FinFET device with extra body portion and method of forming the same
A semiconductor device, including a substrate, a first source/drain region, a second source/drain region, and a gate structure, is provided. The substrate has an extra body portion and a fin protruding from a top surface of the substrate, wherein the fin spans the extra body portion. The first source/drain region and the second source/drain region are in the fin. The gate structure spans the fin, is located above the extra body portion, and is located between the first source/drain region and the second source/drain region.
1 . A semiconductor device, comprising:
a substrate, having an extra body portion and a fin protruding from a top surface of the substrate, wherein the fin extends along a first direction, the extra body portion extends along a second direction different from the first direction, and the extra body portion is only on two sides in the second direction of the fin with an end being connected to the fin;
a first source/drain region and a second source/drain region, in the fin; and
a gate structure, spanning the fin, located above the extra body portion, and located between the first source/drain region and the second source/drain region,
wherein a material of the extra body portion is the same as a material of the substrate.
2 . The semiconductor device according to claim 1 , wherein the gate structure overlaps with the extra body portion.
3 . The semiconductor device according to claim 2 , wherein the gate structure lands on the extra body portion.
4 . The semiconductor device according to claim 2 , wherein a conductivity type of a dopant of the extra body portion is different from a conductivity type of dopants of the first source/drain region and the second source/drain region.
5 . The semiconductor device according to claim 1 , further comprising:
a drift region, located between the first source/drain region and the second source/drain region.
6 . The semiconductor device according to claim 5 , wherein the drift region further extends below the second source/drain region.
7 . The semiconductor device according to claim 6 , further comprising a doped region embedded in the drift region and adjacent to the second source/drain region.
8 . The semiconductor device according to claim 7 , wherein a part of the drift region and a part of the doped region are sandwiched between the gate structure and the extra body portion.
9 . The semiconductor device according to claim 1 , further comprising an isolation structure located on the substrate, wherein the extra body portion is embedded in the isolation structure.
10 . The semiconductor device according to claim 9 , wherein a top surface of the isolation structure is coplanar with a top surface of the extra body portion.
11 . The semiconductor device according to claim 9 , wherein the extra body portion and the fin are of a same material as the substrate.
12 . The semiconductor device according to claim 9 , wherein the gate structure comprises a gate dielectric layer and a gate conductor layer, and the gate dielectric layer is located between the fin and the gate conductor layer, and between the extra body portion and the gate conductor layer.
13 . A method of fabricating a semiconductor device, comprising:
providing a substrate;
forming an extra body portion and a fin on the substrate, wherein the extra body portion and the fin protrude from a top surface of the substrate, the fin extends along a first direction, the extra body portion extends along a second direction different from the first direction, and the extra body portion is only on two sides in the second direction of the fin with an end being connected to the fin;forming a first source/drain region and a second source/drain region in the fin; and
forming a gate structure spanning the fin, wherein the gate structure is located above the extra body portion and is located between the first source/drain region and the second source/drain region,
wherein a material of the extra body portion is the same as a material of the substrate.
14 . The method of fabricating the semiconductor device according to claim 13 , wherein the gate structure overlaps with the extra body portion.
15 . The method of fabricating the semiconductor device according to claim 14 , further comprising:
forming a drift region, wherein the drift region is in the fin between the first source/drain region and the second source/drain region and a part of the extra body portion, and the second source/drain region is located in the drift region.
16 . The method of fabricating the semiconductor device according to claim 15 , further comprising:
forming a doped region in the drift region of the fin and adjacent to the second source/drain region, wherein the doped region and the drift region have different conductivity types.
17 . The method of fabricating the semiconductor device according to claim 16 , wherein a part of the drift region and a part of the doped region are located between the gate structure and the extra body portion.
18 . The method of fabricating the semiconductor device according to claim 14 , further comprising forming an isolation structure located on the substrate and adjacent to the extra body portion and the fin.
19 . The method of fabricating the semiconductor device according to claim 14 , wherein the extra body portion and the fin are formed by etching the substrate.