Devices with strained source/drain structures
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsTsz-Mei KWOK, Hsueh-Chang SUNG, Kuan-Yu CHEN, Hsien-Hsin LIN
Life of this patent
Estimating the term…
Abstract
A device includes a substrate, a gate structure over the substrate, and source/drain (S/D) features in the substrate and interposed by the gate structure. At least one of the S/D features includes a first semiconductor material, a second semiconductor material over the first semiconductor material, and a third semiconductor material over the second semiconductor material. The second semiconductor material has a composition different from the first semiconductor material and the third semiconductor material. The first semiconductor material includes physically discontinuous portions.
Claims20
A device, comprising:
- a substrate;
- a gate structure over the substrate;
- and
- source/drain (S/D) features in the substrate and interposed by the gate structure, wherein at least one of the S/D features comprises:
- a first semiconductor material;
- a second semiconductor material over the first semiconductor material;
- and
- a third semiconductor material over the second semiconductor material, wherein each of the first, second, and third semiconductor materials has a composition of silicon and an additional element, and an atomic ratio of the additional element in the second semiconductor material is different from atomic ratios of the additional element in the first semiconductor material and the third semiconductor material, and
- wherein the first semiconductor material includes discrete portions.
A device, comprising:
- a substrate;
- a gate structure over the substrate;
- and
- source/drain (S/D) features in the substrate and interposed by the gate structure, wherein at least one of the S/D features comprises:
- a first semiconductor material;
- a second semiconductor material over the first semiconductor material;
- and
- a third semiconductor material over the second semiconductor material, wherein the second semiconductor material has a composition different from the first semiconductor material and the third semiconductor material, wherein the first, second, and third semiconductor materials are formed in a trench of the substrate,
- the trench comprises:
- a first sidewall section extending obliquely downward from a top surface of the substrate and away from a center of the trench,
- a second sidewall section further extending obliquely downward from the first sidewall section and toward the center of the trench, and
- a bottom connected to the second sidewall section, and
- the first semiconductor material is included in a tip portion of the trench, the tip portion defined by the first and second sidewall sections.
A device, comprising:
- a substrate;
- a gate structure over the substrate;
- and
- source/drain (S/D) features in the substrate and interposed by the gate structure, wherein at least one of the S/D features comprises:
- a first semiconductor material;
- a second semiconductor material over the first semiconductor material;
- and
- a third semiconductor material over the second semiconductor material,
- wherein the second semiconductor material has a composition different from the first semiconductor material and the third semiconductor material, and
- wherein the first semiconductor material includes physically discontinuous portions.
Dependencies are inferred from the claim text.