ISSN:
1573-4854
Keywords:
porous silicon
;
pore propagation
;
orientation dependence
;
RBS
;
EPR
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract A comparative study is presented on the pore propagation directions of porous silicon layers (PSL) formed on p+-type substrates of different orientations. PSLs were formed on plain (0 0 1) and (1 1 1) silicon wafers as well as on structured (0 0 1) wafers containing facets of various orientations. During anodization, regular pores follow the 〈0 0 1〉 direction on the (0 0 1) planes. While on the (1 1 1) planes fewer regular pores develop and seemingly propagate closely to the 〈1 1 1〉 direction. These results indicate that the pores propagate perpendicular to the surface i.e. along the field lines when the surface orientation is either (0 0 1) or (1 1 1). When the silicon surface provided (1 1 0) orientation (Chuang, Collins, and Smith, 1989), or its position is in between the (0 0 1) and (1 1 1) planes then the pores do not propagate perpendicular to the surface but along the 〈0 0 1〉 direction. All the phenomena exhibited might be explained by presuming that during formation, the pores propagate along the 〈1 0 0〉 directions, and that those 〈1 0 0〉 directions are preferred which are closely to the field lines. In PSLs formed on (0 0 1) surfaces the field lines and the 〈0 0 1〉 crystallographic direction are coincident. However, in the (1 1 1) oriented wafer where three equally probable 〈1 0 0〉 directions exist around the field lines, more irregular structure of PSLs will develop.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1009642605473
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