CMOS compatible low-power volatile atomic switch for steep-slope FET devices

In this paper, we demonstrate a volatile atomic switch that can be utilized for obtaining steep subthreshold swing (SS) (<5 mV/dec) characteristics in FETs. We propose a CMOS-compatible atomic switch (W/Cu₂S/W) that demonstrates volatility and immunity to the voltage-time dilemma. Furthermore, we enhance the device characteristics by examining the composition control, scaling of device size, and film thickness. Then, the atomic switch is integrated with a conventional transistor that has a large SS (>60 mV/dec). The result shows an improvement in the SS, which results from the transition of the atomic switch between the ON and OFF states, which is caused by the formation and rupture of a conductive filament. As a result, excellent switching characteristics are obtained for the FETs, such as low I_OFF (∼10^-5 μA/μm), high I_ON/I_OFF ratio (∼10⁵), low V_DD (∼0.25 V), and steep SS (<5 mV/dec).