SEALING OXIDE POSITIONED BETWEEN METAL LINES FOR VAPOR VERY LOW DIELECTRIC

PURPOSE: Sealing oxide positioned between metal lines is provided to easily set a target of a chemical mechanical polishing by allotting the sealing oxide to a polishing stationary layer. CONSTITUTION: A carbon compound layer(202) is formed on a substrate(201), and oxide of any one selected from a group consisting of Zr, Ce, Mg, Ca and Gd or oxide of a compound mixed with at least two components selected from the group is formed on the carbon compound layer as sealing oxide(203). The sealing oxide and the carbon compound layer are selectively etched to open a portion on which a metal line(204) is formed. The metal line is formed on the entire surface, and is carried out through a chemical mechanical polishing to expose the sealing oxide. An oxygen plasma process is performed to ash the carbon to form a vapor low dielectric(205). At the step of selectively etching the carbon compound layer, a photoresist pattern is formed on the sealing compound, and the sealing compound is etched under a reduction atmosphere.