First observation of bias oscillations in GaN Gunn diodes on GaN substrate

作者：Yilmazoglu Oktay^*; Mutamba Kabula; Pavlidis Dimitris; Karaduman Tamer

来源：IEEE Transactions on Electron Devices, 2008, 55(6): 1563-1567.

DOI：10.1109/TED.2008.921253

• bias oscillation
• GaN
• Gunn diode

In this paper, we report on the bias oscillation of GaN-based Gunn diodes realized on a n(+)-GaN substrate. Different contact materials, ambient gases, and pulsewidths were used and compared with regard to device stability. A wide negative-differential-resistance (NDR) region was measured for electrical-field values E larger than a threshold field E-th of 150 kV/cm. Electrical fields much higher than the threshold value did not lead to any electromigration effects or discharging problems from the contacts. The drift velocity derived from the current-voltage characteristics, diode geometry, and doping concentration in the active layer was estimated to be 1.9 x 10(7) cm/s. Bias oscillations were obtained for the GaN Gunn diodes in the presence of a series inductance.

• 出版日期2008-6