Preparation method of semiconductor device and semiconductor device
By roughening a specific area of the semiconductor device substrate and depositing a silicon nitride layer in this area to react with moisture to form dot-shaped silicon oxide, the problem of dot-shaped silicon oxide defects during SiN deposition is solved, and the position and density of dot-shaped silicon oxide are accurately controlled, thereby reducing production costs.
Patent Information
- Application Number
- CN202510177432.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-18
- Publication Date
- 2025-05-23
AI Technical Summary
During SiN deposition, due to the presence of moisture on the surface of the product sheet, undesired by-products - dot-shaped silicon oxides, which are considered defects.
By roughening a specific region of the substrate and depositing a silicon nitride layer under the condition of moisture present on the surface of the region, the silicon nitride layer reacts with moisture to form dot-shaped silicon oxide.
This method can accurately control the position and density of dotted silicon oxide, and is suitable for applications that require specific surface structures or patterns, with simple process flow and reduced production costs.
Smart Images
Figure CN120033065A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a method for preparing a semiconductor device and a semiconductor device. Background Art
[0002] Microlens (array), as a commonly used optical device, can realize functions such as focusing and collimating light sources, and has important and wide applications in the field of semiconductor optoelectronics.
[0003] In the manufacturing process of semiconductor devices, silicon nitride (SiN) is a commonly used protective layer and passivation layer material. Traditional SiN deposition processes include low-pressure chemical vapor deposition (LPCVD), plasma-enhanced chemical vapor deposition (PECVD), etc. When there is moisture on the surface of the product wafer, undesirable byproducts may be generated during the SiN deposition process - point-like silicon oxide, which is usually regarded as a defect. Summary of the invention
[0004] The purpose of the present invention is to provide a method for preparing a semiconductor device and a semiconductor device, which utilizes "defects" that may occur in the SiN deposition process to make them have unique value.
[0005] In order to solve the above problems, the present invention provides a method for preparing a semiconductor device, the method comprising:
[0006] Providing a substrate, and roughening a specific area of the substrate, wherein the position of the specific area corresponds to a target formation position of dot-shaped silicon oxide; and
[0007] Under the condition that there is moisture on the surface of the specific area, a silicon nitride layer is deposited, and the silicon nitride layer at least covers the specific area, so that the deposited silicon nitride layer reacts with the moisture on the surface of the specific area to generate dot-shaped silicon oxide.
[0008] Optionally, in the method for preparing the semiconductor device, the substrate includes a product sheet and a base layer formed on the surface of the product sheet, the base layer is formed in the specific area, the base layer is roughened and the dot-shaped silicon oxide is formed on the base layer.
[0009] Optionally, in the method for preparing the semiconductor device, the material of the base layer is silicon nitride.
[0010] Optionally, in the method for preparing the semiconductor device, the base layer is roughened by using a dry etching process or a wet etching process;
[0011] Optionally, in the method for preparing the semiconductor device, the etching gas of the dry etching process is a mixed gas including carbon tetrafluoride and oxygen.
[0012] Optionally, in the method for preparing the semiconductor device, the etchant of the wet etching process uses a solution including phosphoric acid.
[0013] Optionally, in the method for preparing the semiconductor device, after the roughening treatment is performed, the method further comprises:
[0014] The existing structure is sequentially subjected to a water or aqueous solution cleaning step, a drying step, and a baking step until only the specific area that has been roughened retains moisture.
[0015] Optionally, in the method for preparing the semiconductor device, the step of forming the silicon nitride layer is performed under high temperature conditions, and after depositing the silicon nitride layer, the method further includes: cooling the existing structure to room temperature to form the dot-shaped silicon oxide.
[0016] Optionally, in the method for preparing the semiconductor device, the process conditions for forming the silicon nitride layer include:
[0017] Under high temperature conditions, ammonia and silane are used as reaction gases, and argon is used as carrier gas.
[0018] The present invention also provides a semiconductor device, which is prepared by using the preparation method as described in any of the above items.
