Isomer composite etching jig

Abstract

The utility model belongs to the field of semiconductor etching technology relates to a kind of isomorphic composite etching fixture, it includes aluminium tray (6), multiple bearing parts (7) are equipped on the aluminium tray (6), sealing ring groove (10) is equipped in the edge area of bearing part (7), one accommodating groove (9) is arranged at each presser jaw action area of bearing part (7) and each accommodating groove (9) is equipped with one heterostructure composite structure module (8), the heterostructure composite structure module (8) is made of non-metallic material with lower thermal conductivity than metal aluminium.It realizes the synergistic effect of plasma energy distribution regulation and control and heat conduction optimization of presser jaw action area by constructing the heterostructure composite structure module with different dielectric characteristics and thermal conductivity, effectively improves the pattern feature size of presser jaw action area.

Description

Technical Field

[0001] This utility model belongs to the field of semiconductor etching technology, and relates to an etching fixture, and more particularly to a heterogeneous composite etching fixture. Background Technology

[0002] In the fabrication process of patterned sapphire substrates, after the sapphire wafer undergoes mask patterning of the photoresist layer on its upper surface during the photolithography process, it is typically mounted on a metal aluminum tray. For example... Figure 1-3 As shown, the aluminum tray 1 is provided with multiple wafer platforms 5. Sealing grooves are provided on the edge regions of the wafer platforms 5. During operation, the sealing rings are fitted into the sealing grooves on the edge regions of the wafer platforms 5, the wafer 4 is placed on the sealing rings, and the edges of the wafer 4 are mechanically fixed by the pressure claws 3 of the cover plate 2, before being transferred into the etching chamber to complete the final pattern transfer. However, due to the structural characteristics of the loading and fixing method, during plasma etching, the local electric field in the area of ​​the pressure claws 3 of the cover plate 2 is distorted due to charge accumulation. Simultaneously, this area exhibits significant differences in flow field distribution and temperature gradient compared to other areas. The coupling effect of multiple factors leads to an imbalance in etching efficiency in the surrounding area of ​​the pressure claws 3, accompanied by plasma shift, resulting in pattern tilting, larger dimensions, and even connection phenomena in the vicinity of the pressure claws 3. Automatic optical inspection reveals a characteristic bluish tint, reflecting severe deterioration of surface flatness, which induces a fogging effect during subsequent epitaxial growth, thus affecting the epitaxial yield.

[0003] Therefore, in order to address the shortcomings of the existing technology, it is necessary to develop a new type of etching fixture. Utility Model Content

[0004] To overcome the shortcomings of existing technologies, this invention proposes a heterogeneous composite etching fixture, which achieves the synergistic effect of plasma energy distribution regulation and heat conduction optimization in the gripper action area by constructing a heterogeneous composite structure module with different dielectric properties and thermal conductivity, thereby effectively improving the graphic feature size of the gripper action area.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A heterogeneous composite etching fixture includes an aluminum tray with multiple support portions. Each support portion has a sealing groove in its edge region. The fixture is characterized in that each pressure claw of the support portion has a receiving groove in its working area, and each receiving groove contains a heterogeneous composite structure module. The heterogeneous composite structure module is made of a non-metallic material with a thermal conductivity lower than that of aluminum.

[0007] Preferably, the sealing ring groove in the heterogeneous composite structure module adopts an arc-shaped design and bypasses the action range of the pressure claw, so that it forms a structure that protrudes towards the center of the bearing part.

[0008] Preferably, the heterogeneous composite structure module is mechanically fixed or riveted together with the aluminum tray.

[0009] Preferably, the length of the front end of the heterogeneous composite structure module is b1, the length of the end is b2, and the length of the front end of the pressure claw action area is W2, then W2≤b1<b2.

[0010] Preferably, the length of the end of the pressure claw's action area is W1, then W1≤b2.

[0011] Preferably, the radial width of the pressure claw's action area is b4, the width of the sealing ring groove in the heterogeneous composite structure module is d1, and the radial width of the heterogeneous composite structure module is b3, then b4 + d1 < b3.

