CONTACTLESS CHARACTERIZATION OF THE RECOMBINATION PROCESS IN SILICON-WAFERS - SEPARATION BETWEEN BULK AND SURFACE CONTRIBUTION

Taking advantage of a new interferometric technique and relying on a s uitable model for the electron-hole transient recombination process, w e propose an all optical measurement procedure able to separate the bu lk contribution from the surface contribution when measuring the recom bination lifetime in silicon wafers. In particular our technique is ab le to measure the bulk lifetime and the surface recombination velocity at low injection levels and allows the characterization of bulk silic on wafers and surface passivation techniques. The validity of our appr oach is confirmed by various numerical simulations and several experim ental results. Copyright (C) 1996 Elsevier Science Ltd