When photoresists are used as masks for rf sputter‐etching of various materials, interactions between the material being etched and the photoresist occur as a result of backscattering of some of the ejected material. We have studied these interactions in a variety of ways. Most of the interactions are similar to the interactions of the materials with carbon, and the intrinsic sputter‐etch rate of photoresists is the same as that of carbon. When metals and photoresists are etched simultaneously, both materials are eroded at the same rate because backscattering converts the surface to a uniform mixture of all materials present. The etch rate of the composite surface increases over the intrinsic etch rate of the photoresist if metal carbide intermetallics can form. When only solid solutions can form, the composite etch rate decreases with decreasing solubility of carbon in the metal. Wnen oxides are backscattered onto photoresists, the etch rate of the composite surface varies in a way which we cannot explain, and the photoresist is etched preferentially because of oxide decomposition followed by “chemical sputtering” The ability of a photoresist to mask oxides varies from one photoresist material to another. It is not possible to correlate the performance of a sputter‐etch resist to its structure at this time, but it is clear that different materials behave differently in every respect.
The discovery by Ziegler of a heterogeneous catalyst system capable of polymerizing ethylene to a high molecular weight solid under extremely mild conditions, and the subsequent work of Natta2 on the extension of the investigation to other a-olefins is well documented. The unusual properties of the polymers obtained from heterogeneous catalysts led to a search for polymerizable monomers other than the purely hydrocarbon types with which the early investigators were occupied.I n this work a series of polar monomers was prepared in order to find a heterogeneous catalyst system suitable for their polymerization, to correlate the effect of the proximity of the polar substituent to the double bond with the ability of the monomers to polymerize, and to determine the effect of the polar substituent on the properties of the polymer. As an indication of the degree of polar, character of the trifluoromethyl group, 3,3,3trifluoropropene is reported to possess a dipole moment of 2.45 D.3 as opposed to 0.34 D. for propylene4 and 3.15 D. for acryl~nitrile.~ EXPERIMENTAL 3,3,3-Trifluoropropene 3,3,3-Trifluoroproperie was prepared according to the procedure of Syverson and Kroetz6 by conversion of 1 ,l,l-trifluoropropano1-2 to and pyrolysis of the acetate. The monomer was purified as the dibromide, prepared according to Henne17 and was regenerated with zinc in refluxing ethanol.
4,4,4-Trifluorobutene-lPreparation of 4,4,4-Trifluorobutanol. 1,1,1,3-Tetrachloropropane was converted to 1,1,l-trifluoro-3-chloropropane according to Haszeldine8 by reaction with antimony trifluoride dichloride.To sublimed magnesium turnings (23.1 g., 0.95 g.-atom) in 300 ml. of * A portion of a thesis submitted by E.B.11. in partial fulfillment of the requirement for the Degree of Doctor of Philosophy in the graduate school of the Polytechnic Institute of Brooklyn.
Bei Verwendung von Photoresists als Masken für das Hochfrequenzzerstäubungsätzen verschiedener Materialien werden infolge einer Rückstreuung von zerstäubtem Material Wechselwirkungen zwischen Photoresist und dem geätzten Material beobachtet.
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