HIGH TRANSCONDUCTANCE-NORMALLY-OFF GAN MODFETS

Normally-off GaN based modulation doped field-effect transistors have been fabricated. The extrinsic transconductance of MODFETs with gate a nd channel lengths of 3 and 5 mu m, respectively, is as high as 120mS/ mm. The devices exhibit 300 mA/mm current al a positive gate bias of 3 V. This transconductance value compares very favourably with the 45mS/ mm and 24mS/mm reported earlier for 1 and 0.23 mu m gate devices, resp ectively.