Thin polymeric films are deposited from tetramethyldisiloxane (TMDS or TMDS O 2 mixture) by cold remote nitrogen plasma (CRNP). X-ray photoelectron spectroscopy (XPS) has been used to characterise the deposited films. SiN bonds are detected for films deposited from TMDS. These bonds disappear for films deposited from TMDS O 2 mixture. Moreover the deposited films were subjected to a further ageing in CRNP or CRNP O 2 media. A smooth etching of the deposit and a surface composition change are evidenced. Oxygen addition to CRNP leads to more pronounced modifications of the film composition and morphology.