AlN/AlGaN/GaN buffer optimization on silicon (111): bow and crystal quality control for Si-CMOS fabs

In GaN-on-silicon there are many challenges which are currently encountered when making this technology compatible with standard Si-CMOS fabs especially the bow. Bringing this technology to CMOS fabs can potentially drive the costs down, in addition to the cost advantage expected from large wafer sizes. We report here on the impact of AlN nucleation layer on crystal quality and bow. The focus will be on V/III ratios and pre-dose conditions for AlN, which have considerable effect on the AlN/AlGaN/GaN buffer structures. We will also discuss how AlN thickness can be used to tune the bow. Finally, a brief description on the effect of surface pits will be presented. [GRAPHICS] The image presents 200 mm GaN-on-silicon wafers placed on a graphite carrier. The MOCVD system is capable of handling three 200 mm wafers.(C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim