Boule‐like growth of GaN by HVPE

GaN substrates are indispensable for fabrication of blue laser diodes. Growth and cutting of HVPE grown GaN boules is currently the most promising route for cost‐efficient supply of 2 inch c‐plane substrates. But boule lengths and growth rates are still rather low constricted by formation of cracks and morphological defects (V‐pits). It is shown here that the formation of morphological defects in HVPE depends on the growth conditions. The control of their formation allows for high growth rates of about 500 μm/h with improving material quality during growth. Using optimized growth parameters a threading dislocation density of 3x106 cm‐2 and narrow line widths below 100 arcsec of x‐ray rocking curves were obtained for a 3 mm thick GaN layer grown on a GaN/sapphire template (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)