Abstract: The process comprises the following steps: a) pretreatment of a surface of the substrate by means of a cold gas plasma at low or medium pressure in order to clean the said surface; b) growth, from the said cleaned surface of the substrate, of a nitride barrier layer by means of a cold gas plasma made up of an N2/H2 mixture at low or medium pressure; and c) deposition, on the nitride barrier layer, of a Ta2O5 dielectric layer by chemical vapor deposition (CVD) or plasma enhanced chemical vapor deposition (PECVD).

Abstract: A process for treating a semiconductor substrate, comprising a prior surface-treatment step using a plasma at medium or low pressure, preferably having an electron concentration N.sub.e .gtoreq.10.sup.11 cm.sup.-3 and preferably producing a small potential difference V.sub.p -V.sub.f <20 V, wherein the surface energy of the treated surface is determined so as optionally to have fast feedback on the control of the process in order to optimize the plasma treatment, and the prior surface treatment step may be followed by a deposition step with a view to filling or planarizing the treated surface or to improving morphological, physical, or electrical characteristics of materials deposited on the treated surface.