Set the coefficients for a generic impurity's kinetics.
SYNOPSIS
- generic
-
( silicon | oxide | oxynit | nitride | gas | poly | gaas )
[ Dix.0 = n ] [ Dix.E = n ]
[ Dim.0 = n ] [ Dim.E = n ]
[ Dimm.0 = n ] [ Dimm.E = n ]
[ Dimmm.0 = n ] [ Dimmm.E = n ]
[ Dip.0 = n ] [ Dip.E = n ]
[ Dipp.0 = n ] [ Dipp.E = n ]
[ Dippp.0 = n ] [ Dippp.E = n ]
[ Fi = n ]
[ implanted ] [ grown.in ]
[ ss.clear ] [ ss.temp = n ] [ ss.conc = n ]
[ ( /silicon | /oxide | /oxynitr | /nitride | /gas | /poly | gaas ) ]
[ Seg.0 = n ] [ Seg.E = n ]
[ Trn.0 = n ] [ Trn.E = n ]
[ ( donor | acceptor ) ]
DESCRIPTION
This statement allows the user to specify values for coefficients of a generic impurity's diffusion and segregation. The diffusion equation for the generic impurity is:
where CT and CA are the total chemical and electrically active concentrations of the generic impurity, CV and CI are the vacancy and interstitial concentrations, the superscript * refers to the equilibrium value, DV and DI are the diffusivities with vacancies and interstitials, and p and ni refer to the hole concentration and the intrinsic electron concentration respectively. The diffusivities are given by:
DX, DM, DMM, DMMM, DP, DPP, and DPPP are described in greater detail below.
The segregation at material interfaces is computed using the following expression:
where C1 and C2 are the concentrations in material 1 and 2 respectively, and the M12 and Tr terms are computed using expressions shown below with the parameters of the models.
- silicon, oxide, oxynitr, nitride, gas, poly, gaas
- These allow the specification of parameters for that material. Only one of these can be specified per statement. The parameters specified in that statement will apply in the material listed. These parameters specify which material is material 1 for the segregation terms.
- Dix.0, Dix.E
- These floating point parameters allow the specification of DX, the generic impurity's diffusivity with neutral defects. Dix.0 is the pre-exponential constant and Dix.E is the activation energy. Dix.0 defaults to 0.0 cm2/sec and Dix.E defaults to 0.0 eV. DX is calculated using a standard Arrhenius relationship.
- Dim.0, Dim.E
- These floating point parameters allow the specification of DM, the generic impurity's diffusivity with singly positive defects. Dim.0 is the pre-exponential constant and Dim.E is the activation energy. Dim.0 defaults to 0.0 cm2/sec and Dim.E defaults to 0.0 eV. DM is calculated using a standard Arrhenius relationship.
- Dimm.0, Dimm.E
- These floating point parameters allow the specification of DMM, the generic impurity's diffusivity with doubly positive defects. Dimm.0 is the preexponential constant and Dimm.E is the activation energy. Dimm.0 defaults to 0.0 cm2/sec and Dimm.E defaults to 0.0 eV. DMM is calculated using a standard Arrhenius relationship.
- Dimmm.0, Dimmm.E
- These floating point parameters allow the specification of DMMM, the generic impurity's diffusivity with triply positive defects. Dimmm.0 is the pre-exponential constant and Dimmm.E is the activation energy. Dimmm.0 defaults to 0.0 cm2/sec and Dimmm.E defaults to 0.0 eV. DMMM is calculated using a standard Arrhenius relationship.
- Dip.0, Dip.E
- These floating point parameters allow the specification of DP, the generic impurity's diffusivity with singly positive defects. Dip.0 is the pre-exponential constant and Dip.E is the activation energy. Dip.0 defaults to 0.0 cm2/sec and Dip.E defaults to 0.0 eV. DP is calculated using a standard Arrhenius relationship.
- Dipp.0, Dipp.E
- These floating point parameters allow the specification of DPP, the generic impurity's diffusivity with doubly positive defects. Dipp.0 is the pre-exponential constant and Dipp.E is the activation energy. Dipp.0 defaults to 0.0 cm2/sec and Dipp.E defaults to 0.0 eV. DPP is calculated using a standard Arrhenius relationship.
- Dippp.0, Dippp.E
- These floating point parameters allow the specification of DPPP, the generic impurity's diffusivity with triply positive defects. Dippp.0 is the pre-exponential constant and Dippp.E is the activation energy. Dippp.0 defaults to 0.0 cm2/sec and Dippp.E defaults to 0.0 eV. DPPP is calculated using a standard Arrhenius relationship.
- Fi
- This parameter allows the specification of the fractional interstitialcy. This value indicates whether generic diffuses through interaction with interstitials or vacancies. The value of Fi defaults to 0.0.
- implanted, grown.in
- Specifies whether the Dix, Dim, Dimm, Dimmm, Dip, Dipp, Dippp, or Fi coefficients apply to implanted or grown-in generic. If neither is specified then a specified parameter applies to both.
- ss.clear
- This parameter clears the currently stored solid solubility data.
- ss.temp, ss.conc
- These parameters add a single temperature solid solubility concentration point to those already stored. The default values are:
- /silicon, /oxide, /oxynit, /nitride, /gas, /poly, /gaas
- These parameters specify material 2. Only one of the these parameters can be specified at one time.
- Seg.0, Seg.E
- These parameters allow the computation of the equilibrium segregation concentrations. The segregation constant follows an Arrhenius relationship.
- Trn.0, Trn.E
- These parameters allow the specification of the transport velocity across the interface given. The units are in cm/sec. The transfer coefficient follows an Arrhenius relationship.
- donor, acceptor
- These parameters determine whether the impurity is to be treated as a donor or as an acceptor in a semiconductor material. These parameters are not presently material specific. There is no default set so the type must be set before using the generic impurity.
EXAMPLES
- generic gaas implanted Dip.0=2.2e-6 Dip.E=1.76
- This command changes the positive defect diffusivity for an implanted generic impurity in gallium arsenide.
- generic gaas /nitride Seg.0=1126.0 Seg.E=0.91 Trn.0=1.66e-7
- This command will change the segregation parameters at the gallium arsenide - silicon nitride interface. The gallium arsenide concentration will be half the nitride concentration in equilibrium at 1100C.
BUGS
As far as the implemented models are physically correct, there are no known bugs.
SEE ALSO
The antimony,
arsenic,
beryllium,
boron,
carbon,
germanium,
interstitial,
magnesium,
phosphorus,
selenium,
isilicon,
tin,
vacancy,
and zinc statements.