Investigation of Reactive-Ion Etching (RIE) Technique for GaN Epitaxial Materials

• Main Authors: C. W. Weng, 翁啟文
• Other Authors: N. C. Chen
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/24976178067356908553

碩士 === 長庚大學 === 電子工程研究所 === 95 === Abstract GaN crystal has become one of the most remarkable photonic materials in the last decade. Blue luminescence of GaN devices makes full-color display into reality. Most importantly, its near-ultraviolet emitting attribute has greatly increased the storage capacity of digital information in the leading multimedia industry. In this study, Reaction Ion etching (RIE) etching was used to investigate the influence of plasma surface treatment on n-GaN ohmic contacts. The research work is divided into two parts. First, the influences of dry etch parameters, including chamber pressure , Cl2 flow rate, Ar flow rate,and CH4 flow rate on etching rate, sidewall profile and surface morphology were studied. As a result, most samples have very smooth surface morphology. Only at the zero CH4 flow rate condition ,the surface morphology will become very rough .Larger Ar flow rate would lead to sloped sidewall profile and lower the etching rate . As for Cl2 flow rate , higher flow rate will lead to higher etching rate .Then, the effects of plasma surface treatment on the electrical characteristics of n-GaN ohmic contacts were studied. The Ar flow rate was the main parameter affect the electric characteristic .The Ar Ion bombard the sample surface will cause nitrogen vacancy and grain defect influence the electric characteristic. Last part electroplates Ni was use to replace the sapphire substrate and laser lift-off process technology to manufacture vertical light-emitting diode , then compare the electric and photon characteristic with traditional light-emitting diode.