CN117219502B - Single-sided thinning method of bonding wafer - Google Patents
Single-sided thinning method of bonding wafer Download PDFInfo
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Abstract
The invention relates to the field of semiconductor manufacturing process, in particular to a single-sided thinning method of a bonding wafer, which comprises the following steps: a) Bonding the wafer and the carrier to form a bonding wafer, thinning one side of a wafer layer in the bonding wafer, and cleaning after thinning; b) After pre-baking, coating positive photoresist on the thinned surface of the wafer layer, and then removing the photoresist in the middle area of the bonding wafer through pre-baking, aligning, exposing, post-baking and developing, and reserving the photoresist on the circumference of the outer side of the wafer; c) After chemical corrosion is carried out on the bonding wafer, ultrasonic cleaning is carried out; d) And removing the outer ring bonding wafer part of the photoresist coating area by adopting laser splinter, and then performing ultrasonic vibration washing to separate the middle area of the bonding wafer from the outer ring bonding wafer part of the photoresist coating area. The invention can meet the ultrathin requirement of the bonding wafer and can avoid the problems of surface damage, brittle fracture, bond and structural damage of the bonding wafer after thinning.
Description
Technical Field
The invention relates to the field of semiconductor manufacturing processes, in particular to a single-sided thinning method of a bonding wafer.
Background
With the trend of miniaturization and high frequency of semiconductor devices, there is a demand for ultra-thin bonding chips in integrated circuits. In general, the existing wafer material belongs to brittle materials, the mechanical strength is low, the bonding wafer is formed by bonding two wafers, the bond and the structure are easily affected by external force, if the bonding wafer is thinned by directly using a thinning machine once, the mechanical strength of the wafer cannot bear the mechanical processing of the thinning machine, and the edge brittle fracture, the bond, the structural fracture and other anomalies are easy to occur. In addition, when the thickness of the wafer is relatively thin, the wafer warpage may be poor and a subsurface damage layer may be generated during long-time machining, and a great negative effect is generated on the electrical performance of the wafer, so that in the process of thinning the wafer, a chemical etching means is used to remove the subsurface damage layer of the thinned surface of the wafer, and the surface quality is ensured while the removal amount of the wafer is obtained. In the chemical etching process, auxiliary measures such as kick, rocker arm and ultrasonic vibration are usually used to ensure uniformity of chemical etching so as to avoid abnormal TTV of wafers generated by uneven etching, but for bonding wafers with thinner thickness, mechanical vibration of the wafers during etching processing often leads the wafers to generate brittle fracture starting from edges or generate bonding wafer deflection, so that bonding strength is reduced.
The invention patent number CN102820218B discloses a wafer thinning method, which can thin the wafer thickness below 100 μm, and the direct purpose of using photoresist in the method is to process the wafer in coordination with wet etching, and the photoresist on the edge of the wafer is removed before wet etching; in addition, when the wafer edge is sprayed by wet etching, the wafer rotation is simply relied on, so that the problem of uneven corrosion is caused, the wafer TTV is poor, and the wafer is poor in secondary thinning; with the spray process, in addition to requiring a single-piece flow operation, the etching efficiency is also significantly lower than direct etching.
The invention patent No. CN104733300B discloses a bonding wafer thinning method, which can thin the bonding wafer to be less than 50 mu m, and in order to avoid sharp corners on the edge of the bonding wafer in the thinning process and the edge of the subsequent wafer to be broken, the arc edge of the wafer is firstly ground and then thinned, so that the bonding area between the bonding wafers is directly reduced, the dislocation risk in the thinning process of the small-size wafer is increased, and the universality is poor; the process has higher precision requirement on the thinning machine, and particularly when the thickness of the thinned wafer is thinner, the edge of the wafer can be cracked in the arc removing process; in addition, grinding the wafer edge also greatly increases the risk of bonding the wafer edge to debond, which can adversely affect subsequent thinning.
In summary, the thinning process in the prior art has corresponding problems and drawbacks, so a more efficient and high-quality single-sided thinning method for bonding wafers is needed to solve the problems in the prior art.
