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

Extrinsic Capacitance2( V + δ ) 4δ⎞ ⎟,0. V1Vgs , overlap= ⎜ ⎛ Vgs+ δ1−gs 1 1 1= 022⎝+ δ⎠(4.5.3)where CKAPPA is a model parameter. CKAPPA is related to the averagedoping of LDD region byCKAPPA=2εqNsi LDD2CoxThe typical value for N LDD is 5×10 17 cm -3 .(ii) Drain Overlap ChargeQW⎛+ CGD1⎜V⎜⎝(iii) Gate Overlap Charge(4.5.4)CKAPPA ⎛− ⎜−1+2 ⎜⎝(4.5.5)V ⎞⎞gd overlap1−⎟⎟CKAPPA ⎟⎟⎠⎠overlap , d4,= CGD0⋅Vgdgd−Vgd, overlapactive2( V + δ ) 4δ⎟⎞, 0. V⎠1Vgd , overlap= ⎜ ⎛ Vgd+ δ 1 −gd 11 1 = 022 ⎝+ δQoverlap , g(4.5.6)( Q + Q + ( CGB ⋅ L ) ⋅V)= −0overlap , doverlap , sactivegbIn the above expressions, if CGS0 and CGD0 (the overlap capacitancesbetween the gate and the heavily doped source/drain regions, respectively)are not given, they are calculated according to the followingCGS0 = (DLC*C ox ) - CGS1 (if DLC is given and DLC > 0)BSIM3v3.2.2 Manual Copyright © 1999 UC Berkeley 4-21