Evaluation of a chemical vapor deposition system by growth oftitanium and tungstencarbonitrides

Sammanfattning

A system previously used for chemical vapor deposition (CVD) of thin coatings has been testedand validated after several years of being unused. The performance of the system was assessedby depositing thin films of titanium carbonitride Ti(C,N) as well as cubic tungsten carbonitrideW(C,N). The coatings were deposited with a gas mixture of ethylene and ammonia and the metalprecursors were titanium tetrachloride and tungsten hexafluoride for the Ti(C,N) and W(C,N) re-spectively. Ti(C,N) was successfully deposited at a temperature of 950 ◦C and slight variationsin composition were achieved by changing the ratio of ethylene to ammonia. Cubic W(C,N) waspossible to deposit at a temperature of 650 ◦C, although with a low carbon content. The de-posited coatings were analysed using X-ray diffraction, scanning electron microscopy and X-rayphotoelectron spectroscopy. The system is equipped with a function that logs the conditions suchas the temperature in the heated zones and the flows of precursor gasses during the depositions.These output files were used to evaluate components such as the heating elements and the massflow controllers. From the results it could be concluded that the system is in an operational state.