MONITORING OF SURFACE MINORITY CARRIER LIFETIME USING MODULATED PHOTOCURRENT

摘要

Effective minority carrier recombination lifetime may vary substantially depending on measurement techniques and sample parameters not directly related to the recombination process. This makes it difficult to measure the bulk recombination lifetime and the surface recombination velocity - the fundamental parameters affecting the recombination of minority carriers in the semiconductor. At the same time, effective lifetime can be used as an efficient monitor of contamination, particularly when combined with statistical process control (SPC). Effective lifetime as measured by the Surface Charge Analyzer SCA-2500 is strongly affected by the surface conditions of the sample and thus is particularly sensitive to surface contamination. No sample preparation is required for the measurements. These features have proven the usefulness of SCA-2500 as an in-line contamination monitor in the production environment.