Method for fabricating a trench contact to a deep trench capacitor having a polysilicon filling

摘要

The instant invention is a method for fabricating a trench contact to a deep trench capacitor with a polysilicon filling in a trench hole formed in a silicon substrate. An epitaxy process is performed to selectively grow silicon above the polysilicon filling in the trench hole. An opening leading to the polysilicon filling is anisotropically etched into the epitaxially grown silicon. The opening has lateral dimensions that are smaller than those of the polysilicon filling, and the opening is filled with polysilicon.