Edge collapse prevention etching method and etching system

Abstract

The invention provides an anti-edge-collapse etching method and an anti-edge-collapse etching system, and relates to the technical field of chip manufacturing. The anti-edge-collapse etching method comprises the following steps: pre-treating a substrate; carrying out photoetching treatment on the substrate for a preset number of times, and sequentially carrying out gluing, exposure, development and photoetching etching on the substrate in each photoetching treatment, and carrying out photoetching etching on the substrate based on different patterns in each photoetching treatment, a step-shaped multi-layer structure is formed on the surface of the substrate, and the projection of the upper-layer structure in the vertical direction completely falls into the adjacent lower-layer structure; and after the multi-layer structure with the preset number of layers is obtained, the substrate is placed in an etching solution to be subjected to wet etching, so that a required pattern structure is formed on the surface of the substrate. The anti-edge-collapse etching method provided by the invention solves the problem of edge collapse of the layer structure caused by adopting a wet etching process, and achieves the effect of improving the performance and yield of a finished product device.

Description

Technical Field

[0001] The present invention relates to the technical field of chip manufacturing, and in particular to an anti-edge collapse etching method and an etching system. Background Art

[0002] Wet etching is a commonly used etching process in the semiconductor manufacturing process. However, when preparing multi-layer structures, the wet etching process often causes the edges of the layer structures to be hollowed out due to chemical corrosion, resulting in edge collapse of the upper structure, which ultimately affects the performance and yield of the finished device.

[0003] There is currently no effective technical solution to the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide an anti-edge collapse etching method and an etching system, which solves the problem of edge collapse of layer structures caused by a wet etching process, thereby achieving the effect of improving the performance and yield of finished devices.

[0005] In a first aspect, the present invention provides an anti-edge collapse etching method, comprising the following steps: S1. Pre-treating the substrate; S2. performing a preset number of photolithography processes on the substrate, wherein each photolithography process includes sequentially coating the substrate with glue, exposing, developing, and photolithography etching, and each photolithography process performs photolithography etching on the substrate based on different patterns, so that a stepped multi-layer structure is formed on the surface of the substrate and projections of the upper structure in the up-down direction all fall within the adjacent lower structure; S3. After obtaining a multilayer structure with a preset number of layers, the substrate is placed in an etching solution for wet etching to form a desired graphic structure on the surface of the substrate.

[0006] The anti-collapse etching method provided by the present invention has a hollowed-out edge of the layer structure, but because the multi-layer structure is stepped, the lower structure has enough area to support the upper structure, so the upper structure can be prevented from collapsing, effectively improving the performance and yield of the finished device.

[0007] Furthermore, the specific steps in step S1 include: S11. Washing the substrate with water.

[0008] Furthermore, the specific steps in step S11 include: S111. Wash the substrate with acetone and anhydrous ethanol.

[0009] Furthermore, the specific steps in step S1 also include: S12. Use a first mixed liquid and a second mixed liquid to perform a first cleaning on the substrate; the first mixed liquid is prepared by mixing sulfuric acid, hydrogen peroxide and water in a ratio of 3:1:1; the second mixed liquid is prepared by mixing hydrogen fluoride and water in a ratio of 1:10.

[0010] Furthermore, the specific steps in step S1 also include: S13. Clean the substrate for a second time using ionized water and dry it for a first time.

[0011] Furthermore, the specific steps in step S1 also include: S14. Clean the substrate for the third time using a 1.5% hydrogen fluoride solution and dry it for the second time.

[0012] The oxides and contamination particles on the surface of the substrate are effectively removed to ensure that the manufactured thin film bulk acoustic wave resonator can be used normally.

[0013] Furthermore, the specific steps in step S2 include: S21. Performing photolithography twice on the substrate, the specific steps comprising: S211. performing a photolithography process on the substrate for the first time and etching a first layer structure based on the first pattern during photolithography; S212. Perform photolithography on the substrate again and obtain a second layer structure by etching based on the second pattern during photolithography; the projections of the first layer structure along the up and down directions all fall within the second layer structure.

[0014] The stepped multi-layer structure ensures that the area of ​​the lower layer between the layer structures is larger than that of the upper layer, which facilitates the provision of sufficient support and makes the stress distribution of each layer structure more uniform, thus avoiding the edge collapse phenomenon.

[0015] In a second aspect, the present invention provides an etching system, comprising: Pretreatment equipment, used for pretreatment of the substrate; A photolithography and etching device, used for performing a preset number of photolithography processes on the substrate, wherein each photolithography process includes sequentially coating, exposing, developing and photolithography etching the substrate, and each photolithography process performs photolithography etching on the substrate based on different patterns, so that the surface of the substrate forms a stepped multi-layer structure and the projections of the upper structure in the up-down direction all fall within the adjacent lower structure; The wet etching equipment is used to place the substrate in an etching solution for wet etching after obtaining a multilayer structure with a preset number of layers, so as to form a desired graphic structure on the surface of the substrate.

