Device for realizing single-side corrosion of silicon wafer
By designing a device including a rotating stage, a corrosion liquid spraying device, a corrosion liquid recovery device and a filtering circulation device, the problem that the prior art cannot differentiate the front and back of the silicon wafer is solved, and differentiated corrosion treatment and corrosion liquid recycling of the silicon wafer surface are realized, meeting customers' requirements for the flatness and texture of the silicon wafer surface.
Patent Information
- Application Number
- CN202421458704.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-25
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2034-06-25
AI Technical Summary
The prior art cannot perform differentiated corrosion treatment on the front and back of the silicon wafer according to the purpose of the silicon wafer or customer needs, resulting in the inability to meet customers' specific requirements for the surface flatness and texture of the silicon wafer.
A device including a rotary stage, a corrosion liquid spraying device, a corrosion liquid recovery device and a filter circulation device is designed. The single-side corrosion of the silicon wafer is achieved through the rotary stage and the spraying device, and the corrosion liquid is circulated by the filter circulation device to ensure that the other side of the silicon wafer is not affected by corrosion.
Differentiated corrosion processing of the non-treated surface and the to-treated surface of the silicon wafer are realized, meeting customers' requirements for the corrosion type, texture and flatness of the silicon wafer surface, while saving the cost of corrosive liquid reagents and avoiding pollution.
Smart Images
Figure CN222867629U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of silicon wafer production technology, in particular to a device for realizing single-side etching of silicon wafers. Background Art
[0002] The rapid development of microelectronics and information technology has put forward higher requirements on the processing quality of optoelectronic components. How to efficiently obtain ultra-smooth and damage-free surfaces of silicon wafers has become the research focus of ultra-precision polishing processing technology. At present, the mainstream technical route is to chemically etch silicon wafers before polishing. Etching is mainly divided into acid etching and alkaline etching. Among them, alkaline etching is widely used because it is easy to control the surface flatness. The traditional etching process is to immerse the silicon wafer in an alkaline solution or mixed acid solution at an appropriate temperature, and control the etching time, etching solution temperature, stirring speed, etc. to achieve the desired etching effect.
[0003] In many cases, the roughness of the back of the silicon wafer is related to the customer's processing machine and the customer's own processing technology. Some customers will specify the type of etching on the processing surface / back of the silicon wafer chip (only acid etching or only alkaline etching) and make specific requirements for the roughness of the front (chip processing surface) and / or back. However, the current acid or alkaline etching process will cause the front and back of the silicon wafer to be corroded at the same time, and it is impossible to differentiate the front and back of the silicon wafer according to the purpose of the silicon wafer or customer needs.
[0004] In summary, the inventor hopes to propose a device that can solve the above problems. Summary of the invention
[0005] 1. Technical issues to be resolved
[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the utility model provides a device for realizing single-sided etching of silicon wafers, which can perform acid etching or alkali etching on a single side of the silicon wafer according to the purpose of the silicon wafer or customer needs, and will not cause corrosion to the other side of the silicon wafer, thereby realizing differentiated processing of the non-processed surface and the surface to be processed of the silicon wafer.
[0007] (II) Technical solution
[0008] In a first aspect, the utility model provides a device for realizing single-sided etching of a silicon wafer, which comprises: a rotating stage, an etching liquid spraying device, an etching liquid recovery device and a filtering circulation device;
[0009] The rotating stage is used to fix the silicon wafer and drive the silicon wafer to rotate synchronously;
[0010] The etching liquid spraying device is used to spray the etching liquid on the upper surface of the silicon wafer;
[0011] The etching liquid recovery device is used to collect the etching liquid that slides off the rotating stage and the silicon wafer;
[0012] The filtering circulation device is used to filter and purify the corrosive liquid collected by the corrosive liquid recovery device, and then circulate it to the corrosive liquid spraying device, and spray it again on the upper surface of the silicon wafer on the rotating stage.
[0013] Preferably, a suction cup is provided on the rotating platform for fixing the silicon wafer.
[0014] Preferably, it also includes a rubber strip enclosure ring, the diameter of which matches the diameter of the silicon wafer, and the rubber strip enclosure ring is arranged on the rotating platform to shield and seal the periphery of the silicon wafer.
[0015] Preferably, a plurality of annular grooves are provided on the rotating platform and located around the suction cup, and the annular grooves are distributed in concentric circles; the annular grooves are used to fix the lower end of the rubber strip retaining ring, and the silicon wafer is fixed inside the rubber strip retaining ring; the rubber strip retaining ring is tightly matched with the periphery of the silicon wafer to seal the periphery of the silicon wafer.
[0016] Preferably, the middle area of the rotating platform is a flat area, and a certain width of the periphery near the edge is a slope inclined downward to guide the etching liquid to flow to the outside of the rotating platform to avoid the etching liquid accumulating on the rotating carrier.
[0017] Preferably, the corrosion liquid recovery device is a container tank, and the rotating platform is fixed in the middle of the container tank through a bracket; or the corrosion liquid recovery device is an annular container with a through hole in the middle, and is set around the rotating platform using the through hole.
