0.2-μm gate-length InGaP-InGaAs DCFETs for C-band MMIC amplifier applications

A C-band In_0.49Ga_0.51P-In_0.15Ga_0.85As doped-channel FET (DCFET) monolithic power amplifier was designed and fabricated using low-k benzocyclobutene (BCB) interlayer technology. With a photosensitive low-k BCB interlayer (ε=2.7), not only can the circuit´s passivation layer, but also the capacitor insulator, via holes, and bridge process be realized simultaneously, where the process complexity and cost can be reduced. In addition, a 0.2-μm T-shaped gate InGaP-InGaAs doped-channel FET with a high current density and a high linearity is introduced to the amplifier using the e-beam lithography. This C-band power amplifier can achieve a linear power gain of 9.3 dB and an output power of 15.3 dBm, which proves that this novel MMIC process using low-k BCB interlayer technology is attractive for microwave and millimeter wave circuit applications.