Doping device for improving radial resistivity distribution of float-zone single silicon crystals

Abstract

The invention creatively provides a doping device for improving the radial resistivity distribution of float-zone single silicon crystals. The doping device comprises a main annular pipe and a doped gas annular pipe nested in a pipe cavity of the main annular pipe; mutually independent air inlets are arranged on the main annular pipe and the doped gas annular pipe respectively; a plurality of main gas outlets are formed in the main annular pipe in a circumferential direction; a plurality of doped gas outlets are arranged on the doped gas annular pipe in the circumferential direction; and the main gas outlets and the doped gas outlets are distributed in a staggering manner. The doping device created by the invention can effectively improve the uniformity and the stability of a concentration of the doped gas in a furnace body and ensures the radial resistivity distribution of the grown float-zone single silicon crystals to be more uniform.

Description

technical field [0001] The invention belongs to the technical field of zone-melting silicon single crystal production, and in particular relates to a doping device for improving radial resistivity distribution of zone-melting silicon single crystal. Background technique [0002] Silicon single crystal is an important semiconductor material, which is generally used to manufacture integrated circuits and other electronic components. Silicon single crystal grown by zone melting method has the advantages of high purity and less defects, so it is used in high-end power electronic devices . During the preparation process of zone melting silicon single crystal, high-purity polysilicon raw materials can be made into doped silicon single crystal with certain electrical properties by doping a certain amount of electroactive impurities. One of the means is that in foreign markets, except for high-voltage, high-current power and electronic devices that use single crystals, separation d...

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Problems solved by technology

During the preparation process of zone melting silicon single crystal, high-purity polysilicon raw materials can be made into doped silicon single crystal with certain electrical properties by doping a certain amount of electroactive impurities. One of the means is that in foreign markets, except for high-voltage, high-current power and electronic devices that use single crystals, separation devices including rectifier module devices use gas-phase doped single crystals, but at present, gas-phase doped single crystals are uniformly doped There are still problems in terms of stability and consistency, resulting in non-uniform radial resistivity distribution of zone-melted silicon single crystals

[0003] Conventional doping pipelines known in the prior art use zone melting main argon and gas-doped dopant gas to enter the furnace cavity from different pipelines. Since the main argon flow rate is significantly greater than the dopant gas flow rate, the dopant gas passes through the diffuse way The furnace cavity is full, which leads to the fluctuation of the doping concentration in the furnace body, and the main argon gas is blown in from the argon hole on the side of the furnace body, which will cause forced convection in the furnace body, and further cause large fluctuations in the doping concentration in the furnace body. The concentration of dopant gas on the surface of the melt is uneven, which in turn affects the uniformity of dopant gas blending into the melt, and finally leads to uneven radial resistivity distribution of zone-melted silicon single crystal

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