[0018] Preferably, the spray head of the corrosive liquid spray device is connected to three supply pipelines, the first one is an alkali liquid supply pipeline, the second one is an acid liquid supply pipeline, and the third one is a pure water pipeline; the three supply pipelines can be switched freely.
[0019] Preferably, the corrosive liquid spraying device comprises a plurality of spray heads, each of which is in a shower-like structure and is disposed above the rotating platform at a distance of 10-15 cm from the rotating platform.
[0020] Preferably, a pure water spraying device is provided above the rotating platform for spraying pure water onto the rotating platform.
[0021] After the etching liquid is sprayed onto the upper surface of the silicon wafer, although it can contaminate and corrode the upper surface of the silicon wafer, the etching liquid will quickly disperse to the surrounding of the silicon wafer under the centrifugal effect, achieving independent corrosion of one surface of the silicon wafer, while the other side does not participate in the corrosion process.
[0022] (III) Beneficial effects
[0023] The utility model can realize differentiated etching processing on the non-treated surface and the surface to be treated of the silicon wafer, so as to meet the customer's requirements on the etching type, surface texture and flatness of the non-treated surface and the surface to be treated of the silicon wafer. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 This is a schematic diagram of a device for implementing single-sided etching of a silicon wafer according to a preferred embodiment of the utility model.
[0025] Figure 2 The utility model discloses a detailed structure of a device for realizing single-sided etching of a silicon wafer.
[0026] Figure 3 The present invention is a schematic diagram of a structure in which a rubber strip retaining ring is combined with an annular groove. DETAILED DESCRIPTION
[0027] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.
[0028] like Figure 1 As shown, it is a schematic diagram of a device for realizing single-sided etching of a silicon wafer in a preferred embodiment of the utility model, and the device includes a rotating stage 10, a corrosive liquid spraying device 30, a corrosive liquid recovery device 20 and a filtering circulation device 50. Among them, the rotating stage 10 is installed in the middle of the corrosive liquid recovery device 20 through a bracket 11. The corrosive liquid recovery device 20 is a container (a fish tank-like structure with a circular or square cross-section) for collecting the corrosive liquid that slides off the rotating stage 10. At least one corrosive liquid spraying device 30 is provided above the rotating stage 10, which includes at least one spray head 31. The spray head 31 is a structure similar to a shower head and is used to spray the corrosive liquid. The spray head 31 is set at a height of 10-15cm above the rotating stage 10. A suction cup 12 is provided in the middle of the rotating stage 10, which can be used to fix the silicon wafer 40. A driving mechanism is provided below the rotating stage 10 to drive the rotating stage 10 to rotate at a certain speed and in a certain direction. In other embodiments, the corrosion liquid recovery device 20 may also be configured as a ring-shaped container with a hole in the middle, and the hole is sleeved around the rotating stage 10, which can also collect the corrosion liquid.
[0029] Combination Figure 2As shown, when processing one surface of the silicon wafer 40, the silicon wafer 40 is fixed on the suction cup 12 with the surface 42 to be processed facing upward (the non-processed surface 41 facing downward). The driving mechanism is turned on to rotate the rotating stage 10. At this time, the spray head 31 of the etching liquid spraying device 30 sprays the etching liquid downward. After the etching liquid stays on the surface 42 to be processed of the silicon wafer 40 for a short time, it is centrifugally thrown out and collected by the etching liquid recovery device 20. The etching liquid recovery device 20 is connected to a filtering circulation device 50 with a filter element 51. The filter element 51 can intercept impurity particles, metals and micelles contained in the etching liquid, thereby purifying the etching liquid and circulating it to the spray head 31 of the etching liquid spraying device 30, so as to realize the recycling of the etching liquid and prevent the impurity particles, metals and micelles from contaminating the surface 42 to be processed of the silicon wafer 40.
[0030] The height between the spray head 31 of the etching liquid spray device 30 and the silicon wafer is 10-15 cm.
[0031] like Figure 2 As shown, in order to prevent the etching liquid from contaminating the non-treated surface 41 of the silicon wafer 40, the middle area of the rotating stage 10 is set as a flat area. This area is the working area for fixing the silicon wafer 40, and a certain width of the periphery near the edge is a downwardly inclined slope 13, which can conveniently guide the etching liquid to flow to the outside of the rotating stage 10 without accumulating.
[0032] Furthermore, a rubber strip enclosure ring 14 is provided on the rotating platform 10, and is provided around the suction cup 12 of the rotating platform 10. The rubber strip enclosure ring 14 can be temporarily bonded / or its lower end can be embedded and fixed on the rotating platform 10, or it can be simply placed on the rotating platform 10. When embedded and fixed, a small annular groove 15 is provided on the rotating platform, and a T-shaped or L-shaped end 141 (such as a rubber strip enclosure ring 14) that can be fixedly engaged with the annular groove 15 is provided at the lower end of the rubber strip enclosure ring 14. Figure 3 As shown). After the silicon wafer 40 is fixed on the suction cup 12, the rubber strip enclosure ring 14 can be tightly fitted around the silicon wafer 40 to seal the edge of the silicon wafer 40. According to the diameter of the different silicon wafers 40, a matching rubber strip enclosure ring 14 is selected. During the spraying of the etching liquid, the rubber strip enclosure ring 14 can prevent the etching liquid from contacting the non-treated surface 41 of the silicon wafer 40. Preferably, there are multiple annular grooves 15, and the multiple annular grooves 15 are distributed in a concentric circle around the suction cup, thereby clamping and fixing the rubber strip enclosure ring 14 of the corresponding diameter size according to the diameter size of the silicon wafer 40 to be processed.