[0012] Preferably, the width d1 of the sealing ring groove in the heterogeneous composite structure module is equal to the width d2 of the sealing ring groove, the depth h2 of the sealing ring groove in the heterogeneous composite structure module is equal to the depth L2 of the sealing ring groove, and the height h1 of the heterogeneous composite structure module after removing the sealing ring groove is equal to the height L1 of the bearing part after removing the sealing ring groove.

[0013] Preferably, the height L4 of the edge region of the bearing portion is less than the height h4 of the end of the heterogeneous composite structure module.

[0014] Preferably, the height h3 of the front end of the heterogeneous composite structure module is equal to the depth L3 of the front end of the receiving groove.

[0015] Compared with the prior art, the heterogeneous composite etching fixture of this utility model has one or more of the following beneficial technical effects:

[0016] 1. This utility model achieves local energy optimization and heat conduction in the etching process through a heterogeneous composite structure module design. By introducing a heterogeneous composite structure module into the claw action area of ​​the tray to replace the traditional homogeneous aluminum structure, a plasma density enhancement zone is formed in the claw action area, effectively increasing the ion bombardment energy under local bias voltage. At the same time, by utilizing the difference in thermal conductivity between the heterogeneous material and metallic aluminum and the control of interface thermal resistance, the heat transfer path and heat flow distribution characteristics of the claw contact area are directionally changed, thereby forming a controllable local temperature field distribution during the etching process. This achieves the correction of key dimensions of the corresponding feature patterns, effectively reducing surface fogging defects during epitaxial layer growth and improving yield.

[0017] 2. This utility model designs the height of the end of the heterogeneous composite structure module according to requirements, adjusts the gap between the tray and the wafer in the gripper action area (the smaller the gap, the smaller the capacitance of the electric field between the wafer and the tray during etching, the larger the VDC, and the stronger the etching capability), and utilizes the difference in heat transfer efficiency between the heterogeneous material and metallic aluminum. In the corresponding area of ​​the gripper and wafer contact, a sealing ring groove arc design is adopted to isolate the helium gas effect, which enhances the heat accumulation in this area during etching and forms a local high temperature area. This achieves the synergistic optimization of the gradient control of the plasma energy field and the local adjustment of the heat conduction efficiency in the gripper action area, thereby changing the pattern transfer effect in this area. Through the key structural dimension design of the heterogeneous composite structure module, the key dimension (CD) of the pattern in the gripper action area can be optimized from above 2.9 micrometers to 2.2-2.5 micrometers, effectively improving the phenomenon of oversized and connected pattern size in the gripper area in the fabrication of patterned substrates using conventional trays, and reducing the fogging defects at the epitaxial end. Attached Figure Description

[0018] Figure 1 This is a schematic diagram showing the position of the clamping claws relative to the wafer after the wafer is loaded onto a conventional tray and secured with a cover plate.

[0019] Figure 2 This is a schematic diagram of an existing standard pallet.

[0020] Figure 3 This is a schematic diagram of an existing cover plate.

[0021] Figure 4 This is a schematic diagram of the heterogeneous composite etching fixture of this utility model.

[0022] Figure 5 This is a schematic diagram of the heterogeneous composite etching fixture of this utility model after the heterogeneous composite structure module has been removed.

[0023] Figure 6 This is an enlarged view of the support portion of this utility model.

[0024] Figure 7 This is a schematic diagram of the heterogeneous composite structure module of this utility model.

[0025] Figure 8 This is a plan view of the heterogeneous composite structure module of this utility model.

[0026] Figure 9 This is a partial enlarged view of the receiving groove portion of the bearing part of this utility model.

[0027] Figure 10 This is a plan view of the area where the pressure claw operates. Detailed Implementation

[0028] Before describing any embodiment of this invention in detail, it should be understood that the invention is not limited in its application to the details of the construction and arrangement of the components set forth in the following description or illustrated in the following figures. The invention is capable of other embodiments and can be practiced or carried out in various ways. Furthermore, it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered limiting. The use of “comprising” or “having” and variations thereof herein is intended to cover the items set forth below and their equivalents, as well as any additional items. Unless otherwise specified or limited, the terms “installation,” “connection,” “support,” and “linkage,” and variations thereof are used broadly and cover both direct and indirect installation, connection, support, and linking. Moreover, “connection” and “linkage” are not limited to physical or mechanical connections or links.

