Predicting bulk lifetime values by applying wet chemistry H-termination for inline quality control of silicon wafers

The measurement of bulk lifetime values of as-cut wafers is a problematic issue. In this work, a MDPLinescan tool was directly integrated in the last stage of an inline wet chemistry tool. It is shown that running as-cut wafers through a bath of 5% HF solution with an inline transportation speed of 1m/min without rinsing will increase the effective lifetime value from 2µs to more than 100µs. Consequently, it is possible to forecast the bulk lifetime at later stages leading to an approach for early inline quality control. Multicrystalline wafers revealed the best correlation with an average prediction error of 15%. Monocrystalline wafers showed an average prediction error of 32%. Finally, a prediction of the bulk lifetime values for n-type wafers showed preliminary correlations with an error of 3%.