Pattern transfer method and semiconductor device
By employing a wet etching method for metal stripping in semiconductor device manufacturing, the photolithography process is simplified, the complexity of photolithography technology and the challenges of overlay are overcome, and a simple and rapid pattern transfer process is achieved, reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XIAN SAIFULESI SEMICON TECH CO LTD
- Filing Date
- 2022-08-12
- Publication Date
- 2026-08-04
AI Technical Summary
In existing semiconductor device manufacturing, the photolithography process is complex and the feature size of the overlay technique is close to the physical limit of optical lithography, resulting in high time and economic costs.
Wet etching is used for metal stripping, simplifying the photolithography process. By forming a nanoporous layer, mask layer, photoresist layer and metal layer on the substrate, and utilizing the channel structure composed of Al2O3 layer and metal layer, complex photolithography processes are avoided.
It simplifies the pattern transfer process, reduces time and economic costs, improves manufacturing speed and operability, and avoids the challenges of small-size photolithography overlay.
Smart Images
Figure CN115483099B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor device manufacturing technology, specifically to an image transfer method and a semiconductor device. Background Technology
[0002] In the semiconductor chip manufacturing process, metal vapor deposition is required to create a mirror-like light-blocking layer and an isolation layer to prevent light crosstalk, which typically involves pattern transfer. The current semiconductor industry usually uses photolithography to achieve pattern transfer. However, photolithography is not only complex, involving four parts: substrate pretreatment, photoresist coating, direct-write exposure, and development; but also, as the size of semiconductor devices continues to shrink, the feature size of photolithography, especially overlay technology, is gradually approaching or even exceeding the physical limits of optical lithography, posing even more severe challenges to semiconductor manufacturing technology, particularly photolithography.
[0003] Therefore, there is an urgent need to propose a simple and fast pattern transfer method to reduce the time and economic costs of semiconductor device manufacturing. Summary of the Invention
[0004] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide an image transfer method and a semiconductor device to reduce the time and economic costs of semiconductor device manufacturing.
[0005] To address the above problems, the first aspect of this invention discloses a graphic transfer method, which includes the following steps:
[0006] A substrate is provided, a target layer is formed on the substrate, and the target layer is etched to form a nanoporous layer;
[0007] A mask layer is formed on the nanoporous layer by depositing a passivation layer mask;
[0008] A photoresist layer is formed on the mask layer, and the photoresist layer is patterned using a photolithography process to form a photoresist pattern.
[0009] Based on the photoresist pattern, the mask layer and the target layer are etched to form the target pattern;
[0010] An Al2O3 layer is deposited on the target pattern, and a metal layer is deposited on the Al2O3 layer;
[0011] Metal stripping is performed by wet etching to remove the mask layer, as well as the Al2O3 layer and metal layer on top of the mask layer, to obtain a patterned metal layer.
[0012] As a further preferred embodiment, in the first aspect of the present invention, the target layer is a dielectric layer or conductive layer formed by etching nanopores.
[0013] As a further preferred embodiment, in the first aspect of the present invention, the target layer is a GaN layer or a GaAs layer.
[0014] As a further preferred embodiment, in the first aspect of the present invention, a mask layer is formed on the nanopore layer by depositing a passivation layer mask by PECVD; or / and, the thickness of the mask layer is 1-2 μm; or / and, the material of the mask layer is any one of SiO2, SiN4, metal and photoresist.
[0015] As a further preferred embodiment, in the first aspect of the present invention, etching the mask layer and the target layer based on the photoresist pattern to form a target pattern includes:
[0016] The mask layer is patterned using photoresist pattern etching to form a mask pattern;
[0017] The target layer is patterned by etching using the mask pattern to form a chip pattern;
[0018] The mask pattern and the chip pattern constitute the target pattern.
[0019] As a further preferred embodiment, in the first aspect of the present invention, the mask layer is patterned by ICP etching using a photoresist pattern to form a mask pattern; or / and, the target layer is patterned by ICP etching using the mask pattern to form a chip pattern; or / and, the chip pattern is a regular square or a circle.
