PSP MOSFET model R. van Langevelde, G.D.J. Smit , A.J. Scholten and - PowerPoint PPT Presentation

Introduction to the PSP MOSFET model R. van Langevelde, G.D.J. Smit , A.J. Scholten and D.B.M. Klaassen G. Gildenblat, X. Li, H. Wang and W. Wu MOS-AK, Grenoble, September 16 th , 2005

outline • introduction & history • introduction & history • model structure and contents • model structure and contents • physical background • physical background • parameter extraction • parameter extraction • conclusions • conclusions PSP, MOS-AK, Grenoble, September 16 th , 2005 2/50

introduction: merger SP and MM11 MOS Model 11 SP (Philips) (Penn State) PSP PSP, MOS-AK, Grenoble, September 16 th , 2005 3/50

introduction: motivation Why PSP? • 2004: CMC calls for next generation industrial standard model for compact CMOS modeling • SP (Penn State) and MOS Model 11 (Philips Research) were both worthy candidates • enhance collaboration rather than competition • make an even better model PSP, MOS-AK, Grenoble, September 16 th , 2005 4/50

introduction: similarities MM11 and SP MOS Model 11 (MM11) and SP are both compact MOSFET models that: • are surface-potential-based • are symmetrical w.r.t. drain and source • make a distinction between local (miniset) and global (maxiset) model parameters • use similar basic equations • are based on mid-point linearization of charges PSP � Combines and enhances the best features of MM11 and SP PSP, MOS-AK, Grenoble, September 16 th , 2005 5/50

introduction: CMC requirements requirements for new standard model: • useful for 90, 65 and 45nm CMOS • model dc-currents + derivatives – distortion – symmetry • model charges + 1 st -order derivative – including accumulation region for varactors • model noise • model source/drain junctions • model non-quasi-static effects • model gate/substrate resistances PSP, MOS-AK, Grenoble, September 16 th , 2005 6/50

introduction: CMC selection procedure selection procedure for next generation model: 07/2004 candidate models: model from type solution • BSIM5 UC Berkeley Q inv iterative • EKV EPFL Q inv iterative • HiSIM ψ s Hiroshima Univ. iterative • PSP ψ s PSU/Philips explicit 10/2005 final selection PSP, MOS-AK, Grenoble, September 16 th , 2005 7/50

outline • introduction & history • model structure and contents • physical background • parameter extraction • conclusions PSP, MOS-AK, Grenoble, September 16 th , 2005 8/50

general: structure of PSP global par set geometry scaling W, L stress scaling SA , SB local parameter set T temperature scaling   currents V SB   V   charges model equations GS   noise V  local model  DS PSP, MOS-AK, Grenoble, September 16 th , 2005 9/50

general: physical effects included • non-uniform lateral doping • non-uniform vertical doping • field-dependent mobility • velocity saturation • conductance effects (CLM, DIBL, etc.) • series-resistance • short-channel effects (incl. RSCE) • narrow-width effects • gate poly-depletion • quantum-mechanical corrections PSP, MOS-AK, Grenoble, September 16 th , 2005 10/50

general: physical effects included (ii) • overlap capacitances ( ψ s -based) • impact ionization current • gate leakage current • gate-induced drain/source leakage (GIDL, GISL) • junction diode I - V and C - V (forward and reverse) • diode reverse breakdown • noise (1/f, thermal, induced gate and shot noise) • non-quasi-static effects • gate and bulk resistances • STI stress effect PSP, MOS-AK, Grenoble, September 16 th , 2005 11/50

general: PSP’s unique features • unique description of CLM in halo-doped devices – reproduces details in long channel g ds • unique gate current model • unique noise model – most complete and robust – correctly including velocity-saturation • unique NQS model – verified against channel segmentation • unique junction diode model (JUNCAP2) unavailable outside PSP context; verified against device simulations and several modern CMOS processes PSP, MOS-AK, Grenoble, September 16 th , 2005 12/50

outline • introduction & history • model structure and contents • physical background • parameter extraction • conclusions PSP, MOS-AK, Grenoble, September 16 th , 2005 13/50

outline: physical background • DC model • DC model • AC model • AC model • noise model • noise model • non quasi static model • non quasi static model • junction diode model • junction diode model PSP, MOS-AK, Grenoble, September 16 th , 2005 14/50

physics: DC: surface-potential-based PSP is surface-potential ( ψ s ) based 10 -4 I DS = I drift + I diff ψ s -based model: 10 -5 I diff 10 -6 single equation for (A) whole operation range : 10 -7 I DS 10 -8 I drift = f( V GB , ψ s0 , ψ sL ) V SB = 0 V 10 -9 I diff = g( V GB , ψ s0 , ψ sL ) 10 -10 V DS = 1 V I drift 10 -11 0 1 2 I DS = I drift + I diff V GS (V) PSP, MOS-AK, Grenoble, September 16 th , 2005 15/50

physics: DC: ψ s - calculation − ϕ −  ψ   ψ  2 V   − − ψ V V B s s −     ϕ ϕ ϕ   = ψ + ϕ ⋅ ⋅ − + ϕ ⋅ − GB FB s e e 1 e 1 T T T       s T T γ       1.2 ψ s obtained from explicit analytical approximation, 0.8 accurate within 1nV under ψ s (V) all relevant conditions 0.4 [R. Rios et al ., IEDM2004]: 0 approximation of ψ s V = 0 V becomes inaccurate for -0.4 high positive back bias -1 0 1 2 V GB - V FB (V) PSP, MOS-AK, Grenoble, September 16 th , 2005 16/50

