A mixed HEMT-HBT MMIC technology using MBE regrowth

Current microwave systems are constructed by integrating a large number of single technology components into a final product due to the limitations of any single transistor technology across all functions and metrics, thereby increasing cost and size of a given system. In this paper, we present a fabrication process using Molecular Beam Epitaxy (MBE) regrowth which allows the combination of High Electron Mobility Transistors (HEMT) with Heterostructure Bipolar Transistors (HBT) on a single GaAs chip without compromising the performance of either the HBT or HEMT. HBT fT/Fmax of 40/85 GHz and Beta of 170 for a collector current of 1mA; and HEMT fT/Fmax of 115/160 GHz with a gm-peak of 755 mS/mm has been achieved. Circuit performance demonstrates the potential of performance advances over HEMT-only circuit embodiments.