Semiconductor device including interconnects formed by damascene process and manufacturing method thereof
AssigneeSanyo Electric Co., Ltd.
InventorsNaoteru Matsubara, Kazunori Fujita
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Abstract
After etching the interlayer dielectric film 4 formed on the lower layer interconnect line 1 into a shape with holes, the upper layer dielectric film 6 is etched into a shape with trenches utilizing the etching stopper 5. The etching stopper 5 which is exposed at the bottom of the trench is removed by additional etching, and then, the interlayer dielectric film 4 which is exposed at the bottom of the trench is etched back to a predetermined thickness. Subsequently, the hole and the trench are filled with an interconnect metal 10.
Claims17
A semiconductor device comprising:
- a semiconductor substrate;
- a multilayered film including a first dielectric film, an etching stopper and a second dielectric film stacked on said semiconductor substrate in this order, the dielectric constant of said etching stopper being larger than that of said first and second dielectric films;
- and
- a metal interconnect formed in said multilayered film;
- wherein the upper surface of said etching stopper is located under the upper surface level of said metal interconnect and the under surface of said etching stopper is located over the under surface level of said metal interconnect.
A method of manufacturing a semiconductor device, comprising:
- forming a first dielectric film on a semiconductor substrate;
- forming an etching stopper that has a higher dielectric constant than said first dielectric film on said first dielectric film;
- forming a second dielectric film that has a lower dielectric constant than said etching stopper on said etching stopper;
- performing selective etching on said second dielectric film to form a trench until said etching stopper is exposed;
- removing said etching stopper exposed at the bottom of said trench until said first dielectric film is exposed;
- performing selective etching on said first dielectric film to a predetermined thickness to have the depth of said trench having a predetermined depth;
- and
- forming a metal film in said trench.
Dependencies are inferred from the claim text.