Doping gas inflating device for producing gas phase doping region molten silicon single crystals

Abstract

The invention discloses a doping gas inflating device for producing gas phase doping region molten silicon single crystals. The device is characterized in that a quartz air guide pipe is fixed on a coil through a fixing device; the quartz air guide pipe is in a conical shape; the small diameter end is an air outlet; the air outlet is pointed at the center of the melting region; the big diameter end is connected with a gas conveying pipe; the cross section of the air outlet is 2mm<2>; the distance from the position of the air outlet to the center point of a coil is 23mm. By using the design, the influence of airflow generated by heat convection in the furnace on the gas of doping agent can be reduced; the air outlet is very near the melting region and is positioned in the middle part, so that phosphorus atoms generated through phosphorene decomposition can directly enter the melting region; the doping efficiency and the electrical resistivity control accuracy are improved; the electrical resistivity control precision is high; the electrical resistivity axial stability is high. Meanwhile, the environment pollution caused by tail gas is avoided. The manufacturing price is low; the useis simple; the device can be flexibly applied to drawing of 0.01 Ohm.CM to 120 Ohm.CM region melt silicon single crystals.

Description

technical field [0001] The invention relates to a technology for growing a single crystal of molten silicon in a gas-phase doped region, in particular to a doping gas filling device for producing a single crystal of molten silicon in a gas-phase doped region. Background technique [0002] Zone-melting silicon single crystal is an important substrate material for the preparation of various power electronic devices. With the development of various power electronic devices towards high voltage and high power, people's requirements for the quality of zone-melting silicon single crystal are also getting higher and higher. , not only requires the zone melting silicon single crystal to have the characteristics of high purity and large size, but also requires good resistivity uniformity and high minority carrier life in the zone melting silicon single crystal. [0003] The traditional method for controlling the resistivity of N-type zone fused silicon single crystal is the neutron t...

AI Technical Summary

Problems solved by technology

[0005] In the traditional gas phase doping method, the dopant gas outlet is set in the furnace, and the doping is performed by controlling the concentration of the dopant in the atmosphere in the furnace. The use efficiency of the dopant is low, and the resistivity is difficult to control accurately. Accumulated in the furnace, the axial resistivity of the single crystal will also change

In addition, since most of the dopants flow out directly through the exhaust port, the cost of exhaust gas treatment is increased

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