International Business Machines Corporation
Vertical transistor with eDRAM

Abstract:

Structures and methods for making vertical transistors in the Embedded Dynamic Random Access Memory (eDRAM) scheme are provided. A method includes: providing a bulk substrate with a first doped layer thereon, depositing a first hard mask over the substrate, forming a trench through the substrate, filling the trench with a first polysilicon material, and after filling the trench with the first polysilicon material, i) growing a second polysilicon material over the first polysilicon material and ii) epitaxially growing a second doped layer over the first doped layer, where the grown second polysilicon material and epitaxially grown second doped layer form a basis for a strap merging the second doped layer and the second polysilicon material.