IN-SITU PLASMA MONITORING OF PULSED-LASER DEPOSITION OF DIAMOND-LIKE CARBON-FILMS

Pulsed laser deposition (PLD) is a dynamically unstable process, which can be controlled by in situ diagnostic methods. Recently, an optical spectrometer (OS) was used to monitor the plasma composition and a qu artz crystal microbalance (QCM) was introduced to control the depositi on rate. In the present studies, the development of PLD in situ contro l is continued by introducing an ion probe into the plasma and using t he OS to measure the kinetic energy of carbon ions in diamond-like car bon (DLC) deposition. An original approach was used to read probe curr ents with 1024 sampling points during the time of flight of ablated sp ecies from the target to the substrate. The method was applied to the deposition of DLC, comparing the ablation of graphite and polycarbonat e targets, using a 248 nm KrF wavelength. The correlation of probe cur rents with QCM and OS data is discussed and compared with results from electron energy loss spectroscopy and microindentation studies. Quant itative dependences between the laser fluence and kinetic energy of ca rbon species, deposition rate and ion current are found. A possible me thod for in situ control of DLC film growth with required properties i s proposed based on the combination of these studies and existing mode ls of DLC deposition and PLD dynamic control.