Amorphous silicon film controllable iso-epitaxial growth method

Abstract

The invention relates to an amorphous silicon film controllable iso-epitaxial growth method which is carried by using long-wave pulse laser technology. The method comprises the following steps: firstly, placing an amorphous silicon film with a monocrystal or polycrystal substrate prepared by chemical vapor deposition into a protective container with inert gas; then, using pulse laser with the wave length between 1.00 to 1.10 micrometers, and regulating the light spot size so that the pulse laser can generate a light spot with the size of 1*1 cm<2> in the positive defocusing amount direction to be used for heating the film for carrying crystallization annealing; and reaching the crystal grain size requirements of the film epitaxial growth through regulating the ratio of the pulse width to the heating time, i.e. the duty ratio under the condition of maintaining the output power unchanged. The invention controls the crystal grain growth in the film through regulating the pulse duty ratio. The method of the invention can be applied to the controllable epitaxial growth of the silicon, and can also be applied to the fast controllable epitaxial growth of materials such as ZnO and the like. The film growing by using the method of the invention can be used for solar energy industry, and can also be used for the manufacture of integrated circuits and electronic elements.

Description

technical field [0001] The invention relates to the modification technology of the amorphous silicon thin film material, in particular to a method for controlling the homogeneous epitaxial growth of the amorphous silicon thin film by using the long-wave pulse laser technology. Background technique [0002] Amorphous silicon is also known as amorphous silicon, and its atomic distribution does not have periodicity and long-term program. Therefore, the density of structural defects and dangling bonds in amorphous silicon materials is high. When carriers are transported in it, they are affected. These defects and the effect of dangling bonds have a higher recombination rate, which reduces the ability of amorphous silicon to transmit current. Solar cells made of amorphous silicon materials have many unfavorable physical changes such as photodegradation, Fermi level shifting to the center of the band gap, reduced carrier lifetime, reduced diffusion length, and increased defects. ...

AI Technical Summary

Problems solved by technology

However, at present, there are two main ways of heating the film by laser: 1) The short-wave pulse laser is absorbed by the amorphous silicon film, and the film itself generates heat to form a polycrystalline film. The crystal orientation is not easy to control and a large number of interface states will be formed on the interface with the substrate, which will affect the efficiency of the battery

2) The long-wave continuous laser passes through the film to heat the substrate, and then transfers the heat energy to the amorphous silicon film, so that the film undergoes epitaxial crystal growth, but the crystallization process is poorly controllable

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