Method for growing sapphire crystal by kyropoulos method

Abstract

The invention provides a method for growing sapphire crystal by a kyropoulos method. The method comprises the following stages: charging of materials, heating for melting the materials, crystal drawing, shoulder-expanding growth, equal-diameter growth, closing growth, lifting separation and cooling. In the process of shoulder-expanding growth, the shoulder-expanding growth speed is not more than 5%-10% of the weight of the crystal, the lifting speed is 0.1-1mm / h, when the weight of the crystal is 500g-1000g, seed crystal rods are lifted up instantaneously by 2mm, and when the weight of the crystal is 1200g-1800g, the seed crystal rods are lifted instantaneously by 2mm; in the closing growth stage, after the weight of the crystal is 70%-80% of the target weight, a weight curve of the crystal becomes a wavy line, and the crystal grows for H hours continuously, and then enters the stage of lifting separation. The method provided by the invention has the beneficial effects that by adoptionof the shoulder-expanding growth process with instantaneous lifting and the closing growth process without bottom lifting, the formation and the enlargement of shoulder-part conical bubbles and bottom-part steamed-bun-shaped bubbles of the crystal are effectively relieved, the applicability to growth of large-size sapphire is achieved, and the growth quality of the sapphire crystal is improved; in addition, the shoulder-expanding process with instantaneous lifting is conductive to round growth of the crystal, cuts off a crystal boundary on the surface of the crystal, and is beneficial to improving the quality of the crystal.

Description

technical field [0001] The invention relates to the technical field of crystal growth, in particular to a method for growing sapphire crystals by a Kyropoulos method. Background technique [0002] Sapphire has the characteristics of high melting point (2045°C), good thermal conductivity, high hardness, good electrical insulation, strong acid and alkali corrosion resistance, and wide light transmission band. It is widely used in civilian equipment such as mobile phone screens and mirrors, and is also used in missiles. Fairing, helicopter shaft and other military enterprises. There are many methods for growing sapphire crystals. Currently, the method commonly used in the industry is mainly the Kyropoulos method. This method grows crystals with fewer defects and low dislocation density, making it the mainstream growth method in the sapphire crystal industry. [0003] The common Kyropoulos method is mainly A-directed crystal growth, and its process mainly includes charging, hea...

AI Technical Summary

Problems solved by technology

[0005] This application provides a method for growing sapphire crystals by the Kyropoulos method to solve the problem of conical bubbles under the head of the crystal and the shoulder surface and bun-shaped bubbles at the bottom of the crystal when the existing Kyropoulos method is used to grow large-sized sapphire crystals. Increased, degraded sapphire crystal quality issues

Images