Semiconductor device and method for fabricating the same
AssigneeUnited Microelectronics Corp.
InventorsChu-Ming Ma, Hung-Chi Huang, Hsien-Ta Chung
Life of this patent
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Abstract
A semiconductor device comprises a substrate, a gate structure disposed on the substrate and a gate dielectric layer disposed between the substrate and the gate structure. The gate structure has a first sidewall and a second sidewall opposite to the first sidewall. A first insulating layer disposed on the gate dielectric layer and on the first sidewall of the gate structure. The first insulating layer has a first bird's beak portion covering a rounded bottom corner of the gate structure. A pair of spacers are disposed on the first insulating layer and on the second sidewall, respectively.
Claims17
A semiconductor device, comprising:
- a substrate;
- a gate structure disposed on the substrate and comprising a first sidewall and a second sidewall opposite to the first sidewall;
- a gate dielectric layer disposed between the gate structure and the substrate;
- a first insulating layer disposed on the gate dielectric layer and covering the first sidewall, wherein the first insulating layer comprises a first bird's beak portion covering a rounded bottom corner of the gate structure;
- a pair of spacers respectively disposed on the first insulating layer and on the second sidewall, wherein the second sidewall is in direct contact with one of the spacer, and the first sidewall is spaced apart from the other one of the spacer by the first insulating layer;
- a second insulating layer formed in the substrate and under the spacer on the first insulating layer;
- and
- a drain region formed in the substrate and adjacent to the spacer on the first insulating layer, wherein a portion of the drain region is under the second insulating layer.
A method for forming a semiconductor device, comprising:
- providing a substrate;
- forming a gate structure on the substrate, wherein the gate structure comprises a first sidewall and a second sidewall opposite to the first sidewall;
- forming a mask layer completely covering the substrate and the gate structure;
- patterning the mask layer to form an opening in the mask layer to expose the first sidewall of the gate structure and a portion of the substrate adjacent to the first sidewall;
- performing an oxidation process to form a first insulating layer on the first sidewall and a second insulating layer in the exposed portion of the substrate;
- removing the mask layer;
- forming a pair of spacer respectively on the first insulating layer and on the second sidewall;
- and
- forming a drain region in the substrate and adjacent to the spacer on the first insulating layer, wherein a portion of the drain region is under the second insulating layer.
Dependencies are inferred from the claim text.