Patent ID: 7033885

Claim:
A deep trench structure manufacturing process, comprising the steps of: providing a substrate; forming a deep trench in said substrate; forming a dielectric layer in said deep trench, said dielectric layer covering the sidewall and bottom of the deep trench; filling the deep trench with a first conductive layer; removing a portion of said dielectric layer not covered by said first conductive layer where a gap is formed between the sidewall of the deep trench and the first conductive layer; refilling the deep trench with another dielectric layer, said another dielectric layer covering a portion of the sidewall of the deep trench not covered by said first conductive layer, and covering the gap; partially removing said another dielectric layer, while leaving at least a portion thereof filled in the gap; forming a collar oxide layer in the deep trench, said collar oxide layer covering a portion of the sidewall of the deep trench not covered by the dielectric layers; filling the deep trench with a second conductive layer; removing a portion of said collar oxide layer not covered by said second conductive layer; and filling the deep trench with a third conductive layer.