[0033] Among them, the etching liquid spraying device 30 can be connected to three supply pipes, one of which is connected to the circulating acid etching liquid, one of which is connected to the alkaline etching liquid, and the third is connected to ultrapure water. The conduction relationship between the three supply pipes and the spray head 31 can be switched freely, and the switching can be automatically switched by means of manual valve switching or electromagnetic control valve. Among them, when the acid etching or alkaline etching treatment of the to-be-treated surface 42 of the silicon wafer is completed, the rotating stage 10 continues to rotate. At this time, the etching liquid is switched to ultrapure water for spraying to clean the etching liquid on the silicon wafer 40 and the rotating stage 10, so as to avoid the etching liquid from contacting the non-treated inner surface 41 of the silicon wafer 40 after the rotating stage 10 stops rotating. Alternatively, a pure water spraying device is separately set up, which is arranged above the rotating stage 10 in parallel with the etching liquid spraying device 30, and the pure water spraying is turned on as needed.
[0034] The device of the utility model can conveniently realize differential etching processing on the non-treated surface and the surface to be treated of the silicon wafer, so as to meet the customer's requirements on the etching type, surface texture and flatness of the non-treated surface and the surface to be treated of the silicon wafer. At the same time, the etching liquid can be recycled by using the filtering circulation device, saving the cost of the etching liquid reagent and also avoiding the impurities and particles contained in the etching liquid from directly contaminating the surface of the silicon wafer.
[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.
Claims
1. A device for realizing single-sided etching of a silicon wafer, characterized in that: It includes: Rotating stage, corrosion liquid spraying device, corrosion liquid recovery device and filtering circulation device; The rotating stage is used to fix the silicon wafer and drive the silicon wafer to rotate synchronously; The etching liquid spraying device is used to spray the etching liquid on the upper surface of the silicon wafer; The etching liquid recovery device is used to collect the etching liquid that slides off the rotating stage and the silicon wafer; The filtering circulation device is used to filter and purify the corrosive liquid collected by the corrosive liquid recovery device, and then circulate it to the corrosive liquid spraying device, and spray it again on the upper surface of the silicon wafer on the rotating stage.
2. The device for realizing single-sided etching of a silicon wafer according to claim 1, characterized in that: The rotating platform is provided with a suction cup for fixing the silicon wafer.
3. The device for realizing single-side etching of silicon wafer according to claim 1, characterized in that: It also includes a rubber strip enclosure ring, the diameter of which matches the diameter of the silicon wafer. The rubber strip enclosure ring is arranged on the rotating platform to shield and seal the periphery of the silicon wafer.
4. The device for realizing single-side etching of silicon wafer according to claim 3, characterized in that: A plurality of annular grooves are provided on the rotating platform and around the suction cup, and the annular grooves are distributed in concentric circles; the annular grooves are used to fix the lower end of the rubber strip enclosure ring, and the silicon wafer is fixed inside the rubber strip enclosure ring; the rubber strip enclosure ring is tightly matched with the periphery of the silicon wafer to seal the periphery of the silicon wafer.
5. The device for realizing single-side etching of silicon wafer according to claim 1, characterized in that: The middle area of the rotating platform is a flat area, and a certain width of the periphery near the edge is a downwardly inclined slope, which is used to guide the corrosion liquid to flow to the outside of the rotating platform to avoid the corrosion liquid accumulating on the rotating carrier.
6. The device for realizing single-side etching of silicon wafer according to claim 1, characterized in that: The corrosion liquid recovery device is a container tank, and the rotating platform is fixed in the middle of the container tank through a bracket; or the corrosion liquid recovery device is an annular container with a through hole in the middle, and is set around the rotating platform using the through hole.
7. The device for realizing single-side etching of silicon wafer according to claim 1, characterized in that: The spray head of the corrosive liquid spray device is connected to three supply pipelines, the first one is an alkali liquid supply pipeline, the second one is an acid liquid supply pipeline, and the third one is a pure water pipeline; the three supply pipelines can be switched freely.
8. The device for realizing single-side etching of silicon wafer according to claim 1, characterized in that: The corrosive liquid spraying device comprises a plurality of spray heads, each of which is in a shower-like structure and is arranged above the rotating platform and is 10-15 cm away from the rotating platform.
9. The device for realizing single-side etching of silicon wafer according to claim 1, characterized in that: A pure water spraying device is also provided above the rotating platform for spraying pure water onto the rotating platform.