Polysilicon silicon chip double-diffusion manufacturing method

Abstract

The invention discloses a method for manufacturing a PN-node by carrying out double diffusion on a polysilicon silicon chip. The method comprises a step S1 of constant-source diffusion, a step S2 of heating limited-source diffusion and a step S3 of constant-source diffusion. In the invention, due to the step S3 of constant-source diffusion, the deposition of a phosphorus impurity on the surface of the polysilicon silicon chip is increased. Therefore, in the step S1, the phosphorus impurity which is deposited in one step can be correspondingly reduced, so that the excessive deposition of the phosphorus impurity is avoided. Moreover, the step S3 is carried out at a high temperature, and at the time, the solid solubility of polysilicon on phosphorus atoms is improved, the deposited phosphorus impurity does not need to be propelled, the dissolved amount of the phosphorus impurity in polysilicon is controlled by controlling the deposition of the phosphorus impurity, and a dead zone generated due to excessive deposition and secondary propelling is avoided. According to the method for manufacturing the PN-node by carrying out the double diffusion on the polysilicon silicon chip, which is provided by the invention, the aim of solving the problem of a dead layer on the surface, which is generated after the PN-node is manufactured by the polysilicon silicon chip, can be fulfilled.

Description

technical field [0001] The invention relates to the technical field of solar cell modules, in particular to a method for manufacturing polycrystalline silicon wafers with double diffusion. Background technique [0002] With the continuous deterioration of the environment and the increasing shortage of energy, strengthening environmental protection and developing clean energy has become a matter of great concern to all countries in the world. As an important photoelectric energy conversion device, the research of solar cells has attracted people's attention. In recent years, with the development and utilization of new technologies, new processes and new structures of solar cells, the photovoltaic industry has developed rapidly. For the polysilicon solar cell industry, reducing the cost of solar cells and improving the conversion efficiency of solar cells have become the two main goals of industry development and competition. From a technical point of view, improving and opt...

AI Technical Summary

Problems solved by technology

Although the impurity phosphorus on the surface of polysilicon can be pushed into the polysilicon, there is still a certain amount of phosphorus atoms deposited on the surface of polysilicon, resulting in a high concentration of impurities on the surface of the diffused silicon, thus forming a certain thickness of "dead layer" that is not easy to conduct electricity.

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