BondLib.Spice.Utilities.MOSeq2

# .BondLib.Spice.Utilities.MOSeq2

Computation of injected drain-source current for Level=2

## Information

This function implements a Spice-style Level-2 model of the current flowing between drain and source of a MOSFET. It is one of the most complex models currently available that computes the current in its linear, saturation, and subthreshold regions. Various channel modulation effects are also considered. The saturation voltage is computed either in accordance with the Grove-Frohman model [1,2] or using Baum's theory of scattering velocity saturation [3].

The model simulates very slowly, and is probably not useful except for simulating across a single switching event.

The model comments the equations by providing the corresponding equation numbers from [4].

    Input variables:

     vds:     Drain-source voltage (Volt)

     vgs:     Gate-source voltage (Volt)

     vbs:     Bulk-source voltage (Volt)

     Tdev:    Device temperature (K)

     sig:     Indicator of operating mode
                sig = +1:  direct mode
                sig = -1:  reverse mode (source and drain are flipped)

    Input parameters:

     Type:    Type of MOSFET (default value = 1)
                Type = +1:  NMOS
                Type = -1:  PMOS

     Tnom:    Reference temperature (default value = 300.15 K)

     VFB:     Flat band voltage at reference temperature (default value = 0 Volt)

     KP:      Transconductance parameter at reference temperature (default value = 0 Amp/Volt2)

     GAMMA:   Body-effect parameter (default value = 0 Volt0.5)

     PHI:     Surface inversion potential at reference temperature (default value = 0 Volt)

     LAMBDA:  Channel length modulation  (default value = 0 1/Volt)

     COX:     Specific capacitance of SiO2 (default value = 0 F/m2)

     NFS:     Surface fast state density (default value = 0 1/m2)

     NEFF:    Total channel charge coefficient (default value = 1)

     XJ:      Metallurgical junction depth (default value = 0 m)

     L:       Channel length (default value = 1e-4 m)

     W:       Channel width (default value = 1e-4 m)

     XD:      Depletion factor (default value = 0 m/Volt0.5)

     U0:      Surface mobility at reference temperature (default value = 0 m2/(V*s))

     UEXP:    Exponential coefficient for mobility (default value = 0)

     UTRA:    Transverse field coefficient (default value = 0)

     VMAX:    Maximum drift velocity of carriers (default value = 0 m/s)
                VMAX = 0: Frohman-Grove model of drain current computation
                VMAX > 0: Baum-Beneking model of drain current computation

     ECRIT:   Critical electric field for pinch-off (default value = 0 V/m)

     DELTA:   Width effect on threshold voltage (default value = 0)

     VBP:     Gate to channel critical voltage (default value = 0 Volt)

     PB:      Built-in potential at reference temperature (default value = 0.8 Volt)

     EG:      Energy gap for temperature effect on saturation current at 0 K (default value = 1.11 Volt)

     EMin:    if x < EMin, the exp(x) function is linearized (default value = -100) Levels 1-3

     EMax:    if x > EMax, the exp(x) function is linearized (default value = 40) Levels 1-3

    Output variables:

     isd0:    Drain-source current (Amp)

     Vfb:     Flat band voltage at device temperature (Volt)

     Vth:     Threshold voltage (Volt)

     vdsat:   Saturation voltage (Volt)

     vdsat1:  Adjusted saturation voltage (Volt)

     vpof:    Pinch-off voltage (Volt)

References:

1. Frohman-Bentchkowsky, D. (1968), "On the Effect of Mobility Variation on MOS Device Characteristics," Proc. IEEE, 56, pp.217-218.
2. Frohman-Bentchkowsky, D. and A.S. Grove (1969), "Conductance of MOS Transistors in Saturation," IEEE Trans. Electron Devices, ED-16, pp. 108-113.
3. Baum, G. and H. Beneking (1970), "Drift Velocity Saturation in MOS Transistors," IEEE Trans. Electron Devices, ED-17, pp. 481-482.
4. Massobrio, G. and P. Antognetti (1993), Semiconductor Device Modeling with Spice, 2nd edition, McGraw Hill, New York.

#### Interface

>     function MOSeq2
>       input Modelica.SIunits.Voltage vds "Drain-source voltage";
>       input Modelica.SIunits.Voltage vgs "Gate-source voltage";
>       input Modelica.SIunits.Voltage vbs "Bulk-source voltage";
>       input Modelica.SIunits.Temperature Tdev "Device temperature";
>       input Real sig "sign(vds)";
>       input Integer Level = 2 "Level of MOS model";
>       input Integer Type "Type=1 for NMOS; Type=-1 for PMOS";
>       input Modelica.SIunits.Temperature Tnom "Reference temperature";
>       input Modelica.SIunits.Voltage VFB "Flat band voltage at reference temperature";
>       input Modelica.SIunits.Transconductance KP "Transconductance parameter at reference temperature";
>       input Real GAMMA(unit = "V^0.5") "Body-effect parameter";
>       input Modelica.SIunits.Voltage PHI "Surface inversion potential at reference temperature";
>       input Modelica.SIunits.InversePotential LAMBDA "Channel length modulation";
>       input Real COX(unit = "F/m2") "Specific capacitance of SiO2";
>       input Real NFS(unit = "1/m2") "Surface fast state density";
>       input Real NEFF "Total channel charge coefficient";
>       input Modelica.SIunits.Length XJ "Metallurgical junction depth";
>       input Modelica.SIunits.Length L "Effective hannel length";
>       input Modelica.SIunits.Length W "Effective channel width";
>       input Real XD(unit = "m/V^0.5") "Depletion factor";
>       input Real U0(unit = "m2/(V.s)") "Surface mobility at reference temperature";
>       input Real UEXP "Exponential coefficient for mobility";
>       input Real UTRA "Transverse field coefficient";
>       input Modelica.SIunits.Velocity VMAX "Maximum drift velocity of carriers";
>       input Modelica.SIunits.ElectricFieldStrength ECRIT "Critical electric field for pinch-off";
>       input Real DELTA "Width effect on threshold voltage";
>       input Modelica.SIunits.Voltage VBP "Gate to channel critical voltage";
>       input Modelica.SIunits.Voltage PB "Built-in potential at reference temperature";
>       input Modelica.SIunits.Voltage EG "Energy gap for temperature effect on saturation current at 0 K";
>       input Real EMin "if x < EMin, the exp(x) function is linearized";
>       input Real EMax "if x > EMax, the exp(x) function is linearized";
>       output Modelica.SIunits.Current ids0 "Injected drain-source current";
>       output Modelica.SIunits.Voltage Vfb "Effective flat band voltage at device temperature";
>       output Modelica.SIunits.Voltage Vth "Threshold voltage";
>       output Modelica.SIunits.Voltage vdsat "Saturation voltage";
>       output Modelica.SIunits.Voltage vdsat1 "Adjusted saturation voltage";
>       output Modelica.SIunits.Voltage vpof "Pinch-off voltage";
>     end MOSeq2;

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