Patent ID: 7122437
Filing Date: 2006-10-17
Classification: H01L

Abstract:
1. A method of forming a bottle-shaped deep trench structure, said method comprising: forming a deep trench in a semiconductor substrate; depositing a polysilicon liner layer along a bottom and sidewalls of said deep trench; depositing another liner layer atop said polysilicon liner layer; covering a portion of said another liner layer that lines a lower region of said deep trench with a resist material so that a remaining portion of said another liner layer that lines an upper region of said deep trench is exposed; removing said exposed remaining portion of said another liner layer to expose an underlying portion of said polysilicon liner layer; removing said resist material to expose a lower portion of said another liner layer lining said lower region of said deep trench; forming a further layer from said exposed underlying portion of said polysilicon liner layer; removing said lower portion of said another liner layer and said underlying portion of said polysilicon liner layer using said further layer as a mask so that said sidewalls and said bottom at said lower region of said deep trench are exposed; and etching said sidewalls and said bottom at said lower region of said deep trench so that said deep trench has a bottle shape.