InGaAs MOSHEMT W-Band LNAs on Silicon and Gallium Arsenide Substrates

Abstract

This letter presents the design, performance, and analysis of four low-noise amplifier (LNA) monolithic microwave integrated circuits (MMICs) operating in W-band. Two LNA designs were fabricated in two variations of a 20-nm gate-length metal-oxide-semiconductor high-electron-mobility transistor (MOSHEMT) technology each. While for the first technology version the heterostructure is directly grown on the final gallium arsenide (GaAs) wafer, the second version uses direct wafer bonding to transfer the III-V heterostructure after the epitaxial growth to a silicon (Si) substrate. Based on the measured noise figure (NF) of the four MMICs over a comprehensive set of bias conditions, the impact of short-channel effects on the RF performance and possible improvements are analyzed. The first LNA covers an octave bandwidth with more than 15 dB of gain and an average NF (75-105 GHz) of 3.5 dB on a Si substrate. At 80 GHz, the second amplifier exhibits minimal NFs of 2.3 and 2.5 dB on GaAs and Si substrates, respectively. Compared to previously reported MOS- or Si-based technologies, the presented LNAs demonstrate state-of-the-art noise performance emphasizing the importance of electron confinement for highly scaled transistor technologies.