Semiconductor device
A highly reliable semiconductor device the yield of which can be prevented from decreasing due to electrostatic discharge damage is provided. A semiconductor device is provided which includes a gate electrode layer, a first gate insulating layer over the gate electrode layer, a second gate insulating layer being over the first gate insulating layer and having a smaller thickness than the first gate insulating layer, an oxide semiconductor layer over the second gate insulating layer, and a source electrode layer and a drain electrode layer electrically connected to the oxide semiconductor layer. The first gate insulating layer contains nitrogen and has a spin density of 1×10 17 spins/cm 3 or less corresponding to a signal that appears at a g-factor of 2.003 in electron spin resonance spectroscopy. The second gate insulating layer contains nitrogen and has a lower hydrogen concentration than the first gate insulating layer.
1. A semiconductor device comprising:
a gate electrode layer;
a first gate insulating layer over the gate electrode layer;
a second gate insulating layer over the first gate insulating layer;
an oxide semiconductor layer over the second gate insulating layer; and
a source electrode layer and a drain electrode layer electrically connected to the oxide semiconductor layer,
wherein a thickness of the second gate insulating layer is smaller than a thickness of the first gate insulating layer,
wherein the first gate insulating layer and the second gate insulating layer each include silicon nitride,
wherein the second gate insulating layer has a lower hydrogen concentration than the first gate insulating layer, and
wherein the first gate insulating layer has a spin density of 1×10 17 spins/cm 3 or less corresponding to a signal that appears at a g-factor of 2.003 in electron spin resonance spectroscopy.
2. The semiconductor device according to claim 1 , wherein the gate electrode layer comprises copper.
3. The semiconductor device according to claim 1 , wherein the oxide semiconductor layer comprises a stacked-layer structure of a first oxide semiconductor layer and a second oxide semiconductor layer which have different compositions of same constituent elements.
4. The semiconductor device according to claim 1 , further comprising:
a first insulating layer covering the source electrode layer and the drain electrode layer, and being partly in contact with the oxide semiconductor layer; and
a second insulating layer over the first insulating layer,
wherein the first insulating layer includes a silicon film containing nitrogen and having a lower hydrogen concentration than the second insulating layer, and
wherein the second insulating layer includes a silicon film containing nitrogen and having a spin density of 1×10 17 spins/cm 3 or less corresponding to a signal that appears at a g-factor of 2.003 in electron spin resonance spectroscopy.
5. The semiconductor device according to claim 1 , wherein the semiconductor device is one selected from the group consisting of a table having a display portion, a television device, a computer, and a tablet terminal.
6. A semiconductor device comprising:
a gate electrode layer;
a first gate insulating layer over the gate electrode layer;
a second gate insulating layer over the first gate insulating layer;
an oxide semiconductor layer over the second gate insulating layer; and
a source electrode layer and a drain electrode layer electrically connected to the oxide semiconductor layer,
wherein a thickness of the second gate insulating layer is smaller than a thickness of the first gate insulating layer,
wherein the first gate insulating layer includes a silicon film containing nitrogen and having a spin density of 1×10 17 spins/cm 3 or less corresponding to a signal that appears at a g-factor of 2.003 in electron spin resonance spectroscopy, and
wherein the second gate insulating layer includes a silicon film containing nitrogen and having a lower hydrogen concentration than the first gate insulating layer.
7. The semiconductor device according to claim 6 , wherein the gate electrode layer comprises copper.
8. The semiconductor device according to claim 6 , wherein the oxide semiconductor layer comprises a stacked-layer structure of a first oxide semiconductor layer and a second oxide semiconductor layer which have different compositions of same constituent elements.
9. The semiconductor device according to claim 6 , further comprising:
a first insulating layer covering the source electrode layer and the drain electrode layer, and being partly in contact with the oxide semiconductor layer; and
a second insulating layer over the first insulating layer,
wherein the first insulating layer includes a silicon film containing nitrogen and having a lower hydrogen concentration than the second insulating layer, and
wherein the second insulating layer includes a silicon film containing nitrogen and having a spin density of 1×10 17 spins/cm 3 or less corresponding to a signal that appears at a g-factor of 2.003 in electron spin resonance spectroscopy.
10. The semiconductor device according to claim 6 , wherein the semiconductor device is one selected from the group consisting of a table having a display portion, a television device, a computer, and a tablet terminal.
11. A semiconductor device comprising:
a gate electrode layer;
a first gate insulating layer over the gate electrode layer;
a second gate insulating layer over the first gate insulating layer;
a third gate insulating layer over the second gate insulating layer;
an oxide semiconductor layer over the third gate insulating layer; and
a source electrode layer and a drain electrode layer electrically connected to the oxide semiconductor layer,
wherein a thickness of the second gate insulating layer is larger than a thickness of the first gate insulating layer,
wherein a thickness of the third gate insulating layer is smaller than the thickness of the second gate insulating layer,
wherein the second gate insulating layer includes a silicon film containing nitrogen and having a spin density of 1×10 17 spins/cm 3 or less corresponding to a signal that appears at a g-factor of 2.003 in electron spin resonance spectroscopy, and
wherein the first gate insulating layer and the third gate insulating layer each include a silicon film containing nitrogen and having a lower hydrogen concentration than the second gate insulating layer.
12. The semiconductor device according to claim 11 , wherein the gate electrode layer comprises copper.
13. The semiconductor device according to claim 11 , wherein the oxide semiconductor layer comprises a stacked-layer structure of a first oxide semiconductor layer and a second oxide semiconductor layer which have different compositions of same constituent elements.
14. The semiconductor device according to claim 11 , further comprising:
a first insulating layer covering the source electrode layer and the drain electrode layer, and being partly in contact with the oxide semiconductor layer; and
a second insulating layer over the first insulating layer,
wherein the first insulating layer includes a silicon film containing nitrogen and having a lower hydrogen concentration than the second insulating layer, and
wherein the second insulating layer includes a silicon film containing nitrogen and having a spin density of 1×10 17 spins/cm 3 or less corresponding to a signal that appears at a g-factor of 2.003 in electron spin resonance spectroscopy.
15. The semiconductor device according to claim 11 , wherein the semiconductor device is one selected from the group consisting of a table having a display portion, a television device, a computer, and a tablet terminal.