Semiconductor device and manufacturing method thereof
View Patent ↗The semiconductor device includes a gate electrode over a substrate, a gate insulating layer over the gate electrode, an oxide semiconductor layer over the gate insulating layer, and a source electrode and a drain electrode over the oxide semiconductor layer. A length of part of an outer edge of the oxide semiconductor layer from an outer edge of the source electrode to an outer edge of the drain electrode is more than three times, preferably more than five times as long as a channel length of the semiconductor device. Further, oxygen is supplied from the gate insulating layer to the oxide semiconductor layer by heat treatment. In addition, an insulating layer is formed after the oxide semiconductor layer is selectively etched.
1. A semiconductor device comprising:
a gate electrode over a substrate;
a gate insulating layer over the gate electrode;
an oxide semiconductor layer over the gate insulating layer; and
a source electrode and a drain electrode over the oxide semiconductor layer,
wherein an entire bottom surface of the source electrode and an entire bottom surface of the drain electrode are in contact with the oxide semiconductor layer,
wherein an outer edge of a first part of the oxide semiconductor layer coincides with part of an outer edge of the source electrode,
wherein an outer edge of a second part of the oxide semiconductor layer coincides with part of an outer edge of the drain electrode,
wherein the first part and the second part of the oxide semiconductor layer intersect with an outer edge of the gate electrode, and
wherein a third part of the oxide semiconductor layer which is provided inside the outer edge of the gate electrode has a width larger than a width of each of the first part, the second part, the source electrode and the drain electrode.
2. The semiconductor device according to claim 1 , wherein a total length of parts of an outer edge of the oxide semiconductor layer which does not overlap with the source electrode and the drain electrode is more than five times as long as a channel length of the semiconductor device.
3. The semiconductor device according to claim 1 , further comprising an insulating film containing oxygen over the oxide semiconductor layer, the source electrode and the drain electrode, wherein the insulating film covers a side surface of the oxide semiconductor layer.
4. The semiconductor device according to claim 1 , wherein the oxide semiconductor layer comprises at least one element selected from In, Ga, Sn, and Zn.
5. The semiconductor device according to claim 1 , wherein the oxide semiconductor layer is non-single-crystal.
6. A semiconductor device comprising:
a gate electrode over a substrate;
a gate insulating layer over the gate electrode;
an oxide semiconductor layer over the gate insulating layer;
a source electrode and a drain electrode over the oxide semiconductor layer; and
an insulating film containing oxygen over the oxide semiconductor layer, the source electrode and the drain electrode,
wherein the insulating film covers a side surface of the oxide semiconductor layer,
wherein an entire bottom surface of the source electrode and an entire bottom surface of the drain electrode overlap with the oxide semiconductor layer,
wherein an outer edge of a first part of the oxide semiconductor layer coincides with part of an outer edge of the source electrode,
wherein an outer edge of a second part of the oxide semiconductor layer coincides with part of an outer edge of the drain electrode,
wherein each of the first part and the second part of the oxide semiconductor layer intersects with an outer edge of the gate electrode, and
wherein a third part of the oxide semiconductor layer which is provided inside the outer edge of the gate electrode has a width lamer than a width of each of the first part, the second part, the source electrode and the drain electrode.
7. The semiconductor device according to claim 6 , further comprising:
a source region between the entire bottom surface of the source electrode and the oxide semiconductor layer; and
a drain region between the entire bottom surface of the drain electrode and the oxide semiconductor layer,
wherein each of the source region and the drain region comprises a conductive metal oxide layer.
8. The semiconductor device according to claim 6 , further comprising an insulating layer over and in contact with the oxide semiconductor layer,
wherein the source electrode and the drain electrode are over and in contact with the insulating layer.
9. The semiconductor device according to claim 6 , wherein the oxide semiconductor layer comprises at least one element selected from In, Ga, Sn, and Zn.
10. The semiconductor device according to claim 6 , wherein the oxide semiconductor layer is non-single-crystal.