Nanostructure Fabrication by Reactive-Ion Etching of Laser-Focused Chromium on Silicon

As a demonstration of how the technique of laser-focused atomic deposition can be broadened to make other types of structures, we have shown [EPG Pub# 681] that arrays of well-isolated Cr nanowires 68 mm: wide, or trenches in Si 85 mm: wide, can be made by applying a relatively simple reactive-ion etch process. When our as-deposited Cr on Si sample is placed in a commercial parallel-plate etching chamber with a SF₆ plasma, sputtering of the Cr begins to occur. As the valleys between the Cr ridges become cleared of material, reactive etching begins in the Si at a rate about 100 times faster than the sputtering. Trenches rapidly develop as the Cr peaks are slowly thinned and narrowed. Depending on the contrast of the deposited Cr, patterns can be made ranging from narrow trenches in the Si separated by Cr (which can be easily stripped if desired) to narrow Cr wires. This work suggests a number of further extensions, such as including another layer of any desired material between the Cr and the Si, or using a specific substrate (other than silicon) in which such patterns might be desirable.

Nanostructure Fabrication by Reactive-ion Etching of Laser-Focused Chromium on Silicon

Jabez J. McClelland - NIST
Robert J. Celotta - NIST

Rajeev Gupta

George Porkolab- Laboratory for Physical Sciences

Online: July 1999
Last Updated: February 2008

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