Disclosure of Invention
The invention aims to develop a single-sided thinning method of a bonding wafer, which is used for reducing the risks of brittle fracture, bond and structural damage existing at the edge in the thinning process of the bonding wafer and relieving the problems of wafer surface damage such as too deep subsurface damaged layer and poor warping degree. The invention provides a single-sided thinning method of a bonding wafer, which specifically comprises the following steps:
a) Bonding the wafer and the carrier into a bonding wafer, and then thinning a single face of a wafer layer in the bonding wafer, and cleaning after thinning;
b) After pre-baking, coating positive photoresist on the thinned surface of the wafer layer, and then performing pre-baking, alignment, exposure, post-baking and development to remove the photoresist in the middle area of the wafer through development, and reserving the photoresist on the periphery of the outer side of the wafer;
c) Carrying out chemical corrosion on the bonding wafer, and then carrying out ultrasonic cleaning on the bonding wafer;
d) Removing the outer ring bonding wafer part of the photoresist coating area by adopting a laser lobe, mainly taking the center of the bonding wafer as the center, carrying out laser drilling at the edge of the photoresist, then carrying out ultrasonic vibration washing, and carrying out vibration washing on the middle area of the bonding wafer and the outer ring bonding wafer part of the photoresist coating area until the bonding wafer part is separated.
Preferably, in the step a), the wafer is made of piezoelectric material or semiconductor material, preferably, the wafer is made of monocrystalline silicon, silicon carbide, quartz, lithium niobate, indium phosphide or gallium arsenide, the diameter of the wafer is 4-12 inches, and the warpage of the wafer is less than 10 μm;
preferably, in the step a), a bonding method capable of ensuring bonding quality is selected according to the requirement of the material to be bonded, wherein the bonding method is anodic bonding, metal bonding or ultraviolet light activated bonding;
preferably, in the step a), the wafer layer of the bonded wafer is thinned by using a resin bond diamond grinding wheel, wherein the diameter of the grinding wheel is more than 200mm, the wafer layer of the bonded wafer is thinned to 200+/-20 μm in the first stage, the wafer layer of the bonded wafer is thinned to 100+/-10 μm in the second stage, and the wafer layer of the bonded wafer is thinned to 70-80 μm in the third stage;
preferably, in the step a), after the thinning of each stage is completed, the mixed solution of ammonium bifluoride and RO water is used for cleaning, and the mass ratio of the ammonium bifluoride to the RO water is 4:1-5:1.
Preferably, in the step b), the bonding wafer is glued under the conditions that the temperature is 20-25 ℃, the temperature stability is +/-1 ℃, the relative air humidity is 35-50%, and the spin coating rotating speed is 2000-4000 rpm; after pre-baking, in order to enhance the adhesive force of the photoresist, a reinforcing agent is coated on the thinned surface, wherein the reinforcing agent is one of hexamethyldisilane and AR 300-80; the photoresist in the middle area of the bonded wafer was removed by development, leaving the photoresist 5.+ -. 0.1mm wide from the outer circumference of the wafer.
Preferably, in the step c), the chemical agent used for the chemical etching is composed of hydrofluoric acid, nitric acid, dimethylformamide, or hydrofluoric acid, the etching amount is 3-50 μm, the ultrasonic cleaning is performed by using RO water and absolute ethyl alcohol, and the concentration of the absolute ethyl alcohol is 75-90%.
As a preferred aspect, after chemical etching of the bonded wafer, the wafer layer of the bonded wafer is thinned to 10-50 μm, which is most remarkable in reducing brittle fracture at the wafer edge.
Preferably, in the step d), laser drilling is performed at a position 5+/-0.1 mm away from the edge of the photoresist, wherein the diameter of the hole is 0.8-1.2 μm, and the center distance of the hole is 8.5-9.5 μm;
preferably, in the step d), the vibration washing solution is ammonium bifluoride solution, the ultrasonic current intensity is 0.5-1A, and the vibration washing time is 5-20 min until the middle area of the bonding wafer is separated from the outer ring bonding wafer of the photoresist coating area;
preferably, in the step d), the roundness of the bonded wafer after breaking is not more than 0.03mm, the crack length is not more than 2 μm, the pitch of the dicing streets is not more than 10 μm, and the dicing streets are dicing traces formed after laser drilling.
