Lateral oxidation of nfet high-k gate stacks
AssigneeInternational Business Machines Corporation
InventorsTakashi Ando, Robert H. Dennard, Martin M. Frank
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Abstract
A method for fabricating a semiconductor circuit includes obtaining a semiconductor structure having a gate stack of material layers including a high-k dielectric layer; oxidizing in a lateral manner the high-k dielectric layer, such that oxygen content of the high-k dielectric layer is increased first at the sidewalls of the high-k dielectric layer; and completing fabrication of a n-type field effect transistor from the gate stack after laterally oxidizing the high-k dielectric layer of the gate stack.
Claims20
A method for fabricating a semiconductor circuit, the method comprising the steps of:
- obtaining a semiconductor structure having a gate stack of material layers including a high-k dielectric layer;
- oxidizing in a lateral manner the high-k dielectric layer, such that the oxygen content of the high-k dielectric layer is increased first at the sidewalls of the high-k dielectric layer;
- and
- completing fabrication of a n-type field effect transistor from the gate stack after laterally oxidizing the high-k dielectric layer of the gate stack.
A method for fabricating a semiconductor circuit, the method comprising:
- obtaining a semiconductor structure having a first gate stack and a second gate stack, each containing material layers that include a high-k dielectric layer;
- oxidizing in a lateral manner (i) the high-k dielectric layer of the first gate stack, such that the oxygen content of the high-k dielectric layer of the first gate stack increases first at the sidewalls of the high-k dielectric layer of the first gate stack, and (ii) the high-k dielectric layer of the second gate stack, such that the oxygen content of the high-k dielectric layer of the second gate stack increases first at the sidewalls of the high-k dielectric layer of the second gate stack;
- and
- fabricating (i) a n-type field effect transistor from the first gate stack after laterally oxidizing at least the high-k dielectric layer of the first gate stack, and (ii) a p-type field effect transistor from the second gate stack after laterally oxidizing at least the high-k dielectric layer of the second gate stack.
A semiconductor structure, comprising:
- a n-type field effect transistor having a high-k dielectric layer that has higher concentration of oxygen at the sidewalls of the high-k dielectric layer than at the center of the high-k dielectric layer.
Dependencies are inferred from the claim text.