Method for manufacturing semiconductor device
View Patent ↗A highly reliable semiconductor device which includes a transistor including an oxide semiconductor is provided. In the semiconductor device including a bottom-gate transistor including an oxide semiconductor layer, a stacked layer of an insulating layer and an aluminum film is provided in contact with the oxide semiconductor layer. Oxygen doping treatment is performed in such a manner that oxygen is introduced to the insulating layer and the aluminum film from a position above the aluminum film, whereby a region containing oxygen in excess of the stoichiometric composition is formed in the insulating layer, and the aluminum film is oxidized to form an aluminum oxide film.
1. A method for manufacturing a semiconductor device comprising the steps of:
forming a gate electrode layer;
forming a gate insulating layer over the gate electrode layer;
forming an oxide semiconductor layer overlapping with the gate electrode layer with the gate insulating layer interposed therebetween;
forming a source electrode layer and a drain electrode layer which are electrically connected to the oxide semiconductor layer:
forming an insulating layer over the source electrode layer and the drain electrode layer and in contact with the oxide semiconductor layer;
forming an aluminum film in contact with the insulating layer; and
performing an oxygen doping treatment on the insulating layer and the aluminum film, so that at least a portion of the aluminum film is oxidized to be an aluminum oxide film.
2. The method for manufacturing a semiconductor device according to claim 1 , further comprising a step of performing heat treatment on the aluminum film after the step of the performing an oxygen doing treatment.
3. The method for manufacturing a semiconductor device according to claim 1 , wherein the aluminum film is oxidized to be an aluminum oxide layer.
4. The method for manufacturing a semiconductor device according to claim 1 , wherein the insulating layer comprises an oxygen excess region.
5. The method for manufacturing a semiconductor device according to claim 1 , wherein the insulating layer comprises a layer containing nitrogen.
6. The method for manufacturing a semiconductor device according to claim 1 , further comprising a step of performing heat treatment on the insulating layer before the aluminum film is formed.
7. The method for manufacturing a semiconductor device according to claim 1 , wherein the gate insulating layer comprises an oxygen excess region.
8. The method for manufacturing a semiconductor device according to claim 7 , wherein the oxygen excess region is formed by performing an oxygen doping treatment on the gate insulating layer.
9. A method for manufacturing a semiconductor device comprising the steps of:
forming a gate electrode layer;
forming a gate insulating layer over the gate electrode layer;
performing heat treatment on the gate insulating layer to reduce hydrogen in the gate insulating layer;
forming an oxide semiconductor layer overlapping with the gate electrode layer with the gate insulating layer interposed therebetween;
forming a source electrode layer and a drain electrode layer which are electrically connected to the oxide semiconductor layer:
forming an insulating layer over the source electrode layer and the drain electrode layer and in contact with the oxide semiconductor layer;
forming an aluminum film in contact with the insulating layer; and
performing an oxygen doping treatment on the insulating layer and the aluminum film, so that at least a portion of the aluminum film is oxidized to be an aluminum oxide film.
10. The method for manufacturing a semiconductor device according to claim 9 , further comprising a step of performing heat treatment on the aluminum film after the step of the performing an oxygen doing treatment.
11. The method for manufacturing a semiconductor device according to claim 9 , wherein the aluminum film is oxidized to be an aluminum oxide layer.
12. The method for manufacturing a semiconductor device according to claim 9 , wherein the insulating layer comprises an oxygen excess region.
13. The method for manufacturing a semiconductor device according to claim 9 , wherein the insulating layer comprises a layer containing nitrogen.
14. The method for manufacturing a semiconductor device according to claim 9 , further comprising a step of performing heat treatment on the insulating layer before the aluminum film is formed.
15. The method for manufacturing a semiconductor device according to claim 9 , wherein the gate insulating layer comprises an oxygen excess region.
16. The method for manufacturing a semiconductor device according to claim 15 , wherein the oxygen excess region is formed by performing an oxygen doping treatment on the gate insulating layer.