The beneficial effects of the invention are as follows:
1. by adopting the single-sided thinning method of the bonding wafer, the thickness of the wafer layer can be thinned to 10-50 mu m, the surface quality and the edge quality of the bonding wafer after thinning are greatly improved, the risks of breakage, splitting, bonding and structural damage of the bonding wafer are reduced, the thinning processing quality of the bonding wafer with large size is particularly improved, the product yield is improved, and the production cost is reduced;
2. in chemical corrosion, in order to ensure that the concentration of hydrofluoric acid on the surface of a wafer is uniformly distributed, measures such as kick or ultrasonic waves are added in corrosive agents to assist the flow of acid liquor, and the measures can lead to mechanical collision between wafers;
3. on the basis of protecting the edge of the outer ring of the bonding wafer by photoresist, chemical corrosion can be fully used to remove the subsurface damage layer, so that the wafer warpage is optimized, brittle fracture of the bonding wafer is avoided, the surface quality of the wafer is ensured, and the process yield and efficiency are improved;
4. after chemical corrosion, the outer ring bonding wafer part of the photoresist coating area is removed by adopting a laser splitting and ultrasonic vibration washing mode, and even if the bonding wafer has the defects of edge breakage and the like in the thinning processing, the bonding wafer can be removed, so that the method unifies the bonding wafer edge standard and improves the bonding wafer edge quality.
Drawings
FIG. 1 is a schematic flow chart of a thinning method according to embodiment 2 of the present invention;
FIG. 2 is a schematic cross-sectional view of a lithium niobate wafer bonded to a sapphire carrier sheet according to example 2 of the present invention;
FIG. 3 is a schematic diagram of a photoresist coated area on the edge of a bonded wafer according to embodiment 2 of the present invention;
FIG. 4 is a schematic cross-sectional view of a laser drilling process according to example 2 of the present invention;
the device comprises a 21-lithium niobate wafer, a 22-sapphire carrier, a 31-bonding wafer edge photoresist region, a 41-dicing street spacing and a 42-dicing street.
The invention is further described below with reference to the accompanying drawings.
Detailed Description
The following specific examples are set forth to further illustrate the invention, and it should be understood that the examples are not intended to limit the scope of the invention.
Example 1 is as follows:
a) Bonding the single-sided sandblasted lithium tantalate wafer with a silicon wafer slide, wherein the non-sandblasted surface is attached to one side of the slide, the diameter of the lithium tantalate wafer is 110mm, the thickness of the lithium tantalate wafer is 300 mu m, and the diameter of the silicon wafer slide is 110mm and the thickness of the silicon wafer slide is 550 mu m; carrying out first-stage single-sided thinning on the sand blasting surface of a lithium tantalate wafer by using a 2000-mesh resin binder diamond grinding wheel, thinning a lithium tantalate wafer layer to 200 mu m, wherein the diameter of the grinding wheel is more than 200mm, the geometric shape of the grinding wheel is rectangular, the rotating speed of the grinding wheel is 2000rpm, the rotating speed of the wafer is 400rpm, the feeding amount is 20 mu m/min, and then cleaning the bonded wafer by using ammonium bifluoride and RO water; carrying out second-stage single-sided thinning on the sand blasting surface of the lithium tantalate wafer by using a 4000-mesh resin binder diamond grinding wheel, thinning a lithium tantalate wafer layer to 100 mu m, wherein the diameter of the grinding wheel is more than 200mm, the geometric shape of the grinding wheel is rectangular, the rotating speed of the grinding wheel is 1500rpm, the rotating speed of the wafer is 150rpm, the feeding amount is 9 mu m/min, and then cleaning the bonded wafer by using ammonium bifluoride and RO water; carrying out third-stage single-sided thinning on the sand blasting surface of a lithium tantalate wafer by using a 6000-mesh resin binder diamond grinding wheel, thinning a lithium tantalate wafer layer to 70 mu m, wherein the diameter of the grinding wheel is more than 200mm, the geometric shape of the grinding wheel is rectangular, the rotating speed of the grinding wheel is 800rpm, the rotating speed of the wafer is 130rpm, the feeding amount is 6 mu m/min, and then cleaning the bonded wafer by using ammonium bifluoride and RO water;
b) After pre-baking the bonding wafer, coating positive photoresist on the thinned surface of the wafer, and then removing the photoresist in the middle area of the bonding wafer through pre-baking, aligning, exposing, post-baking and developing, and reserving the photoresist with the width of 5mm from the outer circumference of the edge of the wafer, wherein the pre-baking temperature of the wafer is set to 200 ℃, and the baking time is set to 2min. After pre-baking, hexamethyldisilane is coated on the sandblasted surface of the lithium tantalate wafer to enhance the adhesive force of the photoresist. The glue coating condition is that the temperature is 23 ℃, the temperature stability is +/-1 ℃, the relative air humidity is 43%, and the spin coating rotating speed is 4000rpm;
c) Etching after mixing hydrofluoric acid and nitric acid, wherein the etching amount is 50 mu m, etching the middle area of the lithium tantalate wafer layer to 20 mu m at 40 ℃, wherein the mass ratio of hydrofluoric acid is 10%, and then performing ultrasonic cleaning by RO water and absolute ethyl alcohol, wherein the concentration of absolute ethyl alcohol is 75%;
d) And (3) splitting by using a laser splitting machine, taking the center of a bonding wafer as the center, carrying out laser drilling on the outer circumference with the diameter of 100mm, wherein the diameter of a hole is 1 mu m, the distance between the centers of the holes is 9.5 mu m, then using an ultrasonic cleaning machine, using an oscillation cleaning solution as ammonium bifluoride solution, separating the middle part of the bonding wafer from the bonding wafer part of an outer ring photoresist coating area, carrying out ultrasonic current intensity of 1A, and oscillation cleaning for 5min, thereby finally obtaining the thinned bonding wafer, wherein the roundness of the bonding wafer is not more than 0.03mm, the crack length is not more than 2 mu m, and the cutting path distance is not more than 10 mu m.
