ACCURATE DETERMINATION OF MAJORITY THERMAL-CAPTURE CROSS-SECTIONS OF DEEP IMPURITIES IN P-N-JUNCTIONS

A new method for the direct determination of majority thermal-capture cross sections and concentration of deep levels in p-n junctions is pr oposed. The combined use of a capacitance technique and a numerical si mulation (which reproduces the experimental details) provides accurate results through the fitting of experimental and numerical capture tra nsients. The sensitivity of the method to these electrical magnitudes is also shown. This procedure is applicable not only to abrupt p+-n ju nctions, which have been quite thoroughly analyzed, but also to sample s where a nonabrupt shallow-dopant profile together with a high concen tration of deep levels makes them respond to a capture pulse in ways n ot reported until now. This method was used to analyze the two levels of platinum in silicon in nonabrupt p+-n junctions with a platinum con centration comparable to that of the shallow dopant.