Integrated Circuit-on-Glass (ICoG): A Self-Packaged 3D-Heterogeneous Integration (3DHI) Platform for Millimeter-Wave Circuits With Embedded GaN-on-Si Dielets

This work proposes a novel integrated circuit-on-glass (ICoG) platform for the 3D-heterogeneous integration (3DHI) of highly scaled gallium nitride (GaN) dielets for fabrication of millimeter-wave (mmWave) circuits. Au-free GaN-on-Si high electron mobility transistor (HEMT) dielets are fabricated using a copper gate technology and singulated to a size of$350\times 540$$\mu $m. The GaN dielets are embedded into a glass interposer featuring a two-layer redistribution layer (RDL) and copper back-end-of-line (BEOL) fabricated using semi-additive (SAP) processing. After quantifying the RDL loading effects on the GaN, a model of the dielet after integration is developed. This model was then used for the design and fabrication of two amplifiers, one targeting the fifth-generation (5G) new radio (NR) frequency range 2 (FR2) 28 GHz band and a 10 GHz amplifier featuring high linearity for future 5G NR frequency range 3(FR3) applications.