Influence of Electrostatic Charge on Recombination Lifetime and Native Oxide Growth on HF-Treated Silicon Wafers

Abstract

This paper reports on the influence of electrostatic charge on the time-dependent change in the hydrogen-terminated surface of HF-treated silicon wafers. The change in the hydrogen-terminated silicon surfaces were evaluated from the changes in recombination lifetime and the rate of native oxide growth. It is known that electrostatic charges are generated on silicon wafers by wet processing, such as HF treatment. This study notes that the electrostatic charge on wafers is modified over time to achieve an equilibrium, resulting from the interactions between charged wafers and the ambient. Using these characteristics of the electrostatic charge, the conditions under which changes in recombination lifetime and native oxide growth could be controlled were found. Furthermore, this mechanism was considered to influence the electrostatic charge on the band structure of p-type silicon. Using this phenomenon, native oxide growth on a silicon surface could be suppressed and HF treatment would provide a simple surface passivation method for recombination lifetime measurement.