Improvement of AlGaN/GaN High-Electron-Mobility Transistor Radio Frequency Performance Using Ohmic Etching Patterns...

Area of Science:

• Materials Science
• Electrical Engineering
• Semiconductor Devices

Background:

• AlGaN/GaN high-electron-mobility transistors (HEMTs) are crucial for high-frequency applications.
• Improving radio frequency (RF) performance and reducing resistances in HEMTs is essential for advanced communication systems.

Purpose of the Study:

• To investigate the impact of ohmic etching patterns (OEPs) on AlGaN/GaN HEMTs.
• To optimize OEP designs for enhanced RF performance in Ka-band applications.
• To reduce source and drain resistances for improved device characteristics.

Main Methods:

• Fabrication of AlGaN/GaN HEMTs with various OEPs (1 μm hole, 3 μm hole, 1 μm line, 3 μm line).
• Measurement of small signal performance, large signal performance, and minimum noise figure (NF).
• Characterization of cut-off frequency (fT), maximum oscillation frequency (fmax), and output power density (Pout,max) using load-pull measurements.

Main Results:

• The 1 μm line OEP HEMT exhibited optimized cut-off frequency (fT) of 36.4 GHz and maximum oscillation frequency (fmax) of 158.29 GHz.
• Maximum output power density (Pout,max) of 1.94 W/mm at 28 GHz was achieved with the 1 μm line OEP HEMT.
• An optimized minimum noise figure (NF) of 1.75 dB at 28 GHz was recorded for the 1 μm line OEP HEMT.
• Reduced contact resistance due to increased contact area between ohmic metal and AlGaN.

Conclusions:

• The 1 μm line OEP HEMT design significantly improves RF performance for Ka-band applications.
• OEPs effectively reduce source and drain resistances, leading to better device characteristics.
• The fabricated OEP HEMTs demonstrate potential for next-generation high-frequency electronic devices.