Abstract: A process for forming an planar dielectric layer over metallurgy lines using an in situ multi-step electron cyclotron resonance (ECR) oxide deposition process. A substrate with metallurgy lines on its surface is covered with a protective ECR oxide layer. The novel ECR process for the protective layer does not have an argon flow and does not etch the surface (e.g., metal lines) it is deposited upon. Next, a gap-fill step is formed over the protective layer. The gap-fill step uses Argon flow and rf power to enhance the deposition in gaps and the planarization. The gap-fill layer etches the underlying protective layer but the protective layer prevents the gap-fill deposition/etch process from attacking and damaging the metallurgy lines. Next, the protective layer and the gap-fill layer sequence are repeated until the desired thickness is obtained. A thick capping protective layer and a capping gap-fill layer are used to complete the planarization process.