MOdels forms general scattering drive terms numerical
The MODELS line sets the temperature for the simulation and specifies model flags to indicate the inclusion of various physical mechanisms and models. Some non-material dependent model parameters are also specified here.
C1.Sign = integer (default is -1) C2.Sign = integer (default is +1) C1.Type = integer (default is 1) C2.Type = integer (default is 2) JTherm = logical (default is true) ET.form = logical (default is false)
C1.SIGN and C2.SIGN control the sign of the electric charge associated with carrier 1 and 2; C1.TYPE and C2.TYPE control the type (1=electrons, 2=holes) associated with carriers 1 and 2. JTHERM controls the inclusion of the thermoelectric current in the energy balance models. ET.FORM specifies a new form of the energy transport equations be used (see D. Chen, et. al.); ET.FORM=false is the standard energy balance formulation.
general
SRh = logical (default is false) AUger = logical (default is false) DIrect = logical (default is false) DEeptrap = logical (default is false) CONLife = logical (default is false) IMpact = logical (default is false) TUnneling = logical (default is false) Laser = logical (default is false) BGn = logical (default is false) STatistics = logical (default is "boltzmann") INcomplete = logical (default is false) Print = logical (default is false) TEmperature = real (default is 300K)
SRH, AUGER and DIRECT specify Shockley-Read-Hall, Auger and direct radiative recombination respectively. DEEPTRAP activates acceptor and donor deep-level traps, where the trap occupancy is equivalent to SRH however with a charge density which is included in the Poisson equation. SRH, DEEPTRAP and DIRECT can optionally use concentration-dependent lifetimes by specifying CONLIFE. IMPACT incorporates an impact ionization generation term. TUNNELING specifies that a band-to-band tunneling model is turned on. LASER is a recombination model which simulates the effects of stimulated-emission.
BGN is band-gap narrowing. STATISTICS indicates the type of carrier statistics to be used ("boltzmann", "fermi" or "2dgas"), while INCOMPLETE indicates that incomplete-ionization of impurities should be accounted for. PRINT prints the status of all models and a variety of coefficients and constants. TEMPERATURE is the ambient temperature and should be specified in Kelvin units.
scattering
CONMob = logical (default is false) CCmob = logical (default is false) FLDMob = logical (default is false) GAtmob = logical (default is false) FLDDif = logical (default is false) NEutral = logical (default is false) E.Region = integer (default is all regions) G.Region = integer (default is all regions) D.Region = integer (default is all regions)
The parameters above specify which carrier transport models are to be used. CONMOB is concentration-dependent, ionized impurity scattering model. CCMOB includes a carrier-carrier scattering term in the mobility, and NEUTRAL incorporates a neutral impurity scattering effect (re. Sklar). FLDMOB specifies a nonlinear drift velocity-field model (i.e., a parallel field or temperature dependent mobility), GATMOB includes a vertical field dependence and FLDDIF includes a field-dependent, diffusivity to mobility ratio. E.REGION, G.REGION and D.REGION apply the velocity saturation, gate-field and diffusivity-field models respectively only within selected regions of the device.
drive terms
I.Current = character (default is "jmag") E.Drive = character (default is "qf") G.Drive = character (default is "exqf") D.Drive = character (default is "qf") I.Drive = character (default is "eoj")
I.CURRENT specifies the way carrier currents are computed in the expression for impact ionization; "jmag" forces the use of the actual magnitude of electron and hole currents, and "jsat" uses the product of the local densities and respective saturation velocities (times q). The parallel (for drift-diffusion), gate, diffusivity field and impact ionization models require a driving force or field term. E.DRIVE, G.DRIVE, D.DRIVE and I.DRIVE are character strings which define various possibilities:
E.Drive = eoj E-j dot-product
eoqf E-(grad qf) dot-product
ex X-component of E (abs value)
ey Y-component of E (abs value)
emag Magnitude of E
qf Magnitude of (grad qf)
qfb E-Magnitude of (grad qf) with numerical smooth
G.Drive = exj E-j cross-product
exqf E-(grad qf) cross-product
ex X-component of E (abs value)
ey Y-component of E (abs value)
emag Magnitude of E
D.Drive (same choices as E.DRIVE)
I.Drive (same choices as E.DRIVE)
For energy-balance simulations, each of these models (except gate-field) have temperature dependencies and the driving forces are ignored.
Noise Models
gen.nois = logical (default is false) diff.noi = logical (default is false) 1overf.n = logical (default is false)
The parameters above specify which type of noise sources are desired for device noise calculations.
numerical
EEth.mu = real (default is 1 V/cm) [Expert] GEth.mu = real (default is 1 V/cm) [Expert] DVside = real (default is 1.0e-6 kT/q) [Expert] GZth.mu = real (default is 0.03mm) JTh.mu = real (default is 1.0e-6) [Expert] AJMin = real (default is 1.0e-20) [Expert] AJRoff = real (default is 1.0) [Expert] II.Cut = real (default is -10) [Expert] II.Hyp = real (default is 5.0e-3) [Expert] II.Tanh = real (default is 50) [Expert] II.Sig = real (default is 500) [Expert] E.Vertex = logical (default is false) [Expert] Qf.np0 = real (default is 1.0e-5) [Expert]
EETH.MU, GETH.MU, DVSIDE, GZTH.MU and JTH.MU are thresholds used in the
field-dependent models. EETH.MU and GETH.MU are minimum fields used in
the parallel and gate field mobility models (basically a zero field offset for
a hyperbola). DVSIDE is a minimum potential difference across an edge, used
in any field computation. GZTH.MU is a threshold on the distance from an
insulator-semiconductor interface where the gate field models are
included. JTH.MU, AJMIN and AJROFF are low current thresholds used in
E . j, E x j and |J| computations
(see E.DRIVE, et. al. above); JTH.MU is
a threshold relative to the maximum current density over the device,
AJMIN is an absolute quantity (in A-cm**2), and AJROFF is
a multiplicative factor applied to internally computed maximum
roundoff currents (in A-cm**2).
II.CUT specifies an initial ionization threshold field be applied
for fields below the cutoff for a given material; the field used
is |II.CUT|*beta0, where beta0 is the threshold
in the first field interval (see B*.ION on the MATERIAL line).
II.HYP > 0 specifies that a hyperbolic approximation to the
(log) piecewise-linear ionization rates be used; the value of
II.HYP defines the relative offset of the rate at the intersection
of adjacent intervals, and II.TANH defines the multiplicative
term in front of the argument to a tanh function which blends
consecutive hyperbolas. II.SIG performs the same function as
II.TANH, but for II.HYP <= 0 (the lower II.TANH or II.SIG, the
smoother - but less accurate - the adjusted function becomes).
E.VERTEX computes fields at verticies
instead of a single value over the entire element.
QF.NP0 defines the minimum concentration for use in the
numerical smooth qf driving force estimates; the value given
is multiplied by the local intrinsic concentration.
Run a simulation with Shockley-Reed-Hall recombination using concentration dependent lifetimes. Field-dependent models are only applied in regions 1 and 2 however. The ambient temperature is 425K.
MODELS TEMP=425 SRH FLDMOB E.REGION=12