Metal-assisted chemical etching in HF/H{sub 2}O{sub 2} produces porous silicon
A simple and effective method is presented for producing light-emitting porous silicon (PSi). A thin (d<10 nm) layer of Au, Pt, or Au/Pd is deposited on the (100) Si surface prior to immersion in a solution of HF and H{sub 2}O{sub 2}. Depending on the type of metal deposited and Si doping type and doping level, PSi with different morphologies and light-emitting properties is produced. PSi production occurs on the time scale of seconds, without electrical current, in the dark, on both p- and n-type Si. Thin metal coatings facilitate the etching in HF and H{sub 2}O{sub 2}, and of the metals investigated, Pt yields the fastest etch rates and produces PSi with the most intense luminescence. A reaction scheme involving local coupling of redox reactions with the metal is proposed to explain the metal-assisted etching process. The observation that some metal remains on the PSi surface after etching raises the possibility of fabricating in situ PSi contacts.
- Sponsoring Organization:
- (US)
- OSTI ID:
- 40205300
- Journal Information:
- Applied Physics Letters, Vol. 77, Issue 16; Other Information: DOI: 10.1063/1.1319191; Othernumber: APPLAB000077000016002572000001; 055042APL; PBD: 16 Oct 2000; ISSN 0003-6951
- Publisher:
- The American Physical Society
- Country of Publication:
- United States
- Language:
- English
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