Upgrade of Drain Current Compact Model for Nanoscale Triple-Gate Junctionless Transistors to Continuous and Symmetric

Triple-gate junctionless MOSFETs

“…where W eff = N fin (2H fin + W fin ) is the effective width, N fin is the number of fins, H fin and W fin are the fin height and fin width respectively, L is the channel length, C ox is the gate oxide capacitance per unit area and V th is the thermal voltage. The normalized charge at Chapter 4: Continuous and symmetric compact modeling 74 coordinate y along the channel, q y , is given by (4.13) in terms of the threshold voltage V t and the ideality factor ε defined in [154] for TG JLTs:…”

“…where F = W eff C ox  eff V d R sd /L, R sd is the series resistance, L eff = L -L and L is the channel length shortening due to short-cannel effects. Both  eff and L are expressed in terms of the normalized charges q s and q d [154]. In JL transistors, the channel is buried in the center of the nanowire and the association of the gate oxide capacitance per unit area C ox with the depletion capacitance C dep due to the depletion formed between the gate oxide and the mobile charges, reduces the total capacitance that drives the drain current.…”

“…In addition to the drain current symmetry [154], the terminal charges and, therefore, the trans-capacitances should also satisfy the symmetry condition. According to [132], These figures also show the first derivatives d cg /dV x and d csd /dV x ,which highlight the smoothness and continuity of the trans-capacitance compact model.…”

“…Specifically, a compact model should be able to succeed both the DC and AC source-drain symmetry test. A few compact models have achieved the DC source-drain symmetry test for junctionless devices so far [61], [148][149], [154] but there is a lack of investigation on the AC symmetry of those models.…”

“…In this chapter, the symmetric and continuous drain current compact model for triplegate (TG) JLTs in [154] is utilized, to acquire the expressions of the total terminal charges for long-channel devices required to develop a continuous and symmetric transcapacitance compact model.…”