Out-of-the-box sapphire wafer cleaning process

Abstract

The invention discloses a sapphire wafer cleaning process that can be used out of the box. It includes first using a cleaning agent and ultrapure water to ultrasonically wash the sapphire wafer multiple times to remove dirt and fine particles on the wafer surface; and secondly brushing the wafer to remove dirt and fine particles. Large particles on the surface of the wafer; then spray emulsifier on the wafer to control the adsorption state of the wafer surface; then use organic solvent to spray the wafer to avoid secondary adsorption of pollutants; finally use a spin dryer to dry the wafer, then let it stand and bake Dry. The invention can obtain a higher finished product yield by directly using the wafer during PSS production after cleaning the sapphire wafer.

Description

technical field [0001] The invention relates to the technical field of sapphire processing, in particular to a sapphire wafer cleaning process that can be used out of the box. Background technique [0002] At present, sapphire has been widely used as the substrate material for making GaN-based LED chips on the market. However, due to the large lattice mismatch thermal expansion coefficient difference between nitride and sapphire, the nitride material grown on the substrate has dislocations and defects. The high density affects the luminous efficiency and life of the device. The patterned substrate (PSS) technology can effectively reduce the dislocations and defects of epitaxial materials, and is widely used in the preparation of nitride devices. [0003] In PSS production, if there is contamination or metal ions on the surface of the sapphire wafer, in the photolithography process, the impurities will cause uneven coating and poor wetting, resulting in unclear images, change...

AI Technical Summary

Problems solved by technology

[0002] At present, sapphire has been widely used as the substrate material for making GaN-based LED chips on the market. However, due to the large lattice mismatch thermal expansion coefficient difference between nitride and sapphire, the nitride material grown on the substrate has dislocations and defects. The density is high, which affects the luminous efficiency and life of the device. The patterned substrate (PSS) technology can effectively reduce the dislocations and defects of epitaxial materials, and is widely used in the preparation of nitride devices.

[0003] In PSS production, if there is contamination or metal ions on the surface of the sapphire wafer, in the photolithography process, the impurities will cause uneven coating and poor wetting, resulting in unclear images, changes in height and size, and greatly reducing the quality of the finished product. Therefore, before the wafer is put into PSS patterned substrate production, it is necessary to add a pre-cleaning operation, and the cleaning quality of the sapphire wafer is particularly important.

[0004] The inventor found through investigation and research that when the sapphire wafers cleaned by the traditional cleaning process are used in PSS production, the yield rate of the finished product is only 70% at the highest. In order to improve the yield rate, it may need to be cleaned again