We have calculated the surface peak intensity of GaAs and InP in high-energy ion scattering by the Monte Carlo simulation method, assuming a variety of surface dynamics. Effects of thermal vibration, displacements of surface atoms, disorder of surface layer and the effect of multiple scattering of the projectile in penetrating deposited films have been evaluated in the megaelectron-volt range of the He' ion incident energy. The present study describes an attempt to carry out a comprehensive calculation of the surface peak for the surface and interface of insulator/III-V compound semiconductor systems. From these analyses, we can directly evaluate the amount of disorder at the surface and the interface of insulator/III-V compound semiconductor systems.
INTRODUC~ON
Compound semiconductors have many useful and potentially advantageous characteristics for high-speed electronic and optoelectronic devices. However, the interface between the compound semiconductor, such as GaAs or InP, and the dielectric film exhibits various instabilities in contrast to the Si/Si02 case. Previous structural studies' have revealed several imperfection structures such as the pile-up of column V elements at the interface2 formation of highly unstable native oxide layers3 and morphologically rather rough interfaces. Moreover, the density of interface states for compound semiconductors is extremely high compared with the case of the Si/Si02 interface. Although the origin of the interface states is not yet clarified, it must be related to some aspects of the interface structure. However, the atomic structure at the interface has not yet been clarified in detail. High-energy ion scattering (HEIS) in combination with the channelling technique is a powerful tool which allows a microscopic, quantitative and displacement-sensitive analysis of the solid surface. In HEIS, monoenergetic (MeV) ions such as helium or hydrogen ions in the incident beam collide with target atoms and are scattered backwards into the detectoranalysis system, which measures the ion energies. Then, we can obtain the energy spectrum of backscattering particles. In this spectrum we can isolate the surface peak (SP), which is due to particles backscattered by