Measurements of electroluminescence intensity distribution in the direction of gate width of n(+) self-aligned gate GaAs metal-semiconductor field-effect transistors

We studied electroluminescence (EL) intensity distributions in the directio n of gate width of n(+) self-aligned gate GaAs metal-semiconductor field-ef fect transistors (MESFETs). Nonuniform EL was observed along the gate-width direction, suggesting the nonuniform high-field formation in the direction of the gate. It has also been found that the EL at the source side shows g entler distribution than that at the drain side. These features suggest tha t the nonuniform hole distribution generated by impact ionization at the dr ain side becomes gradual during the process of their flow into the source a nd gate electrodes.