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 deposition method comprising:
positioning a substrate in a sputtering chamber, the sputtering chamber comprising a zinc-containing target;
delivering a sputtering gas to the sputtering chamber;
activating the sputtering gas; and
depositing an amorphous oxynitride semiconductor layer on a substrate, the semiconductor layer comprising a ternary compound of zinc, oxygen and nitrogen, wherein the semiconductor layer has a transmittance of less than 80 percent.
2. The deposition method of claim 1 , further comprising annealing the semiconductor layer.
3. The deposition method of claim 1 , wherein the semiconductor layer is annealed at a temperature of about 400 degrees C.
4. The deposition method of claim 1 , wherein the sputtering gas comprises an oxygen-containing gas and a nitrogen-containing gas.
5. The deposition method of claim 4 , wherein the oxygen-containing gas and a nitrogen-containing gas are delivered at a flow ratio of 10:1 to 100:1.
6. The deposition method of claim 1 , wherein the ternary compound comprises ZnN x O y .
7. The deposition method of claim 1 , wherein the sputtering gas further comprises B 2 H 6 , CO 2 , CO, CH 4 or combinations thereof.
8. The deposition method of claim 1 , wherein the ternary compound comprises a dopant.
9. The deposition method of claim 1 , wherein the dopant is aluminum.