Semiconductor device and manufacturing method thereof
A semiconductor device for high power application in which a novel semiconductor material having high mass productivity is provided. An oxide semiconductor film is formed, and then, first heat treatment is performed on the exposed oxide semiconductor film in order to reduce impurities such as moisture or hydrogen in the oxide semiconductor film. Next, in order to further reduce impurities such as moisture or hydrogen in the oxide semiconductor film, oxygen is added to the oxide semiconductor film by an ion implantation method, an ion doping method, or the like, and after that, second heat treatment is performed on the exposed oxide semiconductor film.
1. A method for manufacturing a semiconductor device comprising:
forming an oxide semiconductor layer containing indium by sputtering method;
forming a conductive film comprising a region in contact with the oxide semiconductor layer; and
etching the conductive film for forming a source electrode and a drain electrode and etching a region of the oxide semiconductor layer which is not covered by the source electrode or the drain electrode,
wherein the oxide semiconductor layer comprises a region in which a c-axis of a crystal is aligned along a direction perpendicular to a surface of the oxide semiconductor layer.
2. The method for manufacturing a semiconductor device according to claim 1 ,
wherein the oxide semiconductor layer further comprises gallium and zinc.
3. A method for manufacturing a semiconductor device comprising:
forming an oxide semiconductor layer containing indium by sputtering method;
forming a conductive film comprising a region in contact with the oxide semiconductor layer; and
etching the conductive film for forming a source electrode and a drain electrode and etching a region of the oxide semiconductor layer which is not covered by the source electrode or the drain electrode,
wherein the oxide semiconductor layer comprises a first region in which a c-axis of a crystal is aligned along a direction perpendicular to a surface of the oxide semiconductor layer and a second region containing a microcrystal is under the first region.
4. The method for manufacturing a semiconductor device according to claim 3 ,
wherein the oxide semiconductor layer further comprises gallium and zinc.
5. The method for manufacturing a semiconductor device according to claim 3 ,
wherein the first region is partially thinned in the step of etching the region of the oxide semiconductor layer.
6. A method for manufacturing a semiconductor device comprising:
forming an oxide semiconductor layer containing indium by sputtering method, the oxide semiconductor layer comprising a first region and a second region under the first region;
forming a conductive film comprising a region in contact with the oxide semiconductor layer; and
etching the conductive film for forming a source electrode and a drain electrode and etching a region of the first region of the oxide semiconductor layer which is not covered by the source electrode or the drain electrode,
wherein a c-axis of a crystal is aligned along a direction perpendicular to a surface of the oxide semiconductor layer in the first region, and
wherein the second region containing a microcrystal is under the first region.
7. The method for manufacturing a semiconductor device according to claim 6 ,
wherein the oxide semiconductor layer further comprises gallium and zinc.
8. The method for manufacturing a semiconductor device according to claim 6 ,
wherein the first region is partially thinned in the step of etching the region of the first region of the oxide semiconductor layer.