Steep-slope field-effect transistors with AlGaN/GaN HEMT and oxide-based threshold switching device

We report the demonstration of a steep-slope field-effect transistor with AlGaN/GaN MIS-HEMTs employing SiO₂-based threshold switching devices in series with the source. The SiO₂-based threshold switching devices exhibited steep slope when changing resistance states. The integrated steep-slope transistor showed a low subthreshold swing of sub-5 mV/dec with a transition range of over 10⁵ in the transfer characteristics in both sweep directions at room temperature, as well as the low leakage current (10⁻⁵ μA μm⁻¹) and a high I _ON/I _OFF ratio (>10⁷). Moreover, with the SiO₂-based threshold switching devices we also observed a positive shift of threshold voltages of the integrated device. Results from more than 50 transfer characteristics measurements also indicate the good repeatability and practicability of such a steep-switching device, where the average steep slopes are below 10 mV/decade. This steep-slope transistor with oxide-based threshold switching devices can be further extended to various transistor platforms like Si and III–V and are of potential interest for the development of power switching and high frequency devices. (paper)