Influence of content and structure of hydrocarbon polymers on erosion by atomic oxygen

From a comprehensive analysis of erosion data for materials exposed to low-Earth-orbit space environment, to fast atomic-oxygen beams, and in plasma facilities it is shown that different correlations can be found between the thermal and hyperthermal atomic-oxygen erosion yield of hydrocarbon polymers and their chemical structure and content. Correlations have been found of the hyperthermal atomic-oxygen erosion yield of many polymeric materials in flight experiments with their inverse mass density of effective (not bonded with oxygen) carbon atoms, and with their degree of aromaticity. These correlations were used to identify the rate-limiting factors of erosion processes and to predict the erosion rate for polymer-based materials in low Earth orbit. The first correlation was not found in the interaction of thermal atomic oxygen with a number of polymers, and the second is strongly pronounced. The results are explained on the basis of physical and chemical processes affecting differently the erosion rates of polymers by thermal and by fast atomic oxygen. Subthreshold bombardment-induced and -enhanced degradation and surface chemical etching are proposed to be the major mechanisms of erosion by fast atomic oxygen.

[1]  S. J. Moss.  Polymer degradation in reactive-gas plasmas , 1987 .

[2]  L. Pederson.  Structural Composition of Polymers Relative to Their Plasma Etch Characteristics , 1982 .

[3]  R. Tennyson.  Atomic oxygen effects on polymer-based materials , 1991 .

[4]  E. Collart,et al.  Ion‐induced etching of organic polymers in argon and oxygen radio‐frequency plasmas , 1994 .

[5]  A. Sukhov,et al.  Apparatus and techniques for the investigation of methods of generating molecular beams , 1993 .

[6]  H. Fukuyama.  Interaction effects in the weakly localized regime and the anomalous conductivity of Sb-doped Ge at low temperature , 1985 .

[7]  S. Koontz,et al.  Vacuum ultraviolet radiation/atomic oxygen synergism in materials reactivity , 1990 .

[8]  Stephen R. Leone,et al.  Enhanced etching of Si(100) by neutral chlorine beams with kinetic energies up to 6 eV , 1992 .

[9]  S. Koontz,et al.  Atomic oxygen testing with thermal atom systems - A critical evaluation , 1991 .

[10]  Oxygen ion beam etching for pattern transfer , 1984 .

[11]  A. A. Haasz,et al.  Chemically enhanced self‐sputtering of carbon , 1990 .

[12]  V. Philipps,et al.  The reaction of energetic O2+, thermal O2, and thermal O2/ar+ on graphite and the use of graphite for oxygen collector probes , 1987 .

[13]  T. Wydeven,et al.  Reactions of atomic oxygen (O/3P/) with various polymer films , 1988 .

[14]  J. Newman,et al.  The Mechanism of Plasma Etching of Polymers and Its Relevance to Adhesion , 1987 .

[15]  A. Dunnet,et al.  Intelsat solar array coupon atomic oxygen flight experiment , 1994 .

[16]  A. P. Nikiforov,et al.  Kinetics of polyimide etching by supersonic beams consisting of atomic and molecular oxygen mixtures , 1993 .

[17]  G. Taylor,et al.  Oxygen plasma removal of thin polymer films , 1980 .

[18]  R. H. Hansen,et al.  Effect of atomic oxygen on polymers , 1965 .

[19]  C. W. Jurgensen,et al.  Sheath collision processes controlling the energy and directionality of surface bombardment in O2 reactive ion etching , 1988 .

[20]  D. Zimcik,et al.  Results of apparent atomic oxygen reactions with spacecraft materials during shuttle flight STS-41G , 1985 .

[21]  R. A. Barker,et al.  Simulation of plasma‐assisted etching processes by ion‐beam techniques , 1982 .

[22]  J. Roth,et al.  The sputtering yield of typical impurity ions for different fusion reactor materials , 1981 .

[23]  D. Flamm,et al.  A critical comparison of reactive etching of materials in microelectronics, fusion and space technologies , 1987 .

[24]  P. Varga,et al.  Total sputter yield of LiF induced by hyperthermal ions measured by a quartz microbalance , 1994 .

[25]  D. V. Krevelen.  Properties of Polymers , 1990 .

[26]  M. Tagawa,et al.  Atomic oxygen generators for surface studies in low Earth orbit , 1994 .

[27]  S. J. Moss,et al.  Plasma oxidation of polymers , 1986 .