1 September 1995 Optical scattering enhanced by silicon micromachined surfaces
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Advanced semiconductor detection devices incorporate surface texturing to reduce reflection of the incident radiation, and thus, enhance optical absorption through scattering. Using micromachining techniques, three different silicon surfaces were fabricated, optically characterized, and analyzed in terms of their ability to scatter incident optical energy. The fabricated surfaces consist of: randomly sized and spaced pyramids (RSSPs), deep vertical- wall grooves (DVWGs), and porous silicon. The DVWG structures consist of interdigitated, 270 micrometers deep, 25 micrometers wide, and 1000 micrometers long grooves separated by 5 micrometers wide walls. The RSSP textured surfaces consist of pyramids with random 0.5-12.0 micrometers square base widths and heights, but otherwise consistent shape and symmetry. The pyramid walls make an angle of 54.74 degrees with respect to the sample surface. Porous silicon samples consist of surfaces with etched random pores that are 0.2-5 micrometers in depth, 1-5 micrometers in length, and 0.1-5 micrometers in width. Utilizing a laser scatterometry, the bidirectional reflectance distribution function (BRDF) of silicon textured surfaces has been measured at commercially available laser wavelengths of 1.06 and 10.6 micrometers . A highly- polished, single-crystal silicon wafer was used as a reference surface. The three micromachined surfaces showed an enhanced scatter at 1.06 micrometers as demonstrated by a reduced specular peak and increased average BRDF. The RSSP textured surface also demonstrated a low BRDF at 10.6 micrometers incident laser wavelength.
© (1995) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
David M. Sowders, David M. Sowders, Victor M. Bright, Victor M. Bright, Edward S. Kolesar, Edward S. Kolesar, } "Optical scattering enhanced by silicon micromachined surfaces", Proc. SPIE 2541, Optical Scattering in the Optics, Semiconductor, and Computer Disk Industries, (1 September 1995); doi: 10.1117/12.218323; https://doi.org/10.1117/12.218323


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