[0020] As a further preferred embodiment, the photoresist layer is a negative photoresist layer;
[0021] Based on the photoresist pattern, the mask layer and the target layer are etched to form the target pattern, including:
[0022] Chromium is deposited onto a photoresist pattern and then stripped to form a chromium hard mask.
[0023] The hard mask is used to pattern the mask layer and the target layer by ICP etching to form a target pattern.
[0024] As a further preferred embodiment, in the first aspect of the present invention, the Al2O3 layer is deposited on the target pattern by ALD; or / and the thickness of the Al2O3 layer is 10-50 nm; or / and the metal layer is deposited on the Al2O3 layer by SPutter; or / and the material of the metal layer is a black light-absorbing metal or a white reflective metal, or the material of the metal layer is any one of chromium, tungsten, nickel and titanium.
[0025] As a further preferred embodiment, in the first aspect of the present invention, metal stripping is performed by wet etching to remove the mask layer, as well as the Al2O3 layer and metal layer on the upper end of the mask layer, to obtain a patterned metal layer, including:
[0026] The substrate with the deposited metal layer is placed in a buffer oxide etching solution to perform wet removal of the mask layer;
[0027] After the substrate has been soaked in the buffer oxide etching solution, the Al2O3 layer and metal layer on the top of the mask layer are removed by blue film metal stripping.
[0028] The substrate, after the Al2O3 layer and the metal layer have been stripped, is immersed again in a buffer oxide etching solution to remove the residual mask layer on the target layer, thus obtaining a patterned metal layer.
[0029] A second aspect of the present invention discloses a semiconductor device manufactured using the pattern transfer method described in the first aspect of the present invention.
[0030] Compared with the prior art, the beneficial effects of the embodiments of the present invention are as follows:
[0031] The embodiments of the present invention directly employ wet etching for metal stripping, avoiding the complex photolithography process and the severe challenges posed by small-size photolithography overlay. This pattern transfer method has advantages such as simple process, strong operability and fast manufacturing speed, which greatly simplifies the process of traditional pattern transfer methods and reduces the time and economic costs of semiconductor device manufacturing. Attached Figure Description
[0032] Figure 1 This is a flowchart illustrating a graphic transfer method provided in an embodiment of the present invention;
[0033] Figures 2-9 This is a schematic diagram of the structure of each preparation step in the pattern transfer method provided in the embodiments of the present invention;
[0034] Figure 10 for Figure 9 Top view.
[0035] In the figure: 1. Substrate; 2. Target layer; 3. Mask layer; 4. Photoresist layer; 5. Al2O3 layer; 6. Metal layer. Detailed Implementation
[0036] This specific embodiment is merely an explanation of the embodiments of the present invention and is not intended to limit the embodiments of the present invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the embodiments of the present invention, they are protected by patent law.
[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the embodiments of the present invention.
[0038] The term "comprising" and any variations thereof in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product or device.
[0039] In embodiments of the present invention, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" or "for example" in embodiments of the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.
[0040] This invention discloses a pattern transfer method and a semiconductor device that eliminates the need for photolithography and other redundant processes. It achieves pattern transfer directly on the basis of existing processes using wet metal stripping, which has the advantages of simple process, strong operability and fast manufacturing speed. It greatly simplifies the process of traditional pattern transfer methods. The following is a detailed description with reference to the accompanying drawings.
[0041] Example 1
[0042] Please see Figure 1 , Figure 1 This is a flowchart illustrating a graphic transfer method disclosed in an embodiment of the present invention. Figure 1 As shown, the graphic transfer method includes the following steps:
[0043] S110. A substrate is provided, a target layer is formed on the substrate, and the target layer is etched to form a nanoporous layer.
[0044] Please refer to Figure 2 As shown, substrate 1 can be a sapphire substrate, Al-based substrate, Si-based substrate, etc., and target layer 2 can be any dielectric or conductive layer with nanopores that can be formed by etching, such as GaN layer, GaAs layer, etc. In a preferred embodiment of the present invention, target layer 2 can be an N-GaN layer (N-type gallium nitride).
[0045] The method for forming a nanoporous layer in the target layer can be achieved through electrochemical etching.
[0046] S120. A mask layer is formed on the nanoporous layer by depositing a passivation layer mask.
