Oxide semiconductor film and semiconductor device
An oxide semiconductor film which has more stable electric conductivity is provided. The oxide semiconductor film comprises a crystalline region. The oxide semiconductor film has a first peak of electron diffraction intensity with a full width at half maximum of greater than or equal to 0.4 nm −1 and less than or equal to 0.7 nm −1 in a region where a magnitude of a scattering vector is greater than or equal to 3.3 nm −1 and less than or equal to 4.1 nm −1 . The oxide semiconductor film has a second peak of electron diffraction intensity with a full width at half maximum of greater than or equal to 0.45 nm −1 and less than or equal to 1.4 nm −1 in a region where a magnitude of a scattering vector is greater than or equal to 5.5 nm −1 and less than or equal to 7.1 nm −1 .
1 . A transistor comprising:
a gate electrode having an island shape;
a gate insulating film over the gate electrode; and
an oxide semiconductor film comprising a channel region overlapping with the gate electrode with the gate insulating film therebetween,
wherein the gate electrode comprises copper,
wherein the gate insulating film comprises silicon oxide,
wherein the oxide semiconductor film comprises In, Ga and Zn,
wherein the oxide semiconductor film comprises a first region which does not overlap with the gate electrode,
wherein the first region has a surface parallel or substantially parallel to a side surface of the gate electrode,
wherein the first region comprises a plurality of crystals in which c-axes are aligned in a first direction perpendicular or substantially perpendicular to the surface of the first region, and
wherein the first region comprises an amorphous region surrounding the plurality of crystals.
2 . The transistor according to claim 1 , wherein the oxide semiconductor film is in a non-single-crystal state.
3 . The transistor according to claim 1 , further comprising a source electrode and a drain electrode,
wherein each of the source electrode and the drain electrode is in contact with a top surface of the oxide semiconductor film, and
wherein the source electrode and the drain electrode do not comprise molybdenum and tungsten.
4 . The transistor according to claim 1 ,
wherein the oxide semiconductor film comprises a stack of a first layer and a second layer over and in contact with the first layer, and
wherein a concentration of Ga in the second layer is higher than a concentration of Ga in the first layer.
5 . The transistor according to claim 1 , wherein a concentration of hydrogen in the oxide semiconductor film is 5×10 19 atoms/cm 3 or lower.
6 . The transistor according to claim 1 , wherein an angle between each of the c-axes and a normal of a top surface of the oxide semiconductor film is greater than or equal to 0° and less than or equal to 20°.
7 . A transistor comprising:
a gate electrode having an island shape;
a gate insulating film over the gate electrode;
an oxide semiconductor film comprising a channel region overlapping with the gate electrode with the gate insulating film therebetween; and
a source electrode and a drain electrode electrically connected to the oxide semiconductor film,
wherein the gate electrode comprises copper,
wherein the gate insulating film comprises silicon oxide,
wherein the oxide semiconductor film comprises In, Ga and Zn,
wherein the oxide semiconductor film comprises a first region which does not overlap with the gate electrode,
wherein the first region has a surface parallel or substantially parallel to a side surface of the gate electrode,
wherein the first region comprises a plurality of crystals in which c-axes are aligned in a first direction perpendicular or substantially perpendicular to the surface of the first region,
wherein a crystal in the plurality of crystals has a YbFe 2 O 4 structure, a Yb 2 Fe 3 O 7 structure, a modified structure of the YbFe 2 O 4 structure, or a modified structure of the Yb 2 Fe 3 O 7 structure, and
wherein the first region comprises an amorphous region surrounding the plurality of crystals.
8 . The transistor according to claim 7 , wherein the oxide semiconductor film is in a non-single-crystal state.
9 . The transistor according to claim 7 ,
wherein each of the source electrode and the drain electrode is in contact with a top surface of the oxide semiconductor film, and
wherein the source electrode and the drain electrode do not comprise molybdenum and tungsten.
10 . The transistor according to claim 7 ,
wherein the oxide semiconductor film comprises a stack of a first layer and a second layer over and in contact with the first layer, and
wherein a concentration of Ga in the second layer is higher than a concentration of Ga in the first layer.
11 . The transistor according to claim 7 , wherein a concentration of hydrogen in the oxide semiconductor film is 5×10 19 atoms/cm 3 or lower.
12 . The transistor according to claim 7 , wherein an angle between each of the c-axes and a normal of a top surface of the oxide semiconductor film is greater than or equal to 0° and less than or equal to 20°.
13 . A transistor comprising:
a gate electrode having an island shape; and
an oxide semiconductor film comprising a channel region over the gate electrode,
wherein the gate electrode comprises copper,
wherein the oxide semiconductor film comprises In, Ga and Zn,
wherein the oxide semiconductor film comprises a first region which does not overlap with the gate electrode,
wherein the first region has a surface parallel or substantially parallel to a side surface of the gate electrode,
wherein the first region comprises a plurality of crystals in which c-axes are aligned in a first direction perpendicular or substantially perpendicular to the surface of the first region,
wherein a crystal in the plurality of crystals has a YbFe 2 O 4 structure, a Yb 2 Fe 3 O 7 structure, a modified structure of the YbFe 2 O 4 structure, or a modified structure of the Yb 2 Fe 3 O 7 structure, and
wherein the first region comprises an amorphous region surrounding the plurality of crystals.
14 . The transistor according to claim 13 , wherein the oxide semiconductor film is in a non-single-crystal state.
15 . The transistor according to claim 13 , further comprising a source electrode and a drain electrode,
wherein each of the source electrode and the drain electrode is in contact with a top surface of the oxide semiconductor film, and
wherein the source electrode and the drain electrode do not comprise molybdenum and tungsten.
16 . The transistor according to claim 13 ,
wherein the oxide semiconductor film comprises a stack of a first layer and a second layer over and in contact with the first layer, and
wherein a concentration of Ga in the second layer is higher than a concentration of Ga in the first layer.
17 . The transistor according to claim 13 , wherein a concentration of hydrogen in the oxide semiconductor film is 5×10 19 atoms/cm 3 or lower.
18 . The transistor according to claim 13 , wherein an angle between each of the c-axes and a normal of a top surface of the oxide semiconductor film is greater than or equal to 0° and less than or equal to 20°.