Method for etching c-plane sapphire

Abstract

The invention discloses a method for etching c-plane sapphire. The method comprises the following steps: firstly immersing c-plane sapphire in a mixed solution consisting of hydrofluoric acid and water at 25 DEG C for 20 minutes, then taking out the c-plane sapphire, sequentially performing alcohol washing, supersonic washing and drying to obtain c-plane sapphire treated by hydrofluoric acid; then immersing the c-plane sapphire treated by the hydrofluoric acid in a mixed acid consisting of concentrated sulfuric acid and concentrated phosphoric acid for 20 minutes, naturally cooling, taking out the c-plane sapphire and sequentially performing alcohol washing, supersonic washing and drying to obtain c-plane sapphire treated by the mixed acid; and finally putting the c-plane sapphire treated by the mixed acid in a melting solution of flaky NaOH at the temperature of 325-340 DEG C for 10 minutes, taking out the c-plane sapphire and sequentially performing alcohol washing, supersonic washing and drying to finish the etching of the c-plane sapphire. The method for etching the c-plane sapphire disclosed by the invention has the advantages of good etching effect, good uniformity, good quality, high yield and the like.

Description

technical field [0001] The invention relates to a method for etching c-plane sapphire. Background technique [0002] The main component of sapphire is Al 2 o 3 , commonly known as corundum, is second only to diamond in hardness, belongs to the trigonal crystal system, and has a hexagonal structure. Especially c-plane sapphire, because it is the characteristic orientation of sapphire growth, has higher hardness and more stable performance than sapphire with other orientations, and it is more difficult to etch. However, c-plane sapphire is the main substrate material in the production of chips in the LED industry. [0003] Sapphire has good permeability to the blue light of GaN chips, high mechanical strength, stable chemical properties, resistance to various acids and alkalis at high temperatures, good thermal shock resistance, and high hardness. Radiation immunity and dielectric constant. [0004] The above characteristics of sapphire determine that it can be used in ...

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Problems solved by technology

[0005] At present, the main method is to reduce the grain boundary defects of c-plane sapphire to improve the quality of GaN thin films. Now the most used method is mechanical etching, but this method has some defects. On the one hand, due to the high hardness of c-plane sapphire, mechanical etching is difficult. presents new requirements, on the other hand, mechanical etching methods are aimless for reducing grain boundary defects

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