Semiconductor device and manufacturing method thereof

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.

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.

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.