Hydrogen Passivation

Abstract

The fact that hydrogen interacts efficiently with most defects, shallow dopants as well as deep centers, with the formation of hydrogen-impurity complexes and saturation of dangling bonds as a result, has contributed to a great interest in the hydrogen passivation process. From a technological point of view, the hydrogen passivation plays an important role both at the growth and the processing phases of the semiconductor bulk material. From a fundamental point of view, it is important to reach a thorough understanding of the hydrogen interaction with the impurities. The hydrogen passivation process in quantum wells is significantly less studied than in the case of bulk. One reason for this limited effort is that the driving force for studies of the passivation in bulk, i.e., to improve the radiative recombination efficiency by passivating competing non-radiative processes in as-grown structures constitutes not a similar motivation level in quantum well structures. This fact is due to the considerably higher radiative recombination efficiency in high quality quantum well structures. A comprehensive research has been done on bulk semiconductor materials, particularly on Si. It has been demonstrated that up to 99% of acceptors in Si can be deactivated by atomic hydrogen [239]. In bulk GaAs it is also shown that both donors and acceptors can be passivated by hydrogen. It has been concluded that hydrogen drifts as a positively charged species in p-type GaAs.