Skip to main content
European Commission logo print header

THE DEVELOPMENT OF A NOVEL HYDROGEN PROBE FOR PLASMA CHARACTERISATION AND CONTROL DURING DIAMOND FILM DEPOSITION

Exploitable results

Techniques have been developed to deposit diamond like carbon (DLC) coatings on a range of substrates including glass, metals and polymers. The coatings have outstanding industrial potential due to their wear resistance, low friction, biocompatibility and hermeticity properties. Potential applications include wear resistant coatings for engineering components and orthopaedic implants, vapour barrier coatings on plastics and protective coatings on lenses and glass components. A portable probe has also been developed based on a combination of a Langmuir probe and emission spectroscopy to quantitatively determine the concentration of atomic hydrogen in an rf discharge. Quantitative atomic hydrogen measurements have been made during DLC film deposition and these have been related to film quality.
Measurements of the level of atomic hydrogen in a 13.56 MHz radio frequency plasma have been obtained during the deposition of diamond like carbon (DLC) films. 2 techniques were used, firstly a multiphoton laser induced fluorescence (MPLIF) system and secondly a novel combination of Langmuir probe and emission spectroscopy. In the latter technique the data obtained from electron energy distribution function (EEDF) measurements and hydrogen emission line intensities were combined using a computer modelling technique to give the atomic hydrogen concentration. This system can potentially be used as a portable atomic hydrogen probe. The results obtained were compared with those obtained using the MPLIF technique which in turn can be calibrated using a hydrogen transfer standard which is calibrated by a titration technique. The hydrogen probe technique gave similar relative increases to MPLIF, but the atomic hydrogen concentrations were approximately a factor of 4 higher. More accurate electron collision cross sections and EEDF measurements should produce better agreement. The 2 techniques have been used to measure atomic hydrogen, initially in a hydrogen plasma and subsequently in acetylene/hydrogen containing plasmas during the deposition of DLC films. In conjunction with these measurements in situ ellipsometry was used to obtain film thickness, refractive indices and extinction coefficients. A correlation has been obtained relating the concentration of atomic hydrogen with the insitu ellipsometry data for films with refractive index between 1.6 and 2.1 (at 675 nm).

Searching for OpenAIRE data...

There was an error trying to search data from OpenAIRE

No results available