Aluminum-induced low temperature preparation method of large grain size polysilicon film

Abstract

The invention discloses an aluminum-induced low temperature preparation method of large grain size polysilicon film; the grain size of the prepared polysilicon film reaches above 100 microns and the polysilicon film has smooth surface. The method comprises the following steps: (1) depositing amorphous silicon film on a substrate 2; (2) continuously generating silicon dioxide film; (3) continuously depositing aluminum film to obtain substrate / a-Si / SiO2 / Al lamination; (4) placing the substrate / a-Si / SiO2 / Al lamination in a vacuum annealing furnace to perform three-step annealing under the protection of inert atmosphere; (5) using aluminum corrosive liquid to corrode and remove the residual aluminum on the surface. The method of the invention can prepare polysilicon film with large grain sizeon the cheap substrate at low temperature and the crystallization orientation and surface roughness are controllable, thus the method has broad application prospect in fields such as film solar cellsand the like.

Description

Method for preparing large-grain polysilicon film at low temperature induced by aluminum technical field The invention relates to a method for preparing a large-grain polysilicon film, in particular to a method for rapidly preparing a large-grain polysilicon film with a grain size of 100 microns at low temperature by an aluminum induction method. Background technique Polysilicon is widely used in electronic devices, such as thin film transistors, solar cells, image sensors, etc. Solar cells made of polysilicon thin films have stable performance and low price, and have great application potential. The traditional method of preparing polysilicon film is to directly deposit it on the substrate by low-pressure chemical vapor deposition (LPCVD) and plasma-enhanced chemical reaction vapor deposition (PECVD). Directly deposited polycrystalline silicon has small grains, many defects, and poor electrical properties. The polysilicon formed by the recrystallization of amorphous sil...

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Problems solved by technology

The method of nickel induction can also be used to prepare large-grained polysilicon films with grains up to 100 microns. However, during the preparation process, nickel particles with a very low surface concentration must be prepared on the surface of amorphous silicon. The control process is complicated, the repeatability is poor, and it takes a long time time annealing

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