Method of fabricating semiconductor device with cavity interposed between wirings
AssigneeNEC Corporation
InventorNorio Okada
Life of this patent
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Abstract
A wiring layer is formed on a first interlayer insulation film. An oxide film is formed on the wiring layer. The oxide film is patterned to have a gap corresponding to a gap between wirings. Thereafter, the wiring layer and a surface layer of the first interlayer insulation film are etched using the oxide film remaining on the wiring layer as a mask. On this occasion, two wirings are formed by the wiring layer so as to be separated from each other by the gap. Subsequently, a second interlayer insulation film is formed on the wirings and in the gap between the wirings with a cavity remaining in the gap by means of a bias ECR film deposition method.
Claims14
A method of fabricating a semiconductor device with a cavity interposed between wirings comprising the steps of:
- forming a wiring layer on a first interlayer insulation film;
- forming an oxide film on said wiring layer;
- patterning said oxide film so as to have a gap corresponding to a gap between wirings;
- etching said wiring layer and a surface layer of said first interlayer insulation film using said oxide film as a mask, whereby two wirings are formed by said wiring layer so as to be separated from each other by said gap;
- and
- forming a second interlayer insulation film on said wirings and in said gap, leaving a cavity in said gap.
A method of making a semiconductor device having a low capacitance between wires on the same level, comprising the steps of:
- forming a wiring layer directly on a first level of a first insulation layer;
- forming an oxide film directly on the wiring layer;
- patterning the oxide film to provide an opening corresponding to a gap that is to be formed in the wiring layer;
- etching the wiring layer and a surface of the insulation layer using the oxide film as a mask, forming two wire sections separated by the gap and removing a portion of the first insulation layer beneath the first level and between the two wire sections;
- and
- using a bias ECR film deposition method to form a second insulation layer on the oxide film and in the gap, leaving a cavity in the second insulation film in the gap between the wire sections, the cavity extending beneath the first level of the first insulation layer and above a top surface of the wiring layer.
Dependencies are inferred from the claim text.