Collar process for reduced deep trench edge bias

摘要

Disclosed is a method to provide a new deep trench collar process which reduces encroachment of strap diffusion upon array metal oxide semiconductor field effect transistors (MOSFET's) in semiconductor devices. The invention allows a reduced effective deep trench edge bias at the top of the deep trench, without compromising storage capacitance, by maximizing the distance between the MOSFET gate conductor and the deep trench storage capacitor.