Gated Bow-Tie Diode for Microwave to Sub-Terahertz Detection

Area of Science:

• Semiconductor device physics
• Microwave engineering
• Sensor technology

Background:

• Traditional microwave sensors often face limitations in sensitivity and frequency response.
• Asymmetrical semiconductor structures offer unique electronic properties for device applications.

Purpose of the Study:

• To introduce a novel bow-tie diode design for enhanced microwave radiation sensing.
• To investigate the effect of gate placement on the diode's sensing characteristics.
• To evaluate the sensor's performance in the microwave and sub-terahertz frequency range.

Main Methods:

• Fabrication of a selectively doped semiconductor bow-tie diode with a tunable gate.
• Characterization of the diode's voltage sensitivity and frequency dependence under varying gate conditions.
• Analysis of the thermoelectric electromotive force of hot electrons in the asymmetrical n-n+ junction.

Main Results:

• Gating the active layer significantly enhances voltage sensitivity, increasing it tenfold when the gate is near the wide contact.
• The gate placement influences the detected voltage polarity and its dependence on frequency.
• A gate positioned by the wide contact results in a weak frequency dependence, ideal for broad-spectrum detection.
• A gate near the narrow contact yields a two-order magnitude increase in sensitivity for microwaves, but with strong frequency dependence at higher frequencies.

Conclusions:

• The proposed gated bow-tie diode offers a significant advancement in microwave radiation sensing.
• The device's tunable sensitivity and frequency response characteristics make it a promising candidate for detecting electromagnetic radiation across microwave and sub-terahertz frequencies.
• This design provides a pathway for developing next-generation high-performance microwave and millimeter-wave sensors.