AVS 47th International Symposium
    Plasma Science and Technology Monday Sessions
       Session PS2-MoA

Paper PS2-MoA5
Novel Dry Etch Chemistries for Metals

Monday, October 2, 2000, 3:20 pm, Room 311

Session: Plasma Etching of Conductors
Presenter: A. Orland, Auburn University
Authors: A. Orland, Auburn University
R. Blumenthal, Auburn University
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Magentic metals are the principle components of the read/write heads and magnetic media of the data storage industry and are even finding their way into semiconductor processing. Although "lift-off" techniques, ion milling and non-specific plasma etches have proven adequate for the fabrication today's devices. These methods are simply not capable of fabricating the structures that will be required for the next generation of devices. Many promising chemistries have failed when involatile products form instead of the desired volatile products. This is likely the case for the etching of Fe and Co with CO/NH@sub 3@, where the formation of low vapor pressure dimeric species, such as Fe@sub 2@CO@sub 9@ (as opposed to the high vapor pressure monomeric species, FeCO@sub 5@) may be responsible for the low etch rates that have been previously reported in literature. Modification of the CO/NH@sub 3@ chemistry with the addition of methane, acetone, and/or H@sub 2@ to the mixture will be reported. Addition of these species is intended to result in both methyl and acetyl substitutions on the metal, which are known to inhibit the formation of undesirable, non-volatile, dimeric metal complexes. Other results will include the investigation of new chemistries, such as cyclopentadienyl- carbonyl- chemistries, which will explore entirely new classes of possible volatile metal products. In-situ monitoring with supersonic pulse, plasma sampling mass spectrometry will yield information about all chemical species (both monmeric and dimeric) in the plasma environment, hence, it will provide a basis for understanding the chemical mechanisms of both successful and unsuccessful new etch chemistries.