[0016] Furthermore, the pretreatment equipment includes a water washing device, and the water washing device is used to wash the substrate with water.

[0017] Furthermore, the water washing device is used to wash the substrate with acetone and anhydrous ethanol.

[0018] From the above, it can be seen that the anti-collapse etching method provided by the present invention makes the multi-layer structure into a stepped shape by means of photolithography and etching, thereby ensuring that the lower structure has sufficient area to support the upper structure, and then making the stress distribution of the upper structure more uniform, thereby avoiding the edge collapse problem of the upper structure and achieving the effect of improving the performance and yield of the finished device.

[0019] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or be understood by implementing the embodiments of the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A flow chart of an anti-edge collapse etching method provided in an embodiment of the present invention.

[0021] Figure 2 Schematic diagram of the structure of the substrate and the multilayer structure in an embodiment of the present invention.

[0022] Figure 3 A schematic diagram of the structure of an etching system provided in an embodiment of the present invention.

[0023] Description of labels: 100, substrate; 200, multi-layer structure; 210, first layer structure; 220, second layer structure; 300, pretreatment equipment; 310, water washing device; 320, first cleaning device; 330, second cleaning device; 340, third cleaning device; 400, photolithography etching equipment; 500, wet etching equipment. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0025] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0026] Reference Figure 1 and attached Figure 2 The present invention provides an anti-edge collapse etching method, comprising the following steps: S1. Pre-treating the substrate; S2. performing a preset number of photolithography processes on the substrate, wherein each photolithography process includes sequentially coating the substrate with glue, exposing, developing, and photolithography etching, and each photolithography process performs photolithography etching on the substrate based on different patterns, so that a stepped multi-layer structure is formed on the surface of the substrate and projections of the upper structure in the up-down direction all fall within the adjacent lower structure; S3. After obtaining a multilayer structure with a preset number of layers, the substrate is placed in an etching solution for wet etching to form a desired graphic structure on the surface of the substrate.

[0027] In this embodiment, in actual application, the multilayer structure 200 on the substrate 100 is designed to be stepped through photolithography processing and ensure that the upper structure can be fully supported by the lower structure, thereby ensuring that when the upper structure is wet-etched, even if the edge of the upper structure is corroded and hollowed out, the support of the lower structure can effectively solve the problem of uneven stress caused by the hollowing out of the edge of the upper structure, thereby suppressing or avoiding the collapse of the upper structure, thereby achieving the effect of improving the performance and yield of the finished device.

[0028] In some embodiments, the specific steps in step S1 include: S11. Wash the substrate with water.

[0029] Furthermore, the specific steps in step S11 include: S111. Wash the substrate with acetone and anhydrous ethanol.

[0030] Furthermore, the specific steps in step S1 also include: S12. Use the first mixed liquid and the second mixed liquid to perform the first cleaning on the substrate; the first mixed liquid is prepared by mixing sulfuric acid, hydrogen peroxide and water in a ratio of 3:1:1; the second mixed liquid is prepared by mixing hydrogen fluoride and water in a ratio of 1:10.

[0031] Furthermore, the specific steps in step S1 also include: S13. The substrate is cleaned for a second time using ionized water and dried for a first time.

[0032] Furthermore, the specific steps in step S1 also include: S14. The substrate is cleaned for the third time using a 1.5% hydrogen fluoride solution and dried for the second time.

[0033] The above steps can effectively remove oxides and contamination particles on the surface of the substrate, ensuring that the manufactured thin film bulk acoustic wave resonator can be used normally.

[0034] In some embodiments, the specific steps in step S2 include: S21. Performing two photolithography processes on the substrate, the specific steps include: S211. Performing a photolithography process on the substrate for the first time and etching the substrate based on the first pattern to obtain a first layer structure during photolithography; S212. Perform photolithography on the substrate again and obtain a second layer structure by etching based on the second pattern during photolithography; the projections of the first layer structure along the up and down directions all fall within the second layer structure.

[0035] In this embodiment, in practical application, generally, two photolithography processes are performed on the substrate 100 to obtain the stepped multilayer structure 200. For example, in the first photolithography, a specific photoresist and exposure parameters are used and based on the first pattern, so as to form a first layer structure 210 on the substrate 100; then in the second photolithography, the second pattern is obtained by adjusting the size and shape of the first pattern, and then different photoresists and exposure parameters are selected and based on the second pattern, so as to form a second layer structure 220 on the substrate 100 (at this time, the first layer structure is located above the second layer structure). Compared with the traditional sandwich structure in which the projection of the upper structure in the up and down directions overlaps with or covers the lower structure, this stepped multilayer structure 200 ensures that the area of ​​the lower layer between the layer structures is larger than the upper layer, which is convenient for providing sufficient support, so that the stress distribution of each layer structure is more uniform, thereby avoiding the collapse phenomenon.

