Thin film semiconductor material produced through reactive sputtering of zinc target using nitrogen gases
The present invention generally comprises a semiconductor film and the reactive sputtering process used to deposit the semiconductor film. The sputtering target may comprise pure zinc (i.e., 99.995 atomic percent or greater), which may be doped with aluminum (about 1 atomic percent to about 20 atomic percent) or other doping metals. The zinc target may be reactively sputtered by introducing nitrogen and oxygen to the chamber. The amount of nitrogen may be significantly greater than the amount of oxygen and argon gas. The amount of oxygen may be based upon a turning point of the film structure, the film transmittance, a DC voltage change, or the film conductivity based upon measurements obtained from deposition without the nitrogen containing gas. The reactive sputtering may occur at temperatures from about room temperature up to several hundred degrees Celsius. After deposition, the semiconductor film may be annealed to further improve the film mobility.
1. A semiconductor film comprising a ternary compound of zinc, oxygen, and nitrogen, wherein the semiconductor film has a sheet resistance of between about 100 ohm/sq to about 1×10 5 ohm/sq, and wherein the ternary compound comprises ZnN x O y and a dopant.
2. The semiconductor film of claim 1 , wherein the film has a resistivity of between about 0.001 to about 30 ohm-cm.
3. The semiconductor film of claim 1 , wherein the film has a mobility of greater than about 30 cm 2 /V-s.
4. The semiconductor film of claim 3 , wherein the film has a mobility of greater than about 90 cm 2 /V-s.
5. The semiconductor film of claim 1 , wherein the film has a transmittance of up to about 80 percent.
6. The semiconductor film of claim 1 , wherein the film has a graded band gap energy between about 3.1 eV and about 1.2 eV.
7. The semiconductor film of claim 1 , wherein the dopant comprises aluminum.
8. The semiconductor film of claim 1 , wherein the semiconductor film has a mobility of greater than about 20 cm 2 /V-s.
9. The semiconductor film of claim 1 , further comprising a passivation portion.