Broadband terahertz imaging with highly sensitive silicon CMOS detectors

Area of Science:

• Terahertz (THz) technology
• Silicon CMOS fabrication
• Detector physics

Background:

• Terahertz imaging requires sensitive and cost-effective detectors.
• Existing THz detector technologies often face limitations in cost, sensitivity, or operating frequency.
• Silicon CMOS technology offers a scalable and affordable platform for integrated electronic devices.

Purpose of the Study:

• To investigate the performance of terahertz detectors fabricated in a low-cost 130 nm silicon CMOS technology.
• To assess the responsivity and noise equivalent power of these detectors at room temperature.
• To demonstrate the suitability of these detectors for broadband terahertz imaging applications.

Main Methods:

• Fabrication of nMOS field-effect transistor (FET) based detectors in 130 nm silicon CMOS.
• Integration of a bow-tie coupling antenna with the nMOS FET.
• Characterization of detector responsivity and noise equivalent power (NEP) around 300 GHz.
• Evaluation of detector performance for imaging across a wide frequency range (0.27–1.05 THz).

Main Results:

• Achieved record responsivity exceeding 5 kV/W at room temperature.
• Demonstrated noise equivalent power below 10 pW/Hz(0.5) around 300 GHz.
• Confirmed efficient terahertz imaging capability from approximately 0.27 THz to 1.05 THz.

Conclusions:

• Low-cost silicon CMOS technology can yield high-performance terahertz detectors.
• The developed detectors offer a promising solution for sensitive, broadband terahertz imaging.
• These findings pave the way for high-sensitivity focal plane arrays for terahertz imaging applications.