Annealing and crucible releasing method after crystal growth and crystal preparation method

Abstract

The invention discloses an annealing and crucible releasing method after crystal growth and a crystal preparation method. The annealing and crucible releasing method comprises an annealing step and acrucible releasing step after the annealing step; specifically, the annealing step comprises the following stages: a first stage which is a temperature rise stage: wherein raising the temperature to be higher than the melting point of a covering agent and lower than the dissociation temperature of a crystal surface; a second stage which is a constant temperature stage: wherein maintaining the temperature to be constant for 3 to 7h; a third stage, wherein regulating the inclination angle of a crystal growth furnace, and keeping the longitudinal rotation angle of the crystal growth furnace to be95 to 150 degrees, and maintaining the temperature to be constant for 1-4 hours; a fourth stage which is a cooling stage: wherein reducing the temperature gradually to room temperature; and the crucible releasing step specifically comprises the following steps: taking out a crucible from a quartz ampoule bottle, and carrying out ultrasonic water bath at 40-80 DEG C for 1-4 hours. According to theinvention, crystal preparation procedures can be reduced, damage to the crucible in the crucible releasing process is reduced, the quality of the single crystal is ensured, and the cost is saved.

Description

technical field [0001] The invention relates to the technical field of crystal preparation, in particular to an annealing and depotting method after crystal growth and a crystal preparation method. Background technique [0002] Indium phosphide InP is one of the strategically important semiconductor materials, and has important applications in the fields of optical communication, millimeter wave high frequency, low noise, and broadband microelectronic integration. [0003] At present, the growth methods of indium phosphide single crystal are mainly VGF method (vertical gradient solidification method) and VB method (vertical Bridgman method). The VGF method for crystal growth has the advantages of good repeatability, large-diameter crystal growth, and low dislocation density defects, so it is widely used. [0004] Generally, when using the VGF method, a high-quality, high-purity pyrolytic boron nitride crucible (PBN crucible) is required for crystal growth. The PBN crucible ...

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Problems solved by technology

[0005] As can be seen from the above, in the traditional crucible removal process, since the boron oxide between the conical part of the crystal and the crucible is very thin, the contact surface between boron oxide and water in the conical part of the crystal is relatively small, and this part is difficult to dissolve in water. As a result, it is difficult to remove the conical part of the crystal from the pot, and when the crystal is separated from the PBN crucible, it will cause serious damage to the inner wall of the crucible. Therefore, the usual PBN crucible needs to be replaced after about 2-3 times of use, and the inner wall of the crucible is scratched. twinning

In addition, the annealing process often takes dozens of hours, which lasts for a long time, and the taken out crystal rod needs to be reloaded into the quartz tube, which may cause contamination of the crystal slice and ultimately affect the quality of the crystal

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