CN-114050160-B - Method for manufacturing semiconductor device and semiconductor device

CN114050160BCN 114050160 BCN114050160 BCN 114050160BCN-114050160-B

Abstract

The application provides a manufacturing method of a semiconductor device and the semiconductor device, wherein the method comprises the steps of providing a memory array structure; forming an amorphous silicon film on the surface of the memory array structure, forming a cover layer on the surface of the amorphous silicon film far away from the memory array structure, and annealing the memory array structure with the cover layer so that the amorphous silicon film is converted into a polycrystalline silicon film. The method ensures that the uniformity and the flatness of the obtained polycrystalline silicon film are good.

Inventors

ZHU WENQI
YAN YUAN
ZHANG HAO

Assignees

长江存储科技有限责任公司
长江存储科技有限责任公司

Dates

Publication Date: 20260421
Application Date: 20211109
Priority Date: 20211109

Claims (8)

1. A method of fabricating a semiconductor device, comprising: providing a storage array structure; forming an amorphous silicon film on the surface of the memory array structure; Forming a cover layer on the surface of the amorphous silicon film far away from the storage array structure, wherein the material of the cover layer comprises oxide or nitride, and the thickness of the cover layer is more than 40nm and less than 50nm; and carrying out laser annealing treatment on the memory array structure with the covering layer so that the amorphous silicon film is converted into a polycrystalline silicon film.
2. The method of claim 1, wherein annealing the memory array structure with the cap layer formed thereon to convert the amorphous silicon thin film to a polysilicon thin film comprises: And annealing the amorphous silicon film through the covering layer by utilizing laser so as to convert the amorphous silicon film into the polycrystalline silicon film.
3. The method of claim 2, wherein the laser light has a wavelength in the range of 300nm to 600nm.
4. The method of claim 1, wherein after annealing the memory array structure formed with the capping layer such that the amorphous silicon thin film is converted to a polysilicon thin film, the method further comprises: And removing the covering layer.
5. The method of claim 1, wherein providing a memory array structure comprises: Providing a substrate; Forming a stacked structure on the exposed surface of the substrate, wherein the stacked structure comprises a body structure and a channel hole positioned in the body structure, the bottom of the channel hole penetrates into the substrate, and the body structure comprises insulating medium layers and sacrificial layers which are alternately stacked; And removing at least the substrate so as to expose the bottom of the channel hole.
6. The method of claim 5, wherein forming an amorphous silicon film on a surface of the memory array structure comprises: and forming the amorphous silicon film on the surface of the storage array structure so as to cover the exposed bottom of the channel hole.
7. A semiconductor device manufactured by the method according to any one of claims 1 to 6.
8. A 3D NAND memory characterized in that the 3D NAND memory comprises the semiconductor device of claim 7.

Description

Method for manufacturing semiconductor device and semiconductor device Technical Field The application relates to the field of semiconductors, in particular to a manufacturing method of a semiconductor device, the semiconductor device and a 3D NAND memory. Background In the prior art, in the manufacturing process of the 3D NAND, a laser annealing process is introduced in order to convert surface a-Si (amorphous silicon) into polysilicon and generate GIDL (Gate-Induced DRAIN LEAKAGE) thereof. In the laser annealing process, the non-uniformity of laser energy and the crystallization property of the polysilicon make the surface uniformity of the obtained polysilicon worse and coarser. The above information disclosed in the background section is only for enhancement of understanding of the background art from the technology described herein and, therefore, may contain some information that does not form the prior art that is already known in the country to a person of ordinary skill in the art. Disclosure of Invention The application mainly aims to provide a manufacturing method of a semiconductor device, the semiconductor device and a 3D NAND memory, and aims to solve the problem that in the prior art, a laser annealing process is adopted to convert an amorphous silicon layer into a polycrystalline silicon layer, and the uniformity and roughness of the obtained polycrystalline silicon layer are poor. In order to achieve the above object, according to one aspect of the present application, there is provided a method of manufacturing a semiconductor device including providing a memory array structure, forming an amorphous silicon thin film on a surface of the memory array structure, forming a capping layer on a surface of the amorphous silicon thin film remote from the memory array structure, and annealing the memory array structure formed with the capping layer so that the amorphous silicon thin film is converted into a polysilicon thin film. Optionally, annealing the memory array structure with the cover layer formed thereon to convert the amorphous silicon thin film into a polysilicon thin film includes annealing the amorphous silicon thin film with a laser through the cover layer to convert the amorphous silicon thin film into the polysilicon thin film. Optionally, the wavelength range of the laser is 300 nm-600 nm. Optionally, the thickness of the cover layer is greater than 40nm and less than 50nm. Optionally, after annealing the memory array structure formed with the capping layer such that the amorphous silicon film is converted to a polysilicon film, the method further includes removing the capping layer. Optionally, a memory array structure is provided, comprising a substrate, a stacked structure is formed on the exposed surface of the substrate, the stacked structure comprises a body structure and a channel hole in the body structure, the bottom of the channel hole penetrates into the substrate, the body structure comprises insulating medium layers and sacrificial layers which are alternately stacked, and at least the substrate is removed so that the bottom of the channel hole is exposed. Optionally, forming an amorphous silicon film on the surface of the memory array structure includes forming the amorphous silicon film on the surface of the memory array structure to cover the exposed bottom of the channel hole. Optionally, the material of the cover layer includes an oxide or nitride. According to another aspect of the present application, there is also provided a semiconductor device fabricated by any one of the methods. According to another aspect of the present application, there is also provided a 3D NAND memory including the semiconductor device. By applying the technical scheme of the application, the manufacturing method of the semiconductor device comprises the steps of firstly forming an amorphous silicon film on the surface of a storage array structure, then forming a covering layer on the surface of the amorphous silicon film far away from the storage array structure, and performing annealing treatment to convert the amorphous silicon film into a polycrystalline silicon film. According to the method, before the amorphous silicon film is annealed, a covering layer is formed on the surface of the amorphous silicon film, the covering layer can prevent energy injected into the amorphous silicon film in the annealing process from diffusing into air, so that the energy can be uniformly conducted in the amorphous silicon film in the direction away from the covering layer (namely from top to bottom), the covering layer can promote heat exchange between all positions on the surface of the amorphous silicon film, the temperature distribution of the surface of the amorphous silicon film is uniform, the amorphous silicon film is uniformly crystallized into the polycrystalline silicon film, and the obtained polycrystalline silicon film is uniform. Meanwhile, the crystal grains formed in the crystalliza