Patent ID: 6989311

Claim:
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, which comprises: providing the polysilicon filling in the trench hole formed in the silicon substrate causing the polysilicon filling to be set back from the top side of the silicon substrate; performing an epitaxy process to selectively grow silicon above the polysilicon filling in the trench hole causing the surface of the epitaxially grown silicon layer to be at the same height as or slightly below the top side of the silicon substrate; anisotropically etching an opening in the epitaxially grown silicon layer such that the opening leads to the polysilicon filling and such that the opening has lateral dimensions smaller than those of the polysilicon filling; and filling the opening with polysilicon to provide the trench contact to the deep trench capacitor.