces of copper pillars 1001 on the two substrates due to plasma and water vapor treatment; after the reduction is completed, the catalytic gas inlet 31 is closed, argon is introduced into the thermocompression bonding chamber 3 from the protective gas inlet 32 to create an atmosphere of protective gas, and the heating temperatures of the lower substrate heater 35A and the upper substrate heater 36A are respectively set to 300 ℃, and the heating times are respectively set to 30 minutes; the pressurizing member 37 was activated to bond and press the two substrates, and the pressure was set at 100MPa, thereby obtaining a composite semiconductor substrate.

Application example 3

The device system provided in example 4 is used for preparing a composite semiconductor substrate, and the preparation method specifically comprises the following steps:

(1) Placing thelower substrate 100A and theupper substrate 100B in the upper and lower material chamber 4, and starting a vacuum pump to enable the interior of the upper and lower material chamber 4 to be in a vacuum state; opening the upper andlower material valves 4A and the formicacid reduction valve 1A, taking thelower substrate 100A and theupper substrate 100B out of the upper and lower material chambers 4 by using themechanical arm 6, conveying thelower substrate 100A and theupper substrate 100B into the formicacid reduction chamber 1 through thevacuum conveying chamber 5, and closing the upper andlower material valves 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 respectively, wherein the specific reduction process and conditions are the same as those of the step (1) in the application example 1, so that no description is given here;

(2) Opening the formicacid reduction valve 1A and theplasma activation valve 2A, taking thelower substrate 100A and theupper substrate 100B out of the formicacid reduction chamber 1 by using themechanical arm 6, sending thelower substrate 100A and theupper substrate 100B into theplasma activation chamber 2 through thevacuum conveying chamber 5, and closing the formicacid reduction valve 1A and theplasma activation valve 2A; thesecond heater 24 and therf power supply 23 are started, and nitrogen and water vapor are sequentially introduced to perform surface treatment on thelower substrate 100A and theupper substrate 100B, respectively, and the specific treatment process and conditions are the same as those of the step (2) in application example 1, so that no description will be repeated here;

(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, sending the lower substrate and the upper substrate into the formicacid reduction chamber 1 through thevacuum conveying chamber 5, and closing theplasma activation valve 2A and the formicacid reduction valve 1A; starting thefirst heater 14 and introducing formic acid vapor to perform second reduction on thelower substrate 100A and theupper substrate 100B respectively, wherein the specific reduction process and conditions are the same as those of the step (3) in the application example 1, so that no description is given here;

(4) Opening the formicacid reduction valve 1A and the hot-press bonding valve 3A, taking thelower substrate 100A and theupper substrate 100B out of the formicacid reduction chamber 1 by using themechanical arm 6, sending thelower substrate 100A and theupper substrate 100B into the hot-press bonding chamber 3 through thevacuum conveying chamber 5, and closing the formicacid reduction valve 1A and the hot-press bonding valve 3A; argon is introduced into thethermocompression bonding chamber 3 to create an atmosphere of protective gas, the two substrates are aligned, thelower substrate heater 35A and theupper substrate heater 36A are started to heat the two substrates, and the pressurizingmember 37 is started to bond and compress the two substrates, and the specific thermocompression bonding process and conditions are the same as those in step (4) in application example 1, so that no description is given here;

(5) Opening the hot-press bonding valve 3A and the feeding and dischargingvalve 4A, taking thelower substrate 100A and theupper substrate 100B out of the hot-press bonding chamber 3 by using themechanical arm 6, feeding the lower substrate into the feeding and discharging chamber 4 through thevacuum conveying chamber 5, and closing the hot-press bonding valve 3A and the feeding and dischargingvalve 4A; vacuum is discharged to the loading and unloading chamber 4, the air pressure value is restored to the atmospheric pressure, and the composite semiconductor substrate is taken out.

Application example 4

The device system provided in application example 4 is used for preparing a composite semiconductor substrate, and steps (1), (2) and (4) in the preparation method are the same as those in application example 3, so that description thereof will not be repeated here.

The step (3) is specifically as follows: opening aplasma activation valve 2A and athermocompression bonding valve 3A, taking thelower substrate 100A and theupper substrate 100B out of theplasma activation chamber 2 by using amechanical arm 6, sending the lower substrate and the upper substrate into thethermocompression bonding chamber 3 through avacuum transmission chamber 5, and closing theplasma activation valve 2A and thethermocompression bonding valve 3A; the alignment operation is performed on the two substrates, the heater is started, and formic acid vapor is introduced, so that the second reduction is performed on thelower substrate 100A and theupper substrate 100B respectively, and the specific reduction process and conditions are the same as those in the step (3) in application example 1, so that the description is omitted here; after the reduction is finished, the heater and the pressurizingcomponent 37 are started to attach and compress the two substrates, and the specific hot-press bonding process and conditions are the same as those in the step (4) in the application example 1, so that no description is given here.

Therefore, the invention adopts the volatile formic acid vapor with good reducibility in the first reduction stage and the second reduction stage respectively through the first reduction, the activation, the second reduction and the hot-press bonding which are sequentially carried out, adopts the plasmas and the water vapor in the activation stage to form the water molecule bridging layer on the surface of the polyimide film on the substrate, finally realizes the rapid bonding of the cured polyimide-copper mixed surface in the low-temperature environment (less than or equal to 250 ℃), and combines the bonding strength and the bonding efficiency, thereby obtaining the high-quality composite semiconductor substrate and being beneficial to large-scale popularization and application.

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

Claims

1. A method of preparing a composite semiconductor substrate, the method comprising the steps of:

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

2. The method according to claim 1, wherein the diameter of individual copper pillars among 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 method according to claim 1, wherein the formic acid vapor in step (1) is introduced with a carrier gas, and the flow rate of the carrier gas is 10 to 2000mL/min;

the carrier gas comprises any one or a 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 step (2) is carried out under vacuum conditions and the absolute vacuum is 1X 10^-2 -9×10⁴ Pa；

The plasma in the step (2) is prepared by the induction ionization of the process gas through 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 plasmas in the step (2) is 25-150 ℃ and the treatment time is 1-300s;

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

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

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

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

the pressure applied to the substrate in the thermocompression bonding process in the step (4) is 0.5-100MPa;

the temperature of the hot-press 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 using 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 thermocompression bonding chamber which are sequentially connected in series, wherein a heater is independently provided in each chamber, 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 thermocompression bonding chamber are respectively and independently connected to the vacuum pump and are used for manufacturing a vacuum environment for each chamber;

the robot arm is used for grabbing the substrate and transferring the substrate between the chambers.

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

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

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

the inside of the thermocompression bonding chamber is provided with a pressing member and an alignment member.

9. An apparatus system for manufacturing a composite semiconductor substrate by using the manufacturing 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 with the vacuum conveying chamber through valves;

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 conveying chamber are respectively and independently connected with the vacuum pump;

the mechanical arm is arranged in the vacuum conveying chamber.