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2006
Journal Article
Titel
Advanced defect and impurity diagnostics in silicon based on carrier lifetime measurements
Abstract
An overview is given on recent developments at Fraunhofer ISE in the field of diagnostic techniques based on carrier lifetime measurements. The status of the different lifetime spectroscopy methods and the diagnostic capabilities of infrared carrier lifetime imaging are outlined. A combination of short acquisition times with high spatial resolution and high dynamic range under (quasi-) steady-state conditions gives IR lifetime imaging a high potential for the application in material and process characterization. Measuring in the emission mode provides access to the temperature dependence of lifetime and thus spatially resolved temperature dependent lifetime spectroscopy. Images of injection dependent lifetimes may be measured. For the anomalous increase at low injection a modeling description was developed. Assuming carrier trapping as origin of the increase, spatially resolved trap parameter analysis is possible. A new approach to suppress the anomalous increase by the application of sub-bandgap light was demonstrated.