Preparation method and application method of passivation contact structure

Abstract

The invention discloses a preparation method and an application method of a passivation contact structure. The preparation method comprises the following steps: carrying out microstructure morphology treatment on the silicon substrate; preparing a tunneling oxide layer; loading the silicon substrate by using a first carrier plate with a hollow middle, and depositing a first doped amorphous silicon layer on the surface of the tunneling oxide layer in an upward deposition manner by adopting a PVD (Physical Vapor Deposition) method; loading and covering the local surface of the first doped amorphous silicon layer by using a patterned hollow second carrier plate, and selectively depositing a second doped amorphous silicon layer on the surface of the first doped amorphous silicon layer in an upward deposition manner by adopting a PVD (Physical Vapor Deposition) method; after high-temperature treatment, forming a first doped region in the region where only the first doped amorphous silicon layer is deposited, and forming a second doped region in the region where the first doped amorphous silicon layer and the second doped amorphous silicon layer are deposited; furthermore, the polycrystalline silicon passivation contact structure with selective thickness and doping concentration is prepared, and the preparation method enables the preparation of the passivation contact structure to be more convenient, more accurate and more efficient.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to a preparation method and an application method of a passivation contact structure. Background technique [0002] The TOPCon battery structure is a new type of high-efficiency passivation contact battery structure. Its core structure is a film structure of 1-2nm tunneling silicon oxide superimposed with a certain thickness of heavy phosphorus or boron atom-doped polysilicon. Among them, both the front and back of the double-sided TOPCon battery are printed with fine-grid patterned electrodes, and the back electrodes are generally realized by printing paste and sintering at high temperature. However, when the paste is sintered at high temperature, it will burn through the common passivation layer (such as silicon nitride film) on the surface of the cell and damage the heavily doped polysilicon layer. When the heavily doped polysilicon is thin, the paste will burn through the po...

AI Technical Summary

Problems solved by technology

The disadvantages of this method are: 1. The steps are complicated, and wet etching steps need to be added at the same time as printing masks; 2. By chemical etching, the doping concentration of polysilicon in the electrode area to be printed and the electrode area not to be printed are the same, Differentiation of doping concentration cannot be achieved by this method

The shortcoming of this method is: 1. When the in-situ doped amorphous silicon film is prepared by the PECVD method, the increase of the thickness of the amorphous silicon film will easily lead to the bursting film effect, and then cause its passivation performance to deteriorate sharply, and the film bursting place Polysilicon is easy to fall off, that is, the PECVD method is not suitable for depositing thicker amorphous silicon; 2. It is necessary to add a mask and fix the mask to the corresponding position of the cell, and the process is cumbersome; 3. When using a mask When the stencil covers the amorphous silicon film and deposits amorphous silicon again, when the mask plate is not tightly attached to the cell, the deposition range of the secondary deposited amorphous silicon by the PECVD method will be significantly larger than the hollowed out area. The accuracy is poor; 4. The preparation of in-situ doped amorphous silicon by PECVD method cannot avoid the generation of amorphous silicon film wrapping, and an additional dewound plating process is required

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