BSIM3v3.2.2 MOSFET Model - The University of Texas at Dallas

Extraction Procedureeffects. Regardless of device geometry, each device will have to bemeasured under four, distinct bias conditions.(1) I ds vs. V gs @ V ds = 0.05V with different V bs .(2) I ds vs. V ds @ V bs = 0V with different V gs .(3) I ds vs. V gs @ V ds = V dd with different V bs . (V dd is the maximum drainvoltage).(4) I ds vs. V ds @ V bs = V bb with different V gs . (|V bb | is the maximum bodybias).6.3.2 OptimizationThe optimization process recommended is a combination of Newton-Raphson's iteration and linear-squares fit of either one, two, or threevariables. This methodology was discussed by M. C. Jeng [18]. A flowchart of this optimization process is shown in Figure 6-2. The modelequation is first arranged in a form suitable for Newton-Raphson's iterationas shown in Eq. (6.3.1):(6.3.1)( m) ( m) ( m)∂f P P P f P P P sim fP P m ∂ fsim m ∂ fsim P sim mexp ( 10, 20,30) − ( 1 , 2 , 3 ) = ∆ 1 + ∆ 2 + ∆P3∂ 1 ∂ P2∂ P3The variable f sim () is the objective function to be optimized. The variablef exp () stands for the experimental data. P 10 , P 20, and P 30 represent thedesired extracted parameter values. P(m) 1 , P2(m)and P(m) 3 representparameter values after the mth iteration.6-4 BSIM3v3.2.2 Manual Copyright © 1999 UC Berkeley