70 nm low-noise metamorphic HEMT technology on 4 inch GaAs wafers

A 70 nm gate length metamorphic HEMT technology will be presented. Extrinsic cut-off frequencies of f_t = 293 GHz and f_max = 337 GHz were achieved. The transistors have an on-state breakdown voltage of 1.7 V. A median time to failure of 1×10⁶ h at 125°C and an activation energy of 1.3 eV was extrapolated based on a 10% g_m,max degradation in air. This is significant less than the 1.8 eV activation energy of our 100 nm gate-length 65% In process which is probably due to hot electron effects. The MMIC-process obtains high yields on transistor and circuit level. Low-noise amplifiers demonstrate a small signal gain of 13 dB and a noise figure of 2.8 dB at 94 GHz. The achieved results are comparable to state-of-the-art InP-based HEMT technologies.