Device linearity improvement by Al/sub 0.3/Ga/sub 0.7/As/In/sub 0.2/Ga/sub 0.8/As heterostructure doped-channel FETs

The linearities of pseudomorphic heterostructure Al/sub 0.3/Ga/sub 0.7/As/In/sub 0.2/Ga/sub 0.8/As doped-channel FETs (DCFETs) and HEMTs were evaluated by DC and RF testings. Due to the absence of parallel conduction in the doped-channel approach, as compared to the modulation-doped structure, a wide and flat device performance together with a high current density was achieved. This improvement of device linearity suggests that doped-channel designs are suitable for high frequency power device application.>