Czochralski single crystal process and single crystal

Abstract

The invention discloses a Czochralski single crystal process and a single crystal; the Czochralski single crystal process is characterized in that in an ending stage, the power of a main heater is switched to a power value higher than that at the end of equal diameter, and the power value is maintained until ending is finished; the ending comprises a diameter control stage and a fixing stage, wherein in the diameter control stage, the diameter control value of the crystal is set to be equal to the diameter of the equal-diameter section of the crystal or the difference value between the diameter control value and the diameter of the equal-diameter section of the crystal is within + / - 3mm; the growth rate of the crystal is gradually reduced from a first growth rate value at the end of equal diameter to a second growth rate value at the end of the diameter control stage, and the crystal generated at the diameter control stage is a first stage of the ending stage; For the single crystal prepared by the Czochralski single crystal process, the diameter of the first section of the ending section meets the diameter requirement of the qualified crystal, and the first section and the equal-diameter section can be used as the qualified crystal, so that the utilization rate of raw materials is greatly improved, and the production cost is greatly reduced.

Description

technical field [0001] The invention relates to the technical field of Czochralski single crystal, in particular to a Czochralski single crystal process and a single crystal crystal. Background technique [0002] With the rapid development of technology and equipment in the photovoltaic industry, commissioning production capacity and improving raw material utilization have become important tasks for the industry. [0003] Czochralski single crystal includes temperature stabilization, seeding, shoulder expansion, shoulder rotation, equal diameter, and finishing process. Finishing is the last step before the completion of single crystal growth. Excessive stress generates more crystal dislocations (dislocation single crystal is a substandard product, which is a crystal defect). In the traditional Czochralski single crystal process, after the isodiametric process is completed, it enters the finishing process. During the entire finishing process, from the beginning of the finish...

AI Technical Summary

Problems solved by technology

In the traditional Czochralski single crystal process, after the isodiametric process is completed, it enters the finishing process. During the entire finishing process, from the beginning of the finishing process to the end of the finishing process, the heater power is gradually increased from the value at the end of the isodiametric process to a certain value. As the temperature increases, the diameter of the crystal gradually becomes thinner, and the end of the crystal is in the shape of an inverted cone as a whole (such as figure 1 As shown in middle B), relative to the equal-diameter section A of the crystal, the ending section of the inverted conical shape does not meet the requirements for the diameter of a qualified single crystal crystal, so the ending section B can only be cut off completely and cannot be regarded as a qualified crystal together with the equal-diameter section use, so that the waste of raw materials is serious and the production cost is high

Images