JP2003297832A - Manufacturing method for copper damascene structure, and copper damassin structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper damassin structure wherein the mismatch of dynamical characteristics between inorganic insulating layers used for a copper diffusion prevention insulating layer, a wiring layer, and a via layer is eliminated, and troubles such as exfoliation and cracking ocurring in a CMP process in damascene formation and upon a heat cycle are solved. <P>SOLUTION: In the manufacture of a copper damassin structure, when copper and a barrier metal layer or either of them provided on an inorganic insulating film are chemically and mechanically polished, at least one kind of a metal oxide layer selected from among B, Al, Ga, In, Tl, Ge, Sn, Pb, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Zn, Cd, P, As, Sb, Bi, and Ce, or a silicon oxide layer with higher density than the inorganic insulating film is made to exist on the inorganic insulating film. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wiring formation in a semiconductor device, and more particularly to a method for manufacturing a copper damascene structure suitable for forming copper wiring in a semiconductor and a copper damascene structure obtained by the method.

[0002]

2. Description of the Related Art With the miniaturization of semiconductor devices, there is an increasing trend to switch the wiring material from conventional aluminum to copper. When copper is used as a wiring material, a damascene method is often used. Among them, the dual damascene method capable of simultaneously forming via wiring and trench wiring is considered to be a preferable method because it can reduce the manufacturing cost of a semiconductor device. Currently, in the wiring structure using silica as an insulating film,
Copper wiring technology formed by this dual damascene method is becoming popular. Then, in order to further miniaturize the semiconductor device, not only the wiring material but also the study of switching the insulating material from the current silica (relative dielectric constant 4) to a material having a lower dielectric constant has been activated. Examples of such a low dielectric material include a CVD carbon-containing silica film, a coating type organic insulating film, and a coating type siloxane-based film. In particular, a low dielectric constant material called Ultra low-k having a relative dielectric constant of 2.5 or less has a material density of 1.3 g / cm 3.
^{It is 3} or less, and the mechanical strength is significantly weaker than that of conventional silica. For example, the elastic modulus is
Silica is 72 GPa, whereas low dielectric constant materials are typically 15 GPa or less. The most harsh process for laminating such materials having low mechanical strength to form a damascene structure is a chemical mechanical polishing (CMP) step. Especially in the damascene structure, there are many interfaces between different materials. Among these, the interface of the low dielectric constant material is a copper diffusion prevention insulating layer and a low dielectric material, a copper diffusion prevention conductive layer and a low dielectric material, etc. (see FIG. 1). Many of the materials in contact with these low dielectric materials have mechanical and thermal properties that are completely different from those of the low dielectric materials. Particularly, the barrier metal causes a large compressive stress of several hundred MPa after the film formation. Particularly, in the PVD method, the barrier metal is deposited on the upper surface of the insulating layer as compared with the sidewalls of the trench and the via, and large stress is concentrated on the interface between the upper surface of the insulating layer and the barrier metal. If the adhesion between the insulating layer and the barrier metal is insufficient, for example, C
In the MP process, stress concentration at the interface causes friction and causes problems such as peeling and cracking.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a new laminated structure for forming copper damascene to solve the above problems.

[0004]

According to the present invention, a metal oxide layer or a silicon oxide layer having a higher density than the inorganic insulating film is formed on an inorganic insulating film forming a wiring and a via layer. A laminate structure for copper damascene formation is provided in which the adhesive force between the inorganic insulating film and the barrier metal layer is improved by disposing the laminate structure in the middle of the barrier metal layer. Further, this copper damascene forming laminate structure can prevent peeling and cracking between the barrier metal and the inorganic insulating layer in the CMP process of copper and barrier metal, and improve the yield of the copper damascene wiring forming process.

[0005]Inorganic insulating film layer The inorganic insulating film (see FIG. 1) of the present invention has a relative dielectric constant.
It is a polysiloxane insulating film of 1.5 to 3.2, and is carbonized.
It is preferable to have a hydrogen group. Inorganic insulation film is CVD
Can also be formed by the method
It is preferable to form using a coating solution consisting of machine solvent.
Yes. Here, as the polysiloxane, (A) the following general
A compound represented by the formula (1) (hereinafter referred to as “compound (1)”
And a compound represented by the following general formula (2) (hereinafter,
"Compound (2)" and represented by the following general formula (3)
A group of compounds (hereinafter referred to as “compound (3)”)
Hydrolyzes at least one silane compound selected from
However, a condensed hydrolysis-condensation product may be used.   R_aSi (OR¹)_4-a                (1) (In the formula, R is a hydrogen atom, a fluorine atom or a monovalent organic compound.
Group, R¹Represents a monovalent organic group, and a represents an integer of 1 to 2. )   Si (OR²)_Four                      (2) (In the formula, R²Represents a monovalent organic group. )   R³ _b(R^FourO)_3-bSi- (R⁷)_d-Si (OR^Five)_3-cR⁶ _c                                           ... (3) [In the formula, R³~ R⁶Are the same or different and
The organic groups, b and c are the same or different and have a number of 0 to 2.
Show, R⁷Is an oxygen atom, a phenylene group or-(CH
2) a group represented by n- (where n is an integer of 1 to 6)
, D is 0 or 1. ]

