Abstract： We study the room-temperature dry etching of InP by inductively coupled plasma (ICP) using Cl2/CH4/Ar mixtures. Etches were characterized in terms of anisotropy and surface roughness by scanning electron microscopy and atomic force microscopy, respectively. It is found that the flow ratio between Cl2 and CH4, ICP power, rf chuck power, and table temperature can greatly influence the etching results. By adjusting etching parameters, vertical sidewall and smooth surface can be obtained simultaneously, together with a moderate etch rate and a good select ratio. The root-mean-square surface roughness is measured to be as low as 0.27 nm. To our knowledge, this is the best result for InP to date. The etch rate is 855 nm/min, and the selectivity ratio over SiO2 is estimated to be higher than 15:1. The stoichiometry of the etched surface has also been investigated by Auger electron spectroscopy. The etched surface is found to manifest a slight P deficiency, and the ratio between P and In reaches the stoichiometric value within about 0.75 nm depth into the surface.
SUN Chang-Zheng;ZHOU Jin-Bo;XIONG Bing;WANG Jian;LUO Yi. Vertical and Smooth, etching of InP by Cl2/CH4/Ar Inductively Coupled Plasma at Room Temperature[J]. 中国物理快报, 2003, 20(8): 1312-1314.
SUN Chang-Zheng, ZHOU Jin-Bo, XIONG Bing, WANG Jian, LUO Yi. Vertical and Smooth, etching of InP by Cl2/CH4/Ar Inductively Coupled Plasma at Room Temperature. Chin. Phys. Lett., 2003, 20(8): 1312-1314.
2003, Vol. 20 
