Semiconductor device having hydrogen in a dielectric layer
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsHongfa Luan, Yi-Fan Chen, Chun-Yen Peng, Cheng-Po Chau, Wen-Yu Ku, Huicheng Chang
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Abstract
Embodiment described herein provide a thermal treatment process following a high-pressure anneal process to keep hydrogen at an interface between a channel region and a gate dielectric layer in a field effect transistor while removing hydrogen from the bulk portion of the gate dielectric layer. The thermal treatment process can reduce the amount of threshold voltage shift caused by a high-pressure anneal. The high-pressure anneal and the thermal treatment process may be performed any time after formation of the gate dielectric layer, thus, causing no disruption to the existing process flow.
Claims20
A method of forming a semiconductor device, the method comprising:
- forming a first dielectric layer over a channel region;
- forming a second dielectric layer over the first dielectric layer;
- after forming the first dielectric layer and the second dielectric layer, introducing hydrogen to an interface between the first dielectric layer and the channel region;
- after introducing hydrogen, reducing hydrogen in the second dielectric layer;
- and
- after reducing the hydrogen, forming a gate electrode over the second dielectric layer.
A method of forming a semiconductor device, the method comprising:
- forming a first dielectric layer over a channel region;
- forming a second dielectric layer over the first dielectric layer;
- after forming the second dielectric layer, performing a first process at a first pressure to introduce hydrogen to an interface between the first dielectric layer and the channel region;
- after performing the first process, performing a second process at a second pressure to reduce hydrogen in the second dielectric layer, wherein the first pressure is higher than the second pressure;
- and
- after performing the second process, forming one or more layers of a gate structure over the second dielectric layer.
A method of forming a semiconductor device, the method comprising:
- forming a first dielectric layer over an active region;
- forming a second dielectric layer over the first dielectric layer;
- after forming the first dielectric layer and after forming the second dielectric layer, performing an anneal at a first pressure to introduce first atoms between the second dielectric layer and the active region, wherein the first atoms comprise hydrogen or deuterium;
- performing a post-anneal treatment at a second pressure to reduce the first atoms in the second dielectric layer, wherein the first pressure is higher than the second pressure, wherein after performing the post-anneal treatment the first dielectric layer has a first peak concentration of the first atoms, the second dielectric layer has a second peak concentration of the first atoms, and the first peak concentration is greater than the second peak concentration;
- and
- after performing the post-anneal treatment, forming a gate structure over the first dielectric layer and the second dielectric layer.
Dependencies are inferred from the claim text.