0.15 /spl mu/m double modulation doped InAs-inserted-channel MODFETs: gate recess for optimum RF performances
The effects of gate recess etch profiles on DC and RF characteristics of double-sided doped InAs-inserted-channel MODFETs are investigated. The maximum extrinsic transconductance is as high as 1.3 S/mm at a channel current of ~500 mA/mm. It is found that fT of 220 GHz and fmax of 280 GHz can be realised for 0.15 µm T-gate, with a gate recess with appropriate width. The RF intrinsic elements are extracted and analysed to explain the improved fmax. The breakdown voltage of ~4 V can be achieved for devices with a 50 nm wide lateral recess.