Semiconductor device including porous insulating material and manufacturing method therefor

• US 6,737,744 B2
• Filed: 03/11/2002
• Issued: 05/18/2004
• Est. Priority Date: 09/25/2001
• Status: Expired due to Term

• Current Assignee: Fujitsu Semiconductor Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Limited
• Inventors: Fukuyama, Shun-ichi
• Primary Examiner(s): Clark, Sheila V.
• Application Number:
  US10/093,502
• Publication Number:
  US 20030057561A1
• Time in Patent Office: 799 Days
• Field of Search: 257/750, 257/758, 257/762, 257/622
• US Class Current: 257/750
• CPC Class Codes: H01L 21/76813 involving a partial via etch
• CPC Class Codes: H01L 21/76832 Multiple layers
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

On a substrate, a first insulating film, a first interlayer insulating film, a second and third insulating films, and a second interlayer insulating film are formed. Wire trenches are formed reaching the upper surface of the third insulating film, and via holes are formed from the bottom of the wire trench to the upper surface of the first insulating film. Formation of the wire trench is performed by etching the second interlayer insulating film under a condition in which the second interlayer insulating film is selectively etched. The third insulating film exposed at the bottoms of the wire trenches and the first insulating film exposed at the bottoms of the via holes are removed by etching under a condition in which the third insulating film is selectively etched. Wires are filled in the via holes and the wire trenches.

Claims

1. A semiconductor device comprising:

a first insulating film provided on a surface of a substrate having a conductive area exposed at a part of the surface thereof;

a first interlayer insulating film provided on the first insulating film;

a second insulating film provided on the first interlayer insulating film;

a via hole formed from an upper surface of the second insulating film to a bottom surface of the first insulating film;

a third insulating film which is provided on the second insulating film and which has a different etching resistance from that of the second insulating film;

a second interlayer insulating film which is provided on the third insulating film and which has a different etching resistance from that of the third insulating film;

a wire trench which is provided from an upper surface of the second interlayer insulating film to the upper surface of the second insulating film and which is connected to the via hole at a part of the bottom of the wire trench; and

a wire member which comprises a conductive material and is filled in the via hole and the wire trench.

2. A semiconductor device according to claim 1, wherein the first interlayer insulating film comprises a porous insulating material.

3. A semiconductor device according to claim 1, wherein the first interlayer insulating film comprises porous silica, the second insulating film comprises SiO₂, and the first insulating film and the third insulating film each comprise SiC or SiN.

4. A semiconductor device according to claim 1, wherein a dielectric constant of the second insulating film is lower than that of the third insulating film.

5. A semiconductor device according to claim 1, wherein the third insulating film is thinner than the first insulating film.

6. A semiconductor device according to claim 1, wherein the conductive area exposed at the part of the surface of the substrate comprises a Cu wire formed on the substrate.

7. A semiconductor device comprising:

a first insulating film which comprises a porous insulating material and which is provided on a surface of a semiconductor substrate;

a first etching stopper film which comprises an insulating material and which is provided on the first insulating film;

a second etching stopper film provided on the first etching stopper film, the second etching stopper film comprising another insulating material which has a higher dielectric constant than that of the first etching stopper film;

a second insulating film provided on the second etching stopper film;

a recess which penetrates through the second insulating film and the second etching stopper film and at a bottom of which the first etching stopper film remains; and

a conductive member which comprises a conductive material and is filled in the recess.

8. A semiconductor device according to claim 7, wherein the first insulating film comprises porous silica, the first etching stopper film comprises SiO₂, and the second etching stopper film comprises SiC or SiN.