Have a look at this paper:

Walkiewicz‐Pietrzykowska, Agnieszka, José Cotrino, and Agustin R. González‐Elipe. "Deposition of thin films of SiOxCyH in a surfatron microwave plasma reactor with hexamethyldisiloxane as precursor." Chemical Vapor Deposition 11.6‐7 (2005): 317-323.

Have a look at my paper:

C.C. Nguyen, H. Choi, S.-W. Song, Roles of Oxygen and Interfacial Stabilization in Enhancing the Cycling Ability of Silicon Oxide Anodes for Rechargeable Lithium Batteries, Journal of The Electrochemical Society. 160 (2013) A906–A914.

Many years ago I was trying to develop SiO monoxide films by sputtering.

I don't have these reference papers at the moment. But then it is not so difficult to find these papers.

I did come across many papers dealing with FTIR spectroscopic analysis for characterising the SiOx films with variation in x from 1 to 2. A good literature survey should help you out.

But you may have to deposit your films directly on KBr pellets, and take care to prevent of moisture absorption., or alternately deposit your films on NaCl substrates, which can withstand high temperatures and are rugged enough compared to pressed KBr pellets for FTIR spectroscopy.

K. Sreenivas

Films deposited from a plasma are quite complex, and don't react according to conventional functionality.  As a result, one should not expect a simple spectrum of the resulting film from such techniques as IR. 

Attached are 2 pages from the old Silverstein & Bassler book  Spectrometric Identification of Organic Compounds  (1963, John Wiley & Sons, NY) which show common IR bands.  This will help you understand better the possible source(s) of the peaks you are interested in.  Note that there are a considerable number of possibilities.

Again, because of the plasma deposition, the surviving functional groups in any film will likely be quite different from your starting materials, particularly considering that you used oxygen in additional to your starting materials.  It is quite likely that you do not have a simple SiOx film.

Instead of HR-SEM you should do electron diffraction to determine the radial distribution function and perhaps EF-TEM to check (in)homogeneity, cf Schulmeister & Mader, Journal of non-crystalline Solids, vol. 320, p 143 (2003).

Typically strong peaks for silicon oxide are appeared at ~1080 (Si-O stretching on phase) and ~1150 (Si-O stretching out of phase). Structure or composition may slightly shift peaks positions. In your case, it seems that you may conclude that a silicone oxide is formed.

In this case the HR-SEM is not helpful tool to confirm that obtained material is silica.

Thank you very much for your valuable suggestions.

Have you tried to use spectroscopic ellipsometry as well? i think there you can distinguish the ratio factor of your SiOx. And by making a theta scan i think you will also get the information if your material has some kind of anisotropy in the xy plane.