Performance investigation of hafnium-oxide negative capacitance transistor with remote nitrogen plasma treatment

In this study, we demonstrated the hafnium-oxide negative capacitance transistors using different nitrogen plasma treatments. According to our experimental results, the electrical performance and negative capacitance switch characteristics were also affected by process temperature and ferroelectric/non-ferroelectric crystalline phases in addition to nitrogen species. The transistor device using optimal nitrogen plasma treatment exhibited the excellent performances, including a low off-state current (I_OFF) of ∼10⁻¹³ A/μm, a large on/off-state current ratio (I_ON/I_OFF) of 10⁷ and a steep subthreshold swing (SS) of sub-60 mV/decade with tight switching uniformity under a gate overdrive voltage of 2 V. These experimental results confirm that the negative capacitance transistor adopting hafnium oxide can be further improved by nitrogen species incorporation, which give a promising guidance for the next-generation low-power electronics.