Accurate Boundary Condition for Short-Channel Effect Compact Modeling in MOS Devices

Compact modeling of subthreshold swing in double gate and nanowire MOSFETs, for Si and GaAs channel materials

“…(10) demonstrates that taking into account the x-dependence of the potential in the VDT is equivalent to replacing the oxide thickness t ox with the effective oxide thickness t eff ox . When t eff ox is injected directly into the SS model presented in [6] (with the correction reported in [7] to deal with depletions regions under the junctions), the agreement with the simulations improves (dashed line on Fig. 1a), but still displays large inaccuracies.…”

“…It is assumed that the potential is a combination of exponential functions [14]. After application of the boundary conditions, this potential takes the following form [7]:…”

“…V S bi;eff and V D bi;eff are the potentials at the source and the drain, respectively, whose expressions are detailed in [7]. k is the electrostatic length.…”

“…Eq. (18) is therefore evaluated at a usual value dVg , are known from [7]. As a result, the final SS expression is:…”

“…These models have been extended to the case of lightly doped drain (LDD) devices in [7]. However, they are still based on a one-dimensional description of the potential along the source drain direction.…”