Process method for depositing and doping surface of silicon wafer

Abstract

The invention provides a process method for carrying out deposition doping on a silicon surface. The process method comprises a cavity capable of accommodating a silicon wafer and allowing silicon tobe subjected to surface deposition doping reaction in the cavity, gas used for deposition doping and/or facilitating deposition doping can be introduced into the cavity. The chamber can be sealed, gascan be introduced into or released from the chamber, temperature control or pressure regulation can be carried out in the chamber, and different or the same gas is introduced into the chamber at intervals in turn in the deposition doping reaction process by the process method in the chamber. According to the process method, the doping concentration is improved, and the uniform distribution of thedoping source is improved.

Description

technical field [0001] The invention relates to the fields of solar photovoltaic and semiconductor manufacturing, and is especially suitable for deposition and doping processes therein. Background technique [0002] In the fields of solar photovoltaic and semiconductor manufacturing, diffusion equipment is mainly used for processes such as boron doping or phosphorus doping, and low-pressure chemical vapor deposition (LPCVD) equipment is often used for silicon oxide, silicon nitride, amorphous silicon, polysilicon, phosphorus-doped amorphous Thin films such as crystalline silicon and boron-doped amorphous silicon are grown; after the temperature and pressure of these conventional diffusion equipment reach the process conditions, the doping source gas, carrier gas, and reaction gas enter the furnace together to participate in the reaction. [0003] In the conventional LPCVD doping process, silane is used as the gas for growing silicon, and phosphine, diborane, etc. are used as...

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Problems solved by technology

[0004] It is generally understood that in order to make the reaction more uniform or to make the reaction results such as film thickness and uniformity better, the gas will be mixed as uniformly as possible to achieve the above purpose, but the mixed gas is used for the reaction On the contrary, it will lead to poorer uniformity. The reasons are mainly the following two aspects. First, silane and dopant source gas enter the furnace body at the same time, and the gas concentration in each part is different, that is, the two gases react less near the outlet of the furnace. Intensive, and, due to the different decomposition rates of the blocked gas, during the operation of the gas in the furnace tube, due to the difference in the decomposition rate, the decomposition in the mixed gas is relatively fast and easily consumed in the first half, and in the second half. If the amount is reduced and the decomposition is relatively slow, the reaction is mainly carried out in the second half. This method will cause the problem of uneven film thickness and uneven concentration. In the prior art, the method of supplementing gas is usually used to solve this problem, but In fact, qi supplementation cannot fundamentally solve the above problems

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