Chemical sputtering of hydrocarbon films

被引:113
作者
Hopf, C [1 ]
von Keudell, A [1 ]
Jacob, W [1 ]
机构
[1] EURATOM, Max Planck Inst Plasmaphys, Ctr Interdisciplinary Plasma Sci, D-85748 Garching, Germany
关键词
D O I
10.1063/1.1594273
中图分类号
O59 [应用物理学];
学科分类号
摘要
Erosion of hydrocarbon films at room temperature due to argon ions and thermal atomic hydrogen is investigated in a particle-beam experiment. Physical sputtering by the ions is observed at energies greater than or equal to200 eV and reaches a yield of 0.5 at an ion energy of 800 eV. The measured yields are in agreement with TRIM.SP computer simulations, and a threshold energy of similar or equal to58 eV is derived for physical sputtering. Erosion by simultaneous fluxes of argon ions and thermal hydrogen atoms is observed at all energies investigated down to 20 eV and reaches a yield of about 3 at an ion energy of 800 eV and a hydrogen-atom-to-argon-ion-flux ratio of 400. It is proposed that the significant decrease of the threshold energy as well as the increase of the absolute yields is due to the process of chemical sputtering: Within a collision cascade caused by the incident ions, bonds are broken and instantaneously passivated by the abundant flux of atomic hydrogen. This leads to the formation of hydrocarbon molecules within the common range of ions and hydrogen atoms. Finally, the molecules diffuse to the surface and desorb. The threshold energy of chemical sputtering is on the order of typical carbon-carbon bond energies in organic compounds of several eV. Based on this mechanism a model for the energy dependence of the chemical sputtering yield is presented, which leads to good agreement with the data. (C) 2003 American Institute of Physics.
引用
收藏
页码:2373 / 2380
页数:8
相关论文
共 34 条
[1]  
[Anonymous], 1991, COMPUTER SIMULATION
[2]   New weight-loss measurements of the chemical erosion yields of carbon materials under hydrogen ion bombardment [J].
Balden, M ;
Roth, J .
JOURNAL OF NUCLEAR MATERIALS, 2000, 280 (01) :39-44
[3]   ION-BOMBARDMENT OF POLYETHYLENE [J].
BEARDMORE, K ;
SMITH, R .
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, 1995, 102 (1-4) :223-227
[4]  
BEHRISCH R, 1981, SPUTTERING PARTICLE, V1
[5]   Evaluation of chemical erosion data for carbon materials at high ion fluxes using Bayesian probability theory [J].
Dose, V ;
Preuss, R ;
Roth, J .
JOURNAL OF NUCLEAR MATERIALS, 2001, 288 (2-3) :153-162
[6]   Assessment of erosion and tritium codeposition in ITER-FEAT [J].
Federici, G ;
Brooks, JN ;
Coster, DP ;
Janeschitz, G ;
Kukuskhin, A ;
Loarte, A ;
Pacher, HD ;
Stober, J ;
Wu, CH .
JOURNAL OF NUCLEAR MATERIALS, 2001, 290 :260-265
[7]   High density plasma etching of low k dielectric polymers in oxygen-based chemistries [J].
Fuard, D ;
Joubert, O ;
Vallier, L ;
Bonvalot, M .
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B, 2001, 19 (02) :447-455
[8]  
Garcia-Rosales C., 1994, J NUCL MATER, V218, P8
[9]   Chemical sputtering of hydrocarbon films by low-energy Ar+ ion and H atom impact [J].
Hopf, C ;
von Keudell, A ;
Jacob, W .
NUCLEAR FUSION, 2002, 42 (12) :L27-L30
[10]   Surface reactions during growth and erosion of hydrocarbon films [J].
Jacob, W .
THIN SOLID FILMS, 1998, 326 (1-2) :1-42