Desorption of Arsenic Species during the Surfactant Enhanced Growth of Ge on Si(100)

Abstract

The desorption and scattering of As4 and As2 species from the surface during the growth of germanium films on Si(100) with continuous As4 deposition is monitored using laser ionization time-of-flight mass spectrometry. A significant increase in the flux of As2 from the surface is observed when the Ge flux is admitted to the surface. Upon discontinuation of the germanium growth process, the As4 and As2 signal levels remain at this increased level. A comprehensive study of the desorption fluxes of As4, As2, and As species from both Ge(100) and Si(100) substrates was performed as a function of substrate temperature and incident As4 flux to determine the kinetics of desorption of the different species from the substrates. The behavior of the As2 desorbed fluxes as a function of surface temperature is qualitatively different on the Ge(100) and Si(100) substrates. The results indicate that the catalytic cracking of As4 to As2 is more effective on Ge(100) compared to Si(100) at substrate temperatures between 800...