[0047] Please refer to Figure 3 As shown, to prevent the target layer from being damaged by etching, a mask layer is formed on the nanopore layer as a protection. Mask layer 3 can be a passivation layer such as SiO2, SiN4, metal, or photoresist. A 1µm-2µm mask layer can be formed by depositing the passivation mask on the nanopore layer using PECVD (Plasma Enhanced Chemical Vapor Deposition).
[0048] S130. A photoresist layer is formed on the mask layer, and the photoresist layer is patterned using a photolithography process to form a photoresist pattern.
[0049] Please refer to Figure 4 As shown, photoresist is first spin-coated onto the mask layer to form photoresist layer 4, and then the photoresist layer is patterned using a photolithography process to form a photoresist pattern.
[0050] S140. Based on the photoresist pattern, etch the mask layer and the target layer to form the target pattern.
[0051] First, the mask layer is patterned using photoresist patterning via ICP (Inductively Coupled Plasma) etching to form the mask pattern. Please refer to [reference needed]. Figure 5 As shown. Then, using a mask pattern, the target layer is patterned via ICP etching to form the chip pattern. Please refer to [reference needed]. Figure 6 As shown.
[0052] Chip patterns can be regular polygons, such as squares or regular pentagons, or circles. The mask pattern and chip pattern are collectively referred to as the target pattern.
[0053] S150, Deposit an Al2O3 layer on the target pattern, and deposit a metal layer on the Al2O3 layer.
[0054] Please refer to Figure 7 As shown, an Al2O3 layer 5 can be deposited on the target pattern using ALD (Atomic Layer Deposition) technology. The purpose of depositing the Al2O3 layer is to improve the sidewall coverage of the subsequent metal layer evaporation. In a preferred embodiment of the present invention, the thickness of the Al2O3 layer 5 is 10-50 nm, which allows for optimal sidewall coverage of the metal layer evaporation.
[0055] Please refer to Figure 8 As shown, a metal layer 6 is deposited on the Al2O3 layer 5 by sputtering as an isolation layer to prevent optical crosstalk. For example, the metal layer can be made of black light-absorbing metals such as chromium (Cr) and tungsten (W), or white reflective metals such as nickel (Ni) and titanium (Ti).
[0056] S160. Metal stripping is performed by wet etching to remove the mask layer, as well as the Al2O3 layer and metal layer on the upper end of the mask layer, to obtain a patterned metal layer.
[0057] In a preferred embodiment of the present invention, in order to avoid the complex photolithography process and the severe challenges brought by small-size photolithography overlay in the semiconductor device manufacturing process, wet etching is directly used for metal stripping, thereby greatly simplifying the process of traditional pattern transfer methods.
[0058] Specifically, first, the substrate with the deposited metal layer (i.e., the substrate after completing steps S110-S150) is placed in BOE (buffered oxide etchant) for wet removal of the mask layer; then, the substrate after BOE immersion undergoes blue film metal stripping to remove the Al2O3 layer and metal layer on top of the mask layer; finally, the substrate after the Al2O3 layer and metal layer have been stripped is immersed in BOE solution again to remove the remaining mask layer on the target layer, thereby obtaining the patterned metal layer. Please refer to... Figure 9 and Figure 10 As shown.
[0059] The aforementioned pattern transfer method includes sequentially forming an Al2O3 layer and a metal layer on the surface of a target layer with an already formed chip pattern. The passivation layer is then removed using BOE wet etching or other etching methods, allowing the patterned mask layer on the target layer to pattern the metal layer. In this invention, wet etching is directly used for metal stripping, avoiding the complex photolithography process and the severe challenges posed by small-size photolithography overlay. This pattern transfer method offers advantages such as simple process, high operability, and fast manufacturing speed, greatly simplifying the process flow of traditional pattern transfer methods.
[0060] from Figure 10 It can be seen that forming a channel on the target layer consisting of an Al2O3 layer and a metal layer as a light-blocking (light-absorbing or light-reflecting) structure can prevent light crosstalk.
