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

• Published in: IEEE transactions on components, packaging, and manufacturing technology (2011) Vol. 11; no. 8; pp. 1177 - 1186
• Main Authors: Shoemaker, Daniel, Malakoutian, Mohamadali, Chatterjee, Bikramjit, Song, Yiwen, Kim, Samuel, Foley, Brian M., Graham, Samuel, Nordquist, Christopher D., Chowdhury, Srabanti, Choi, Sukwon
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.08.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aluminum gallium nitride; Aluminum gallium nitrides; Commercial spacecraft; Commercialization; Communications systems; Cooling; Diamond; diamond passivation; Diamonds; Energy gap; Flip-chip devices; gallium nitride; Gallium nitrides; gallium oxide; Gallium oxides; Heat transfer; HEMTs; High electron mobility transistors; Manufacturability; MODFETs; Overheating; Power amplifiers; Radio frequency; radio frequency (RF); Raman scattering; Reliability; Semiconductor devices; Semiconductors; Temperature measurement; Thermal management; thermal management of electronics; Thermal resistance; wide bandgap semiconductors
• ISSN: 2156-3950; 2156-3985
• DOI: 10.1109/TCPMT.2021.3091555

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 <inline-formula> <tex-math notation="LaTeX">\sim 2-\mu \text{m} </tex-math></inline-formula> 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 <inline-formula> <tex-math notation="LaTeX">\beta </tex-math></inline-formula>-Ga 2 O 3 and AlGaN, below that for today's state-of-the-art GaN-on-diamond HEMTs.