Vertical tunneling field-effect transistor cell with coaxially arranged gate contacts and drain contacts
A tunneling field-effect transistor (TFET) device includes a source region, a gate stack, and a drain region. The TFET device further includes a source contact on the source region, a plurality of gate contacts on a planar portion of the gate stack, and a plurality of drain contacts on the drain region. The gate contacts are aligned on a first plurality of lines that intersect at a common point on the source region from a top view. The drain contacts are aligned on a second plurality of lines that intersect at the common point from the top view.
1. A tunneling field-effect transistor (TFET) device, comprising:
a substrate;
a protrusion structure disposed over the substrate;
a gate stack disposed over the substrate, wherein the gate stack includes a planar portion and a gating surface, the planar portion is parallel to a top surface of the substrate, and the gating surface wraps around a middle portion of the protrusion structure;
a source region disposed as a top portion of the protrusion structure;
a drain region disposed over the substrate adjacent to the protrusion structure and extending to a bottom portion of the protrusion structure as a raised drain region;
a source contact disposed on the source region;
a plurality of gate contacts disposed on the planar portion of the gate stack, wherein the plurality of gate contacts includes at least four gate contacts; and
a plurality of drain contacts disposed on the drain region, wherein the plurality of drain contacts includes at least four drain contacts, and wherein:
the gate contacts are aligned on a first plurality of lines that intersect at a common point on the source region from a top view, and each of the first plurality of lines goes through at least two of the gate contacts; and
the drain contacts are aligned on a second plurality of lines that intersect at the common point from the top view, and each of the second plurality of lines goes through at least two of the drain contacts.
2. The TFET device of claim 1 , wherein the source contact is positioned at the common point.
3. The TFET device of claim 1 , wherein angles that are formed by the first plurality of lines intersecting at the common point are equal.
4. The TFET device of claim 3 , wherein the gate contacts are positioned symmetrically about the common point.
5. The TFET device of claim 3 , wherein each of the angles is 90 degrees.
6. The TFET device of claim 3 , wherein each of the angles is 60 degrees.
7. The TFET device of claim 1 , wherein angles that are formed by the second plurality of lines intersecting at the common point are equal.
8. The TFET device of claim 7 , wherein the drain contacts are positioned symmetrically about the common point.
9. The TFET device of claim 7 , wherein each of the angles is 90 degrees.
10. The TFET device of claim 7 , wherein each of the angles is 60 degrees.
11. The TFET device of claim 1 , wherein angles that are formed by the first and second pluralities of lines intersecting at the common point are equal.
12. The TFET device of claim 11 , wherein each of the angles is 45 degrees.
13. The TFET device of claim 1 , wherein the first plurality of lines are the same as the second plurality of lines.
14. A semiconductor device comprising:
a substrate; and
a plurality of tunneling field-effect transistors (TFETs) over the substrate, wherein each of the TFETs comprises:
a source region, a gate region, and a drain region, wherein, from a top view, the source, gate, and drain regions are concentric, the gate region surrounds the source region, and the drain region surrounds the gate region;
a source contact disposed on the source region;
a plurality of gate contacts disposed on the gate region and aligned on a first plurality of lines that intersect at a common point on the source region from the top view, wherein the plurality of gate contacts includes at least four gate contacts, and wherein each of the first plurality of lines goes through at least two of the gate contacts; and
a plurality of drain contacts disposed on the drain region and aligned on a second plurality of lines that intersect at the common point from the top view, wherein the plurality of drain contacts includes at least four drain contacts, and wherein each of the second plurality of lines goes through at least two of the drain contacts, and wherein:
the source contact is positioned at the common point, the gate contacts are positioned symmetrically about the common point, and the drain contacts are positioned symmetrically about the common point.
15. The semiconductor device of claim 14 , wherein:
in each TFET, the gate contacts are aligned on first and second lines that are perpendicular to each other;
the respective first lines of all TFETs are parallel to each other; and
the respective second lines of all TFETs are parallel to each other.
16. The semiconductor device of claim 14 , wherein:
in each TFET, the gate contacts are aligned on first, second, and third lines that form six 60 degree angles at the common point;
the respective first lines of all TFETs are parallel to each other;
the respective second lines of all TFETs are parallel to each other; and
the respective third lines of all TFETs are parallel to each other.
17. The semiconductor device of claim 14 , wherein, in each TFET, the first plurality lines are the same as the second plurality lines.
18. A semiconductor device comprising:
a substrate; and
a plurality of tunneling field-effect transistors (TFETs) over the substrate, wherein each of the TFETs comprises:
a protrusion structure disposed over the substrate;
a gate stack disposed over the substrate, wherein the gate stack includes a planar portion and a gating surface, the planar portion is parallel to a top surface of the substrate, and the gating surface wraps around a middle portion of the protrusion structure;
a source region disposed as a top portion of the protrusion structure;
a drain region disposed over the substrate adjacent to the protrusion structure and extending to a bottom portion of the protrusion structure as a raised drain region;
a source contact disposed on the source region;
a plurality of gate contacts disposed on the planar portion of the gate stack, wherein the plurality of gate contacts includes at least four gate contacts; and
a plurality of drain contacts disposed on the drain region, wherein the plurality of drain contacts includes at least four drain contacts, and wherein:
from a top view, the source, gate, and drain regions are concentric, the gate region surrounds the source region, and the drain region surrounds the gate region;
the gate contacts are positioned symmetrically about the source contact and are aligned on a first plurality of lines that intersect at the source contact from the top view, and each of the first plurality of lines goes through at least two of the gate contacts; and
the drain contacts are positioned symmetrically about the source contact and are aligned on a second plurality of lines that intersect at the source contact from the top view, and each of the second plurality of lines goes through at least two of the drain contacts.
19. The semiconductor device of claim 18 , wherein:
in each TFET, the gate contacts and the drain contacts are aligned on first and second lines that are perpendicular to each other;
the respective first lines of all TFETs are parallel to each other; and
the respective second lines of all TFETs are parallel to each other.
20. The semiconductor device of claim 18 , wherein:
in each TFET, the gate contacts and the drain contacts are aligned on first, second, and third lines that intersect to form six 60 degree angles;
the respective first lines of all TFETs are parallel to each other;
the respective second lines of all TFETs are parallel to each other; and
the respective third lines of all TFETs are parallel to each other.