Minority carrier lifetime and iron concentration measurements on p-Si wafers by infrared photothermal radiometry and microwave photoconductance decay

M. E. Rodrı́guez, A. Mandelis, G. Pan, J. A. Garcı́a, V. Gorodokin, Y. Raskin
2000 Journal of Applied Physics  
A comparative study of electronic transport properties of p-Si wafers intentionally contaminated with Fe was performed using infrared photothermal radiometry ͑PTR͒ and microwave photoconductance decay ͑-PCD͒. Strong correlations were found between PTR and -PCD lifetimes in a lightly contaminated wafer with no significant PTR transient behavior. The absolute PTR lifetime values were larger than the local averaged -PCD values, due to the different excitation wavelengths and probe depths. In a
more » ... be depths. In a heavily contaminated wafer the -PCD and PTR lifetime correlation was poorer. PTR measurements were highly sensitive to iron concentration, most likely due to the dependence of the bulk recombination lifetime on it. Rapid-scanned ͑nonsteady-state͒ PTR images of the wafer surface exhibited strong correlations with both -PCD lifetime and ͓Fe͔ concentration images in both heavily and lightly contaminated wafers. For the lightly and uniformly contaminated wafer, PTR scanning imaging was found to be more sensitive to iron concentration and lifetime variations than -PCD images.
doi:10.1063/1.373506 fatcat:hcv67avhxzhfvgtti3vb6mfs5u