Professor Ronald L. Carter ronc@uta.edu http://www.uta.edu/ronc/ EE5342 – Semiconductor Device Modeling and Characterization Lecture 29 - Spring 2004 Professor Ronald L. Carter ronc@uta.edu http://www.uta.edu/ronc/ L29 May 4

MOSFET Device Structre Fig. 4-1, M&A* L29 May 4

MOSFET equivalent circuit elements Fig 10.51* L29 May 4

n-channel enh. circuit model G RG Cgd RDS Cgs S RD D Cbd RB Cbs Idrain Cgb DSS DSD RB B L29 May 4

MOS small-signal equivalent circuit Fig 10.52* L29 May 4

MOSFET circuit parameters L29 May 4

MOSFET circuit parameters (cont) L29 May 4

Substrate bias effect on VT (body-effect) L29 May 4

Body effect data Fig 9.9** L29 May 4

Fully biased n- channel VT calc L29 May 4

Values for fms with silicon gate L29 May 4

Q’d,max and xd,max for biased MOS capacitor Fig 8.11** |Q’d,max|/q (cm-2) xd,max (microns) L29 May 4

I-V relation for n-MOS ohmic ID non-physical ID,sat saturated VDS,sat L29 May 4

MOS channel- length modulation Fig 11.5* L29 May 4

Analysis of channel length modulation L29 May 4

Channel length mod- ulated drain char Fig 11.6* L29 May 4

Associating the output conductance ID ID,sat VDS,sat VDS L29 May 4

SPICE mosfet Model Instance CARM*, Ch. 4, p. 290 L = Ch. L. [m] W = Ch. W. [m] AD = Drain A [m2] AS = Source A[m2] NRD, NRS = D and S diff in squares M = device multiplier L29 May 4

SPICE mosfet model levels Level 1 is the Schichman-Hodges model Level 2 is a geometry-based, analytical model Level 3 is a semi-empirical, short-channel model Level 4 is the BSIM1 model Level 5 is the BSIM2 model, etc. L29 May 4

SPICE Parameters Level 1 - 3 (Static) L29 May 4

SPICE Parameters Level 1 - 3 (Static) * 0 = aluminum gate, 1 = silicon gate opposite substrate type, -1 = silicon gate same as substrate. L29 May 4

SPICE Parameters Level 1 - 3 (Q & N) L29 May 4

References CARM = Circuit Analysis Reference Manual, MicroSim Corporation, Irvine, CA, 1995. M&A = Semiconductor Device Modeling with SPICE, 2nd ed., by Paolo Antognetti and Giuseppe Massobrio, McGraw-Hill, New York, 1993. M&K = Device Electronics for Integrated Circuits, 2nd ed., by Richard S. Muller and Theodore I. Kamins, John Wiley and Sons, New York, 1986. Semiconductor Physics and Devices, by Donald A. Neamen, Irwin, Chicago, 1997 L29 May 4