Progress in microwave GaN HEMT grown by MBEudon silicon and smart Cut TM engineered substratesudfor high power applications

摘要

SiCOI (SiC On Insulator) compositeudsubstrates obtained by the Smart-Cut TM process areudalternative possible substrates for epitaxial growth of WideudBand Gap (WBG) materials such as GaN and GaN alloys.udSimilar to bonded SOI structure, the SiCOI structuresudbasically comprises a thin film of single SiC crystal bondedudonto a substrate such as, for instance, silicon substrate.udAdditionally to the well known insulation properties, SiCOIudsubstrates have been proven to be adapted to the growth ofudhigh quality GaN layer. This first study has provenudcompatibility of SiCOI structure for single layer GaN MBEudgrowth. We present here last results of AlGaN / GaNudHEMT structure grown by MBE with NH3 as nitrogenudprecursor onto SiCOI (on silicon) structure realised byudSmart Cut ™. First of all, complete SiCOI structureudrealisation will be described and typical physicaludcharacterization results will be presented for this kind ofudsubstrate. Then, will be detailed MBE epitaxy set-up andudgrowth parameters for HEMT structure, including specificudbuffer layer stack description. Finally, physical andudelectrical characterisation results for epi-layers and HEMTudstructure will be presented. Those results show strongudcompatibility of SiCOI structure for MBE epitaxy of GaNudbased HEMT structure and demonstrate the interest ofudSmart Cut ™ approach to build composite substrates, likeudSiCOI, for hetero-epitaxy application.