method for marking / sorting of semiconductor wafers as follows in the predicted behaviour of the sauerstofffaellung's dependence.

摘要

A method for marking/sorting semiconductor wafers in accordance with predicted values of oxygen precipitation in the wafers that will occur after the performance of a thermal process step. In a preferred embodiment, this oxygen precipitation prediction is obtained by means of a correlation equation Y = A0 + A1 OXi + A2/LT + A3C + A12 OXi/LT + A13 OXi C + A23 C/LT, where OXi is the value of interstitial oxygen in the wafer measured prior to the thermal process step, LT is the minority carrier lifetime for the wafer measured prior to the thermal process step, and C is the initial substitutional carbon in the wafer measured prior to the thermal process step. The constants A0, A1, A2, A3, A12, A23, and A13 are initialized on a first sample of wafers representative of a desired range of crystal types. In a preferred embodiment, this initialization is performed using Y values equal to the change in interstitial oxygen after the performance of the thermal process step. This predictive method can be performed on every wafer prior to semiconductor device fabrication therein, thereby improving device yield after wafer processing.