Operational Characteristics of Various AlGaN/GaN High Electron Mobility Transistor Structures Concerning Self-Heating...

Area of Science:

• Semiconductor device physics
• Materials science
• Electrical engineering

Background:

• AlGaN/GaN high electron mobility transistors (HEMTs) are crucial for high-power applications.
• Self-heating effect (SHE) significantly impacts HEMT performance and reliability.
• Optimizing gate structures is essential for mitigating SHE and improving device characteristics.

Purpose of the Study:

• To investigate and compare the DC characteristics of AlGaN/GaN HEMTs with basic T-gate (BT), drain-side extended T-gate (DSET), and source-bridge FP (SBFP) structures.
• To analyze the impact of self-heating effect (SHE) on device performance for different gate designs.
• To identify the optimal gate structure for enhanced breakdown voltage and reduced SHE.

Main Methods:

• Experimental characterization of DC parameters including threshold voltage, transconductance, drain saturation current, and breakdown voltage.
• Device simulation using drift-diffusion and coupled drift-diffusion and self-heating models.
• Analysis of temperature distribution, including hot spots and overall device temperature.

Main Results:

• Experimental data for the BT structure were validated against simulated data.
• DC characteristics were compared across BT, DSET, and SBFP structures, with DSET showing the highest breakdown voltage.
• Increasing the drain-side gate head of the DSET structure to 3 µm further improved breakdown voltage.

Conclusions:

• The DSET structure exhibits superior performance in terms of breakdown voltage compared to BT and SBFP structures.
• The study provides a comparative analysis of different gate designs to mitigate self-heating effects in AlGaN/GaN HEMTs.
• Findings offer valuable guidance for the optimization of AlGaN/GaN HEMTs for high-performance applications.