Isotopic effect between hydrogen and deuterium emission in silicon

Abstract We find an isotope effect between the breaking of SiH and SiD bonds, using tight-binding molecular dynamics simulations. The vibrationally excited Si–D bending modes decay much more rapidly than Si–H bending modes, due to the coupling of SiD modes with the interior silicon–phonon modes. The SiD bond is much more stable than the SiH bond. This stability explains the reduced degradation in deuterated metal-oxide-semiconductor (MOS) devices. For germanium, the GeD and GeH bonds have little difference in their stabilities since their vibrational frequencies are greater than the interior Ge-spectrum, consistent with this vibrational coupling model.