Threshold voltage definition and extraction for deep-submicron MOSFET's

X. Zhou, K.Y. Lim, W. Qian


Figures

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

Fig-1

Fig. 1 Measured linear Ids - Vgs curves (lines) for each device of drawn length Ldrawn as indicated.  Critical currents based on the Icrit@Vt0 definition (solid circles) and the CC definition (open circles) are shown for each device.  The inset shows the corresponding linear transconductance.

Fig-2

Fig. 2 Measured saturation Ids - Vgs curves (lines) for the same set of devices.  Vtsat are interpolated at Vgs at which Ids = Icrit (from Fig. 1 for both methods) for each device. The inset shows the corresponding saturation transconductance.

Fig-3

Fig. 3 Second derivative of the measured linear Ids - Vgs data (lines) for each device, with the corresponding values indicated at the extracted Vt0 for the Icrit@Vt0 definition (solid circles) and the CC definition (open circles)..

Fig-4

Fig. 4 Extracted Vt0 (circles) and Vtsat (triangles) versus Ldrawn for the Icrit@Vt0 definition (solid symbols) and the CC definition (open symbols).  The inset shows the same data against Icrit, as shown by the symbols in Figs. 1 and 2.

Fig-5

Fig. 5 Icrit versus Ldrawn for the Icrit@Vt0 definition (solid circles) and the CC definition (open circles) extracted from the linear Ids - Vgs curves (Fig. 1).  The inset shows log(Icrit) versus log(Ldrawn).

Fig-6

Fig. 6 The same data from Fig. 5 against Ldrawn (solid and open circles).  The Icrit data of the CC definition when plotted against Lg (triangles) or Leff (squares) assuming DCD = 0.02 mm and DL = 0.1 mm.  The empirical model Id0' = I0(Vds/Leff)a fitted to the Icrit@Vt0 data (diamonds).  The inset plots Icrit against Leff for both methods.