High-sensitivity differential terahertz detector based on antenna-coupled InP high-electron-mobility transistors

Area of Science:

• Terahertz (THz) technology
• Semiconductor device physics
• Optoelectronics

Background:

• Terahertz detectors are crucial for various applications, but achieving high sensitivity at room temperature remains a challenge.
• Self-mixing in antenna-coupled field-effect transistors (FETs) offers a promising route for THz detection.
• Improving detector performance requires optimizing design parameters and material properties.

Purpose of the Study:

• To develop an approach for enhancing the sensitivity of terahertz detectors.
• To investigate the impact of a differential detector design on detector performance.
• To achieve a low optical noise-equivalent power (NEP) at room temperature.

Main Methods:

• Utilized self-mixing in antenna-coupled field-effect transistors.
• Employed a differential detector design.
• Optimized electron mobility, ohmic contact resistance, and surface roughness.
• Fabricated an InP high-electron-mobility transistor (HEMT) detector with a 2-μm gate length using contact lithography.

Main Results:

• Achieved a room-temperature optical NEP of 7.7 pW/Hz at 363.7 GHz.
• Demonstrated performance comparable to state-of-the-art CMOS and GaN HEMT detectors with deep-submicron gate lengths.
• The differential detector design significantly enhanced sensitivity.

Conclusions:

• The developed approach effectively enhances terahertz detector sensitivity.
• Further scaling of the InP HEMT detector's gate length is expected to yield sub-pW/Hz NEP at room temperature.
• This work paves the way for next-generation, highly sensitive room-temperature terahertz detectors.