THERMAL-INSTABILITY OF THE MICROSTRUCTURE AND SURFACE MECHANICAL-PROPERTIES OF HYDROGENATED AMORPHOUS-CARBON FILMS

被引:23
作者
KNIGHT, JC
PAGE, TF
CHANDLER, HW
机构
[1] Materials Division, Department of Mechanical, Materials and Manufacturing Engineering, The University, Newcastle upon Tyne
关键词
D O I
10.1016/0257-8972(91)90111-9
中图分类号
TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
The thermal stability of the microstructure and surface mechanical properties of two types of hydrogenated carbon film ("hard" and "soft" versions, both about 2000 angstrom thick) deposited from methane onto Si(100) wafers by a r.f.-plasma-assisted chemical vapour deposition process have been investigated. Whilst Raman spectroscopy indicates the presence of some degree of sp3 bonding in the hard film, the soft coating luminesced and burned away easily in the laser beam. IR reflectance shows the presence of CHx in both films but the amount, and whether it is CH2 or CH3, could not be deduced owing to the strong IR absorbance of the silicon substrate. On annealing in air (in the temperature range 20-600-degrees-C), scanning electron microscopy and energy-dispersive X-ray analysis show that both films are completely oxidized by 500-degrees-C. On annealing in vacuum (at 10(-6) Torr or less) a system of bubbles forms in the hard film at about 530-degrees-C, owing to the liberation of trapped argon, and leads to decohesion of the coating-substrate interface. Also, after annealing in vacuum, transmission electron microscopy shows further marked changes in the nanostructure of the films at elevated temperatures. As expected from these microstructural changes, the microhardness and contact damage resistance of both films are drastically degraded at only relatively modest temperatures. Further, the hard composite exhibits thermal hysteresis of hardness, suggesting the presence of significant compressive residual stress in the film. These results are presented and discussed alongside further insights gained from surface displacement experiments with a nanoindenter.
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页码:519 / 529
页数:11
相关论文
共 21 条
[1]   CHANGING THE SURFACE MECHANICAL-PROPERTIES OF SILICON AND ALPHA-AL2O3 BY ION-IMPLANTATION [J].
BURNETT, PJ ;
PAGE, TF .
JOURNAL OF MATERIALS SCIENCE, 1984, 19 (11) :3524-3545
[2]  
FITZGERALD A, 1988, I PHYS C SER, V93, P273
[3]  
FITZGERALD AC, 1988, I PHYS C SER, V93, P97
[4]  
GILLIES AD, 1989, I PHYS C SER, V98, P319
[5]  
Knight J. C., 1989, Surface Engineering, V5, P213
[6]  
KNIGHT JA, IN PRESS
[7]   THE FINE-SCALE MICROSTRUCTURE OF THIN HARD TIN AND TIC COATINGS ON STEELS [J].
KNIGHT, JC ;
PAGE, TF .
THIN SOLID FILMS, 1990, 193 (1-2) :431-441
[8]   THE EFFECT OF ANNEALING ON THE HARDNESS, INTERFACIAL ADHESION AND WEAR BEHAVIOR OF PLASMA-VAPOR-DEPOSITED TIN COATINGS ON STEELS [J].
KNIGHT, JC .
WEAR, 1990, 138 (1-2) :239-257
[9]  
KNIGHT JC, 1991, IN PRESS J MATER SCI
[10]  
MCHARGUE CJ, 1991, NATO ADV STUD I B, V266