Characterization and optical properties of diamondlike carbon prepared by electron cyclotron resonance plasma

Abstract

Diamondlike carbon (DLC) films have been prepared on radio-frequency (rf) biased substrates maintained at low temperature using electron cyclotron resonance CH 4 -Ar plasma. The effects of negative rf bias and reactant gas composition on the bonding structure, hardness, and resistivity of the films were systematically investigated. DLC films deposited on PMMA (polymethyl methacrylate) were examined by optical methods to determine the absorption coefficients and the optical band gap. It was found that DLC films synthesized at bias voltage of 2(80-100) V and F CH4 ͞F Ar of 0.075-0.086 exhibit extreme hardness of more than 3000 kgf mm 22 , high electrical resistivity up to 10 14 V cm, band gap larger than 2.5 eV, and excellent optical transparency. The results indicate that ECR CH 4 -Ar plasma with low negative rf bias and suitable CH 4 ͞Ar gas ratio can process optically transparent and hard protective DLC films on PMMA plastics.

High aspect ratio wrinkles on a soft polymer

“…A longer Ar ion treatment results in the formation of a thicker surface layer and inherently, a higher level of defect and a stronger optical absorption in the sample. 43,44 The deposition of a carbon film for 10 min results in a reduction in the optical band gap from 3.27 to 2.79 eV. The optical properties of an amorphous carbon film can be changed by changing the chemical bonding structure and by doping of different elements.…”

Advanced carbon hybrid materials

“…The last deposition method discussed is the plasma enhanced chemical vapor deposition(PECVD) [120,[158][159][160][162][163][164][165][166] It consisted of 2 electrodes of differing sizes with rf power capacitively coupled to the smaller electrode and ground connected to the larger one. The rf power thus produces a plasma between the electrodes and due to the difference in mobility of the ions and electrons, a sheath is created at the electrodes causing the plasma to be positively charged relative to the electrodes.…”