Doping Effects from Neutral B2H6 Gas Phase on Plasma Pretreated Si Substrates as a Possible Process in Plasma Doping

In a low-energy plasma doping process, the contribution of not only ionized species but also neutral species to the doping process should be considered. To investigate such a contribution, experiments involving gas phase doping combined with Ar plasma pretreatment were carried out. As a result, a significant increase in boron dose from a neutral gas phase was observed when the substrate surface was subjected to Ar plasma pretreatment prior to exposure to neutral B2H6/He gas. Through a comprehensive study of the effects of plasma pretreatment and gas exposure conditions on the boron dose from the neutral gas phase, the substrate temperature at which the surface was exposed to the neutral B2H6/He gas after the plasma pretreatment was observed to significantly increase the boron dose.