InGaAs Schottky barrier diode array detector for a real-time compact terahertz line scanner

Area of Science:

• Terahertz (THz) technology
• Semiconductor device physics
• Photonics and optoelectronics

Background:

• Terahertz (THz) imaging requires sensitive and efficient detectors.
• Schottky barrier diodes (SBDs) are promising for THz detection due to their fast response.
• Developing array-type detectors with simple fabrication and high yield is crucial for practical applications.

Purpose of the Study:

• To present a novel antenna-integrated 1 × 20 InGaAs Schottky barrier diode (SBD) array detector.
• To characterize the responsivity, noise equivalent power (NEP), and bandwidth of the SBD array detector.
• To demonstrate the feasibility of THz line beam imaging using the developed detector array.

Main Methods:

• Fabrication of a 1 × 20 InGaAs SBD array detector utilizing an SiN(x) layer instead of an air bridge for improved yield.
• Measurement of detector responsivity and NEP at 250 GHz without external amplifiers or Si lenses.
• Characterization of the 3-dB bandwidth of the SBD detector.
• Demonstration of THz line beam imaging using a Gunn diode emitter and the SBD array detector.

Main Results:

• Achieved an average responsivity of 98.5 V/W at 250 GHz.
• Obtained an average noise equivalent power (NEP) of 106.6 pW/√Hz.
• Determined a 3-dB bandwidth of approximately 180 GHz.
• Successfully demonstrated THz line beam imaging.

Conclusions:

• The developed antenna-integrated InGaAs SBD array detector offers high performance for THz applications.
• The simplified fabrication process using an SiN(x) layer enhances yield for array-type detectors.
• The successful THz line beam imaging validates the detector's capability for practical imaging systems.