Semiconductor structure for memory device and method for forming the same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorChien Hung Liu
Life of this patent
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Abstract
A semiconductor device includes a substrate, a gate structure disposed over the substrate, a drain structure disposed in the substrate, and a source structure disposed in the substrate on an n opposite side of the gate structure from the drain structure. The substrate includes a first semiconductor layer, a second semiconductor layer over the first semiconductor layer, and an insulating layer sandwiched between the first semiconductor layer and the second semiconductor layer. The source structure and the drain structure include a same conductivity type. The source structure includes at least an epitaxial layer. The source structure extends deeper into the substrate than the drain structure.
Claims20
A semiconductor device comprising:
- a substrate comprising a first semiconductor layer, a second semiconductor layer over the first semiconductor layer, and an insulating layer sandwiched between the first semiconductor layer and the second semiconductor layer;
- a gate structure disposed over the substrate;
- a drain structure disposed in the substrate at one side of the gate structure and comprising a first conductivity type;
- and
- a source structure disposed in the substrate on an opposite side of the gate structure from the drain structure and comprising the first conductivity type,
- wherein the source structure comprises at least an epitaxial layer, the source structure extends deeper into the substrate than the drain structure, a top surface of the insulating layer is free of the epitaxial layer, the top surface of the insulating layer is in contact with the second semiconductor layer and the drain structure, and a top surface of the epitaxial layer is higher than the top surface of the insulating layer.
A memory device comprising:
- a substrate comprising a first semiconductor layer, a second semiconductor layer over the first semiconductor layer, and an insulating layer sandwiched between the first semiconductor layer and the second semiconductor layer;
- two first gate structures disposed over the substrate, the two first gate structures being spaced apart from each other;
- a source structure disposed in the substrate and between the two first gate structures;
- and
- a second gate structure disposed between the two first gate structures and over the source structure,
- wherein the second gate structure overlaps the source structure from a plane view, the second gate structure is separated from the two first gate structures and the source structure, the source structure comprises an epitaxial layer, a top surface of the insulating layer is free of the epitaxial layer, the top surface of the insulating layer is in contact with the second semiconductor layer and the drain structure, and a top surface of the epitaxial layer is higher than the top surface of the insulating layer.
A semiconductor device comprising:
- a substrate comprising a first semiconductor layer, a second semiconductor layer over the first semiconductor layer, and an insulating layer sandwiched between the first semiconductor layer and the second semiconductor layer;
- a first gate structure disposed over the substrate;
- a drain structure disposed in the substrate at one side of the first gate structure and comprising a first conductivity type;
- a source structure disposed in the substrate on an opposite side of the first gate structure from the drain structure and comprising the first conductivity type;
- and
- a second gate structure disposed over the source structure,
- wherein a bottom boundary of the drain structure and a top boundary of the insulating layer substantially are in a same level, and a bottom boundary of the source structure is lower than the bottom boundary of the drain structure, the second gate structure overlaps the source structure from a plane view, the second gate structure is separated from the first gate structure and the source structure the source structure comprises an epitaxial layer, sidewalls of the epitaxial layer are in contact with the first semiconductor layer, the insulating layer and the second semiconductor layer, a top surface of the insulating layer is in contact with the second semiconductor layer and the drain structure, and a top surface of the epitaxial layer is higher than the top surface of the insulating layer.
Dependencies are inferred from the claim text.