Methods for improved growth of group III nitride buffer layers

摘要

Methods are disclosed for growing high crystal quality group III-nitride epitaxial layers with advanced multiple buffer layer techniques. In an embodiment, a method includes forming group III-nitride buffer layers that contain aluminum on suitable substrate in a processing chamber of a hydride vapor phase epitaxy processing system. A hydrogen halide or halogen gas is flowing into the growth zone during deposition of buffer layers to suppress homogeneous particle formation. Some combinations of low temperature buffers that contain aluminum (e.g., AlN, AlGaN) and high temperature buffers that contain aluminum (e.g., AlN, AlGaN) may be used to improve crystal quality and morphology of subsequently grown group III-nitride epitaxial layers. The buffer may be deposited on the substrate, or on the surface of another buffer. The additional buffer layers may be added as interlayers in group III-nitride layers (e.g., GaN, AlGaN, AlN).

主权项

1. 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, andflowing 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, andflowing 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.