Year: 2025
Type: report
Abstract: SAND2025-07667CAlGaN and the Substrate Problem • AlGaN: -Ultrawide, tunable bandgap -Low carrier mobility loss at high temperature -Limited substrate availability • Ring-type HEMTs -Same active layer configuration -Different substrates 2 Sapphire (Al 2 O 3 ) (+) Wafer Size (Dia.8-12 inch typ.) (+) Commercially Mature: LED industry (4 inch ≈ $180) (-) Low Thermal Conductivity k Sapphire ≈ 47 W/(m•K) at 20 °C Aluminum Nitride (AlN) (+) High Thermal Conductivity k AlN ≈ 347 W/(m•K) at 20 °C (-) High cost (4 inch ≈ $730) (-) Wafer Size (Dia.4-6 inch typ.)How advantageous is AlN as a substrate relative to the cheaper and larger Sapphire alternative?Experiment: Long PW TTI to evaluate the surface temperatures at known power conditions Simulation: Adjust model parameters (TBRs, Thermal Conductivities) to match TTI results Simulation: Simulate non-achievable power conditions for the AlN Substrate Simulation: Evaluate through-thickness temperature distributions Objective: Using experimental and numerical methods, assess the effects of the substrate on the surface temperature of similar HEMTs Key assumption: Long PW TTI is reaching a steady state heating condition and allowing for complete cooling
DOI: 10.2172/3375773
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
OpenAlex ID: W7166356901