Abstract
A novel non-destructive and contactless approach for measuring the base resistivity of emitter-diffused, partially-processed wafers is introduced. The method is based on temperature-dependent resistivity analysis and referred as temperature-dependent resistivity slope model (TRSM). It is developed for p-type boron-doped silicon wafers used in industrial applications with base resistivities ranging from 1 to 5 Ωcm. A sensitivity analysis is carried out on TRSM to determine the limits of this simple approach and the results show that TRSM can determine the base resistivity with an accuracy of 90%. The main limiting factor is the reproducibility from the measuring tool with a mean error of 6% on the TRSM results. Finally, the base resistivity of emitter-diffused, partially-processed wafers (in this work referred as precursor wafers) obtained from TRSM is compared to two reference approaches and showed mean error percentages of less than 10%.