[0019] In summary, the method for preparing a semiconductor device and the semiconductor device provided by the present invention include: providing a substrate, and roughening a specific area of the substrate, the position of the specific area corresponds to the target formation position of the dot-shaped silicon oxide; and, under the condition that there is moisture on the surface of the specific area, depositing a silicon nitride layer, the silicon nitride layer at least covers the specific area, so that the deposited silicon nitride layer reacts with the moisture on the surface of the specific area to generate dot-shaped silicon oxide. The preparation method provided by the present invention can accurately control the position and density of the dot-shaped silicon oxide, which is suitable for applications requiring a specific surface structure or pattern. In addition, the preparation method provided by the present invention can form dot-shaped silicon oxide at the target position through the steps of silicon nitride deposition and roughening, and the process flow is simple, and the production cost can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 A flow chart of a method for preparing a semiconductor device provided by an embodiment of the present invention;
[0021] Figure 2-Figure 5 for Figure 1Schematic diagram of device structure corresponding to each step shown;
[0022] The descriptions of the reference numerals are as follows:
[0023] 10-product sheet; 20-base layer; 30-water; 40-silicon nitride layer; 50-dot silicon oxide. DETAILED DESCRIPTION
[0024] The following is a further detailed description of the method for preparing a semiconductor device and a semiconductor device provided by the present invention in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are all in an inaccurate scale, which is only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis required to be shown in each drawing is different, and sometimes different scales are used. It should be recognized that relative terms such as "above", "below", "top", "bottom", "above" and "below" shown in the drawings can be used to describe the relationship between various elements. These relative terms are intended to cover different orientations of elements other than the orientations depicted in the drawings. For example, if the device is inverted relative to the view in the drawings, for example, an element described as "above" another element will now be below the element. It should also be understood that, unless otherwise specified or indicated, the terms "first", "second", "third" and the like in the specification are only used to distinguish between the various components, elements, steps, etc. in the specification, rather than to represent the logical relationship or sequential relationship between the various components, elements, steps, etc.
[0025] like Figure 1 As shown, the method for preparing a semiconductor device provided in this embodiment includes the following steps:
[0026] S1, providing a substrate, and performing a roughening process on a specific area of the substrate, wherein the position of the specific area corresponds to a target formation position of dot-shaped silicon oxide;
[0027] S2, under the condition that there is moisture on the surface of the specific area, depositing a silicon nitride layer, wherein the silicon nitride layer at least covers the surface of the specific area, so that the deposited silicon nitride layer reacts with the moisture on the surface of the specific area to form dot-shaped silicon oxide.
[0028] The following combination Figure 2 to Figure 5 The method for preparing the semiconductor device provided in this embodiment is further described.
[0029] First, perform step S1 to provide a substrate, see Figure 2 In this embodiment, the substrate includes a product sheet 10 and a base layer 20 formed on the surface of the product sheet 10, and the base layer 20 is formed in the specific area, such as Figure 3 As shown, roughening a specific area of the substrate is roughening the base layer 20. The base layer 20 is formed on the product wafer 10, and the formation position of the dot-shaped silicon oxide layer is positioned by the base layer 20, so as to avoid damage to the product wafer 10 caused by the roughening process.
[0030] The specific formation process of the base layer 20 can be as follows:
[0031] forming an initial base layer on the surface of the product sheet, the initial base layer covering the surface of the product sheet;
[0032] Forming a patterned mask layer on the surface of the initial base layer, the patterned mask layer defines the formation position of the microlens structure, and the material of the mask layer may be, for example, photoresist;
[0033] The initial base layer is etched using the patterned mask layer as a mask to obtain the base layer 20 , so that the formation position of the base layer 20 corresponds to the target formation position of the microlens.
[0034] Preferably, the base layer 20 is made of the same material as the subsequent cover layer, that is, the base layer 20 is also made of silicon nitride, and the thickness of the base layer 20 can be selected according to the actual process conditions. In order to ensure the effect of roughening the base layer 20, the thickness of the base layer 20 can be designed to be about 100nm.
