A non-destructive method to determine impurity-profiles in non-abrupt p-n junctions with deep levels

A non-destructive capacitance method has been developed to calculate the concentration of shallow and deep impurities in an arbitrary junction. It is a comparative procedure based on an analytical expression of the high-frequency capacitance. It was applied to platinum-doped silicon-diodes in which platinum was diffused in the range 850-920°C. Two deep levels were detected with concentrations being equal for both, in accordance with other authors' results on the tripolar nature of platinum in silicon. The validity of the method has been proved and our results have been compared with others obtained from purely experimental methods on samples with different shallow-dopant profiles. This numerical-experimental method is thus of general applicability to any type of p-n junction with deep levels.