InGaAs/AlInAs HEMT technology for millimeter wave applications

AlInAs-GaInAs modulation-doped structures grown by MBE (molecular-beam epitaxy) on InP substrates have demonstrated excellent electronic and optical properties. Extremely high sheet charge densities (n/sub S/ approximately 5*10/sup 18/ cm/sup -3/) and room temperature mobilities ( mu approximately 9500 cm/sup 2/ V/sup -1/ s/sup -1/) have been achieved. 0.1- mu m-gate-length HEMTs (high-electron-mobility transistors) have exhibited an f/sub t/ (unity current gain cutoff frequency) approximately 170 GHz, whereas single stage amplifiers using 0.2- mu m-gate HEMTs have demonstrated a minimum noise figure of 0.8 dB and an associated gain of 8.7 dB. Ring oscillators have demonstrated 6-ps switching speeds and static frequency dividers operated at 26.7 GHz at room temperature.<
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