Selective Dry Etching of GaAs/AlAs Based on SiCl4/SF6 Mixtures by ICP
基于SiCl4/SF6的GaAs/AlAs ICP选择性干法刻蚀

Selective dry etching of GaAs/AlAs with SiCl4/SF6 mixtures by inductively coupled plasma (ICP) is reported.With different SiCl4/SF6 ratios,chamber pressure,and RF chuck power,the average etch rates of GaAs,AlAs,and their selectivity are studied.Proper gases ratios of SiCl4/SF6(15/5sccm),lower RF chuck power,and higher chamber pressure enhance the formation of AlF3 nonviolent produce and encourage to the selectivity of GaAs/AlAs.When the gases ratios of SiCl4/SF6 are at 15/5sccm,RF chuck power is 10W,source power is 500W,and chamber pressure is 2Pa,the selectivity of GaAs/AlAs reaches at least 1500.The plasma damage of etched GaAs substrate is conducted by Raman spectroscope under different RF chuck power and chamber pressure,atomic force microscope (AFM),and scanning electron microscope (SEM) also have been applied to view the surface morphology and sidewall,respectively.