In this investigation, a suppressed channel-rectangular core-shell double gate junctionless field effect transistor (SC_RCS_DGJLFET) is simulated to enhance the junctionless device's performance. This study leverages a core-shell architecture and channel suppression technique to improve the gate controllability over the channel region which helps in substantial depletion of the shells in the OFF state of the device. When compared to conventional double gate JLFETs (C_DGJLFET) and rectangular core-shell double gate JLFETs (RCS_DGJLFET), the performance of the SC_RCS_DGJLFET is superior in terms of IOFF, ION/IOFF ratio, DIBL and subthreshold slope (SS). The SC_RCS_DGJLFET achieves an ultra-low IOFF of 10-16 A, indicating a low leakage current with an impressive ION/IOFF = 1011. Additionally, to analyze the effect of doping on the device performance, the core doping in SC_RCS_DGJLFET is varied for fixed shell doping. The study found that fixing core doping to an appropriate value is a crucial parameter to achieve good device performance. The impact of variation of oxide extension towards the source and drain LextS/LextD in SC_RCS_DGJLFET is also studied for the first time in the core-shell architecture which has further improved the device's performance. Finally, a CMOS inverter is designed using the proposed device that provides valuable insights into its suitability for digital circuit applications and verifies its performance benefits compared to existing transistor technologies. The SC_RCS_DGJLFET based CMOS inverter shows a sharp transition in voltage transfer characteristics (VTC), indicating fast switching speed and precise signal processing capabilities when compared to a CMOS inverter based on a conventional double gate junctionless field effect transistor (C_DGJLFET). Moreover, the transient characteristics of the SC_RCS_DGJLFET based CMOS inverter exhibit an improved output voltage swing, suggesting enhanced dynamic behaviour and stability during logic state transitions.
