Hetero-Integration of InP Chiplets on a 300 mm RF Silicon Interposer for mm-wave Applications

Abstract

We report measurements of a 300 mm RF Silicon Interposer featuring three thick metal Redistribution Layers (RDL) with spin-coated low RF loss polymer. We also present hetero-integration of passive and active InP chiplets mounted with a 40 um flip-chip pitch. Microstrip lines on the RF Interposer show wideband performance from 20 to 170 GHz with 0.23 and 0.3 dB/mm line loss at 140 GHz for two RDL layers. Passive flip-chip interconnects between InP chiplets and RF Silicon Interposer show 0.1 dB insertion loss per transition at 140 GHz. A two-stage InP Power Amplifier (PA) measured on the Interposer (including flip-chip assembly) shows 116 – 148 GHz (24%) small-signal 3 dB bandwidth and 16.3 dB small signal gain. Large signal measurements show P1 dB of 13 – 15 dBm and PAE of 15 – 28 % between 125 – 135 GHz. These results are state of the art for the RF Silicon Interposer and InP chiplet integration above 100 GHz.