Nanoribbon thick gate device with hybrid dielectric tuning for high breakdown and VT modulation
Embodiments disclosed herein include semiconductor devices and methods of forming such semiconductor devices. In an embodiment, the semiconductor device comprises a substrate, and a first transistor over the substrate. In an embodiment, the first transistor comprises a first semiconductor channel above the substrate, a first gate dielectric surrounding the first semiconductor channel, and a first gate electrode over the first gate dielectric. In an embodiment, the semiconductor device further comprises a second transistor over the substrate. In an embodiment, the second transistor comprises a second semiconductor channel above the substrate, a second gate dielectric surrounding the second semiconductor channel, where the second gate dielectric is different than the first gate dielectric, and a second gate electrode over the second gate dielectric, where the first gate electrode and the second gate electrode comprise the same material.
1 . A semiconductor device, comprising:
a substrate;
a first transistor over the substrate, the first transistor comprising:
a first semiconductor channel above the substrate, the first semiconductor channel having a first vertical thickness and a first bottommost surface;
a first gate dielectric surrounding the first semiconductor channel; and
a first gate electrode over and in contact with the first gate dielectric; and
a second transistor over the substrate, the second transistor comprising:
a second semiconductor channel above the substrate, the second semiconductor channel having a second vertical thickness and a second bottommost surface, the second vertical thickness the same as the first vertical thickness, and the second bottommost surface at a same level as the first bottommost surface;
a second gate dielectric surrounding the second semiconductor channel, wherein the second gate dielectric is different than the first gate dielectric; and
a second gate electrode over and in contact with the second gate dielectric, wherein the first gate electrode and the second gate electrode comprise the same material.
2 . The semiconductor device of claim 1 , wherein the first transistor is a P-type transistor, and wherein the second transistor is an N-type transistor.
3 . The semiconductor device of claim 2 , wherein a threshold voltage (VT) of the P-type transistor is higher than a VT of the N-type transistor.
4 . The semiconductor device of claim 1 , wherein the first gate dielectric and the second gate dielectric comprise SiO 2 , and wherein the first gate dielectric is annealed with a first annealing treatment, and wherein the second gate dielectric is annealed with a second annealing treatment.
5 . The semiconductor device of claim 4 , wherein one or both of the first annealing treatment and the second annealing treatment are implemented in an NH 3 atmosphere, and wherein a first concentration of nitrogen at an outer surface of the first gate dielectric is different than a second concentration of nitrogen at an outer surface of the second gate dielectric.
6 . The semiconductor device of claim 1 , wherein one or both of the first gate dielectric and the second gate dielectric comprise a first layer and a second layer.
7 . The semiconductor device of claim 6 , wherein the first layer is an oxide material, and wherein the second layer is a dipole material.
8 . The semiconductor device of claim 7 , wherein the oxide material is SiO 2 or HfO 2 , and wherein the dipole material is at least one of La 2 O 3 , ZrO 2 , Y 2 O 3 , and TiO 2 .
9 . The semiconductor device of claim 1 , wherein the first gate dielectric has a first thickness and the second gate dielectric has a second thickness, and wherein the first thickness and the second thickness are both greater than 3 nm.
10 . The semiconductor device of claim 9 , wherein the first thickness is different than the second thickness.
11 . The semiconductor device of claim 10 , wherein the first semiconductor channel and the second semiconductor channel are nanowires or nanoribbons.
12 . A semiconductor device comprising:
a substrate;
a first gate all around (GAA) transistor over the substrate, the first GAA transistor comprising a first gate dielectric and a first gate electrode in contact with the first gate dielectric, wherein the first gate dielectric has a first thickness, the first GAA transistor having first semiconductor channel having a first vertical thickness and a first bottommost surface;
a second GAA transistor over the substrate, the second GAA transistor comprising a second gate dielectric and a second gate electrode in contact with the second gate dielectric, the second gate electrode having a same composition as the first gate electrode, wherein the second gate dielectric has a second thickness that is greater than the first thickness, and wherein the second GAA transistor is an N-type transistor, the second GAA transistor having second semiconductor channel having a second vertical thickness and a second bottommost surface, the second vertical thickness the same as the first vertical thickness, and the second bottommost surface at a same level as the first bottommost surface; and
a third GAA transistor over the substrate, the third GAA transistor comprising a third gate dielectric that is different than the second gate dielectric and the third GAA transistor comprising a third gate electrode having a same composition as the first and second gate electrodes, wherein the third gate dielectric has a third thickness that is greater than the first thickness, and wherein the third GAA transistor is a P-type transistor.
13 . The semiconductor device of claim 12 , wherein the first GAA transistor has a first channel length, and wherein the second GAA transistor and the third GAA transistor have a second channel length that is larger than the first channel length.
14 . The semiconductor device of claim 12 , wherein each of the first GAA transistor, the second GAA transistor, and the third GAA transistor comprise:
a plurality of semiconductor channels, wherein the semiconductor channels are oriented in a vertical stack.
15 . The semiconductor device of claim 14 , wherein a first spacing between semiconductor channels in the first GAA transistor is equal to a second spacing between semiconductor channels in the second GAA transistor and the third GAA transistor.
16 . The semiconductor device of claim 15 , wherein the first spacing is approximately 10 nm or less.
17 . The semiconductor device of claim 16 , wherein the first thickness is approximately 3 nm or less, and wherein the second thickness and the third thickness are approximately 3 nm or greater.
18 . The semiconductor device of claim 12 , wherein the second gate dielectric and the third gate dielectric comprise SiO 2 , wherein an outer surface of the second gate dielectric has a first concentration of nitrogen, and wherein an outer surface of the third gate dielectric comprises a second concentration of nitrogen that is different than the first concentration of nitrogen.
19 . The semiconductor device of claim 12 , wherein one or both of the second gate dielectric and the third gate dielectric comprise a first layer and a second layer.
20 . The semiconductor device of claim 19 , wherein the first layer comprises SiO 2 or HfO 2 , and wherein the second layer comprises at least one of La 2 O 3 , ZrO 2 , Y 2 O 3 , and TiO 2 .