Deposition method of III group nitride compound semiconductor laminated structure
The present invention provides a deposition method of a multilayered structure composed of a III group nitride compound semiconductor having good crystallinity on a substrate. The multilayered structure comprises at least a buffer layer and an underlying layer from the substrate side, and the buffer layer and the underlying layer are formed by a sputtering method. A deposition temperature of the buffer layer is adjusted to a temperature lower than a deposition temperature of the underlying layer, or the thickness of the buffer layer is adjusted to 5 nm to 500 nm. Furthermore, the multilayered structure comprises at least an underlying layer and a light-emissive layer from the substrate side and the underlying layer is formed by a sputtering method, and the method comprises the step of forming the light-emissive layer by a metal-organic chemical vapor deposition (MOCVD method).
1. A deposition method of a multilayered structure composed of a III group nitride compound semiconductor on a substrate, characterized in that:
the multilayered structure comprises at least a buffer layer formed on a surface of the substrate, and an underlying layer formed on a surface of the buffer layer,
the buffer layer and the underlying layer are laminated by a sputtering method, and
a deposition temperature of the buffer layer is adjusted to a temperature lower than a deposition temperature of the underlying layer
wherein a ratio of a nitrogen flow rate to a flow rate of nitrogen and argon is from 75% to 100% during deposition of the underlying layer.
2. The deposition method of a III group nitride compound semiconductor laminated structure according to claim 1 , wherein the buffer layer contains Al.
3. The deposition method of a III group nitride compound semiconductor laminated structure according to claim 2 , wherein the buffer layer is formed of AlN.
4. The deposition method of a III group nitride compound semiconductor laminated structure according to claim 2 , wherein the buffer layer is formed of an aggregate of a columnar crystal.
5. The deposition method of a III group nitride compound semiconductor laminated structure according to claim 2 , wherein at least 60% of the substrate is coated with the buffer layer.
6. The deposition method of a III group nitride compound semiconductor laminated structure according to claim 2 , wherein the buffer layer has a thickness of 20 to 100 nm.
7. The deposition method of a III group nitride compound semiconductor laminated structure according to claim 1 , wherein the underlying layer contains Ga.
8. The deposition method of a III group nitride compound semiconductor laminated structure according to claim 7 , wherein the underlying layer is formed of GaN.
9. The deposition method of a III group nitride compound semiconductor laminated structure according to claim 1 , wherein the buffer layer is formed of AlN and the underlying layer is formed of GaN.
10. The deposition method of a III group nitride compound semiconductor laminated structure according to claim 1 , wherein the buffer layer has a deposition temperature of room temperature to 800° C.
11. The deposition method of a III group nitride compound semiconductor laminated structure according to claim 1 , wherein the underlying layer has a deposition temperature of 300 to 1,500° C.
12. The deposition method of a III group nitride compound semiconductor laminated structure according to claim 1 , wherein a difference in the deposition temperature between the buffer layer and the underlying layer is 100° C. or higher.