Simple estimation of intrinsic electrical parameters in junctionless transistors

Abstract

Junctionless transistors (JLTs) are an attractive candidate for advanced complementary metal oxide semiconductor technologies, but their mode of operation is very different from that of conventional inversion-mode transistors. In this study, we explore the close relationship between the key electrical parameters of JLTs, such as doping concentration (Nd), threshold voltage (Vth), and flat-band voltage (Vfb). The separation between Vfb and Vth in JLTs increases linearly with Nd, and the rate of increase in the separation was affected by the maximum depletion depth (Dmax) at given Nd. These findings will enable researchers to estimate simply the Nd or Vfb values of not only JLTs but also JLT-like multi-layer transition metal dichalcogenide-based transistors.

Junctionless Electric-Double-Layer MoS2 Field-Effect Transistor with a Sub-5 nm Thick Electrostatically Highly Doped Channel

“…The MoS 2 channel is electrostatically doped by the positive V gb . The electron charge ( Q n ) per unit area can be derived using the depletion approximation: where q , t MoS2 , ε MoS2 , and C EDL are the electron charge, MoS 2 channel thickness, MoS 2 permittivity, and EDL capacitance per unit area, respectively. , Q n ( V th ) should be zero when V g = V th ; thus, V th can be derived by assuming that V fb ≈ 0 with a proper calculation. Eq shows that V th is linearly proportional to − N d, which is consistent with the data shown in the inset in Figure a. Therefore, the effective doping level ( N d_eff ) in the channel for a particular V gb value can be estimated by the comparison of Figures c and a.…”

Channel-Width-Dependent Mobility Degradation in Bulk Conduction Regime of Tri-Gate Junctionless Transistors

“…Recently, junctionless transistors (JLTs) have received considerable attention to overcome scaling challenges for advanced sub-5nm nodes. Extremely simple structures without p-n-junctions, better reliability and lower flicker noise are key advantages of JLTs [7][8][9][10][11][12][13][14][15]. An additional implantation process on source and drain regions can also improve performance of JLTs with reducing access resistance [16].…”