5.3.1 Dual Pearson Distribution Functions



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5.3.1 Dual Pearson Distribution Functions

  A single Pearson distribution, is characterized by four parameters , , , and . describes the position of the peak, the straggle, is the skewness which indicates the tilting of the profile, and is the kurtosis which tells the flatness at the top of the profile. The concentration, of some impurity, at any given point, in Silicon is given by:

The Pearson type IV function is implemented in SUPREM3 [38] as:

For a dual Pearson approach, two sets of the above four parameters are needed, plus a ninth parameter describing the relative proportions of the two Pearson's. If and denote the two Pearson distributions, describing the region of the profile closest to the surface and describing the deeper channeled region, then the two sets of parameters are , , , and for use in and , , , and for use in . The concentration at any position is:


is the concentration at the peak of the distribution and is the ratio describing the relative proportions of the two Pearson functions (the ninth parameter).


Martin Stiftinger
Tue Aug 1 19:07:20 MET DST 1995