Semiconductor device

A semiconductor device comprising:

• a gate electrode including a plurality of pairs of first protrusions and a second protrusion provided between the plurality of pairs of first protrusions;
• a gate insulating film over the gate electrode;
• a semiconductor film which is in contact with the gate insulating film and overlaps with the plurality of pairs of first protrusions and the second protrusion;
• and
• a pair of electrodes which is in contact with the semiconductor film and overlaps with the plurality of pairs of first protrusions,
• wherein one of side edges of the semiconductor film in a direction of a channel width are provided over top surfaces of the plurality of pairs of first protrusions, and the other of the side edges of the semiconductor film in the direction of the channel width is provided over top surfaces of a pair of first protrusions which is different from the one of the plurality of pairs of first protrusions, and
• wherein one of side edges of the pair of electrodes in the direction of the channel width are provided over top surfaces of the plurality of pairs of first protrusions, and the other of the side edges of the pair of electrodes in the direction of the channel width is provided over top surfaces of a pair of first protrusions which is different from the one of the plurality of pairs of first protrusions.

A semiconductor device comprising:

• a structure which includes an insulating surface, and includes a pair of first protrusions and a second protrusion provided between the pair of first protrusions;
• a semiconductor film which is in contact with the pair of first protrusions and the second protrusion;
• a pair of electrodes which is in contact with the semiconductor film and overlaps with the pair of first protrusions;
• a gate insulating film over the structure, the semiconductor film, and the pair of electrodes;
• and
• a gate electrode which is in contact with the gate insulating film and is provided between the pair of electrodes,
• wherein side edges of the semiconductor film are on outer sides of top surfaces of the pair of first protrusions in a direction of a channel width of the semiconductor film, and
• wherein side edges of the pair of electrodes are on the outer sides of top surfaces of the pair of first protrusions in the direction of the channel width of the semiconductor film.

A semiconductor device comprising:

• a structure which includes an insulating surface, and includes a plurality of pairs of first protrusions and a second protrusion provided between the plurality of pairs of first protrusions;
• a semiconductor film which is in contact with the plurality of pairs of first protrusions and the second protrusion;
• a pair of electrodes which is in contact with the semiconductor film and overlaps with the plurality of pairs of first protrusions;
• a gate insulating film over the structure, the semiconductor film, and the pair of electrodes;
• and
• a gate electrode which is in contact with the gate insulating film and is provided between the pair of electrodes,
• wherein one of side edges of the semiconductor film in a direction of a channel width is provided over top surfaces of one of the plurality of pairs of first protrusions, and the other of the side edges of the semiconductor film in the direction of the channel width is provided over top surfaces of a pair of first protrusions which is different from the one of the plurality of pairs of first protrusions, and
• wherein one of side edges of the pair of electrodes in the direction of the channel width is provided over top surfaces of one of the plurality of pairs of first protrusions, and the other of the side edges of the pair of electrodes in the direction of the channel width is provided over top surfaces of a pair of first protrusions which is different from the one of the plurality of pairs of first protrusions.