Influence of Field Plate, Gate Width, and Voltage Dependence of Thermal Resistance ( R TH) for AlGaN/GaN HEMT
Year: 2024
Type: article
Abstract: The thermal resistance (${R}_{\text {TH}}$) of 0.15- and 0.25-$\mu $m AlGaN/GaN high-electron mobility transistor (HEMT) is computed from the linear portion of simulated change in channel temperature ($\Delta {T}$) versus power dissipation (${P}_{D}$) plot. The simulated I–V characteristics are validated with measured data using the Sentaurus thermodynamic TCAD model. Subsequently,${R}_{\text {TH}}$is estimated for the HEMT with and without a gate field-plate (FP) structure. Three linear${R}_{\text {TH}}$regions are observed for HEMT with FP, due to the variation in the hotspot position with the increasing drain voltage, whereas a single${R}_{\text {TH}}$is identified for the HEMT without FP, as the hotspot remains at the drain side of the gate edge over a wide range of dissipated power.${R}_{\text {TH}}$is also reported for the HEMT with different FP lengths (${L}_{\text {FP}}$), showing that${R}_{\text {TH}}$decreases as${L}_{\text {FP}}$increases.${R}_{\text {TH}}$is found to decrease with the gate width, which is consistent with the theory as well as the thermoreflectance and pulsed I– V measurements. A slight increase in${R}_{\text {TH}}$is observed upon reducing the gate voltage. Furthermore, the change in${R}_{\text {TH}}$is evaluated by placing thermal contact at three different locations (substrate bottom, buffer and substrate sidewall, and contacts) in the simulation. Similar observations are detected for 0.25-$\mu $m AlGaN/GaN HEMTs.
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4402570763