Novel high temperature metal organic chemical vapor deposition vertical rotating-disk reactor with multizone heating for GaN and related materials

Abstract

In the past several years developments in epitaxial growth of GaN have made this material varible for device applications such as UV and blue-light-emitting diodes and short-wavelength lasers in optical memory. At the same time, metal organic vapor-phase epitaxial growth of GaN presents several technical challenges including high growth temperatures (in the range of 1100 °C), a small process parameter window, and strict requirements for highly uniform flow and temperature distribution over the area of deposition. Finite element analysis thermal modeling in combination with a novel experimental technique for real-time thermal mapping of the rotating wafer under actual deposition parameters was used for the development of a multizone heating system that provided temperature uniformity better than 3.3 °C for a 50 mm wafer at a deposition temperature of 1050 °C. Computational flow modeling was also used during design optimization. High flow and temperature uniformity provided by a new metal organic vapor-phase epitaxy rotating-disk reactor allowed us to deposit GaN films with very good surface morphology (roughness less than 100 Å) and with thickness uniformity to less than 2% across 50 mm wafers.