An AlGaN/GaN current regulating diode

AlGaN/GaN lateral current regulating diodes (CRDs) featuring Ohmic anodes and hybrid trench cathodes have been proposed and successfully demonstrated on silicon substrates. By the introduction of a trench with a depth of 16.4 nm in the cathode, the regulating current dramatically decreases from 457.4 to 33.1 mA/mm. In such case, the device can deliver a constant current and keep from thermal runaway under high forward bias. A maximum current hysteresis of 0.698 mA/mm is observed. The measured forward breakdown voltages of the fabricated CRDs are over 200 V in wide temperature ranges from 25 to 250 °C, and the calculated peak dynamic resistance is beyond 0.9 MΩ. Temperature dependent and pulse I-V measurements show that the CRDs possess minor temperature coefficients and fast response capabilities. Both of the two characteristics are essential for the CRD to keep a stable regulating current. Owing to the same GaN material system, the proposed CRD is potentially to be the drivers monolithically integrated with GaN-based LEDs towards a compact and robust single-chip illumination system.