LIGHT SCATTER FROM POLYSILICON AND ALUMINUM SURFACES AND COMPARISON WITH SURFACE-ROUGHNESS STATISTICS BY ATOMIC-FORCE MICROSCOPY

Optical-scatter measurements from polysilicon and aluminum surfaces we re performed by using 632.8-nm illumination at 45 deg and 488-nm illum ination at 76.8 deg. Scatter was recorded up to 60 deg from the specul ar beam by using a concentric ring photodetector. The results are comp ared with surface statastics derived from atomic force microscopy. Qua ntitative predictions of the scatter were derived from power spectral density curves and angle-resolved-scattering theory. The agreement was fair for polysilicon samples with rms surface roughnesses of approxim ately 18 and 42 nm and aluminum with 17-nm rms roughness but poor for other samples. The discrepancy is attributed primarily to internal sca tter within the measuring instrument.