DC and RF characteristics of doped multichannel AlAs0.56Sb0.44/In0.53Ga0.47As field effect transistors with variable gate-lengths

Depletion-mode doped-channel field effect transistors (DCFETs) using AlAs0.56Sb0.44/In0.53Ga0.47As heterostructure with multiple channels grown by molecular beam epitaxy (MBE) on InP substrate are presented. Devices with gate-lengths ranging from 0.2 mum to 1.0 mum have been fabricated. Three doped In0.53Ga0.47As channels separated by undoped AlAs0.56Sb0.44 layers are used for the devices. The devices exhibit unity current gain cut-off frequencies typically between 18 GHz and 73 GHz and corresponding maximum oscillation frequencies typically between 60 GHz and 160 GHz. The multiple channel approach results in wide linearity of de and RF performance of the device.