Sub-quarter micron gate length high electron mobility transistors processing technology

This paper describes the design principle of modulation doped AlGaAs/GaAs field effect transistors (HEMT). Processing steps of gate length as short as 0. 2 /spl mu/m with T-shape gate and the condition of the E-Beam lithography to obtain submicron gate length. Transcanductances of the order of 200ms/mm at room temperature and 375ms/mm at 77K are measured.