Dual-SiGe epitaxy for MOS devices
First Claim
Patent Images
1. A semiconductor structure comprising:
- a semiconductor substrate;
a gate stack on the semiconductor substrate; and
an epitaxial stressor having at least a portion in the semiconductor substrate and adjacent to the gate stack, wherein the epitaxial stressor comprises;
a first stressor region formed in a deep recess spaced apart from the gate stack; and
a second stressor region on the first stressor region formed in a shallow recess that extends under a gate spacer, wherein the second stressor region extends laterally closer to a channel region underlying the gate stack than the first stressor region, the first stressor region having different stress characteristics than the second stressor region.
1 Assignment
0 Petitions
Accused Products
Abstract
A semiconductor includes a semiconductor substrate, a gate stack on the semiconductor substrate, and a stressor having at least a portion in the semiconductor substrate and adjacent to the gate stack. The stressor includes a first stressor region and a second stressor region on the first stressor region, wherein the second stressor region extends laterally closer to a channel region underlying the gate stack than the first stressor region.
31 Citations
20 Claims
-
1. A semiconductor structure comprising:
-
a semiconductor substrate; a gate stack on the semiconductor substrate; and an epitaxial stressor having at least a portion in the semiconductor substrate and adjacent to the gate stack, wherein the epitaxial stressor comprises; a first stressor region formed in a deep recess spaced apart from the gate stack; and a second stressor region on the first stressor region formed in a shallow recess that extends under a gate spacer, wherein the second stressor region extends laterally closer to a channel region underlying the gate stack than the first stressor region, the first stressor region having different stress characteristics than the second stressor region. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A semiconductor structure comprising:
-
a semiconductor substrate; a gate stack on the semiconductor substrate; a gate spacer on a sidewall of the gate stack; a shallow epitaxial stressor disposed in a shallow recess having at least a portion in the semiconductor substrate and adjacent to the gate stack, wherein the containing the shallow epitaxial stressor extends under the gate spacer; and a deep epitaxial stressor underlying and adjoining the shallow epitaxial stressor and disposed in a deep recess in the semiconductor substrate and spaced apart from the gate stack, wherein the region of the semiconductor substrate directly underlying the gate spacer is free from the deep epitaxial stressor, the shallow epitaxial stressor being a different material than the deep epitaxial stressor. - View Dependent Claims (9, 10, 11, 18, 19, 20)
-
-
12. A semiconductor structure comprising:
-
a semiconductor substrate; a gate stack on the semiconductor substrate; and a SiGe stressor having at least a portion in the semiconductor substrate and adjacent to the gate stack, wherein the SiGe stressor comprises; a first SiGe region formed as a first epitaxial layer in a deep recess spaced apart from the gate stack and having a first atomic percentage of germanium to germanium and silicon; and a second SiGe region formed as a second epitaxial layer in a shallow recess that extends under the gate stack and formed on the first SiGe region and having a second atomic percentage of germanium to germanium and silicon, wherein the second atomic percentage is greater than the first atomic percentage, and wherein the second SiGe region is laterally closer to a channel region than the first SiGe region. - View Dependent Claims (13, 14, 15, 16, 17)
-
Specification