Accurate method for the determination of bulk minority-carrier lifetimes of mono- and multicrystalline silicon wafers

An accurate method for the determination of the bulk minority-carrier recombination lifetime of crystalline silicon wafers of typical thickness (< 0.5 mm) is presented. The method consists of two main steps: first, both wafer surfaces are passivated with silicon nitride films fabricated at low temperature (< 400 degrees C) in a remote plasma-enhanced chemical vapor deposition system. Second, the effective minority-carrier lifetime of the wafer is measured by means of the contactless microwave-detected photoconductance decay technique, Due to the outstanding degree of surface passivation provided by remote-plasma silicon nitride films, the bulk minority-carrier lifetime can be very accurately determined from the measured effective minority-carrier lifetime. The method is suited for the hulk minority-carrier lifetime determination of p-type and n-type silicon wafers with doping concentrations in the 10(14)-10(17) cm(-3) range. We demonstrate the potential of the method for commercially available float-zone, Czochralski, and multicrystalline silicon wafers of standard thickness. (C) 1997 American Institute cf Physics.