CONTAct number workfunction special conditions misc
The CONTACT line defines the physical parameters of an electrode. If no contact line is supplied for an electrode, it is assumed to be charge-neutral (ohmic). Lumped elements are also specified here.
number
NUmber = integer
or
ALL = logical
NUMBER gives the number of a previously defined electrode to which properties are to be assigned. Using ALL instead of NUMBER defines properties for all electrodes.
workfunction is one of:
Material Work function used
NEutral (calculated from doping)
ALUminum 4.17
P.polysilicon 4.17 + Egap
N.polysilicon 4.17
MOLybdenum 4.53
TUNgsten 4.63
MO.disilicide 4.80
TU.disilicide 4.80
or
Workfunction = real
MIN.workfunction = real
The work function defines a barrier height to majority carriers and is set to the above values for the standard materials, or to the given value WORKFUNCTION (in volts). NEUTRAL (the default) stands for charge-neutral (ohmic). The default barrier height for minority carriers is also computed from the work function; however by using the MIN.WORKFUNCTION parameter, a different barrier height can be established.
special conditions
Surf.rec = logical (default is false)
N.surf.rec = logical (default is false)
P.surf.rec = logical (default is false)
VSURFN = real (default is computed)
VSURFP = real (default is computed)
BArrierl = logical (default is false)
ALPha = real (default is 0)
BEta = real (default is 0)
or
CUrrent = real (default is false)
Distributed = real (default is false)
or
Resistance = real (default is 0)
CApacitance = real (default is 0)
Inductance = real (default is 0)
Distributed = real (default is false)
or
Distributed = real (default is false)
or
CON.resist = real (default is 0)
or
R.Table = character
R.Scale = real (default is 1)
If none of the above are specified, this contact is a normal ohmic (Dirichlet) boundary condition. If SURF.REC is specified, finite surface recombination velocities are used for both holes and electrons at the respective contact. N.SURF.REC and P.SURF.REC allow finite recombination velocities for electrons and holes separately (the other carrier is fixed using the standard Dirichlet condition). VSURFN and VSURFP are the electron and hole surface recombination velocities themselves and have the units cm/sec; their defaults are calculated using the associated Richardson constants (see the MATERIAL line). BARRIERL is a flag to turn-on the barrier lowering mechanism, while ALPHA is the linear dipole barrier lowering coefficient. CURRENT denotes a current boundary condition. RESISTANCE specifies a lumped resistance value (ohms), CAPACITANCE a lumped capacitance value (F) and INDUCTANCE a lumped inductance value (H) to be attached, in parallel, to the contact. The current, resistance or capacitance can be equally distributed (rather than lumped) along the contact by supplying the DISTRIBUTED parameter. CON.RESIST is a distributed contact resistance and has an identical effect as a total resistance (RESISTANCE) with the DISTRIBUTED flag, except that the units are given in ohm-cm**2. R.TABLE corresponds to a table of voltages and resistances so that two-terminal lumped elements with non-linear IV characteristics can be attached. R.SCALE is a scale factor that the resistances in the table are multiplied by to account for differences in device width.
misc
1d.base = logical (default is false) CONC0 = vector
1D.BASE specifies that a contact be an internal base contact, in which case only the majority carrier quasi-fermi potential is fixed (to the applied bias, possibly through a lumped element). CONC0 is a vector which allows the user to specify an equilibrium electron and hole density, overriding the default which is based on doping and space charge neutrality.
Define all electrodes except number 2 to be neutral, and number 2 is aluminum. Besides a workfunction, electrode number 2 also includes finite surface recombination velocities and barrier lowering. Note that the definition on the second line overrides that of the first.
CONTACT ALL NEUTRAL CONTACT NUM=2 ALUM SURF BARR
Attach a lumped resistor to contact number 2 with a value of 1.0e5 ohms. Include distibuted contact resistance (1.0e-6 ohm-cm**2 ~ Aluminum) on contact 4.
CONTACT NUM=2 RESIS=1E5 CONTACT NUM=4 CON.RES=1E-6