Abstract: A method of forming a wiring level and an electrical isolation associated with the wiring level on a surface of a semiconductor wafer comprises the steps of providing the semiconductor wafer having said surface, forming a plurality of electrically conductive wiring lines upon said surface, each of the wiring lines having a spacing with respect to neighboring one of the wiring lines, depositing a first layer of amorphous carbon upon the wiring lines by means of non-conformal plasma enhanced chemical vapor deposition (PECVD), such that air-filled voids formed below the first layer within the spacings between neighboring wiring lines. Alternatively, OSG (organo-silicon glass) or FSG (fluorine doped silicon glass) may be deposited to yield air-filled voids within the spacings. According to an embodiment, the carbon, OSG or FSG layers are used as an IMD-layer (line-to-line isolation), added by a further layer of a dielectric material, which then serves as an ILD-layer (level-to-level isolation).

Abstract: A method of forming a wiring level and an electrical isolation associated with the wiring level on a surface of a semiconductor wafer comprises the steps of providing the semiconductor wafer having said surface, forming a plurality of electrically conductive wiring lines upon said surface, each of the wiring lines having a spacing with respect to neighboring one of the wiring lines, depositing a first layer of amorphous carbon upon the wiring lines by means of non-conformal plasma enhanced chemical vapor deposition (PECVD), such that air-filled voids formed below the first layer within the spacings between neighboring wiring lines. Alternatively, OSG (organo-silicon glass) or FSG (fluorine doped silicon glass) may be deposited to yield air-filled voids within the spacings. According to an embodiment, the carbon, OSG or FSG layers are used as an IMD-layer (line-to-line isolation), added by a further layer of a dielectric material, which then serves as an ILD-layer (level-to-level isolation).