[0029] Furthermore, firstly, in the disclosure of this utility model, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as a limitation on this utility model. Secondly, the term "a" should be understood as "at least one" or "one or more," that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple. The term "a" should not be construed as a limitation on the quantity.

[0030] To address the shortcomings of existing technologies, this invention provides a heterogeneous composite etching fixture. Through the design of a heterogeneous composite structure module, it achieves local energy optimization and heat transfer in the etching process. Specifically, a heterogeneous composite structure module is introduced into the gripper action area of ​​the tray, replacing the traditional homogeneous aluminum structure. This creates a plasma density enhancement zone in the gripper action area, effectively increasing the ion bombardment energy under local bias voltage. Simultaneously, by utilizing the difference in thermal conductivity between the heterogeneous material and metallic aluminum, and by controlling the interfacial thermal resistance, the heat transfer path and heat flow distribution characteristics in the gripper action area are directionally altered. This results in a controllable local temperature field distribution during etching, achieving the correction of key dimensions of the corresponding feature patterns, effectively reducing surface fogging defects during epitaxial layer growth, and improving yield.

[0031] like Figure 4-6 As shown, similar to existing technologies, the heterogeneous composite etching fixture of this invention includes an aluminum tray 6. The aluminum tray 6 has multiple support portions 7. Sealing ring grooves 10 are provided in the edge regions of the support portions 7. In use, a sealing ring is placed within the sealing ring groove 10, and the wafer is placed on the sealing ring, through… Figure 3 The existing cover plate 2 and the pressure claws 3 on the cover plate 2 shown are used to fix the wafer.

[0032] Unlike existing technologies, in this invention, each pressure claw area of ​​the bearing portion 7 is provided with a receiving groove 9, and each receiving groove 9 contains a heterogeneous composite structure module 8. The heterogeneous composite structure module 8 is made of a non-metallic material with a thermal conductivity lower than that of aluminum.

[0033] In this invention, the material of the heterogeneous composite structure module 8 can be a high-performance composite material with high etching resistance, lower thermal conductivity than aluminum, and the ability to be mechanically fixed or riveted to the aluminum disk. The composite material can be carbon fiber reinforced thermosetting resin, carbon fiber reinforced PEEK / PI thermoplastic resin, etc., whose thermal conductivity and etching resistance can be optimized by selecting a low thermal conductivity matrix and controlling fiber orientation / layout design. High-performance ceramics (such as zirconia ceramics, silicon nitride ceramics, etc.) can also be used. By setting the heterogeneous composite structure module 8, the heat dissipation rate of the corresponding region is lower than that of the aluminum region during etching, thereby forming a higher temperature region and enhancing the etching efficiency of the corresponding region.

[0034] The heterogeneous composite structure module 8 and the aluminum tray 5 can be mechanically fixed or riveted together.

[0035] Conventional wafer trays use a circular sealing ring design, with the wafer edge positioned horizontally and evenly on the sealing ring. Helium holes are regularly distributed within the sealing ring's support section, maintaining a relatively uniform and balanced temperature across the wafer during etching under the influence of helium gas. However, in this invention... Figure 7 and 8 As shown, the sealing ring groove in the heterogeneous composite structure module 8 adopts an arc-shaped design and bypasses the action range of the pressure claw, forming a structure that protrudes towards the center of the support part 7. Therefore, the wafer in this area is no longer directly subjected to back-helium cooling, and the heat generated by plasma bombardment during etching cannot be conducted by helium in a timely manner, further exacerbating heat accumulation in this area and increasing the etching rate.

[0036] In this utility model, such as Figure 7-8 As shown in Figure 10, the length of the front end of the heterogeneous composite structure module 8 is b1, the length of the rear end is b2, the length of the front end of the pressure claw action area is W2, and the length of the rear end of the pressure claw action area is W1. Therefore, W2 ≤ b1 < b2, and W1 ≤ b2. Simultaneously, the radial width of the pressure claw action area is b4, the width of the sealing ring groove in the heterogeneous composite structure module 8 is d1, and the radial width of the heterogeneous composite structure module 8 is b3. Therefore, b4 + d1 < b3. This ensures that the pressure claw action area is completely on the heterogeneous composite structure module 8.

