In situ characterization of plasma-deposited a-C:H thin films by spectroscopic infrared ellipsometry
A computer-controlled rotating polariser ellipsometer, operating in the infrared spectral region between 3.00 and 3.75 micron, has been developed for in situ characterisation of amorphous hydrocarbon (a-C:H) thin films, deposited from methane in a rf plasma-enhanced chemical vapour deposition reactor. Spectroscopic IR ellipsometry permits insight into the chemical bonding structure of a-C:H coatings by the nondestructive detection of infrared stimulated C:H stretch vibrations. It is shown that the sp(2)CH(x)/sp(3)CH(x) ratio, the content of bonded hydrogen, the infrared linewidth, and the real refractive index of the films depend on the negative self-bias voltage, which is formed at the samples during the deposition process. A transition from a-C:H films with polymerlike properties to hard a-C:H films was attained at a self-bias voltage of approximately -75 V.
Bibliographic Reference: Article: Review of Scientific Instruments, Vol. 65 (1994) No. 9, pp. 2882-2889
Record Number: 199411444 / Last updated on: 1994-12-06
Original language: en
Available languages: en