Optical constants of silicone-like (Si:Ox:Cy:Hz) thin films deposited on quartz using hexamethyldisiloxane in a remote RF hollow cathode discharge plasma

Deposition of amorphous silicone-like (Si:O_x:C_y:H_z) thin films in a remote RF hollow cathode discharge plasma using hexamethyldisoloxane as monomer and Ar as feed gas has been investigated for films optical constants and plasma diagnostic as a function of RF power (100-300 W) and precursor flow rate (1-10 sccm). Plasma diagnostic has been performed using Optical Emission Spectroscopy (OES). The optical constants (refractive index, extinction coefficient and dielectric constant) have been obtained by reflection/transmission measurements in the range 300-700 nm. It is found that the refractive index increases from 1.92 to 1.97 with increasing power from 100 to 300 W, and from 1.70 to 1.92 with increasing precursor flow rate from 1 to 10 sccm. The optical energy band gap E_g and the optical-absorption tail ΔE have been estimated from optical absorption spectra, it is found that E_g decreases from 3.28 to 3.14 eV with power increase from 100 to 300 W, and from 3.54 to 3.28 eV with precursor flow rate increase from 1 to 10 sccm. ΔE is found to increase with applied RF power and precursor flow rate increase. The dependence of optical constants on deposition parameters has been correlated to plasma OES.     

Active species characterization in RF remote oxygen plasma using actinometry OES and electrical probes

Actinometry optical emission spectroscopy (AOES), single cylindrical Langmuir probe and electrostatic planar probe were used to investigate the active species (electrons, ions and atomic oxygen) of remote oxygen plasma in an RF (13.56 MHz) hollow cathode discharge system, as a function of applied power and gas pressure. The electron density and electron temperature were determined from Langmuir probe. The atomic oxygen (AO) density was measured using argon actinometry method. Positive ion flux rate was estimated from the positive ion saturation current of the planar probe, and the combination of the planar and Langmuir probes enabled the determination of the negative ion fraction in the discharge. The explanation of the behavior of the different active plasma species was performed on the basis of the main kinetic reactions of oxygen plasma.