Crystalline oxide semiconductor film and semiconductor device
A crystalline oxide semiconductor film with an enhanced electrical property is provided. By use of a mist CVD apparatus, a crystalline oxide semiconductor film with a corundum structure and a principal plane that is an a-plane or an m-plane was obtained on a crystalline substrate by atomizing a raw-material solution containing a dopant that is an n-type dopant to obtain atomized droplets, carrying the atomized droplets by carrier gas onto the crystalline substrate that is an a-plane corundum-structured crystalline substrate or an m-plane corundum-structured crystalline substrate placed in a film-formation chamber, and the atomized droplets were thermally reacted to form the crystalline oxide semiconductor film on the crystalline substrate.
1. A crystalline oxide semiconductor film comprising:
a corundum-structured crystalline oxide semiconductor as a major component;
a principal plane that is an a-plane or an m-plane; and
a carrier concentration that is 1.0×10 18 /cm 3 or more wherein the crystalline oxide semiconductor film has a mobility that is 40 cm 2 /Vs or more even in a low temperature region below 150 K.
2. The crystalline oxide semiconductor film of claim 1 ,
wherein the crystalline oxide semiconductor film comprises a full width at half maximum of 300 arcsec or more.
3. The crystalline oxide semiconductor film of claim 1 ,
wherein the crystalline oxide semiconductor film has electrical resistivity that is 50 mΩcm or less.
4. The crystalline oxide semiconductor film of claim 1 ,
wherein the crystalline oxide semiconductor film comprises an off-angle.
5. The crystalline oxide semiconductor film of claim 1 ,
wherein the crystalline oxide semiconductor film comprises a dopant that comprises tin, germanium, or silicon.
6. The crystalline oxide semiconductor film of claim 1 ,
wherein the corundum-structured crystalline oxide semiconductor further comprises at least one of indium or aluminum.
7. A semiconductor device comprising:
at least an electrode and the crystalline oxide semiconductor film of claim 1 as a semiconductor layer.
8. A semiconductor system comprising:
the semiconductor device of claim 7 .
9. The crystalline oxide semiconductor film of claim 1 , wherein
the crystalline oxide semiconductor film has a mobility that is 60 cm 2 /Vs or more in a temperature region of 150 K to 300 K.
10. The crystalline oxide semiconductor film of claim 1 , comprising:
a surface area of at least 3 mm 2 without cracks.
11. A crystalline oxide semiconductor film comprising:
a corundum-structured crystalline oxide semiconductor as a major component;
a principal plane that is an m-plane; and
a carrier concentration that is 1.0×10 18 /cm 3 or more wherein the crystalline oxide semiconductor film has a mobility that is 40 cm 2 /Vs or more even in a low temperature region below 150 K.
12. The crystalline oxide semiconductor film of claim 11 ,
wherein the crystalline oxide semiconductor film comprises a dopant that comprises tin.
13. The crystalline oxide semiconductor film of claim 11 , wherein
the principal plane is the m-plane with an off-angle inclined to a direction of an a-axis from the m-plane, and the crystalline oxide semiconductor film has a mobility that is 50 cm 2 /Vs or more.
14. The crystalline oxide semiconductor film of claim 11 , wherein the crystalline oxide semiconductor film comprises an n-type dopant.
15. A semiconductor device comprising:
the crystalline oxide semiconductor film of claim 11 ;
a first electrode electrically connected to the crystalline oxide semiconductor film; and
a second electrode electrically connected to the crystalline oxide semiconductor film.
16. The crystalline oxide semiconductor film of claim 11 , wherein
the crystalline oxide semiconductor film has an electrical resistivity that is 10 mΩcm or less.
17. A crystalline oxide semiconductor film comprising:
a corundum-structured crystalline oxide semiconductor as a major component;
a principal plane that is an m-plane with an off-angle inclined to the direction of the a-axis from the m-plane; and
a carrier concentration that is 1.0×10 18 /cm 3 or more wherein the crystalline oxide semiconductor film has a mobility that is 40 cm 2 /Vs or more even in a low temperature region below 150 K .
18. The crystalline oxide semiconductor film of claim 17 , wherein
the off-angle inclined to the direction of the a-axis from the m-plane is in a range of 0.5° to 3.0°.
19. The crystalline oxide semiconductor film of claim 18 comprising:
a mobility that is 90 cm 2 /Vs or more.
20. The crystalline oxide semiconductor film of claim 17 ,
wherein the crystalline oxide semiconductor film has an electrical resistivity that is 10 mΩcm or less.