Diffusion length and resistivity distribution characteristics of silicon wafer by photoluminescence

• Analytical photoluminescence efficiency calculation and PL intensity ratio method are developed.
• Wafer resistivity and diffusion length characteristics are investigated by PL intensity ratio.
• PL intensity is well correlated with resistivity, diffusion length or defect density on wafer measurement.

Photoluminescence is a convenient, contactless method to characterize semiconductors. Its use for room-temperature silicon characterization has only recently been implemented. We have developed the PL efficiency theory as a function of substrate doping densities, bulk trap density, photon flux density, and reflectance and compared it with experimental data initially for bulk Si wafers. New developed PL intensity ratio method is able to predict the silicon wafer properties, such as doping densities, minority carrier diffusion length and bulk trap density.

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