Method of manufacturing semiconductor device having oxide semiconductor layer
View Patent ↗An object is to provide favorable interface characteristics of a thin film transistor including an oxide semiconductor layer without mixing of an impurity such as moisture. Another object is to provide a semiconductor device including a thin film transistor having excellent electric characteristics and high reliability, and a method by which a semiconductor device can be manufactured with high productivity. A main point is to perform oxygen radical treatment on a surface of a gate insulating layer. Accordingly, there is a peak of the oxygen concentration at an interface between the gate insulating layer and a semiconductor layer, and the oxygen concentration of the gate insulating layer has a concentration gradient. The oxygen concentration is increased toward the interface between the gate insulating layer and the semiconductor layer.
1. A method for manufacturing a semiconductor device, comprising the steps of:
forming an insulating layer comprising an oxide over a substrate;
adding oxygen to the insulating layer to increase an oxygen concentration in the insulating layer;
forming an oxide semiconductor layer over the insulating layer after adding oxygen to the insulating layer; and
heating the oxide semiconductor layer at a temperature of 200° C. or higher.
2. The method according to claim 1 , wherein the step of adding oxygen is performed by a radical treatment using plasma containing oxygen radicals.
3. The method according to claim 1 , wherein the step of heating is performed at a temperature of 600° C. or lower.
4. The method according to claim 1 , further comprising the step of:
forming a source electrode layer and a drain electrode layer over the oxide semiconductor layer.
5. The method according to claim 1 , wherein the oxide semiconductor layer comprises In, Ga and Zn.
6. The method according to claim 1 , wherein the oxide semiconductor layer comprises In and Zn.
7. A method for manufacturing a semiconductor device, comprising the steps of:
forming a gate electrode layer over a substrate;
forming a gate insulating layer comprising an oxide over the gate electrode layer;
adding oxygen to the gate insulating layer to increase an oxygen concentration in the gate insulating layer;
forming an oxide semiconductor layer on the gate insulating layer after adding oxygen to the gate insulating layer; and
heating the oxide semiconductor layer at a temperature of 200° C. or higher.
8. The method according to claim 7 , wherein the step of adding oxygen is performed by a radical treatment using plasma containing oxygen radicals.
9. The method according to claim 7 , wherein the step of heating is performed at a temperature of 600° C. or lower.
10. The method according to claim 7 , wherein the oxide semiconductor layer comprises In, Ga and Zn.
11. The method according to claim 7 , wherein the oxide semiconductor layer comprises In and Zn.
12. A method for manufacturing a semiconductor device, comprising the steps of:
forming an insulating layer comprising an oxide over a substrate;
adding oxygen to the insulating layer to increase an oxygen concentration in the insulating layer;
forming an oxide semiconductor layer over the insulating layer after adding oxygen to the insulating layer;
forming an insulating film over the oxide semiconductor layer; and
heating the oxide semiconductor layer at a temperature of 200° C. or higher.
13. The method according to claim 12 , wherein the step of adding oxygen is performed by a radical treatment using plasma containing oxygen radicals.
14. The method according to claim 1 , wherein the step of heating is performed at a temperature of 600° C. or lower.
15. The method according to claim 12 , further comprising the step of:
forming a source electrode layer and a drain electrode layer over the oxide semiconductor layer.
16. The method according to claim 12 , wherein the oxide semiconductor layer comprises In, Ga and Zn.
17. The method according to claim 12 , wherein the oxide semiconductor layer comprises In and Zn.