An analytical effective channel-length modulation model for velocity overshoot in submicron MOSFETs based on energy-balance formulation

Khee Yong Lim and Xing Zhou

Figures

Fig. 1 | Fig. 2 | Fig. 3 | Fig. 4 | Fig. 5 | Fig. 6

Fig-1a(a)
Fig-1b(b)

Fig. 1 Measured (symbols) and modeled (lines) (a) Ids - Vds (b) gds - Vds characteristics at Vgs = 1.5 V, Vbs = -2.7 V for five devices as indicated.

Fig-2a

Fig. 2 Effective saturation field (left axis) and effective Early voltage (right axis) versus gate length at four Vgs as indicated.

Fig-3

Fig. 3 Interpretation of the effective Early voltage in terms of the “pinch-off” model, showing the VAeff versus Vgs behavior at two body biases for two devices as indicated.  The inset shows the schematic view of VAeff.

Fig-4a

Fig. 4 Interpretation of the effective velocity (vh) versus field relationship, compared with the conventional one (v0) showing the “overshoot” effect by the proposed energy-balance approach.

Fig-5a

Fig. 5 Effective velocity (circles) versus gate length at three drain biases as indicated, compared with the conventional one without electron-temperature gradient (crosses).

Fig-6a(a)
Fig-6b(b)

Fig. 6 Effective voltage drops across the intrinsic channel (Vch0), velocity-saturation region (VVSR), and series resistance (VRsd) at four gate biases as indicated in (a) saturation and (b) linear mode.