Steep Subthreshold Swing in GaN Negative Capacitance Field-Effect Transistors

Due to the Boltzmann distribution of carriers, the subthreshold swing (SS) of traditional metal-oxide-semiconductor field-effect transistors (MOSFETs) is above 60 mV/dec at room temperature. In this article, GaN-based negative capacitance field-effect transistors (NCFETs) were fabricated by introducing HfO2/P(VDF-TrFE) stack as the gate dielectric layer. With the voltage amplification effect of the ferroelectric, the GaN NCFETs demonstrate the ultralow SS value of 36.3 mV/dec at room temperature, which also advances the MOSFETs in terms of saturation current (633.4 mu A/mu m) and ON - OFF ratio (> 10(7)). Therefore, this article demonstrates the feasibility of NCFETs for breaking the Boltzmann limit in III-V semiconductors-based transistors and opens up an avenue for switching electronic devices for portable applications.