Low-temperature-deposited AlGaN interlayer for improvement of AlGaN/GaN heterostructure

We have studied the effect of a low-temperature-deposited (LT-) AlGaN inter layer on AlGaN/GaN heterostructure. High-crystalline-quality and crack-free AlGaN layers covering the entire compositional range were realized using t he LT-AIN interlayer. We also showed that AlGaN is applicable as the LT-int erlayer under the condition that the AlN molar fraction of the LT-AlGaN int erlayer is equal to or larger than that of the overgrown,AlGaN layer. Furth ermore, electrically conductive LT-Al0.1Ga0.9N has been realized with an in termediate deposition temperature and very high SiH4 flow rate, in addition to the high-quality overgrown AlGaN layer, It is thought that the LT-inter layer technology call overcome the challenges of glowing a high-quality AlG aN layer with high AlN mole fraction on GaN layers. (C) 2001 Published by E lsevier Science B.V.