Patent ID: 8502219

Claim:
A method for growing a ZnO-based crystal layer on a substrate of a zinc oxide (ZnO) single crystal by an MOCVD method, said method comprising: a low-temperature growth step of growing a ZnO-based single crystal buffer layer on said substrate at a growth temperature in the range of 250° C. to 450° C. using a polar oxygen material and a metalorganic compound containing no oxygen, wherein a growth pressure in said low-temperature growth step falls within the range of 1 kPa to 30 kPa, and a growth rate of said ZnO-based single crystal buffer layer falls within the range of 0.4 nm/min to 9.0 nm/min; a step of performing a heat treatment of said ZnO-based single crystal buffer layer to effect a transition of said ZnO-based single crystal buffer layer to a thermostable-state ZnO-based single crystal buffer layer; and a high-temperature growth step of growing said ZnO-based single crystal layer on said thermostable-state ZnO-based single crystal buffer layer at a growth temperature in the range of 600° C. to 900° C. using the polar oxygen material and the metalorganic compound containing no oxygen, wherein said buffer layer produces a solid solution with an impurity included in said substrate, and wherein a concentration of the impurity in said buffer layer is larger than a concentration of the impurity in said substrate.