Heterogeneously-Integrated Amplifier-on-Glass with Embedded Gallium Nitride (GaN) Dielet for mmWave Applications

This work presents the first demonstration of a heterogeneously integrated millimeter-wave (mmWave) amplifier-on-glass with embedded Gallium Nitride (GaN) high-electron-mobility transistors (HEMT) dielet. With the embedded GaN dielet in the prepared glass cavity, redistribution layers (RDL) on the glass package serve as the back-end-of-lines (BEOL) of the circuit and interconnections to other integrated components. In this work, the effects of embedding on GaN performance are studied and a single-stage mmWave amplifier is designed. The amplifier fabrication is enabled by the in-house process capabilities from GaN HEMT preparation to package BEOL build-up. The realized GaN amplifier-on-glass shows >7 dB gain with a bandwidth of $27.35-34.63 \mathrm{GHz}$. This work offers a self-packaged, cost-effective solution for future GaN-based, heterogeneously integrated mmWave systems.