Improved patterned sapphire substrate developing method

Abstract

The invention discloses an improved patterned sapphire substrate developing method. The improved patterned sapphire substrate developing method is characterized by including the steps of adding at least two milliliters of developing solution, developing for 5-10 seconds while rotating a sapphire substrate at a speed of 30-60 revolutions / minute, rotating the sapphire substrate at a speed of 1500-3000 revolutions / minute after developing, throwing off the residual developing solution on the sapphire substrate, decreasing the rotating speed of the sapphire substrate to 30-60 revolutions / minute prior to cleaning for 5-10 seconds by deionized water, rotating the sapphire substrate at the speed of 1500-3000 revolutions / minute, and throwing off impurities, residual developing solution and the deionized water; adding at least two milliliters of developing solution again, and repeating the steps for two or four times. The improved patterned sapphire substrate developing method is more complete in developing and solves the problem of PSS (patterned sapphire substrate) pattern irregularity during developing in the prior art.

Description

technical field [0001] The invention relates to the field of LED chip manufacturing, in particular to an improved developing technology for patterned substrates. Background technique [0002] Patterned substrate technology is usually called PSS, which is the abbreviation of Patterned Sapphire Substrate. Usually, patterns such as triangular pyramids or triangular prisms are produced on the sapphire flat substrate by etching. On the one hand, when the GaN material is grown on the PSS substrate, its vertical epitaxy becomes lateral epitaxy, and as a result, the dislocation density of the GaN epitaxial material can be effectively reduced, thereby reducing the non-radiative recombination of the active region and reducing the reverse leakage. On the other hand, the light emitted by the active area is scattered multiple times by the interface between GaN and sapphire substrate, which changes the exit angle of total reflection light, increases the probability of light exit, and imp...

AI Technical Summary

Problems solved by technology

That is to say, the entire PSS graphic should be able to change the exit angle of the total reflection light everywhere, but now only the upper part of the conical figure can change the exit angle of the total reflection light, which reduces the reflection effect of the PSS and the light extraction efficiency.

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