Patent ID: 8778783

Claim:
A method of depositing multiple buffer layers in a processing chamber of a hydride vapor phase epitaxy processing system, comprising: providing a substrate in the processing chamber of the hydride vapor phase epitaxy processing system; forming a first group III nitride buffer layer that contains aluminum by flowing ammonia gas to a growth zone of the processing chamber, flowing one or more metal halide containing precursors including at least one aluminum halide containing precursor, and flowing halogen gas or hydrogen halide gas into the growth zone at the same time; and forming a second group III nitride buffer layer that contains aluminum over the first buffer layer by flowing ammonia gas to a growth zone of the processing chamber, flowing one or more metal halide containing precursors including at least one aluminum halide containing precursor, and flowing halogen gas or hydrogen halide gas into the growth zone at the same time, wherein the first group III-nitride buffer layer is aluminum nitride (AlN) layer formed at a temperature of approximately 500 to 800 degrees Celsius, the second group III-nitride buffer layer is aluminum nitride (AlN) layer formed at a temperature of 900 degrees Celsius or higher.