A kind of LED surface roughening process

Abstract

An LED GaN epitaxial wafer surface roughening process comprises the following steps: (1) ICP etching is performed on the surface of a GaN epitaxial wafer, the power of the ICP is 150-200W, the direct-current self-bias voltage is 100V, etching is performed by the use of Cl2 and He inductively coupled plasmas, and the roughness RMS of the etched GaN surface is 0.15-0.18nm; (2) the GaN epitaxial wafer is cleaned: the GaN epitaxial wafer is sequentially put in acetone for 2-5 minutes of ultrasonic cleaning, put in alcohol for 2-3 minutes of ultrasonic cleaning, and put in de-ionized water for 2-3 minutes of ultrasonic cleaning; and (3) the GaN epitaxial wafer is heated by microwave and preheated for one minute to enable the temperature to reach 200-220 DEG C, KOH heated to a melt state is evenly applied on the surface of the GaN epitaxial wafer, microwave heating is performed to make the temperature kept at 250 DEG C, and corrosion is constantly performed for 1.2 minutes.

Description

technical field [0001] The invention relates to a manufacturing process of an LED. Background technique [0002] At present, the manufacturing technology of LED is relatively mature, and the injection efficiency and internal quantum efficiency can reach a relatively high level. However, due to the critical angle of total reflection of the chip and the packaging medium, the absorption of the chip material and other factors, the light extraction efficiency of the LED has a large room for improvement. Surface roughening techniques are often used to reduce total reflection of light. Surface roughening techniques include dry etching and wet etching. Among them, dry etching includes reactive ion etching (RIE), high-density plasma etching, electron cyclotron resonance plasma etching (ECR), inductively coupled plasma etching (ICP), etc., wet etching includes NaOH solution etching, electrochemical etching, etc. corrosion etc. Wet etching has many advantages, such as providing low...

AI Technical Summary

Problems solved by technology

Wet etching has many advantages, such as providing low-damage etching effect and low price, but it also has many limitations, such as slow speed, isotropic, poor controllability, etc.; while dry etching such as IPC has relatively Good anisotropy, uniformity, controllability, higher etch rate