METHOD FOR FABRICATING A STRAINED STRUCTURE
First Claim
1. A field effect transistor comprising:
- a substrate comprising a top surface;
a gate stack over the substrate;
an isolation structure in the substrate; and
a source/drain (S/D) recess cavity below the top surface of the substrate disposed between the gate stack and the isolation structure, the recess cavity comprising;
a lower portion, the lower portion further comprising a first strained layer and a first dielectric film, wherein the first strained layer is disposed between the isolation structure and the first dielectric film; and
an upper portion comprising a second strained layer overlying the first strained layer and first dielectric film.
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Accused Products
Abstract
A structure for a field effect transistor on a substrate that includes a gate stack, an isolation structure and a source/drain (S/D) recess cavity below the top surface of the substrate disposed between the gate stack and the isolation structure. The recess cavity having a lower portion and an upper portion. The lower portion having a first strained layer and a first dielectric film. The first strained layer disposed between the isolation structure and the first dielectric film. A thickness of the first dielectric film less than a thickness of the first strained layer. The upper portion having a second strained layer overlying the first strained layer and first dielectric film.
67 Citations
20 Claims
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1. A field effect transistor comprising:
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a substrate comprising a top surface; a gate stack over the substrate; an isolation structure in the substrate; and a source/drain (S/D) recess cavity below the top surface of the substrate disposed between the gate stack and the isolation structure, the recess cavity comprising; a lower portion, the lower portion further comprising a first strained layer and a first dielectric film, wherein the first strained layer is disposed between the isolation structure and the first dielectric film; and an upper portion comprising a second strained layer overlying the first strained layer and first dielectric film. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for fabricating a semiconductor device, comprising:
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providing a substrate; forming a recess cavity comprising an upper portion and a lower portion in the substrate, wherein one sidewall of the recess cavity is dielectric and other sidewall of the recess cavity is the substrate; forming a dielectric film on the substrate sidewall portion and a bottom portion of the recess cavity; removing the dielectric film on the bottom portion of the recess cavity; epi-growing a first strained layer in the lower portion of the recess cavity adjacent to a portion of the dielectric film; removing a portion of the dielectric film not adjacent to the first strained layer; and epi-growing a second strained layer in the upper portion of the recess cavity. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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Specification