Structure of wafer fixing ring

Abstract

The invention relates to a structure of a wafer fixing ring, which comprises a base, a fixing ring and a cover piece, the base comprises a grinding part, a fixing part, a through hole and a groove, the grinding part is arranged on one side of the fixing part, the through hole penetrates through the grinding part and the fixing part, the groove is annularly arranged on one upper side of the grinding part, and the cover piece is arranged on the fixing part. The grinding part is provided with a groove, the exhaust grooves are formed in the lower side of the grinding part relative to the groove, the fixing ring is arranged in the groove, and the cover piece covers one side of the fixing ring and is located in the groove.

Description

TECHNICAL FIELD

[0001] The present invention relates to a structure, and more particularly to a structure of a wafer fixing ring. BACKGROUND

[0002] Wafer is a short name of semiconductor crystal round sheet, which is a thin sheet processed by high-precision sawing of cylindrical semiconductor crystal (such as single crystal silicon) and used as a carrier substrate in integrated circuit manufacturing process. It can also be applied to the manufacture of solar cells, micro-electro-mechanical systems (MEMS), optoelectronic elements and other high-tech products. Because its shape is round, it is commonly known as wafer. The most common wafer is silicon wafer, but with the development of application fields, wafers of third-generation semiconductor materials such as gallium nitride (GaN) and silicon carbide (SiC) have also been introduced.

[0003] Generally speaking, the wafer is based on monocrystalline silicon grown by the Czochralski method, and high-precision carrier platforms are formed through cutting, grinding, polishing, diffusion, etching and coating processes.

[0004] With the rapid evolution of semiconductor manufacturing technology, to meet the needs of high operation performance and low power consumption, the microscale of integrated circuits continues to advance, and the requirements for wafer manufacturing precision and surface quality are also becoming increasingly stringent. In order to increase the number of chips that can be made from a single wafer and reduce unit costs, wafer diameters have gradually increased from 100 mm and 150 mm in the early days to 200 mm and even 300 mm, and 400 mm research samples have also been introduced.

[0005] However, with the increase in wafer size, challenges such as warping, edge cracking and flatness reduction are also brought about. In particular, in processes such as chemical mechanical polishing (CMP), uneven stress on the edge or inconsistent contact with the polishing disc often leads to the "edge over-polishing" phenomenon, which in turn affects the yield of finished products and the utilization rate of wafers. To solve such problems, the industry generally adds a fixing ring or retaining ring around the wafer to fix the wafer and provide structural support, while suppressing excessive polishing to ensure uniformity and stability of the polishing process.

[0006] Traditional fixing rings are usually composed of a combination of metal materials and plastic materials, such as an aluminum alloy structural frame covered with a layer of wear-resistant engineering plastic (such as polyether ether ketone PEEK, polyimide PI, etc.), which are joined by bolts, dowels or adhesive methods.

[0007] However, when such structure is placed in a high-speed and high-pressure CMP grinding environment for a long time, if there are unevenness, machining burrs or micro air gaps between the metal and the plastic, micro vibration and thermal stress concentration will be easily generated at high speed, which will cause the joint to loosen, the structure to peel off, and even damage the wafer edge, affecting the product yield. This potential risk is particularly serious for thin wafers or large-size wafers in advanced processes, and improvement is urgently needed.

[0008] In addition, if there are exposed areas of metal materials during use, the surface of the retaining ring will be easily oxidized or corroded due to the infiltration of sweat of the operator, on-site dust or chemical agents (such as grinding fluid, cleaning agent, etc.), which not only reduces the service life of the retaining ring, but also may become a source of wafer contamination.

[0009] Furthermore, due to the difference in the thermal expansion coefficient between the metal and the plastic, after experiencing repeated heating and cooling cycles, inconsistent deformation due to thermal expansion and contraction will occur at the structure interface, causing the overall deformation of the retaining ring, the decrease of the tightness, the unstable positioning of the wafer, and even leading to failure.

[0010] Therefore, the traditional metal-plastic composite retaining ring has gradually shown its inadequacy in the process environment with high precision and high stability, and there is an urgent need in the market for innovative retaining ring designs with good structural stability, edge buffering capacity, chemical resistance and low particle contamination.

[0011] Therefore, how to provide a retaining ring design with high structural stability, good edge buffering effect and low wafer contamination is a problem that must be solved by those skilled in the art. SUMMARY

[0012] An object of the present application is to provide a structure of a wafer retaining ring, which solves the problem of wafer damage caused by poor structure of the traditional known wafer retaining ring by embedding a stainless steel retaining member in an integrally formed plastic base, and provides a yield of wafer processing.

