AlGaN/GaN C-HEMT structures for dynamic stress detection

In our work, we investigated the possibility of dynamic stress detection based on the piezoelectric polarization using AlGaN/GaN circular high electron mobility transistors (C-HEMTs). In our knowledge, stress sensors in that account are introduced for the first time. The sensor structures exhibit good linearity in the piezoelectric response under dynamic stress conditions. The measurements reveal excellent stress detection sensitivity that is independent on the measured frequency range. The sensitivity of the devices can be easily increased by increase of the area of the Schottky gate ring electrode. The further increase of the sensitivity can be tuned by an optimal selection of the DC drain and gate bias.