SIMULATION OF PHOSPHORUS DIFFUSION IN SILICON USING A PAIR DIFFUSION-MODEL WITH A REDUCED NUMBER OF PARAMETERS

In this work, we describe a general model for dopant diffusion via dop ant-defect pairs containing all possible charge states of species unde r the assumption of local equilibrium for electronic processes, but no t for chemical processes. We present a method by which the unknown par ameters can be reduced efficiently. With the aid of this method all th e backward reaction rate coefficients can be replaced by the forward r eaction rate coefficients and two new parameters. Introducing the intr insic diffusion coefficient, one of the two new parameters can be repl aced, too. Thus, we have only one constant parameter instead of all ba ckward reaction rate coefficients, and additionally the model automati cally yields the correct results in the intrinsic case. In our model w e use the barrier energy for the Frenkel pair mechanism and the point defect parameters which we have determined from gold diffusion experim ents previously. We present several simulations of phosphorus diffusio n and compare the results with experiments published in the literature . Very good agreement between simulations and experiments has been obt ained. As a result we suggest a complete set of parameters for phospho rus diffusion in silicon for the temperature range from 900 to 1200 de grees C.