A new method to map the thermal donor concentration in silicon wafers using carrierdensity imaging is presented. A map of the thermal donor concentration is extractedwith high resolution from free carrier density images of a silicon wafer before andafter growth of thermal donors. For comparison, free carrier density mapping isalso performed using the resistivity method together with linear interpolation. Bothmethods reveal the same distribution of thermal donors indicating that the carrierdensity imaging technique can be used to map thermal donor concentration. Theinterstitial oxygen concentration can also be extracted using the new method incombination withWijaranakula’s model. As part of this work, the lifetime at mediuminjection level is correlated to the concentration of thermal donors in the as-grownsilicon wafer. The recombination rate is found to depend strongly on the thermaldonor concentration except in the P-band region.
展开▼
