Patent ID: 7575970

Claim:
A method of forming a deep trench capacitor in a silicon-on-insulator (SOI) substrate, the SOI substrate including a silicon layer on a buried silicon oxide (BOX) layer, the SOI substrate formed on a silicon substrate, the method comprising: forming a trench opening into the SOI substrate to the silicon substrate; depositing a sidewall spacer in the trench opening prior to forming a deep trench; etching the trench opening to shape the sidewall spacer and form the deep trench into the silicon substrate; forming a first electrode by implanting a dopant into the silicon substrate, whereby the sidewall spacer protects the BOX layer and the silicon layer; removing all of the sidewall spacer from the deep trench; depositing a node dielectric within the deep trench; and forming a second electrode by depositing a conductor in the deep trench.