1. A semiconductor device including a multilayer wiring comprising:
a semiconductor substrate;
an insulating film formed on the semiconductor substrate, at least one part of the insulating film being formed of a first insulating film and a second insulating film;
a wiring groove and a via hole formed in the insulating film;
a wire and a connecting plug formed from a metal respectively filled in the wiring groove and the via hole; and
a modified layer formed on at least one of an interface between the first insulating film and the metal and an interface between the first insulating film and the second insulating film,
wherein the first insulating film is at least one layer insulating film including a siloxane structure containing silicon, oxygen and carbon,
the siloxane structure in the inner part of the first insulating film contains a larger number of carbon atoms than the number of silicon atoms, and
the modified layer contains a smaller number of carbon atoms and a larger number of oxygen atoms per unit volume than the inner part of the first insulating film.
2. The semiconductor device according to claim 1,
wherein the first insulating film containing the siloxane structure contains a larger number of carbon atoms than the number of oxygen atoms per unit volume in the inner part.
3. The semiconductor device according to claim 1,
wherein the siloxane structure contains both of a hydrocarbon group including at least 3 carbon atoms and an unsaturated hydrocarbon group.
4. The semiconductor device according to claim 1,
wherein the siloxane structure includes a cyclic siloxane structure containing an oxygen atom and a silicon atom.
5. The semiconductor device according to claim 4,
wherein the cyclic siloxane structure is formed of a three-membered cyclic structure including three Si\u2014O units each of which is formed of an oxygen atom and a silicon atom.
6. The semiconductor device according to claim 1,
wherein the modified layer contains a larger number of oxygen atoms than the number of carbon atoms per unit volume.
7. The semiconductor device according to claim 1,
wherein the modified layer contains a larger number of oxygen atoms and nitrogen atoms in total than the number of carbon atoms per unit volume.
8. The semiconductor device according to claim 1,
wherein the modified layer has a thickness of 20 nm or less.
9. The semiconductor device according to claim 1,
wherein the modified layer has a density of 2.0 gcm3 or larger.
10. The semiconductor device according to claim 1,
wherein the first insulating film has the density of 1.2 gcm3 or smaller in the inner part.
11. The semiconductor device according to claim 1,
wherein the first insulating film is formed of an interlayer insulating film between vias in a via plug portion, an interlayer insulating film between wirings in a wiring portion and a hard mask film in the wiring portion, which is sequentially stacked from a semiconductor substrate side,
any film of the hard mask film, the interlayer insulating film between the wirings and the interlayer insulating film between the vias is an insulating layer containing a siloxane structure containing silicon, oxygen and carbon,
the modified layers are formed on any of an interface between the hard mask film and the metal, an interface between the interlayer insulating film between the wirings and the metal, and an interface between the interlayer insulating film between the vias and the metal,
the modified layers have the composition containing a smaller number of carbon atoms and a larger number of oxygen atoms per unit volume than the inner part of the first insulating film corresponding to each of the modified layers, and
the number of carbon atoms per unit volume in the modified layers decreases in order of the modified layer between the interlayer insulating film between the wirings and the metal, the modified layer between the interlayer insulating film between the vias the metal and the modified layer between the hard mask film and the metal.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A method for forming an ultra fine contact hole in a semiconductor device with use of a KrF light source, the method comprising:
forming a KrF photoresist pattern on an insulation layer disposed on a semiconductor substrate, the KrF photoresist pattern exposing a predetermined region of the insulation layer for forming a contact hole in the insulation layer;
forming a chemically swelling process (CSP) by depositing a chemical material-containing layer that is reactive to the KrF photoresist pattern on an entire surface of the photoresist pattern and insulating layer;
forming a chemical material-containing pattern encompassing the KrF photoresist pattern by reacting the chemical material-containing layer with the KrF photoresist pattern through the chemically swelling process to decrease a critical dimension of the contact hole;
rinsing the semiconductor substrate; and
increasing a thickness of a sidewall of the chemical material-containing pattern to a predetermined thickness by performing a resist flow process (RFP) that makes the chemical material-containing pattern flowed to decrease the critical dimension (CD) of the contact hole.
2. The method as recited in claim 1, wherein the CSP chemical material-containing layer has a resist composition comprising de-ionized (DI) water, a cross-linker, a solvent and a photo acid generator (PAG), wherein the DI water constitues about 90% of the above composition while the remaining components constitute about 10% thereof.
3. The method as recited in claim 1, wherein the CSP chemical material-containing layer has a thickness ranging from about 1000 to about 3000 .
4. The method as recited in claim 1, wherein the CSP is carried out by employing a series of processes including a heat process, a photo-exposure process and an electron beam exposure process.
5. The method as recited in claim 4, wherein the heat process is carried out at a temperature ranging from about 90 C. to about 130 C.
6. The method as recited in claim 4, wherein the photo-exposure process uses photo-exposure energy ranging of above about 20 mJcm to about 30 mJcm2 in case of using the KrF light source.
7. The method as recited in claim 1, wherein at the step of rinsing the semiconductor substrate, DI water is used to rinse the semiconductor substrate.