The process flow of example 2 is shown in fig. 1, and the specific method is as follows:
a) Bonding the single-sided sandblasted lithium niobate wafer 21 with a sapphire slide 22, wherein the non-sandblasted surface is attached to one side of the slide, as shown in fig. 2, the diameter of the lithium niobate wafer is 160mm, the thickness of the lithium niobate wafer is 300 mu m, the diameter of the sapphire slide is 160mm, and the thickness of the sapphire slide is 600 mu m; carrying out first-stage single-sided thinning on the sand blasting surface of a lithium niobate wafer by using a 2000-mesh resin binder diamond grinding wheel, thinning a lithium niobate wafer layer to 200 mu m, wherein the diameter of the grinding wheel is more than 200mm, the geometric shape of the grinding wheel is rectangular, the rotating speed of the grinding wheel is 1000rpm, the rotating speed of the wafer is 200rpm, the feeding amount is 15 mu m/min, and then cleaning by ammonium bifluoride and RO water; carrying out second-stage single-sided thinning on the sand blasting surface of the lithium niobate wafer by using a 4000-mesh resin binder diamond grinding wheel, thinning a lithium niobate wafer layer to 100 mu m, wherein the diameter of the grinding wheel is more than 200mm, the geometric shape of the grinding wheel is rectangular, the rotating speed of the grinding wheel is 800rpm, the rotating speed of the wafer is 100rpm, the feeding amount is 5 mu m/min, and then cleaning the bonded wafer by using ammonium bifluoride and RO water; carrying out third-stage single-sided thinning on the sand blasting surface of a lithium niobate wafer by using a 6000-mesh resin binder diamond grinding wheel, thinning a lithium tantalate wafer layer to 70 mu m, wherein the diameter of the grinding wheel is more than 200mm, the geometric shape of the grinding wheel is rectangular, the rotating speed of the grinding wheel is 500rpm, the rotating speed of the wafer is 100rpm, the feeding amount is 4 mu m/min, and then cleaning the bonded wafer by using ammonium bifluoride and RO water;
b) After pre-baking the bonding wafer, coating positive photoresist on the thinned surface of the wafer, and then removing the photoresist in the middle area of the bonding wafer through pre-baking, aligning, exposing, post-baking and developing, and reserving the photoresist area 31 at the edge of the bonding wafer, namely the photoresist area 5mm wide from the outer circumference of the edge of the bonding wafer, wherein the pre-baking temperature of the wafer is set to 200 ℃ and the baking time is set to 2min, as shown in fig. 3. After pre-baking, in order to enhance the adhesive force of the photoresist, hexamethyldisilane serving as an enhancer is coated on the sandblasted surface of the lithium niobate wafer. The wafer gluing condition is that the temperature is 23 ℃, the temperature stability is +/-1 ℃, the relative air humidity is 43%, and the spin coating rotating speed is 2000rpm;
c) Etching after mixing hydrofluoric acid and nitric acid, wherein the etching amount is 50 mu m, etching the middle area of the lithium niobate wafer layer to 20 mu m, the temperature is 30 ℃, the mass ratio of hydrofluoric acid is 10%, then performing ultrasonic cleaning by RO water and absolute ethyl alcohol, and the concentration of absolute ethyl alcohol is 75%;
d) The laser splitting machine is used for splitting, the bonded wafer circle center is taken as the center, laser drilling is carried out at the outer circumference with the diameter of 150mm, the diameter of the hole is 1 mu m, the distance between the circle centers of the holes is 8.5 mu m, the schematic diagram of the cross section of the laser drilling is shown in fig. 4, and the cutting trace formed after the laser drilling is the cutting trace 42. And then using an ultrasonic cleaner, separating the middle wafer from the outer ring by using an ammonium bifluoride solution as a vibration cleaning solution, wherein the ultrasonic current intensity is 0.5A, and the vibration cleaning time is 8min, so that the thinned bonding wafer is finally obtained, the roundness of the bonding wafer is not more than 0.03mm, the crack length is not more than 2 mu m, and the cutting path spacing 41 is not more than 10 mu m.
