Non-uniform gate dielectric for u-shape mosfet
AssigneeInternational Business Machines Corporation
InventorsPranita Kerber, Effendi Leobandung, Philip J. Oldiges
Life of this patent
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Abstract
A U-shaped gate dielectric structure is provided that has a horizontal gate dielectric portion having a vertical thickness, and a vertical gate dielectric wall portion extending upwards from the horizontal gate dielectric portion. The vertical gate dielectric wall portion has a lateral thickness that is greater than the vertical thickness of the horizontal gate dielectric portion. The U-shaped gate dielectric structure houses a gate conductor portion. Collectively, the U-shaped gate dielectric structure and the gate conductor portion provide a functional gate structure that has reduced capacitance.
Claims20
A method of forming a semiconductor structure, said method comprising:
- forming a gate material stack on a semiconductor material portion, said gate material stack comprising, from bottom to top, a horizontal gate dielectric portion and a gate conductor portion, wherein said horizontal gate dielectric portion has a vertical thickness;
- forming a vertical gate dielectric wall portion surrounding sidewalls of said gate material stack and extending upwards from said horizontal gate dielectric portion, said vertical gate dielectric wall portion having a lateral thickness that is greater than said vertical thickness of said horizontal gate dielectric portion;
- and
- forming a source-side semiconductor material on one side of said gate material stack and a drain-side semiconductor material on another side of said gate material side, wherein a sidewall edge of each of said source-side semiconductor material and said drain-side semiconductor material contacts an outer sidewall of said vertical gate dielectric wall portion.
Dependencies are inferred from the claim text.