[0036] Reference Figure 2 The present invention provides an etching system, comprising: A pre-treatment device 300, for pre-treating a substrate; A photolithography and etching device 400 is used to perform a preset number of photolithography processes on a substrate, wherein each photolithography process includes sequentially coating, exposing, developing and photolithography etching the substrate, and each photolithography process performs photolithography etching on the substrate based on different patterns, so that a stepped multi-layer structure is formed on the surface of the substrate and projections of the upper structure in the up-down direction all fall within the adjacent lower structure; The wet etching device 500 is used to place a substrate in an etching solution for wet etching after obtaining a multi-layer structure with a preset number of layers, so as to form a desired graphic structure on the surface of the substrate.

[0037] In some embodiments, the pretreatment equipment 300 includes a water washing device 310, a first cleaning device 320, a second cleaning device 330 and a third cleaning device 340, the water washing device 310 is used to wash the substrate with water; the first cleaning device 320 is used to use a first mixed liquid and a second mixed liquid to perform a first cleaning on the substrate; the first mixed liquid is prepared by mixing sulfuric acid, hydrogen peroxide and water in a ratio of 3:1:1; the second mixed liquid is prepared by mixing hydrogen fluoride and water in a ratio of 1:10; the second cleaning device 330 is used to use ionized water to perform a second cleaning on the substrate and perform a first drying; the third cleaning device 340 is used to use a hydrogen fluoride solution with a concentration of 1.5% to perform a third cleaning on the substrate and perform a second drying.

[0038] Furthermore, the water washing device 310 is used to wash the substrate with acetone and anhydrous ethanol.

[0039] In some embodiments, the photolithography etching device 400 performs the following when performing a predetermined number of photolithography processes on a substrate: S21. Performing two photolithography processes on the substrate, the specific steps include: S211. Performing a photolithography process on the substrate for the first time and etching the substrate based on the first pattern to obtain a first layer structure during photolithography; S212. Perform photolithography on the substrate again and obtain a second layer structure by etching based on the second pattern during photolithography; the projections of the first layer structure along the up and down directions all fall within the second layer structure.

[0040] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0041] The above description is only an embodiment of the present invention and is not intended to limit the protection scope of the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preventing edge collapse etching, characterized in that: The following steps are involved: S1. Pre-treating the substrate; S2. performing a preset number of photolithography processes on the substrate, wherein each photolithography process includes sequentially coating the substrate with glue, exposing, developing, and photolithography etching, and each photolithography process performs photolithography etching on the substrate based on different patterns, so that a stepped multi-layer structure is formed on the surface of the substrate and projections of the upper structure in the up-down direction all fall within the adjacent lower structure; S3. After obtaining a multilayer structure with a preset number of layers, the substrate is placed in an etching solution for wet etching to form a desired graphic structure on the surface of the substrate.

2. The anti-edge collapse etching method according to claim 1, characterized in that: The specific steps in step S1 include: S11. Washing the substrate with water.

3. The anti-edge collapse etching method according to claim 2, characterized in that: The specific steps in step S11 include: S111. Wash the substrate with acetone and anhydrous ethanol.

4. The anti-edge collapse etching method according to claim 2, characterized in that: The specific steps in step S1 also include: S12. Use a first mixed liquid and a second mixed liquid to perform a first cleaning on the substrate; the first mixed liquid is prepared by mixing sulfuric acid, hydrogen peroxide and water in a ratio of 3:1:1; the second mixed liquid is prepared by mixing hydrogen fluoride and water in a ratio of 1:

10.

5. The anti-edge collapse etching method according to claim 4, characterized in that: The specific steps in step S1 also include: S13. Clean the substrate for a second time using ionized water and dry it for a first time.

6. The anti-edge collapse etching method according to claim 5, characterized in that: The specific steps in step S1 also include: S14. Clean the substrate for the third time using a 1.5% hydrogen fluoride solution and dry it for the second time.

7. The anti-edge collapse etching method according to claim 1, characterized in that: The specific steps in step S2 include: S21. Performing photolithography twice on the substrate, the specific steps comprising: S211. performing a photolithography process on the substrate for the first time and etching a first layer structure based on the first pattern during photolithography; S212. Perform photolithography on the substrate again and obtain a second layer structure by etching based on the second pattern during photolithography; the projections of the first layer structure along the up and down directions all fall within the second layer structure.

8. An etching system, characterized in that: include: Pretreatment equipment, used for pretreatment of the substrate; A photolithography and etching device, used for performing a preset number of photolithography processes on the substrate, wherein each photolithography process includes sequentially coating, exposing, developing and photolithography etching the substrate, and each photolithography process performs photolithography etching on the substrate based on different patterns, so that the surface of the substrate forms a stepped multi-layer structure and the projections of the upper structure in the up-down direction all fall within the adjacent lower structure; The wet etching equipment is used to place the substrate in an etching solution for wet etching after obtaining a multilayer structure with a preset number of layers, so as to form a desired graphic structure on the surface of the substrate.

9. The etching system according to claim 8, characterized in that: The pretreatment equipment comprises a water washing device, and the water washing device is used to wash the substrate with water.

10. The etching system according to claim 9, characterized in that: The water washing device is used to wash the substrate with acetone and anhydrous ethanol.

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