[0035] When the material of the base layer 20 is silicon nitride, as an example, the formation process of the initial base layer may be as follows:
[0036] The product wafer 10 is placed in a silicon nitride deposition reaction chamber, the deposition temperature is set to 800°C, the pressure is set to 100Pa, ammonia and silane are used as reaction gases, wherein the ammonia flow rate is 100sccm, the silane flow rate is 50sccm, and an appropriate amount of argon is added as a carrier gas with a flow rate of 500sccm.
[0037] The present invention does not limit the formation process of the base layer 20. In some other embodiments, other silicon nitride deposition processes may be used to form the base layer 20, such as a PECVD (plasma enhanced chemical vapor deposition) process.
[0038] Specifically, the base layer 20 may be roughened by a dry etching process or a wet etching process. When the base layer 20 is made of silicon nitride, if the base layer 20 is roughened by a dry etching process, the etching gas of the dry etching process may be a mixed gas including carbon tetrafluoride and oxygen, the power may be about 150w, and the time may be about 3 minutes; when the base layer 20 is made of silicon nitride, if the base is roughened by a wet etching process, the etchant of the wet etching process may be a solution including phosphoric acid, the phosphoric acid concentration may be about 85%, the etching temperature may be about 80°C, and the etching time may be about 5 minutes.
[0039] Next, execute step S2, see Figure 4 and Figure 5 , under the condition that there is water 30 on the surface of the specific area, the silicon nitride layer 40 is deposited. When there is water 30 on the surface of the specific area, the silicon nitride layer 40 deposited on the surface will react with water to generate dot-shaped silicon oxide 50.
[0040] In order to form the dot-shaped silicon oxide 50 in a specific area, it is necessary to ensure that moisture 30 exists only in the specific area, while moisture 30 does not exist in other areas except the specific area. Therefore, preferably, before depositing the silicon nitride layer 40, the substrate can be sequentially subjected to a water or aqueous solution cleaning step, a drying step, and a baking step until only the roughened specific area of the substrate (i.e., the base layer 20) retains moisture 30.
[0041] The cleaning step may be specifically rinsed with water or an aqueous solution, and the drying step may be specifically spin-dried to improve drying efficiency. Since the base layer 20 has been roughened, it is more difficult to remove the water 30 on the surface of the concave area of the surface than on the surface of other areas of the substrate. In view of this difference, after the cleaning step, the drying step and the baking step, only the roughened surface of the base layer 20 retains the water 30.
[0042] The present application does not impose any particular restrictions on the process conditions of the cleaning step, the drying step, and the baking step. The specific process conditions of the three steps are closely related to each other, and only when they work together can the base layer 20 retain the moisture 30 due to the roughening treatment when the moisture 30 in other areas is removed.
[0043] The silicon nitride layer 40 can be formed by a process similar to that of the base layer 20, that is, the silicon nitride layer 40 is formed under high temperature conditions using ammonia and silane as reaction gases and argon as carrier gas, which will not be described in detail here. Since the step of forming the silicon nitride layer 40 is performed under high temperature conditions, after the silicon nitride layer 40 is deposited, the preparation method provided in this embodiment further includes: cooling the existing structure to room temperature to form the silicon oxide.
[0044] Through the description of the above steps, it can be seen that the preparation method provided by this embodiment can accurately control the position and density of the dot-shaped silicon oxide 50, which is suitable for applications requiring a specific surface structure or pattern. In addition, by using the preparation method provided by this embodiment, the dot-shaped silicon oxide 50 can be formed at the target position through the silicon nitride deposition and roughening treatment steps, the process flow is simple, and the production cost is reduced.
[0045] This embodiment also provides a semiconductor device, which is manufactured using the manufacturing method described in this embodiment.
[0046] As described above, the preparation method provided in this embodiment can accurately control the position and density of the dot-shaped silicon oxide 50, and is suitable for applications requiring a specific surface structure or pattern.
