US 6,333,255 B1 · Method for making semiconductor device containing low carbon film for interconnect structures

Abstract

A lower carbon film as a provisional film, a lower SiO2 film and an upper carbon film are formed, and then trenches having a wiring pattern are formed in the upper carbon film. Next, contact holes are formed through the lower carbon film and the lower SiO2 film. Then, wires and plugs are formed by filling in the trenches and contact holes with a barrier metal film and a Cu alloy film. After these process steps are repeatedly performed several times, a dummy opening is formed to extend downward through the uppermost SiO2 film. Thereafter, the carbon films are removed by performing ashing with oxygen introduced through the dummy opening. As a result, gas layers are formed to surround the wires and plugs. In this manner, a highly reliable gas-dielectric interconnect structure can be obtained by performing simple process steps.

Claims12

Dependent claims

A method for fabricating a semiconductor device, said method comprising the steps of:

a) forming a plurality of interconnect layers by sequentially stacking plugs and wires on a substrate, and forming an insulating film and a provisional film for each said interconnect layer;
wherein for each interconnect layer, the insulating film of a given interconnect layer laterally interconnects the wires of the given interconnect layer to each other, the provisional film filling in regions surrounding the plugs and the wires;
b) forming an opening to pass through at least the uppermost one of the insulating films and the uppermost one of the provisional films that are formed in step a);
and
c) removing all the provisional films while leaving the insulating films, thereby turning the regions where the provisional films existed into gas layers.

2 more elements

Dependencies are inferred from the claim text.

Method for making semiconductor device containing low carbon film for interconnect structures

Life of this patent

Method for making semiconductor device containing low carbon film for interconnect structures

Life of this patent

Abstract

Claims12