The impact of shallow trench isolation (Si]) on non volatile memories becomes much more severe with the CMOS technology scaling down to sub 90 nm In this work the Impact of STI on a polysilicon-oxide-nitride-oxide-silicon (SONOS) type memory has been investigated based on the experiments and TCAD simulation analysis It has been found edge cells adjacent to STI have the lower channel hot-electron (CHE) injection programming efficiency than center cells In addition edge cells exhibit different initial threshold voltage (V-t) distribution compared with center cells Si] impact is thought to be the main reason for these problems To reduce the impact of STI an additional boron implantation in STI BL contacts region is developed as a new solution As a result the performance differences between edge and center cells have been substantially minimized (C) 2010 Elsevier Ltd All rights reserved