Structure and method for forming asymmetrical overlap capacitance in field effect transistors
AssigneeInternational Business Machines Corporation
InventorHaining Yang
Life of this patent
Estimating the term…
Abstract
A method for forming asymmetric spacer structures for a semiconductor device includes forming a spacer layer over at least a pair of adjacently spaced gate structures disposed over a semiconductor substrate. The gate structures are spaced such that the spacer layer is formed at a first thickness in a region between the gate structures and at a second thickness elsewhere, the second thickness being greater than said first thickness. The spacer layer is etched so as to form asymmetric spacer structures for the pair of adjacently spaced gate structures.
Claims13
A semiconductor device, comprising:
- at least a pair of field effect transistor (FET) structures including a pair of adjacently spaced gate structures formed over a semiconductor substrate;
- each of said pair of FET structures having a pair of asymmetric spacer structures adjacent sidewalls thereof;
- wherein inner spacer structures located in a region between said pair of gate structures are thinner than outer spacer structures located on the outside of said pair of gate structures.
A field effect transistor (FET) device, comprising:
- a gate structure formed over a semiconductor substrate;
- a first pair of spacer structures formed on sidewalls of said gate structure;
- a second pair of spacer structures formed adjacent said first pair of spacer structures, said second pair of spacer structures having an asymmetrical thickness with respect to one another;
- a source region and extension thereof implanted on one side of said gate structure;
- and
- a drain region and extension thereof implanted on the other side of said gate structure;
- wherein the extension of said source region has a different length than the extension of said drain region, in accordance with said asymmetrical thickness of said second pair of spacer structures.
Dependencies are inferred from the claim text.