Desorption kinetics of hydrogen from the Si(111)7×7 surface

Abstract
Thermal desorption of hydrogen from the Si(111)7×7 surface was investigated using optical second‐harmonic generation to monitor the hydrogen coverage from 0.2 monolayer to below 0.01 monolayer. The results of isothermal desorption measurements are found to be compatible neither with simple first nor second‐order kinetic behavior. It is suggested that different binding sites available for Si–H monohydride states on the Si(111)7×7 surface give rise to the apparent intermediate reaction order.