and the authors have ascribed this phenomenon to the declined nucleation rate caused by the inhibition effect of HCl . A continued increase in the ppadded HCl does not lead to further drastic decrease in the growth rate. In terms of the coating conformality, although the initial deposition condition (padded HCl= 0) has resulted in an almost-conformal coating, the additional HCl has brought the growth into the superconformal regime where the step coverage is higher than 1. With padded HCl= 14 Pa, a closed coating was only observed at the bottom of the trench while only isolated islands were observed at the top.