The disclosure relates to a method for manufacturing a planarized etch-stop layer, ESL, for a hydrofluoric acid, HF, vapor phase etching process. The method includes providing a first planarized layer on top of a surface of a substrate, the first planarized layer having a patterned and structured metallic material and a filling material. The method further includes depositing on top of the first planarized layer the planarized ESL of an ESL material with low HF etch rate, wherein the planarized ESL has a low surface roughness and a thickness of less than 150 nm, in particular of less than 100 nm.