INTERACTION OF H AND H-2 WITH THE SILICON DANGLING ORBITAL AT THE (111) SI/SIO2 INTERFACE

We present a molecular-orbital study of trivalent silicon atoms on the <111> Si/SiO2 interface in the presence of atomic and molecular hydrogen. We consider both passivation and depassivation of dangling silicon orbitals as a function of charge state. Our results for the neutral charge state are in good agreement with experiment. We predict a 1.32 eV activation energy for the concerted reaction involving H-2 dissociation and Si-H bond formation, compared with Brower's experimental value of 1.66 eV, and we predict a Si-H detachment energy of 2.7 eV, compared with 2.5 eV obtained by Brower and Myers. We predict that biased annealing would lead to strikingly different passivation kinetics.