physics: DC: ψ s –based model ψ s -calculation: d escription of ideal long-channel MOSFET in ‘real’ device: • mobility reduction • velocity saturation • short-channel effects (DIBL, non-ideal slope) • gate current PSP, MOS-AK, Grenoble, September 16 th , 2005 17/50

physics: DC: mobility reduction mobility reduction due to phonon, surface- roughness, and Coulomb scattering + η Q ⋅ Q = − E b inv PSP: eff ε Si • PH ( ) THEMU ⋅ MUE E • SR eff µ 1 − µ ∝ E 3 ph eff • CS • parameters: + − 2 Q Q µ ∝ E µ ∝ BETN, MUE, THEMU, inv b sr eff C Q b CS, XCOR E eff PSP, MOS-AK, Grenoble, September 16 th , 2005 18/50

physics: DC: mobility reduction (ii) g m versus V GS (100µm/10µm n-MOS, V DS =30mV) V SB =0V 100 100 (µA/V) (µA/V) µ A/V) µ A/V) V SB =1.2V 50 50 m ( m ( CS CS g m g g m g switched switched on off 0 0 0.0 0.4 0.8 1.2 0.0 0.4 0.8 1.2 V GS (V) V GS (V) V GS (V) V GS (V) model measurement PSP, MOS-AK, Grenoble, September 16 th , 2005 19/50

physics: DC: velocity saturation in PSP: µ ⋅ E = || v • integration of v 2 µ   + ⋅ 1  E  v ||   v = along channel v sat sat W ∫ = − ⋅ ⋅ ⋅ I Q v d x D inv L v µ ⋅ E = || v µ v = µ · E || + ⋅ 1 E • parameters: v || sat THESAT, (THESATG, THESATB) E x PSP, MOS-AK, Grenoble, September 16 th , 2005 20/50

physics: DC: velocity saturation (ii) I D vs V DS I D vs V GS V DS =1.2V V GS =1.2V 4 4 (mA) (mA) D (mA) D (mA) V GS =0.8V 0.6V 2 2 I I I D I D 50mV V GS =0.4V 0 0 0.0 0.4 0.8 1.2 0.0 0.4 0.8 1.2 V GS (V) V DS (V) V DS (V) V GS (V) 10/0.12 n-MOS measurement PSP PSP, MOS-AK, Grenoble, September 16 th , 2005 21/50

physics: DC: velocity saturation (iii) g DSi (= ∂ i I D / ∂ V DS g mi (= ∂ i I D / ∂ V GS i ) vs V DS i ) vs V GS g m3 -1 g DS3 10 -1 10 (A/V i ) (A/V i ) DS i (A/V i ) i (A/V i ) -2 10 g DS2 -2 10 -3 10 g m1 m g DSi g DS1 g mi g g -4 10 -3 10 V GS =1.2V V DS =1.2V g m2 -5 10 0.0 0.3 0.6 0.9 0.0 0.4 0.8 1.2 V DS (V) V GS (V) V DS (V) V GS (V) 10/0.12 NMOS measurement PSP PSP, MOS-AK, Grenoble, September 16 th , 2005 22/50

physics: DC: short-channel effects non-ideal subthreshold slope and DIBL (due to 2D-effects): Poisson equation: (in subthreshold) ⋅ ∂ ∂ ψ ψ ∂ ∂ ∂ ∂ ψ ψ ψ ψ ⋅ ⋅ ρ ∂ ψ 2 2 2 2 2 2 2 q q q N N N + + = ≈ ≈ ≈ − − n + n + eff A A ++++++ ++++++ +++ +++ ∂ ∂ ∂ ∂ ∂ ∂ ε ε ε ε ∂ 2 2 2 2 2 2 2 x x y y y y x - - -- - - -- - - -- - - -- - - n + n + - - - - - - x - - - - - - Si Si Si Si n + n + x - - - - - - - - - - - - - - - -- - - - - -- - - - - - lateral gradient factor f : - - - - - - - - - - - - - - - - - - - - ( ) y y - - - - - - = ⋅ N N f V , V , V p p eff A GS DS SB PSP-parameters: F0, AF, BF, CF, (CFB) PSP, MOS-AK, Grenoble, September 16 th , 2005 23/50

physics: DC: channel length modulation in PSP: uniformly doped device pocket implanted device • effect of pockets on V G V G conductance included V D • both below and above N sub V D N pck N sub N pck threshold • parameters: ALP1, ALP2 electron potential V DS PSP, MOS-AK, Grenoble, September 16 th , 2005 24/50

physics: DC: CLM (ii) I D - V DS and g DS - V DS for V SB =0V and T =25°C 0.20 0.15 -4 10 (A/V) (mA) DS (A/V) D (mA) 0.10 -5 10 I g DS g I D 0.05 -6 10 -7 0.00 10 0.0 0.4 0.8 1.2 0.0 0.4 0.8 1.2 V DS (V) V DS (V) V DS (V) V DS (V) 10µm/10µm NMOS (90nm process) PSP, MOS-AK, Grenoble, September 16 th , 2005 25/50