Photovoltaic cell surface passivation system and passivation method

Abstract

The invention discloses a photovoltaic cell surface passivation system and a passivation method. The photovoltaic cell surface passivation system at least comprises a multifunctional PECVD device, anannealing furnace and a PEALD device, wherein the annealing furnace is located after the multifunctional PECVD process; the process chambers of the annealing furnace and the multifunctional PECVD device are matched with the same corresponding graphite boat; the graphite boat carries a silicon wafer which is integrally transferred between the annealing furnace and the multifunctional PECVD device;the multifunctional PECVD device plates the back surface of the silicon wafer with a silicon oxide film and an amorphous silicon layer and performs in-situ doping on the amorphous silicon layer, the corresponding reaction temperature is 400 to 600 DEG C, the annealing furnace heats the plated silicon wafer to more than 600 DEG C, the amorphous silicon layer is converted to a polysilicon layer andthe temperature falls to 400 to 600 DEG C; and the PECVD device plates the front surface of the silicon wafer with an aluminum oxide film and a silicon nitride film. The overall structure of the device and the existing process steps are simplified, cleaning and etching processes are saved, adverse effect on front surface plating of the silicon wafer are reduced, the operation is more convenient, and the production efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of solar cell passivation, in particular to a photovoltaic cell surface passivation system and a passivation method involving an ultra-thin tunnelable oxide layer and a highly doped polysilicon thin layer. Background technique [0002] Solar photovoltaic cell is a new type of battery that directly converts the sun's light energy into electrical energy. Silicon photovoltaic cells based on silicon are commonly used at present, including monocrystalline silicon, polycrystalline silicon and amorphous silicon photovoltaic cells. At present, relatively mature passivation film materials for photovoltaic cells include aluminum oxide (Al 2 o 3 ), silicon oxide (SiO 2 ), silicon oxynitride (SiO x N y ), silicon nitride (Si x N y )Wait. TOPCon (Tunnel Oxide Passivated Contact), as a new passivation technology, is mostly used in N-type crystalline silicon solar cells, which is characterized by plating silicon ox...

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Problems solved by technology

[0006] In view of the shortcomings of the existing TOPCon battery surface passivation technology, such as cumbersome procedures, time-consuming and laborious, high production costs, low production efficiency, and high risk of unfinished products, the applicant provides a photovoltaic battery surface passivation system with reasonable structure and passivation technology. For the back of the silicon wafer, the multifunctional PECVD + annealing furnace heating and cooling process that deposits multiple films in the same chamber can be used to replace the existing LPCVD + cleaning and etching process to achieve separate deposition on the back of the silicon wafer; for the front of the silicon wafer The PEALD equipment can successively realize the coating process of depositing aluminum oxide, silicon oxide, silicon oxynitride, silicon nitride film or some of them, simplify the overall structure of the equipment and the existing process steps, save the cleaning and etching process, and reduce the impact on the The adverse effect of the front coating of the silicon wafer makes the operation more convenient, improves the production efficiency and reduces the production cost

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