Dynamical behavior of methylchloride on GaAs(0Â 0Â 1)

The dynamical behavior of methylchloride (CH3Cl), which has a possibility of an important precursor in the atomic-order etching of III-V compounds, was studied on a GaAs(0 0 1) − 2 × 4 surface using a supersonic molecular beam. When the surface temperature was below 570 K, the incident CH3Cl molecule had two kinds of reaction channels. The one was a trapping/desorption channel, where CH3Cl loosely trapped in the surface potential well. The other was a direct inelastic scattering channel, where CH3Cl was unable to lose sufficient translational energy on the surface and directly scattered into the vacuum. In the low incident energy, the reaction through the former channel was dominant, but the reaction through the latter one drastically increased with the incident energy.