Method for preparing pyramidal patterned substrate through twice corrosion

Abstract

The invention provides a method for preparing a pyramidal patterned substrate through twice corrosion, which comprises the following steps of: 1. depositing a silicon dioxide layer or a silicon nitride layer on a sapphire substrate and forming mask patterns by using a photoetching method; 2. placing the substrate with silicon dioxide or silicon nitride masks into a heated mixed solution of sulphuric acid and phosphoric acid mixed solution to carry out primary corrosion, removing the silicon dioxide or silicon nitride mask layer on the substrate and cleaning with pure water; and 3. placing thesubstrate subjected to the primary corrosion into the mixed solution for secondary corrosion, taking out the substrate and cleaning the substrate with the pure water to obtain the sapphire pyramidal patterned substrate. In the invention, by preparing the pyramidal patterned substrate through twice corrosion, the problem that an epitaxial layer cannot evenly grow on the truncated cone-shaped patterned substrate and has poor crystal quality is solved, and meanwhile, the light emergent area is also increased.

Description

technical field [0001] The invention relates to a method for preparing a tapered pattern substrate through two times of etching, which belongs to the field of optoelectronic technology. Background technique [0002] For the production of LED chips, the selection of substrate materials is the primary consideration. Which kind of suitable substrate should be used needs to be selected according to the requirements of equipment and LED devices. At present, there are generally three materials on the market that can be used as substrates: sapphire, Si, and SiC. Typically, epitaxial layers of GaN-based materials and devices are mainly grown on sapphire substrates. Sapphire substrates have many advantages: First, the production technology of sapphire substrates is mature and the device quality is good; second, sapphire has good stability and can be used in high temperature growth process; finally, sapphire has high mechanical strength and is easy to handle and cleaning. Therefor...

AI Technical Summary

Problems solved by technology

The above-mentioned patent documents use a mixed acid etching solution of sulfuric acid and phosphoric acid, and the pattern of corrosion is not easy to control. The corrosion rate of sulfuric acid is fast and difficult to control, and there is a platform on the surface of the pattern, and there is a three-dimensional growth in the epitaxial growth. The surface of the epitaxial wafer Not easy to grow flat

Images