Abstract: Van der Pauw's function is often used in the measurement of a semiconductor's resistivity. However, it is difficult to obtain its value from voltage measurements because it has an implicit form. If it can be expressed as a polynomial, a semiconductor's resistivity can be obtained from such measurements. Normally, five orders of the abscissa can provide sufficient precision during the expression of any non-linear function. Therefore, the key is to determine the coefficients of the polynomial. By taking five coefficients as weights to construct a neuronetwork, neurocomputing has been used to solve this problem. Finally, the polynomial expression for van der Pauw's function is obtained.

Key words: measurement of the semiconductor's resistivity, van der Pauw function, reversal development, neurocomputing, polynomial match, learning rate of weight vector regulation