[0061] Example 2
[0062] This second embodiment provides a novel pattern transfer method. Its basic steps are largely the same as those in the first embodiment, except that, corresponding to step S140 in the first embodiment, in this second embodiment, a negative photoresist layer is formed on the mask layer, and the negative photoresist layer is patterned using a photolithography process to form a photoresist pattern. Then, Cr metal is deposited on the photoresist pattern, and the metal is stripped to form a Cr hard mask. Corresponding to step S150 in the first embodiment, in this second embodiment, the mask layer and the target layer are patterned by ICP etching using the hard mask to form the target pattern.
[0063] Example 3
[0064] Example 3 provides a semiconductor device that can be manufactured using any pattern transfer method in Example 1 or Example 2, and can be applied to circuit boards in different scenarios.
[0065] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the embodiments of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the embodiments of the present invention.
Claims
1. A method for transferring graphics, characterized in that, It includes the following steps: A substrate is provided, a target layer is formed on the substrate, and the target layer is etched to form a nanoporous layer; A mask layer is formed on the nanoporous layer by depositing a passivation layer mask; A photoresist layer is formed on the mask layer, and the photoresist layer is patterned using a photolithography process to form a photoresist pattern. Based on the photoresist pattern, the mask layer and the target layer are etched to form the target pattern; An Al2O3 layer is deposited on the target pattern, and a metal layer is deposited on the Al2O3 layer; Metal stripping is performed by wet etching to remove the mask layer, as well as the Al2O3 layer and metal layer on top of the mask layer, to obtain a patterned metal layer.
2. The graphic transfer method according to claim 1, characterized in that, The target layer is a dielectric or conductive layer formed by etching nanopores.
3. The graphic transfer method according to claim 2, characterized in that, The target layer is a GaN layer or a GaAs layer.
4. The graphic transfer method according to claim 1, characterized in that, A mask layer is formed by depositing a passivation layer mask on the nanoporous layer via PECVD; or / and the thickness of the mask layer is 1-2 μm; or / and the material of the mask layer is any one of SiO2, SiN4, metal and photoresist.
5. The graphic transfer method according to claim 1, characterized in that, Based on the photoresist pattern, the mask layer and the target layer are etched to form the target pattern, including: The mask layer is patterned using photoresist pattern etching to form a mask pattern; The target layer is patterned by etching using the mask pattern to form a chip pattern; The mask pattern and the chip pattern constitute the target pattern.
6. The graphic transfer method according to claim 5, characterized in that, The mask layer is patterned using photoresist patterning via ICP etching to form a mask pattern; or / and the target layer is patterned using the mask pattern via ICP etching to form a chip pattern; or / and the chip pattern is a regular square or a circle.
7. The graphic transfer method according to claim 1, characterized in that, The photoresist layer is a negative photoresist layer; Based on the photoresist pattern, the mask layer and the target layer are etched to form the target pattern, including: Chromium is deposited onto a photoresist pattern and then stripped to form a chromium hard mask. The hard mask is used to pattern the mask layer and the target layer by ICP etching to form a target pattern.
8. The graphic transfer method according to any one of claims 1-7, characterized in that, The Al2O3 layer is deposited on the target pattern by ALD; or / and the thickness of the Al2O3 layer is 10-50 nm; or / and the metal layer is deposited on the Al2O3 layer by SPutter; or / and the metal layer is made of black light-absorbing metal or white reflective metal or the metal layer is made of any one of chromium, tungsten, nickel and titanium.
9. The graphic transfer method according to any one of claims 1-7, characterized in that, Metal stripping is performed by wet etching to remove the mask layer, as well as the Al2O3 layer and metal layer on top of the mask layer, to obtain a patterned metal layer, including: The substrate with the deposited metal layer is placed in a buffer oxide etching solution to perform wet removal of the mask layer; After the substrate has been soaked in the buffer oxide etching solution, the Al2O3 layer and metal layer on the top of the mask layer are removed by blue film metal stripping. The substrate, after the Al2O3 layer and the metal layer have been stripped, is immersed again in a buffer oxide etching solution to remove the residual mask layer on the target layer, thus obtaining a patterned metal layer.
10. A semiconductor device, characterized in that, It is manufactured using the graphic transfer method described in any one of claims 1-9.