Comparative example:
a) Bonding the single-sided sand-blasted lithium niobate wafer with a sapphire slide, wherein the non-sand-blasted surface is attached to one side of the slide, the diameter of the lithium niobate wafer is 150mm, the thickness of the lithium niobate wafer is 300 mu m, and the diameter of the sapphire slide is 150mm, and the thickness of the sapphire slide is 600 mu m; the grinding wheel thinning process is the same as in step a) of example 2;
b) And (3) mixing hydrofluoric acid and nitric acid, then carrying out corrosion, wherein the corrosion amount is 50 mu m, corroding the lithium niobate wafer layer to 20 mu m, the temperature is 30 ℃, the mass ratio of hydrofluoric acid is 10%, then carrying out ultrasonic cleaning by RO water and absolute ethyl alcohol, and finally obtaining the thinned bonding wafer by using the absolute ethyl alcohol with the concentration of 75%.
The bonded wafer performance effects obtained in examples 1, 2 and comparative example are shown in table 1:
table 1 comparison of bonded wafer properties obtained in examples 1, 2 and comparative example
| Parameter name | Example 1 | Example 2 | Comparative example |
| Wafer layer thickness (μm) | 10.5 | 18.3 | 18.2 |
| Wafer layer crystal orientation deviation (°) | 0.04 | 0.06 | 0.05 |
| Wafer layer flatness (μm) | 1.27 | 1.44 | 1.65 |
| Wafer layer warp (μm) | 14.6 | 15.8 | 17.1 |
| Bond Strength (J/m) 2 ） | 2.01 | 1.84 | 1.68 |
| RTY（%） | 79 | 82 | 65 |
As can be seen from the above table, the bonded wafers of examples 1 and 2 have good overall performance and high yield due to the slightly better flatness and warpage of the wafer layer after processing the smaller bonded wafer of example 1. These two embodiments are referred to as being applicable to bonding wafers of different materials. As a control, the number of edge crack pieces exceeding 2 μm in length was significantly increased and the bonding strength was also relatively weak compared to example 2, thus resulting in a drastic decrease in yield loss.
Although embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes, modifications and alternatives may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
Claims (10)
1. A single-sided thinning method of a bonding wafer is characterized by comprising the following specific steps:
a) Bonding the wafer and the carrier to form a bonding wafer, thinning one side of a wafer layer in the bonding wafer, and cleaning after thinning;
b) After pre-baking, coating positive photoresist on the thinned surface of the wafer layer, and then removing the photoresist in the middle area of the bonding wafer through pre-baking, aligning, exposing, post-baking and developing, and reserving the photoresist at the peripheral edge of the outer side of the wafer;
c) Carrying out chemical corrosion on the bonding wafer, and then carrying out ultrasonic cleaning on the bonding wafer;
d) Removing the outer ring bonding wafer part of the photoresist coating area by adopting a laser lobe, mainly taking the center of the bonding wafer as the center, carrying out laser drilling at the edge of the photoresist, then carrying out ultrasonic vibration washing, and carrying out vibration washing on the middle area of the bonding wafer and the outer ring bonding wafer part of the photoresist coating area until the bonding wafer part is separated.
2. The method for single-sided thinning of bonded wafer according to claim 1, wherein in the step a), the wafer is made of piezoelectric material or semiconductor material, and may be monocrystalline silicon, silicon carbide, quartz, lithium niobate, indium phosphide or gallium arsenide, the diameter of the wafer is 4-12 inches, and the warpage of the wafer is less than 10 μm.
