Semiconductor device
View Patent ↗An object is to prevent an impurity such as moisture and oxygen from being mixed into an oxide semiconductor and suppress variation in semiconductor characteristics of a semiconductor device in which an oxide semiconductor is used. Another object is to provide a semiconductor device with high reliability. A gate insulating film provided over a substrate having an insulating surface, a source and a drain electrode which are provided over the gate insulating film, a first oxide semiconductor layer provided over the source electrode and the drain electrode, and a source and a drain region which are provided between the source electrode and the drain electrode and the first oxide semiconductor layer are provided. A barrier film is provided in contact with the first oxide semiconductor layer.
1. A method of manufacturing a semiconductor device comprising:
forming a gate electrode layer;
forming a gate insulating layer over the gate electrode layer;
forming an oxide semiconductor layer over the gate electrode layer with the gate insulating layer interposed therebetween, the oxide semiconductor layer comprising a channel formation region;
forming a conductive film on the oxide semiconductor layer, the conductive film comprising an alloy including copper and manganese;
heating the conductive film after forming the conductive film;
etching the conductive film to form a first conductive layer and a second conductive layer;
forming an insulating film over the first conductive layer and the second conductive layer, wherein the insulating film is in contact with a portion of the oxide semiconductor layer between the first conductive layer and the second conductive layer.
2. The method according to claim 1 , wherein the insulating film comprises aluminum and oxygen.
3. The method according to claim 1 , wherein the insulating film comprises silicon and oxygen.
4. The method according to claim 1 , wherein the oxide semiconductor layer contains sodium at a concentration less than or equal to 5×10 19 /cm 3 .
5. The method according to claim 1 , wherein the oxide semiconductor layer comprises In, Ga and Zn.
6. The method according to claim 1 , further comprising a step of forming a pixel electrode electrically connected to one of the first conductive layer and the second conductive layer.
7. The method according to claim 1 , wherein the step of heating the conductive film is performed at 200° C. to 600° C.
8. A method of manufacturing a semiconductor device comprising:
forming a gate electrode layer;
forming a gate insulating layer over the gate electrode layer;
forming an oxide semiconductor layer over the gate electrode layer with the gate insulating layer interposed therebetween, the oxide semiconductor layer comprising a channel formation region;
forming a conductive film on the oxide semiconductor layer, the conductive film comprising an alloy including copper and manganese;
heating the conductive film after forming the conductive layer;
etching the conductive film to form a first conductive layer and a second conductive layer;
etching a portion of the oxide semiconductor layer between the first conductive layer and the second conductive layer so that the oxide semiconductor layer is thinner in a region between the first conductive layer and the second conductive layer than in regions below the first conductive layer and the second conductive layer;
forming an insulating film over the first conductive layer and the second conductive layer, wherein the insulating film is in contact with a portion of the oxide semiconductor layer between the first conductive layer and the second conductive layer.
9. The method according to claim 8 , wherein the insulating film comprises aluminum and oxygen.
10. The method according to claim 8 , wherein the insulating film comprises silicon and oxygen.
11. The method according to claim 8 , wherein the oxide semiconductor layer contains sodium at a concentration less than or equal to 5×10 19 /cm 3 .
12. The method according to claim 8 , wherein the oxide semiconductor layer comprises In, Ga and Zn.
13. The method according to claim 8 , further comprising a step of forming a pixel electrode electrically connected to one of the first conductive layer and the second conductive layer.
14. The method according to claim 8 , wherein the step of heating the conductive film is performed at 200° C. to 600° C.
15. A method of manufacturing a semiconductor device comprising:
forming a gate electrode layer;
forming a gate insulating layer over the gate electrode layer;
forming a first oxide semiconductor layer over the gate electrode layer with the gate insulating layer interposed therebetween, the first oxide semiconductor layer comprising a channel formation region;
forming a second oxide semiconductor layer over the first oxide semiconductor layer;
forming a conductive film on the second oxide semiconductor layer, the conductive layer comprising an alloy including copper and manganese;
heating the conductive film after forming the conductive layer;
etching the conductive film to form a first conductive layer and a second conductive layer;
etching a portion of the second oxide semiconductor layer between the first conductive layer and the second conductive layer to form a source region and a drain region;
forming an insulating film over the first conductive layer and the second conductive layer, wherein the insulating film is in contact with a portion of the first oxide semiconductor layer between the first conductive layer and the second conductive layer.
16. The method according to claim 15 , wherein the insulating film comprises aluminum and oxygen.
17. The method according to claim 15 , wherein the insulating film comprises silicon and oxygen.
18. The method according to claim 15 , wherein the first oxide semiconductor layer contains sodium at a concentration less than or equal to 5×10 19 /cm 3 .
19. The method according to claim 15 , wherein the first oxide semiconductor layer comprises In, Ga and Zn.
20. The method according to claim 15 , further comprising a step of forming a pixel electrode electrically connected to one of the first conductive layer and the second conductive layer.
21. The method according to claim 15 , wherein the step of heating the conductive film is performed at 200° C. to 600° C.