A Pretreatment Process for Improving the Quality of Polysilicon Thin Film

Abstract

The invention relates to a pretreatment technology for improving the quality of a polycrystalline silicon film. The pretreatment technology is characterized in that the content of hydrogen in noncrystalline silicon is controlled effectively by controlling the annealing temperature and the annealing time before aluminum-induced crystallization (AIC), and the noncrystalline silicon film is annealed in nitrogen or argon shield gas. The annealing temperature is 350-500 DEG C and the annealing time is 0.1-5h. After the noncrystalline silicon film is subjected to annealing treatment at different temperature, the content of hydrogen in the film is reduced to 1.4% from 10%, so that the polycrystalline silicon film prepared via aluminum induction is dry, smooth and complete in surface. According to the pretreatment technology, the high-quality polycrystalline silicon film can be prepared at lower temperature and in shorter time. Compared with the traditional AIC polycrystalline silicon preparation method, an annealing and dehydrogenation step is added before the AIC, so that the content of hydrogen in a precursor a-Si:H can be controlled effectively, and the polycrystalline silicon film with larger grain size, smaller stress and smoother and more complete surface can be prepared.

Description

technical field [0001] The invention relates to a method for preparing a polysilicon film, more specifically to a pretreatment process for inducing crystallization of amorphous silicon by using aluminum to improve the quality of the polysilicon film, and belongs to the field of polysilicon film preparation. Background technique [0002] Polycrystalline silicon (Poly-Si) thin film has high carrier mobility, light absorption rate and stable photoelectric performance, so it is widely used in solar cells, thin film transistors, liquid crystal displays and image sensors. At present, the methods for preparing polysilicon thin films mainly include chemical vapor deposition, solid phase crystallization, laser crystallization and metal-induced crystallization. [0003] Among them, ① chemical vapor deposition method requires high temperature to obtain polysilicon film, and the obtained polysilicon grain size is very small, only nm level; representative literature reports include "Liu ...

AI Technical Summary

Problems solved by technology

[0005] ③The laser crystallization method is fast, but the equipment is complicated and the cost is high; the representative literature report has "C.T.Angelis, C.A.Dimitriadis, F.V.Farmakis, et al., Solid-StateElec., 44 (6) (2000) 1081- 1087."

[0006] ④Metal-induced crystallization method, for Ni, Cu, Pt and other metals used for metal-induced crystallization of amorphous silicon thin films, it is easy to generate deep energy levels in Si and form recombination centers, which will affect the electrical properties of polycrystalline silicon thin film batteries; And these metals are easy to form silicide with Si, which is not conducive to the smooth progress of induced crystallization

Images