[0013] To achieve the above object, the present application provides a structure of a wafer retaining ring, a base comprising a grinding portion, a fixed portion, a through hole and a groove, the grinding portion being arranged on one side of the fixed portion, the through hole being arranged through the grinding portion and the fixed portion, the groove being arranged on an upper side of the grinding portion, a plurality of exhaust grooves being arranged on a lower side of the grinding portion opposite to the groove, a retaining ring being arranged in the groove, and a cover member being arranged on one side of the retaining ring and located in the groove.

[0014] In an embodiment of the present application, the through hole comprises a vertical portion and a tapered portion, one end of the vertical portion being connected to one end of the tapered portion, and the tapered portion tapering from the upper side of the grinding portion to the vertical portion.

[0015] In an embodiment of the present application, a first diameter of the grinding portion is smaller than a second diameter of the fixed portion.

[0016] The present invention provides an embodiment in which the base includes a plurality of snap-fit ​​parts disposed at the bottom of the groove, each snap-fit ​​part including a round hole and an elongated hole, the round hole communicating with one side of the elongated hole.

[0017] The present invention provides an embodiment in which the fixing ring includes a plurality of fixing holes, one of which corresponds to a circular hole of one of the plurality of buckle portions.

[0018] The present invention provides an embodiment that further includes a plurality of fasteners, which are respectively disposed in the plurality of fastening holes. Each fastener includes a locking part and a locking part, and one end of the locking part is connected to the locking part.

[0019] The present invention provides an embodiment in which the locking part is disposed in the circular hole and rotated to engage with the elongated hole.

[0020] The present invention provides an embodiment in which the base is made of polyphenylene sulfide (PPS), polyether ether ketone (PEEK), or polycarbonate (PC).

[0021] The present invention provides an embodiment in which the retaining ring is made of stainless steel, low carbon steel, medium carbon steel or high carbon steel.

[0022] The present invention provides an embodiment in which the cover is made of polyphenylene sulfide, polyetheretherketone, polycarbonate, stainless steel, low carbon steel, medium carbon steel or high carbon steel.

[0023] The present invention provides an embodiment in which a gap is formed between the fixing ring and the groove, and an adhesive is disposed in the gap. Attached Figure Description

[0024] Figure 1A This is a three-dimensional structural schematic diagram of one embodiment of the present invention;

[0025] Figure 1B This is a schematic diagram of the structure of one embodiment of the present invention;

[0026] Figure 1C This is a schematic diagram of the structure of one embodiment of the present invention;

[0027] Figure 1D This is a cross-sectional structural schematic diagram of one embodiment of the present invention;

[0028] Figure 1E This is an enlarged schematic diagram of one embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of rotational fixing according to one embodiment of the present invention;

[0030] Figure 3A This is a structural cross-sectional schematic diagram of a second embodiment of the present invention.

[0031] Figure 3B This is an enlarged schematic diagram of one embodiment of the present invention; and

[0032] Figure 4 This is a schematic diagram illustrating the usage state of one embodiment of the present invention.

[0033] Symbol explanation:

[0034] 1. Structure of the wafer retaining ring

[0035] 10 bases

[0036] 11 Grinding section

[0037] 111 Exhaust Channel

[0038] 12. Buckle section

[0039] 121 round hole

[0040] 123 Long hole

[0041] 13 Fixing part

[0042] 15. Perforation

[0043] 151 Vertical section

[0044] 153. Tapered section

[0045] 17 Grooves

[0046] 20. Fixing ring

[0047] 22 Fixing holes

[0048] 24 gaps

[0049] 26 Colloids

[0050] 30 Cover pieces

[0051] 40 Fasteners

[0052] 42. Fastening section

[0053] 44 Locking part

[0054] 50 Grinding Head

[0055] 60 wafers

[0056] 70 Grinding Platform

[0057] D1 First Diameter

[0058] D2 is the second diameter. Detailed Implementation

[0059] To enable the examiner to have a better understanding of the features and effects of the present invention, preferred embodiments and detailed descriptions are provided below.

[0060] It is known that most wafer retaining rings are composed of dissimilar materials such as metal and plastic. Although they can achieve the basic functions of wafer positioning and edge protection, during long-term or high-speed polishing processes, if there are processing burrs or poor adhesion at the interface between the dissimilar materials, it can easily cause the retaining ring to loosen or break. It may also lead to defects such as scratches and cracks on the wafer edges. In addition, due to the large difference in the coefficients of thermal expansion between metal and plastic, the retaining ring is prone to deformation after repeated heating and cooling cycles, which will affect the wafer positioning accuracy and stability. Even worse, if there are exposed areas on the metal parts, they may corrode due to contact with polishing fluid, cleaning fluid or chemical agents, which will release contaminants and affect the process yield and wafer surface quality.

