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Diamond-Incorporated Flip-Chip Integration for Thermal Management of GaN and Ultra-Wide Bandgap RF Power Amplifiers

MetadataDetails
Publication Date2021-06-22
JournalIEEE Transactions on Components Packaging and Manufacturing Technology
AuthorsDaniel Shoemaker, Mohamadali Malakoutian, Bikramjit Chatterjee, Yiwen Song, Samuel Kim
InstitutionsPennsylvania State University, Stanford University
Citations50

GaN radio frequency (RF) power amplifiers offer many benefits including high power density, reduced device footprint, high operating voltage, and excellent gain and power-added efficiency. Accordingly, these parts are enabling next-generation technologies such as fifth-generation (5G) base transceiver stations and defense/aerospace applications such as high-performance radar and communication systems. However, these benefits can be overshadowed by device overheating that compromises the performance and reliability. In response to this, researchers have focused on GaN-on-diamond integration during the past decade. However, manufacturability, scalability, and long-term reliability remain as critical challenges toward the commercialization of the novel device platform. In this work, a diamond-incorporated flip-chip integration scheme is proposed that takes advantage of existing semiconductor device processing and growth techniques. Using an experimentally validated GaN-on-SiC multifinger device model, the theoretical limit of the cooling effectiveness of the device-level thermal management solution has been evaluated. Simulation results show that by employing a ~ 2-μm diamond passivation overlayer, gold thermal bumps, and a commercial polycrystalline carrier wafer, the power amplifier’s dissipated heat can be effectively routed toward the package, which leads to a junction-to-package thermal resistance lower than GaN-on-diamond high electron mobility transistors (HEMTs). Furthermore, simulation results show that this approach is even more promising for lowering the device thermal resistance of emerging ultra-wide bandgap devices based on β-Ga <sub xmlns:mml=ā€œhttp://www.w3.org/1998/Math/MathMLā€ xmlns:xlink=ā€œhttp://www.w3.org/1999/xlinkā€&gt;2&lt;/sub> O <sub xmlns:mml=ā€œhttp://www.w3.org/1998/Math/MathMLā€ xmlns:xlink=ā€œhttp://www.w3.org/1999/xlinkā€&gt;3&lt;/sub> and AlGaN, below that for today’s state-of-the-art GaN-on-diamond HEMTs.