It was observed, during a study of the dissociation kinetics of Si-H and Si-D complexes, that - for a given incident ultra-violet photon density - the concentration of dissociated Si-D complexes was 10 to 20 times below the concentration of dissociated Si-H complexes. This marked isotope effect was explained in terms of excitation models for Si-H(D) bonds at Si surfaces and Si/SiO2 interfaces.

Strong Isotope Effects in the Dissociation Kinetics of Si-H and Si-D Complexes in GaAs Under Ultraviolet Illumination J.Chevallier, M.Barbé, E.Constant, D.Loridant-Bernard, M.Constant: Applied Physics Letters, 1999, 75[1], 112-4