Composite contact between backside power element and source/drain region
A semiconductor device includes a transistor having a source/drain region and a contact disposed on the source/drain region. The semiconductor device further includes a via extending from the contact along a side of the source/drain region to a power element. The contact and the via each comprise a plurality of conductive materials.
1 . A semiconductor device, comprising:
a transistor comprising a source/drain region;
a contact disposed on the source/drain region; and
a via extending from the contact along a side of the source/drain region to a power element;
wherein the contact and the via each comprise a plurality of conductive materials; and
wherein the contact comprises:
a liner layer comprising a first conductive material;
a first fill layer on a first portion of the liner layer and comprising a second conductive material; and
a second fill layer on a second portion of the liner layer and comprising a third conductive material.
2 . The semiconductor device of claim 1 , wherein the power element comprises a power rail.
3 . The semiconductor device of claim 1 , further comprising an isolation region, wherein the power element is disposed on the isolation region and the via extends through the isolation region to contact the power element.
4 . The semiconductor device of claim 1 , wherein at least a portion of the first fill layer is disposed between the second fill layer and the liner layer.
5 . The semiconductor device of claim 1 , wherein the first conductive material comprises one of tantalum, tantalum nitride and titanium nitride, the second conductive material comprises a noble metal and the third conductive material comprises one of cobalt, copper and tungsten.
6 . The semiconductor device of claim 1 , wherein the via comprises:
a liner layer comprising a first conductive material;
a first fill layer on a first portion of the liner layer and comprising a second conductive material; and
a second fill layer on a second portion of the liner layer and comprising a third conductive material.
7 . The semiconductor device of claim 6 , wherein a portion of the second fill layer extends in the via along part of the side of the source/drain region.
8 . The semiconductor device of claim 7 , wherein the portion of the second fill layer is bordered on two sides by the first fill layer and on one side by the liner layer.
9 . The semiconductor device of claim 6 , wherein the first fill layer occupies a majority of the via.
10 . The semiconductor device of claim 6 , wherein the first conductive material comprises one of tantalum, tantalum nitride and titanium nitride, the second conductive material comprises a noble metal and the third conductive material comprises one of cobalt, copper and tungsten.
11 . An integrated circuit comprising:
a transistor comprising a source/drain region;
a contact disposed on the source/drain region;
a power element;
an isolation region disposed on the power element; and
a via extending from the contact through the isolation region to the power element;
wherein the contact and the via each comprise a plurality of conductive materials; and
wherein the via comprises:
a liner layer comprising a first conductive material;
a first fill layer on a first portion of the liner layer and comprising a second conductive material; and
a second fill layer on a second portion of the liner layer and comprising a third conductive material.
12 . The integrated circuit of claim 11 , wherein the power element comprises a power rail.
13 . The integrated circuit of claim 11 , wherein at least a portion of the via is disposed along a side of the source/drain region.
14 . The integrated circuit of claim 11 , wherein a portion of the second fill layer extends in the via along part of a side of the source/drain region, and wherein the portion of the second fill layer is bordered on two sides by the first fill layer and on one side by the liner layer.
15 . A semiconductor device, comprising:
a source/drain region disposed on a first side of a semiconductor layer;
a contact disposed on the source/drain region on the first side of the semiconductor layer;
a power element disposed on a second side of the semiconductor layer; and
a via extending from the contact along a side of the source/drain region to the power element;
wherein the contact and the via each comprise a plurality of conductive materials; and
wherein the via comprises:
a liner layer comprising a first conductive material;
a first fill layer on a first portion of the liner layer and comprising a second conductive material; and
a second fill layer on a second portion of the liner layer and comprising a third conductive material.
16 . The semiconductor device of claim 15 , wherein the power element comprises a power rail.
17 . The semiconductor device of claim 15 , further comprising an isolation region disposed on a side of the semiconductor layer, wherein the via extends through the isolation region to contact the power element.