A Comparison of CH 4 :H 2 and C 2 H 6 :H 2 Morie of GaAs

A comparative study is made of CH4:H2 and CH3−CH3:H2 metal-organic reactive ion etching of molecular beam epitaxially grown GaAs. The etch rates are measured to be proportional to both CH4 and CH3−CH3 concentrations, with empirically determined order of reactions at 1.1 W.cm−2 of, 0.57 ± 0.1 and 0.32 ± 0.01. Approximately twice the number of CH4 molecules are required to produce the equivalent etch rate as CH3−CH3 molecules. The measured apparent activation energies are low, Ea ≤ 6 meV, and GaAs area loading effects are the same. These results indicate that methyl radicals are predominately responsible for the reaction.