Expitaxially regrown heterostructure nanowire lateral tunnel field effect transistor
After forming a buried nanowire segment surrounded by a gate structure located on a substrate, an epitaxial source region is grown on a first end of the buried nanowire segment while covering a second end of the buried nanowire segment and the gate structure followed by growing an epitaxial drain region on the second end of the buried nanowire segment while covering the epitaxial source region and the gate structure. The epitaxial source region includes a first semiconductor material and dopants of a first conductivity type, while the epitaxial drain region includes a first semiconductor material different from the first semiconductor material and dopants of a second conductivity type opposite the first conductivity type.
1. A semiconductor structure comprising:
a gate structure located on a substrate and wrapping around at least one nanowire segment, the at least one nanowire segment having a first end and a second end opposite the first end;
an epitaxial source region extending from the first end of the at least one nanowire segment, the epitaxial source region comprising a first semiconductor material and dopants of a first conductivity type; and
an epitaxial drain region extending from the second end of the at least one nanowire segment, the epitaxial drain region comprising a second semiconductor material different from the first semiconductor material and dopants of a second conductivity type opposite the first conductivity type.
2. The semiconductor structure of claim 1 , wherein the at least one nanowire segment comprises the second semiconductor material and is intrinsic.
3. The semiconductor structure of claim 2 , wherein the epitaxial source region comprises p-doped germanium, the epitaxial drain region comprises n-doped silicon, and the at least one nanowire segment comprises intrinsic silicon.
4. The semiconductor structure of claim 2 , wherein the epitaxial source region comprises p-doped GaAsSb, the epitaxial drain region comprises n-doped InGaAs, and the at least one nanowire segment comprises InGaAs.
5. The semiconductor structure of claim 1 , wherein the at least one nanowire segment comprises a plurality of nanowire segments, the epitaxial source region merging the plurality of nanowire segments at the first end and the epitaxial drain region merging the plurality of nanowire segments at the second ends.
6. The semiconductor structure of claim 1 , wherein the substrate comprises a handle substrate and a buried insulator layer present over the handle substrate, wherein the gate structure is present on a recessed region of the buried insulator layer.
7. The semiconductor structure of claim 1 , further comprising a first metal semiconductor alloy region atop the epitaxial source region, and a second metal semiconductor alloy region atop the epitaxial drain region.
8. The semiconductors structure of claim 7 , wherein each of the first metal semiconductor alloy and the second metal semiconductor alloy region has faceted surfaces.
9. The semiconductor structure of claim 1 , wherein the gate structure comprises a gate stack surrounding a channel portion of at least one nanowire segment and a gate spacer located on sidewalls of the gate stack.
10. The semiconductor structure of claim 1 , wherein the first end of the at least one nanowire segment is vertically aligned with a first sidewall of the gate structure, and a second end of the at least one nanowire segment is vertically aligned with a second sidewall of the gate structure opposite the first sidewall.