Semiconductor manufacturing method for inter-layer insulating film
Provided is a technology capable of improving the reliability of a semiconductor device using a SiOC film as an interlayer film. In the invention, by forming an interlayer film from a SiOC film having a Si—CH 3 bond/Si—O bond ratio less than 2.50% or having a strength ratio determined by the FT-IR of a Si—OH bond to a SiO—O bond exceeding 0.0007, a strength ratio of a SiH bond to a SiO—O bond at a wavelength of 2230 cm −1 exceeding 0.0050 and a strength ratio of a Si—H bond to a SiO—O bond at a wavelength of 2170 cm −1 exceeding 0.0067, the interlayer film has a relative dielectric constant of to 3 or less, and owing to suppression of lowering in hardness or elastic modulus, has improved mechanical strength.
1. A manufacturing method of a semiconductor device, which comprises forming a single-layer or multilayer wiring made of a metal material over a semiconductor substrate, wherein:
an interlayer film for electrically isolating two adjacent wirings is formed from a SiOC film that is formed under a pressure between 400 and 600 Pa: and
a ratio of a Si—CH 3 bond to a Si—O bond of the SiOC film as determined by FT-IR is less than 2.50%.
2. A manufacturing method of a semiconductor device according to claim 1 , wherein the ratio of a Si—CH 3 bond to a Si—O bond of the SiOC film falls within a range of 2.05 to 2.49%.
3. A manufacturing method of a semiconductor device according to claim 1 , wherein the SiOC film has a relative dielectric constant of 3 or less.
4. A manufacturing method of a semiconductor device according to claim 1 , wherein the SiOC film has a hardness of 2.8 Gpa or greater.
5. A manufacturing method of a semiconductor device according to claim 1 , wherein the SiOC film has an elastic modulus of 18 Gpa or greater.
6. A manufacturing method of a semiconductor device according to claim 1 , wherein the SiOC film is formed by plasma CVD method.
7. A manufacturing method of a semiconductor device according to claim 6 , wherein the SiOC film is formed under the following film forming conditions: DMDMOS flow rate between 200 and 350 sccm, He flow rate between 100 and 200 sccm, RF power of 3000 to 4000W and substrate temperature between 350 and 400° C.
8. A manufacturing method of a semiconductor device according to claim 1 , wherein the wiring is damascene wiring having copper as a main conductor layer.
9. A manufacturing method of a semiconductor device according to claim 1 , wherein the ratio of Si—CH 3 bond to Si—O bond of the SiOC film falls within a range of 2.30 to 2.40%.
10. A manufacturing method of a semiconductor device according to claim 1 , wherein the SiOC film has a strength ratio of a Si—OH bond to a SiO—O bond exceeding 0.0007, a strength ratio of a Si—H bond to a SiO—O bond at a wavelength of 2230 cm −1 exceeding 0.0050 and a strength ratio of a Si—H bond to a SiO—O bond at a wavelength of 2170 cm −1 exceeding 0.0067, each determined by the FT-IR.