[0047] For example, the formed dot-shaped silicon oxide 50 can provide different refractive indices and enhance light absorption, thereby improving the sensitivity and response speed of the photodetector and enhancing its performance under low light conditions. The dot-shaped silicon oxide 50 can also be used as a microlens to improve the light gathering efficiency, enhance the intensity and uniformity of the light signal, and is suitable for applications requiring high-precision light transmission, such as optical sensors, optical communication devices, etc. In addition, the spherical structure of the dot-shaped silicon oxide 50 is combined with the silicon nitride coating to form a refractive index gradient from air to silicon nitride and then to silicon oxide, reducing interface reflection. The microlens effect of the spherical structure and the smooth refractive index transition work together to achieve an effective anti-reflection effect, especially in the wavelength range of 900nm-1500nm, which can significantly reduce reflection and improve light transmittance, and is suitable for a variety of applications such as photodetectors, solar cells and optical sensors.
[0048] In summary, the method for preparing a semiconductor device and the semiconductor device provided by the embodiment of the present invention include: providing a substrate, and roughening a specific area of the substrate, the position of the specific area corresponds to the target formation position of the dot-shaped silicon oxide; and, under the condition that there is moisture on the surface of the specific area, depositing a silicon nitride layer, the silicon nitride layer at least covers the specific area, so that the deposited silicon nitride layer reacts with the moisture on the surface of the specific area to generate dot-shaped silicon oxide. The preparation method provided by the present invention can accurately control the position and density of the dot-shaped silicon oxide, which is suitable for applications requiring a specific surface structure or pattern. In addition, the preparation method provided by the present invention can form dot-shaped silicon oxide at the target position through silicon nitride deposition and roughening steps, the process flow is simple, and the production cost is reduced.
[0049] It should be noted that, although the present invention has been disclosed as a preferred embodiment, the above embodiment is not intended to limit the present invention. For any technician familiar with the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or modified into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belongs to the scope of protection of the technical solution of the present invention.
Claims
1. A method for preparing a semiconductor device, characterized in that: The method comprises: Providing a substrate, and roughening a specific area of the substrate, wherein the position of the specific area corresponds to a target formation position of dot-shaped silicon oxide; and Under the condition that there is moisture on the surface of the specific area, a silicon nitride layer is deposited, and the silicon nitride layer at least covers the specific area, so that the deposited silicon nitride layer reacts with the moisture on the surface of the specific area to generate dot-shaped silicon oxide.
2. The method for preparing a semiconductor device according to claim 1, wherein: The substrate includes a product sheet and a base layer formed on the surface of the product sheet, the base layer is formed in the specific area, the base layer is roughened and the dot-shaped silicon oxide is formed on the base layer.
3. The method for preparing a semiconductor device according to claim 2, wherein: The base layer is made of silicon nitride.
4. The method for preparing a semiconductor device according to claim 3, wherein: The base layer is roughened by using a dry etching process or a wet etching process.
5. The method for preparing a semiconductor device according to claim 4, characterized in that: The etching gas of the dry etching process is a mixed gas including carbon tetrafluoride and oxygen.
6. The method for preparing a semiconductor device according to claim 4, wherein: The wet etching process uses an etchant containing a phosphoric acid solution.
7. The method for preparing a semiconductor device according to claim 1, wherein: After the roughening process is performed, the method further comprises: The substrate is sequentially subjected to a water or aqueous solution cleaning step, a drying step, and a baking step until only the roughened specific area retains moisture.
8. The method for preparing a semiconductor device according to claim 1, wherein: The step of forming the silicon nitride layer is performed under high temperature conditions. After the silicon nitride layer is deposited, the method further comprises: cooling the existing structure to room temperature to form the dot-shaped silicon oxide.
9. The method for preparing a semiconductor device according to claim 1, wherein: The process conditions for forming the silicon nitride layer include: Under high temperature conditions, ammonia and silane are used as reaction gases, and argon is used as carrier gas.
10. A method for preparing a semiconductor device, characterized in that: The semiconductor device is manufactured using the manufacturing method according to any one of claims 1 to 9.