[0061] This invention uses a plastic material to integrally encapsulate metal, forming a composite ring-shaped component with structural stability and external cleanliness. This effectively reduces the risk of wafer edge damage and improves chemical resistance and thermal stability, making it suitable for high-cleanliness and high-precision grinding process environments.

[0062] The invention will be described in detail below with reference to the accompanying drawings, illustrating various embodiments thereof. However, the concept of the invention may be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein.

[0063] First, please refer to Figure 1A This is a three-dimensional structural schematic diagram of one embodiment of the present invention, and please refer to it as well. Figure 1B ,and Figure 1C The figure shows a schematic diagram of the structure of one embodiment of the present invention. As shown in the figure, the structure 1 of the wafer fixing ring of the first embodiment includes a base 10, a plurality of fixing members 20 and a cover member 30.

[0064] In this embodiment, the base 10 includes a grinding part 11, a fixing part 13, a through hole 15, and a groove 17. The grinding part 11 is disposed on one side of the fixing part 13, the through hole 15 passes through the grinding part 11 and the fixing part 13, the groove 17 is arranged around the upper side of the fixing part 13, and a plurality of exhaust grooves 111 are disposed on the lower side of the grinding part 11 opposite to the groove 17.

[0065] In this embodiment, please refer to Figure 1D This is a cross-sectional structural schematic diagram of one embodiment of the present invention, and Figure 1EThe figure shows an enlarged schematic diagram of one embodiment of the present invention. As shown, the perforation 15 includes a vertical portion 151 and a tapered portion 153. One end of the vertical portion 151 is connected to one end of the tapered portion 153. The tapered portion 153 tapes from the upper side of the fixed portion 13 toward the vertical portion 151.

[0066] The base 10 in this embodiment includes a plurality of snap-fit ​​parts 12, which are disposed at the bottom of the groove 17. Each snap-fit ​​part 12 includes a round hole 121 and an elongated hole 123, and the round hole 121 communicates with one side of the elongated hole 123.

[0067] In this embodiment, the first diameter D1 of the grinding part 11 is smaller than the second diameter D2 of the fixing part 13. Furthermore, in this embodiment, the base 10 is made of polyphenylene sulfide (PPS), polyether ether ketone (PEEK), or polycarbonate (PC).

[0068] In this embodiment, the fixing ring 20 is disposed in the groove 17, and the cover 30 covers one side of the fixing ring 20 and is located in the groove 17. The fixing ring 20 is made of stainless steel, low carbon steel, medium carbon steel or high carbon steel. Furthermore, the cover 30 is made of polyphenylene sulfide, polyether ether ketone, polycarbonate, stainless steel, low carbon steel, medium carbon steel or high carbon steel.

[0069] As mentioned above, please refer to the following: Figure 1A The fixing ring 20 includes a plurality of fixing holes 22, one of which is correspondingly provided with the circular hole 121 of one of the plurality of buckle parts 12. A plurality of fixing members 40 are respectively provided in the plurality of fixing holes 22. Each fixing member 40 includes a locking part 42 and a locking part 44. One end of the locking part 42 is connected to the locking part 44.

[0070] In this embodiment, please refer to Figure 2 The figure shows a rotating and fixing schematic diagram of one embodiment of the present invention. As shown, the locking part 42 is disposed in the round hole 121 of one of the plurality of buckle parts 12, and the fixing ring 20 is rotated so that the locking part 42 is rotated and engaged with the elongated hole 123 of the plurality of buckle parts 12.

[0071] The advantage of this embodiment is that the integrated wafer retaining ring structure effectively reduces the risk of wafer edge damage and improves chemical resistance and thermal stability, making it suitable for high-cleanliness and high-precision grinding process environments.

[0072] Next, please refer to the second embodiment of the present invention. Figure 3A This is a structural cross-sectional schematic diagram of a second embodiment of the present invention, andFigure 3B The figure shows an enlarged schematic diagram of a second embodiment of the present invention. As shown in the figure, the base 10, the fixing ring 20 and the cover 30 in this embodiment are the same as those in the previous embodiment, so they will not be described in detail here.

[0073] In this embodiment, the first outer diameter (not shown) of one of the fixing rings 20 is smaller than the second outer diameter (not shown) of one of the grooves 17, so that there is a gap 24 between the fixing ring 20 and the groove 17, and a colloid 26 is disposed in the gap 24.

[0074] In this embodiment, the colloid 26 is made of epoxy resin, polyurethane or silicone. The colloid 26 can be injected into the gap 24 through a needle to quickly fix the fixing ring 20 in the groove 17.

[0075] The advantage of this embodiment is that by injecting the colloid into the gap 26, the fixing ring 20 is quickly fixed and will not shift within the groove 17, so that the fixing ring 20 will not vibrate during the grinding process, thereby reducing the occurrence of poor wafer surface quality.

