Thermal Optimization and Validation of GaN High Electron Mobility Transistor

Download or read book Thermal Optimization and Validation of GaN High Electron Mobility Transistor written by Tanmay Pradip Kavade and published by . This book was released on 2017 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gallium Nitride (GaN) is a binary III/V wide band gap semiconductor used in power electronics for operations at high power densities and high speeds. GaN has excellent characteristics like high break-down voltage, high thermal conductivity, and high electron saturation velocity which have led to an intensive study and wide use of GaN in many fields. Some of these fields range from amplifiers, MMIC, laser diodes, pulsed radars and counter-IED jammers to CAT-V modules and fourth generation infrastructure base-stations. In this study package level thermal analysis and management of GaN high electron mobility transistor was carried out for determination of junction temperature and junction-case thermal resistance (Rjc). Two commercially available models were used as a reference for analysis. The sizes for both the models were 3 x 3 mm and 4 x 4 mm with host substrate SiC and Si respectively. The model considers the thickness of GaN and host substrate layers, the gate pitch, length, width, and thermal conductivity of GaN, and host substrate. The analysis is carried out on FEA software. Initially mesh sensitivity analysis was carried out to determine the best possible grid count for CFD analysis. Both the models were analyzed for steady state condition at various radio frequency power output to map the increment in the junction temperature. A parametric study is being carried out to optimize and reduce the maximum junction temperature and junction to case thermal resistance (Rjc) by providing convective air cooling and heat sink. The other part of this study includes optimization of the model using diamond as the host substrate and ceramic as mold compound material to monitor the decrease in the thermal resistance value. Comparative results in this study show the percentage reduction in the estimated Rjc value. Thermal resistance value is estimated using the below formula, Rjc = Tj - Tc / P From the results obtained a significant reduction in the estimated Rjc value was observed when compared for no flow, air flow with heat-sink, different host substrate and different mold compound material conditions. In conclusion GaN HEMT can be optimized to achieve a significant improvement in operation. This would allow operation of GaN devices at high temperature without damaging the reliability and operation life-span.