Advantages of AlN/GaN metal insulator semiconductor field effect transistor using wet chemical etching with hot phosphoric acid

An AlN/GaN metal insulator semiconductor field effect transistor (MISFET) was fabricated using a technique of wet chemical etching with hot phosphoric acid. This technique improved ohmic contact resistances for the source and drain, and provided a new and simple fabrication process for the MISFET. In our MISFET with a 3 mum gate length, a maximum transconductance (g(m max)) of 130 mS/mm and a maximum drain current (I-D max) of over 600 mA/mm were obtained. We also fabricated the AlGaN/GaN heterostructure field effect transistor (HFET) with the conventional fabrication process and compared the operating characteristics.