[0076] Next, to more clearly illustrate the state of this embodiment, a practical application example is provided below. Please refer to Figure 3, which is a schematic diagram of the usage state of one embodiment of the present invention, and please refer to it again. Figure 1A As shown in the figure, the explanation is as follows.

[0077] When the wafer retaining ring of this embodiment is applied to the chemical mechanical polishing (CMP) process of semiconductor wafers, the user first places a wafer 60 on a polishing platform 70 and positions the wafer 60 in the position of structure 1 of the wafer retaining ring of this embodiment under a polishing head 50.

[0078] In this embodiment, the wafer fixing ring structure 1 embeds the fixing ring 20 into the groove 17 of the base 10, and the locking part 42 of one of the plurality of fixing parts 40 is inserted into the round hole 121 of one of the plurality of locking parts 12, and rotated to be positioned into the elongated hole 123. Through the above steps, the fixing ring 20 can be firmly locked onto the base 10. Then, the cover 30 is used to further fix the fixing ring 20 into the base 10. Through the wafer fixing ring structure 1 of this embodiment, the edge of the wafer 60 can be stably pressed against the inner side of the grinding part 11, so as to facilitate the subsequent stable grinding process.

[0079] During the grinding of the wafer 60, the plurality of venting grooves 111 located on the lower side of the grinding section 11 can guide the discharge of gas or grinding fluid, reduce pressure concentration, and maintain the stable cleanliness of the fixed area. Furthermore, since the thickness of the vertical portion 151 of the perforation 15 is greater than the thickness of the wafer 60, it can be ensured that the wafer 60 does not wobble during the grinding process, improving the overall grinding accuracy and preventing the wafer 60 from warping.

[0080] The embodiments described above represent a wafer fixing ring structure. Through an integrally molded base, a ring-shaped component with structural stability and external cleanliness is formed, effectively reducing the risk of wafer edge damage and improving chemical resistance and thermal stability.

[0081] Therefore, this invention is indeed novel, inventive, and industrially applicable, and undoubtedly meets the requirements for patent application under the Patent Law. Thus, I hereby file an invention patent application in accordance with the law, and earnestly pray that the Bureau will grant the patent as soon as possible.

[0082] However, the above description is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. All equivalent variations and modifications made in accordance with the shape, structure, features and spirit described in the claims of the present invention should be included within the scope of the patent application of the present invention.

Claims

1. A structure for a wafer fixing ring, comprising: A base includes a grinding part, a fixing part, a through hole and a groove. The grinding part is disposed on one side of the fixing part, the through hole passes through the grinding part and the fixing part, the groove is arranged around the upper side of the fixing part, and a plurality of venting grooves are disposed on the lower side of the grinding part opposite to the groove. A retaining ring, which is disposed within the groove; and A cover is provided on one side of the retaining ring and located within the groove.

2. The structure of the wafer fixing ring as described in claim 1, characterized in that, The perforation includes a vertical portion and a tapered portion, one end of the vertical portion is connected to one end of the tapered portion, and the tapered portion tapes from the upper side of the fixed portion toward the vertical portion.

3. The structure of the wafer fixing ring as described in claim 1, characterized in that, The first diameter of the grinding part is smaller than the second diameter of one of the fixing parts.

4. The structure of the wafer fixing ring as described in claim 1, characterized in that, The base includes multiple latching parts disposed at the bottom of the groove. Each latching part includes a round hole and an elongated hole, with the round hole communicating with one side of the elongated hole.

5. The structure of the wafer fixing ring as described in claim 4, characterized in that, The retaining ring includes multiple retaining holes, one of which corresponds to a circular hole of one of the multiple snap-fit ​​parts.

6. The structure of the wafer fixing ring as described in claim 5, characterized in that, It also includes multiple fasteners, which are respectively disposed in the multiple fixing holes. Each fastener includes a locking part and a locking part, with one end of the locking part connected to the locking part.

7. The structure of the wafer fixing ring as described in claim 6, characterized in that, The locking part is provided in the round hole and rotates to engage with the elongated hole.

8. The structure of the wafer fixing ring as described in claim 1, characterized in that, The base is made of polyphenylene sulfide, polyetheretherketone, or polycarbonate.

9. The structure of the wafer fixing ring as described in claim 1, characterized in that, The retaining ring is made of stainless steel, low carbon steel, medium carbon steel or high carbon steel.

10. The structure of the wafer fixing ring as described in claim 1, characterized in that, The cover is made of polyphenylene sulfide, polyetheretherketone, polycarbonate, stainless steel, low carbon steel, medium carbon steel or high carbon steel.

11. The structure of the wafer fixing ring as described in claim 1, characterized in that, There is a gap between the retaining ring and the groove, and a colloid is disposed in the gap.

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