3. The method for thinning one surface of a bonded wafer according to claim 1, wherein in the step a), the bonding method is anodic bonding, metal bonding or ultraviolet light activated bonding.
4. The method for single-sided thinning of bonded wafer according to claim 1, wherein in the step a), the bonded wafer is thinned by using a resin bond diamond grinding wheel with a diameter of 200mm or more, the wafer layer in the bonded wafer is thinned to 200+ -20 μm in the first stage, the wafer layer in the bonded wafer is thinned to 100+ -10 μm in the second stage, and the wafer layer in the bonded wafer is thinned to 70-80 μm in the third stage.
5. The method for single-sided thinning of bonded wafer according to claim 1, wherein in the step a), after the thinning of each stage is completed, the mixed solution of ammonium bifluoride and RO water is used for cleaning, and the mass ratio of ammonium bifluoride to RO water is 4:1-5:1.
6. The method for single-sided thinning of a bonded wafer according to claim 1, wherein in the step b), the bonding wafer is glued under the conditions that the temperature is 20-25 ℃, the temperature stability is + -1 ℃, the relative air humidity is 35-50%, and the spin-coating rotating speed is 2000-4000 rpm; after pre-baking, in order to enhance the adhesive force of the photoresist, a reinforcing agent is coated on the thinned surface, wherein the reinforcing agent is one of hexamethyldisilane and AR 300-80; the photoresist in the middle area of the bonded wafer was removed by development, leaving the photoresist 5.+ -. 0.1mm wide from the outer circumference of the wafer.
7. The method for single-sided thinning of bonded wafer according to claim 1, wherein in the step c), the chemical agent used for chemical etching is composed of hydrofluoric acid, nitric acid, dimethylformamide, hydrofluoric acid, and the etching amount is 3-50 μm; and ultrasonic cleaning is carried out by adopting RO water and absolute ethyl alcohol, and the concentration of the absolute ethyl alcohol is 75-90%.
8. The method for single-sided thinning of bonded wafer according to claim 1, wherein in the step d), laser drilling is performed at a distance of 5+ -0.1 mm from the edge of photoresist, the diameter of the hole is 0.8-1.2 μm, and the center distance of the hole is 8.5-9.5 μm.
9. The method for single-sided thinning of a bonded wafer according to claim 1, wherein in the step d), the vibration washing solution is an ammonium bifluoride solution, the ultrasonic current intensity is 0.5-1 a, and the vibration washing time is 5-20 min until the middle area of the bonded wafer is separated from the outer ring bonded wafer of the photoresist coating area.
10. The method for single-sided thinning of bonded wafers according to claim 1, wherein in step d), the roundness of bonded wafers after breaking is not more than 0.03mm, the crack length is not more than 2 μm, and the pitch of scribe lines is not more than 10 μm.
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| CN106158594A (en) * | 2015-04-16 | 2016-11-23 | 中芯国际集成电路制造(上海)有限公司 | Photoetching method and technique for applying thereof |
| WO2022057013A1 (en) * | 2020-09-16 | 2022-03-24 | 武汉新芯集成电路制造有限公司 | Wafer bonding method |
| CN114883186A (en) * | 2022-07-11 | 2022-08-09 | 成都功成半导体有限公司 | Wafer back processing method based on temporary bonding and wafer |
| CN116053126A (en) * | 2023-01-16 | 2023-05-02 | 合肥沛顿存储科技有限公司 | Ultrathin chip plasma cutting process |
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| US8476165B2 (en) * | 2009-04-01 | 2013-07-02 | Tokyo Electron Limited | Method for thinning a bonding wafer |
| US12341056B2 (en) * | 2021-08-30 | 2025-06-24 | Taiwan Semiconductor Manufacturing Company Ltd. | Method of fabricating a semiconductor structure and semiconductor structure obtained therefrom |
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| CN106158594A (en) * | 2015-04-16 | 2016-11-23 | 中芯国际集成电路制造(上海)有限公司 | Photoetching method and technique for applying thereof |
| WO2022057013A1 (en) * | 2020-09-16 | 2022-03-24 | 武汉新芯集成电路制造有限公司 | Wafer bonding method |
| CN114883186A (en) * | 2022-07-11 | 2022-08-09 | 成都功成半导体有限公司 | Wafer back processing method based on temporary bonding and wafer |
| CN116053126A (en) * | 2023-01-16 | 2023-05-02 | 合肥沛顿存储科技有限公司 | Ultrathin chip plasma cutting process |
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