The Effects of Cl Inductively Coupled Plasma on p-GaN Thin Film

碩士 === 義守大學 === 電子工程學系 === 91 === The etching rate is increasing with the larger RF power because the larger RF power, the stronger ion energy. The etching rate also increases with the ICP power from 400 to 600W because the higher ion density. However, The etching rate decreases when the...

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Bibliographic Details
Main Authors: Chung-Tung Tseng, 曾仲冬
Other Authors: Meiso Yokoyama
Format: Others
Language:en_US
Published: 2003
Online Access:http://ndltd.ncl.edu.tw/handle/27356389590754625854
Description
Summary:碩士 === 義守大學 === 電子工程學系 === 91 === The etching rate is increasing with the larger RF power because the larger RF power, the stronger ion energy. The etching rate also increases with the ICP power from 400 to 600W because the higher ion density. However, The etching rate decreases when the ICP power from 600 to 800W. Then there is no obvious change of etching rate from 800 to 1000W. The decreased and relatively constant etch rates at higher powers(800, 1000W) might be explained by either sputter desorption of species or competition between the sputtering and the etch reaction. A reduction of Ni/Au ohmic contact on p-type GaN is obtained by surface treatment on GaN films using Cl2 inductively coupled plasma(ICP). X-ray photoelectron spectroscopy (XPS) shows the shift in binding energy of Ga 3d and Cl 2p spectra after Cl2 ICP treatment. It suggests GaClx or GaOx is formed. After removing the GaClx or GaOx by HCl boil solution, the Ga-vacancies at the p-type GaN surface are produced and acting as acceptors for holes. It will result Fermi level (EF) moved near the valence band and lead to the reduction in the contact resistivity through the decrease of the Schottky barrier for the conduction of holes. However, the varying in ohmic contact behavior should be nothing to do with GaOx because there is no obvious binding energy shifting for Oxygen XPS resuts.