Preparation process of P-type low-dislocation germanium single crystal

Abstract

The invention belongs to the technical field of single crystal growth, and discloses a preparation process of a P-type low-dislocation germanium single crystal, and the preparation process specifically comprises the following steps: raw material acid corrosion, thin neck leading, shoulder enlarging, shoulder rotating, equal-diameter growth, ending annealing and cooling, according to the process, the temperature is kept constant in the shoulder enlarging stage, and the crystal growth speed is linearly reduced in two stages, the growth speed is reduced from 2.0 mm / min to 2.5 mm / min to 0.5 mm / min to 1.0 mm / min; in the second stage, the growth speed is reduced from 0.5 mm / min to 1.0 mm / min to 0.2 mm / min to 0.25 mm / min within 5 h to 5.5 h. According to the method, the shouldering process is improved on the basis of the original CZ process, the P-type germanium single crystal with low dislocation density can be grown, and a solid foundation is laid for realizing the zero-dislocation and low-defect solar-grade P-type germanium single crystal in the future.

Description

technical field [0001] The invention belongs to the technical field of single crystal growth, and more specifically relates to a P-type low dislocation germanium single crystal preparation process. Background technique [0002] Germanium single crystals were originally used as raw materials for semiconductors. Since the late 1970s, germanium single crystals have been replaced by cheaper silicon single crystals. However, due to the higher electron mobility of germanium and higher frequency of germanium devices than silicon, the strength is better than silicon. , so germanium materials still occupy a dominant position in the fields of high frequency, far infrared and aviation and aerospace. In addition, the application of germanium in military thermal imagers, night vision devices and radiation detectors is also developing rapidly. With the development of modern technology, germanium is widely used in optical fibers, solar cells, phosphors, medicines and catalysts. With the ...

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Problems solved by technology

[0004] The Chinese patent with the application number CN200710099557.5 discloses a process and device for growing low-dislocation germanium single crystals by the Czochralski method. Above) low dislocation germanium single crystal, can not effectively control the surface oxide scum, so the dislocation density is high

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