[0037] Furthermore, preferably, the width d1 of the sealing ring groove in the heterogeneous composite structure module 8 is equal to the width d2 of the sealing ring groove 10, the depth h2 of the sealing ring groove in the heterogeneous composite structure module 8 is equal to the depth L2 of the sealing ring groove 10, and the height h1 of the heterogeneous composite structure module 8 after removing the sealing ring groove is equal to the height L1 of the support portion 7 after removing the sealing ring groove. This ensures that the wafer is horizontal on the sealing ring, achieving a good sealing effect without causing helium leakage.

[0038] Furthermore, preferably, the height L4 of the edge region of the support portion 8 is less than the height h4 of the end of the heterogeneous composite structure module 8. As the difference between h4 and L4 increases, the gap between the wafer and the tray is gradually reduced, thereby decreasing the capacitance of the electric field in the corresponding region and increasing the bias voltage accordingly. This enhances the etching energy intensity in the region, causing the over-etching degree of the pattern in the corresponding region to increase, and the pattern size to gradually decrease. The difference between h4 and L4 can be adjusted according to actual needs to control the size of the pattern feature size (CD) of the corresponding region of the gripper.

[0039] Finally, preferably, the height h3 of the front end of the heterogeneous composite structure module 8 is equal to the depth L3 of the front end of the receiving groove 9. This ensures that the surface flatness of the wafer area surrounded by the sealing ring and the support portion 7 is consistent, thereby ensuring that the temperature balance and etching energy intensity of other areas of the wafer, except for the area where the pressure claws act, are consistent and unaffected by the heterogeneous composite structure module 8.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model, and are not intended to limit the scope of protection of this utility model. Those skilled in the art can modify or make equivalent substitutions to the technical solution of this utility model based on the concept of this utility model, without departing from the essence and scope of the technical solution of this utility model.

Claims

1. A heterogeneous composite etching fixture, comprising an aluminum tray (6), wherein the aluminum tray (6) is provided with a plurality of support portions (7), and the edge region of the support portions (7) is provided with sealing ring grooves (10), characterized in that, Each of the bearing parts (7) has a receiving groove (9) in the area of ​​each pressure claw, and each receiving groove (9) has a heterogeneous composite structure module (8) made of a non-metallic material with a thermal conductivity lower than that of aluminum.

2. The heterogeneous composite etching fixture according to claim 1, characterized in that, The sealing ring groove in the heterogeneous composite structure module (8) adopts an arc-shaped design and bypasses the action range of the pressure claw, so that it forms a structure that protrudes towards the center of the bearing part (7).

3. The heterogeneous composite etching fixture according to claim 2, characterized in that, The heterogeneous composite structure module (8) is mechanically fixed or riveted together with the aluminum tray (6).

4. The heterogeneous composite etching fixture according to any one of claims 1-3, characterized in that, The length of the front end of the heterogeneous composite structure module (8) is b1, the length of the end end is b2, and the length of the front end of the pressure claw action area is W2, then W2≤b1<b2.

5. The heterogeneous composite etching fixture according to claim 4, characterized in that, If the length of the end of the pressure claw's action area is W1, then W1 ≤ b2.

6. The heterogeneous composite etching fixture according to claim 5, characterized in that, The radial width of the pressure claw's action area is b4, the width of the sealing ring groove in the heterogeneous composite structure module (8) is d1, and the radial width of the heterogeneous composite structure module (8) is b3, then b4+d1<b3.

7. The heterogeneous composite etching fixture according to claim 6, characterized in that, The width d1 of the sealing ring groove in the heterogeneous composite structure module (8) is equal to the width d2 of the sealing ring groove (10), the depth h2 of the sealing ring groove in the heterogeneous composite structure module (8) is equal to the depth L2 of the sealing ring groove (10), and the height h1 of the heterogeneous composite structure module (8) after removing the sealing ring groove is equal to the height L1 of the bearing part (7) after removing the sealing ring groove.

8. The heterogeneous composite etching fixture according to claim 7, characterized in that, The height L4 of the edge region of the bearing part (7) is less than the height h4 of the end of the heterogeneous composite structure module (8).

9. The heterogeneous composite etching fixture according to claim 8, characterized in that, The height h3 of the front end of the heterogeneous composite structure module (8) is equal to the depth L3 of the front end of the receiving groove (9).

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