Maximum etch rates of were obtained for and thin films in inductively coupled plasmas (ICP). There is a small chemical contribution to the etch mechanism (i.e., formation of metal carbonyls) as determined by a comparison with Ar and physical sputtering. The etch rates are a strong function of ion flux, ion energy, pressure, substrate temperature, and discharge composition. The discharge should be ‐rich to achieve the highest etch rates. Several different mask materials were investigated, including photoresist, thermal oxide, and deposited oxide. Photoresist etches very rapidly in and use of a hard mask is necessary to achieve pattern transfer. Due to its physically dominated nature, the chemistry appears suited to shallow etch depth (≤0.5 μm) applications, but mask erosion leads to sloped feature sidewalls for deeper features. © 1999 The Electrochemical Society. All rights reserved.
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