Reaction unit and method for atom layer film deposition

Abstract

The invention provides a reaction unit and a method for atom layer film deposition, and belongs to the technical field of manufacturing, assembly and processing of solar cells. The reaction unit comprises a reaction deposition chamber, a reaction emptying chamber and a vacuum system connected in sequence, wherein a silicon wafer bearing unit, a heating unit, a precursor feeding unit and a blowing gas charging unit are arranged inside the reaction deposition chamber. According to the method disclosed by the invention, at least two gaseous precursors are fed into a reactor in a pulse alternation manner and chemically adsorbed on a depositing base body for reaction so as to form a deposited film. The reaction unit and the method disclosed by the invention have the advantages of effectively remedying the defects that in the existing reaction unit, the productivity is low, the gaseous reactant precursors are distributed on the surface of the silicon wafer unevenly, temperature gradient exists on the surface of the silicon wafer and the gaseous reactant precursors cannot be discharged completely and the like, greatly improving the productivity and the depositing speed of the silicon wafer of an atom layer film depositing device and effectively improving the deposition quality of the atom layer film.

Description

technical field [0001] The invention belongs to the technical field of solar cell manufacturing, assembly and processing, and in particular relates to a reaction device and method for atomic layer film deposition. Background technique [0002] As the solar cell process technology continues to advance, the requirements for the thickness uniformity and quality of the thin film process are increasing day by day. The traditional CVD deposition technology has been difficult to effectively control the film characteristics and meet the increasingly stringent technical requirements. Atomic Layer Deposition (ALD) was originally called Atomic Layer Epitaxy (ALE). It is called atomic layer chemical vapor deposition (Atomic Layer Chemical Vapor Deposition, ALCVD), which uses the gas-solid phase reaction between the reaction gas and the substrate to complete the process requirements. Because it can complete the process with high precision, it is regarded as One of the key links in the d...

AI Technical Summary

Problems solved by technology

However, this device has the following defects: (1) the silicon wafer carrying unit can only carry one silicon wafer at a time, the silicon wafers for depositing thin films have low productivity and high equipment cost; (2) the gaseous reaction precursor is vertically sprayed on the center of the silicon wafer surface, and the Diffusion from the center of the silicon wafer to the surroundings leads to low utilization of gaseous reaction precursors; (3) gaseous reaction precursors and reaction by-products are likely to remain at the bottom of the silicon wafer carrying unit, which is difficult to empty, resulting in the formation of gas field vortex areas, gas field vortex areas The gaseous reaction precursors and reaction by-products in the interior are difficult to evacuate, and the residues adhere to the surface of the silicon wafer, resulting in a decrease in the quality of atomic layer film deposition

However, this device has the following defects: (1) increasing the number of silicon wafer carrying units increases the production capacity of silicon wafers, resulting in a complex structure of the reaction chamber, high processing and maintenance costs, and a limited increase in the number of silicon wafers; The remaining gaseous reaction precursors between the unit and the silicon wafer are difficult to empty, and the residue adheres to the surface of the silicon wafer, resulting in a decrease in the deposition quality of the atomic layer film; (3) the uneven distribution of the heating units in the reaction chamber makes the inner wall of the reaction chamber There is a temperature gradient on the surface, so that there is a temperature gradient on the surface of the silicon wafer, resulting in uneven thickness of the atomic layer film on the surface of the silicon wafer; (4) The path from the gaseous reaction precursor to the surface of the silicon wafer is L-shaped, which can only be reached after a right-angle turn Wafer surface, therefore, the kinetic energy of the gaseous reactive precursors to reach the wafer surface is not strong

[0006] To sum up, those skilled in the art need to develop a new reaction device for atomic layer film deposition to solve the problem of low productivity of silicon wafers and temperature gradients on the surface of silicon wafers in existing reaction devices. Problems such as uneven distribution on the surface of the sheet, slow deposition rate, and inability to evacuate gaseous reaction precursors

Images