Pulsed laser deposition of titanium nitride and diamond-like carbon films on polymers

Abstract

We have investigated the deposition of titanium nitride (TiN) and diamond-like carbon (DLC ) films on polymethylmethacrylate (PMMA) substrates using pulsed laser deposition (PLD) technique. The TiN and diamond-like films were deposited by laser ablation (KrF excimer laser λ = 248 nm, pulse duration τ∼25 × 10−9 s, energy density ∼2−15J/cm2) of TiN and graphite targets, respectively, at room temperature. These films were characterized by transmission electron microscopy, scanning electron microscopy, x-ray diffraction, Auger electron spectroscopy, UV-visible absorption spectroscopy, and Raman spectroscopy. The TiN films were smooth and found to be polycrystalline with average grain size of 120A. The diamond-like carbon films were amorphous with a characteristic Raman peak at 1550 cm−1. The TiN films are highly adherent to the polymer substrates as compare to DLC films. The adhesion strength of DLC films on polymers was increased by interposing thin TiN layer (200A) on polymers byin-situ pulsed laser deposition. The DLC films were found to be amorphous with good adhesion to TiN/PMMA substrates.