A process for producing an electronic component includes covering a substrate with a portion defining, with the substrate, a volume at least partly filled with a temporary material. The temporary material is then removed via chimney for access to said volume. A deposition of a fill material is then made in said volume, the fill material being obtained from precursors supplied via the chimney. The process is particularly suitable for producing a gate of an MOS-type transistor. In this case, the fill material is conducting or semiconducting, and an electrically insulating coating material may also be deposited in said volume before the (semi) conducting fill material. The process also includes defining a trench in a substrate filled with a temporary material. The filled trench is then covered with a circuit portion. The temporary material is then removed via a chimney for access to the trench. A deposition of low dielectric fill material is then made in the trench.