Sarikov, A.; Stegemann, B.; Schmidt, M.: A model of the passivation of ultrathin SiO2 layer/Si substrate interfaces by atomic hydrogen from a thermalised plasma source. Thin Solid Films 518 (2010), p. 4662-4666
A theoretical model is developed to account for the kinetics of the decrease of the density of recombination active centres at the interface of SiO2 layers with Si(111) substrates as a result of treatment by thermalised hydrogen plasma. The recombination active centres at the SiO2/Si interface are ascribed to be the Pb centres. The model developed takes into account the kinetics of the incorporation of hydrogen atoms into the SiO2 layer from the plasma source and their interaction with both passivated and unpassivated Pb centres. A special attention is given to ultrathin (∼2 nm) SiO2 layers. A simplification of the general model to this important case allows one to obtain analytical solution for the density of unpassivated recombination active Pb centres as a function of the flow of hydrogen atoms from plasma, the initial density of Pb centres, and the treatment time. The model applicability is verified comparing the results of calculations with the experimentally measured values of the relative density of recombination active centres at the ultrathin SiO2/Si(111) substrate interface upon passivation by atomic hydrogen from thermalised plasma source. A conformity of the model predictions to the experimental results is demonstrated.