Trench sidewall structure

摘要

The invention provides a trench sidewall structure and a method of forming and using the same to reduce parasitic sidewall leakage through a trench sidewall, for example from bitline contact to storage node or from storage node to substrate. The method involves placing a polysilicon layer of the same polarity as that of the array well, along with a diffusion barrier layer such an titanium nitride, between the storage node poly and the oxide collar.