A thorough FT-IR spectroscopy study on micrometric silicon oxide films deposited by atmospheric pressure microwave plasma torch

SiOxHyCz micrometer thick films are deposited from an argon/hexamethyldisiloxane mixture on Si (100) substrate by plasma enhanced chemical vapour deposition process using an axial injection torch at atmospheric pressure. Results highlight a similar effect of low and high substrate temperatures both on the deposition process and on the microstructure of the deposited films. Mesoscopically, scanning electron microscopy analyses reveal that particles are promptly produced in the gas phase and incorporated to the film. Microscopically, a detailed infrared analysis in transmission mode demonstrates a high carbon contamination in the low and high temperature intervals resulting in a lower stoichiometry. This work allows to define an optimum growth window for the substrate temperature, leading to smooth, particle-free and carbon-free films: [60 degrees C; 90 degrees C].