Macropore growth in a prepatterned p-type silicon wafer

✍ Scribed by Kobayashi, K. ;Harraz, F. A. ;Izuo, S. ;Sakka, T. ;Ogata, Y. H.

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 421 KB
• Volume: 204
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200674325

✦ Synopsis

Abstract

The formation process of ordered macropores in a prepatterned p‐type silicon wafer was investigated. FE‐SEM observation focusing on the early stage of the pore growth clarified the two‐step process of macropore formation, whose first step was isotropic pore expansion from prepared etch pits and the second was anisotropic growth in the depth direction. Investigation using different etch‐pit patterns revealed that ordered macropores with constant diameters were obtained when the spacing of etch pits was 3–8 μm, while the spacing of 2 μm resulted in the pore‐wall collapse. The diameter and the wall thickness of macropores showed a tendency to decrease with decreasing the spacing of prepared etch pits, which could not be explained only from the width of the space‐charge region. The resistance distribution in a silicon substrate was proposed as a parameter playing a crucial role in determination of the wall thickness. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)