AlGaN HEMTs on patterned resistive/conductive SiC templates

High performance GaN-based high electron mobility transistors (HEMTs) on SiC require low-miscut (~0.45°), resistive substrates, which are very expensive. A cost-effective solution is to use resistive SiC template i.e., grow a thick resistive SiC epitaxial layer on cheap, conductive SiC substrate. However, this approach requires much higher miscut (2-8°). In the present work we show a lateral patterning technology capable to locally decrease the high miscut of the resistive SiC template, down to a level acceptable for GaN epitaxy. On such patterned SiC templates we grew smooth AlGaN/GaN structures. The maximum width of flat regions available for device fabrication was nearly 100 µm. In these flat regions AlGaN-based HEMTs were fabricated and characterized.