Radio-Frequency Plasma Enhanced Chemical Vapour Deposition (RF-PECVD), and Pulsed Laser Deposition (PLD) techniques were used to deposit boron carbide (BxC) thin films. Films were investigated to compare crystallinity, chemical composition, optical properties, and residual stress. X-ray diffraction analysis revealed that the film deposited by PLD was amorphous, while PECVD technique yielded crystalline BxC film. PLD technique provided films with better stoichiometric purity with B4C being the most dominant phase, as observed in XPS spectra. However, super-stoichiometric phase (BxC (x > 4)) was dominant in PECVD film. Moreover, the PECVD film had greater adhesion (Lc(3) similar to 29.5 N), hardness (similar to 2798 HK), and lubricity (COF similar to 0.03) compared to PLD deposited film. Optically, PECVD deposited film have higher value of refractive indices (1.82 at 600 nm) and lower extinction coefficient. Finally, residual stress measured via substrate curvature method revealed that for PLD 400 C film, the stress was compressive in nature while the same for PECVD -100 V film was tensile, with 10 times less in magnitude. Ultimately, this study provides the user with opportunity to weigh the advantages and disadvantages of PECVD and PLD techniques for deposition of functional BxC films.

BxC thin films were deposited on silicon (100) and sodalime glass substrates using Radio Frequency Plasma Enhanced Chemical Vapour Deposition (RF-PECVD) technique, at different substrate self-bias varying from -100V to -250V. Optical property, structure and stoichiometry of the films were determined by spectrophotometry, X-ray diffraction and proton elastic backscattering spectrometric measurements respectively to investigate the effect of film composition on microstructure and optical properties. Film refractive index at a typical wavelength of 400 nm increased from 1.87 to 1.97 on account of increasing packing density of the films with substrate self- bias. Decrease in direct and indirect optical band gap with increasing substrate self-bias, has been explained on the basis of compositional variation i.e. boron/carbon stoichiometric ratio. Finally, soft X-ray reflectivity in the wavelength range of 40 angstrom-360 angstrom has been measured to explore its potential for application as optical material in this region of electromagnetic spectrum.

Diamond like carbon (DLC) films were deposited on Si (111) substrates by microwave electron cyclotron resonance (ECR) plasma chemical vapour deposition (CVD) process using plasma of argon and methane gases. During deposition, a d.c. self-bias was applied to the substrates by application of 13·56 MHz rf power. DLC films deposited at three different bias voltages (−60 V, −100 V and −150 V) were characterized by FTIR, Raman spectroscopy and spectroscopic ellipsometry to study the variation in the bonding and optical properties of the deposited coatings with process parameters. The mechanical properties such as hardness and elastic modulus were measured by load depth sensing indentation technique. The DLC film deposited at −100 V bias exhibit high hardness (∼ 19 GPa), high elastic modulus (∼ 160 GPa) and high refractive index (∼ 2·16–2·26) as compared to films deposited at −60 V and −150 V substrate bias. This study clearly shows the significance of substrate bias in controlling the optical and mechanical properties of DLC films.

Diamond like carbon (DLC) coatings were deposited on silicon(1 1 1) substrates by microwave electron cyclotron resonance (ECR) plasma CVD process using a plasma of Ar and CH4 gases under the influence of DC self bias generated on the substrates by application of RF (13.56 MHz) power. DLC coatings were deposited under the varying influence of DC bias (−60 V to −150 V) on the Si substrates. Deposited films were analyzed by different techniques like: X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry (SE), atomic force microscopy (AFM), Hardness and elastic modulus determination technique, Raman spectroscopy, scanning electron microscopy (SEM) and contact angle measurement. The results indicate that the film grown at −100 V bias has optimised properties like high sp3/sp2 ratio of carbon bonding, high refractive index (2.26–2.17) over wide spectral range 400–1200 nm, low roughness of 0.8 nm, high contact angle (80°) compared to the films deposited at other bias voltages (−60 V and −150 V). The results are consistent with each other and find august explanation under the subplantation model for DLC growth.