Method for manufacturing an electrical device with an anodic porous oxide region delimited by planarizing a stack of materials

A method for manufacturing an electrical device, the method comprising:

• providing an anodizable metal layer above a substrate;
• anodizing a portion of the anodizable metal layer so as to obtain an anodic porous oxide region and an anodizable metal region adjoining the anodic porous oxide region, the anodizable metal region having a top surface and the anodic porous oxide region also having a top surface, the anodic porous oxide region being thicker than the anodizable metal region so that the top surface of the anodic porous oxide region is higher than the top surface of the anodizable metal region;
• depositing a layer of liner material on the top surface of the anodic porous oxide region and on the top surface of the anodizable metal region;
• depositing a layer of filler material on the layer of liner material, the layer of filler material having a thickness, above the anodizable metal region, that is greater than the height difference between the top surface of the anodic porous oxide region and the top surface of the anodizable metal region, the filler material being different from the liner material, to obtain a stacked structure having a top surface;
• planarizing the stacked structure from a top surface thereof until reaching the layer of liner material, so as to expose a portion of the liner material located above at least a portion of the anodic porous oxide region, and so that the layer of filler material has a thickness, above the anodizable metal region, that is substantially equal to a height difference between the top surface of the anodic porous oxide region and a top surface of the liner material overlaying the anodizable metal region;
• and
• removing the exposed portion of the liner material.