Compound (1): In the above general formula (1), examples of the monovalent organic group represented by R and R ¹ include an alkyl group, an aryl group, an allyl group and a glycidyl group. Further, in the general formula (1), R is preferably a monovalent organic group, particularly an alkyl group or a phenyl group. Here, as the alkyl group, a methyl group,
Examples thereof include an ethyl group, a propyl group and a butyl group, preferably having 1 to 5 carbon atoms, and these alkyl groups may be linear or branched, and further have a hydrogen atom substituted with a fluorine atom or the like. May be. Examples of the aryl group in the general formula (1) include a phenyl group, a naphthyl group, a methylphenyl group, an ethylphenyl group, a chlorophenyl group, a bromophenyl group and a fluorophenyl group.

Specific examples of the compound represented by the general formula (1) include trimethoxysilane, triethoxysilane, tri-n-propoxysilane, tri-iso-propoxysilane, tri-n-butoxysilane and tri-. sec-butoxysilane, tri-tert-butoxysilane, triphenoxysilane, fluorotrimethoxysilane, fluorotriethoxysilane, fluorotri-n-propoxysilane, fluorotri-iso-propoxysilane,
Fluorotri-n-butoxysilane, fluorotri-s
ec-butoxysilane, fluorotri-tert-butoxysilane, fluorotriphenoxysilane and the like;

Methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-iso-propoxysilane, methyltri-n
-Butoxysilane, methyltri-sec-butoxysilane, methyltri-tert-butoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri-n-propoxysilane, ethyltri-iso-propoxysilane, ethyltri-n -Butoxysilane, ethyltri-sec-butoxysilane, ethyltri-tert-butoxysilane,
Ethyltriphenoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri-n-propoxysilane, vinyltri-iso-propoxysilane, vinyltri-n-butoxysilane, vinyltri-s.
ec-butoxysilane, vinyltri-tert-butoxysilane, vinyltriphenoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltri-n-propoxysilane, n-propyltri-iso-propoxysilane , N-propyltri-n-butoxysilane, n-propyltri-sec
-Butoxysilane, n-propyltri-tert-butoxysilane, n-propyltriphenoxysilane, i-
Propyltrimethoxysilane, i-propyltriethoxysilane, i-propyltri-n-propoxysilane,
i-Propyltri-iso-propoxysilane, i-propyltri-n-butoxysilane, i-propyltri-
sec-butoxysilane, i-propyltri-tert
-Butoxysilane, i-propyltriphenoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-butyltri-n-propoxysilane, n-butyltri-iso-propoxysilane, n-
Butyltri-n-butoxysilane, n-butyltri-s
ec-butoxysilane, n-butyltri-tert-butoxysilane, n-butyltriphenoxysilane, se
c-butyltrimethoxysilane, sec-butyltriethoxysilane, sec-butyl-tri-n-propoxysilane, sec-butyl-tri-iso-propoxysilane, sec-butyl-tri-n-butoxysilane, s
ec-butyl-tri-sec-butoxysilane, sec
-Butyl-tri-tert-butoxysilane, sec-
Butyl-triphenoxysilane, t-butyltrimethoxysilane, t-butyltriethoxysilane, t-butyltri-n-propoxysilane, t-butyltri-iso.
-Propoxysilane, t-butyltri-n-butoxysilane, t-butyltri-sec-butoxysilane, t-
Butyltri-tert-butoxysilane, t-butyltriphenoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltri-n-propoxysilane, phenyltri-iso-propoxysilane, phenyltri-n-butoxysilane, phenyltri -Sec-butoxysilane, phenyltri-tert-
Butoxysilane, phenyltriphenoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ
-Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-trifluoropropyltrimethoxysilane, γ-trifluoropropyltrisilane Ethoxysilane etc .;

Dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyl-di-n-propoxysilane,
Dimethyl-di-iso-propoxysilane, dimethyl-
Di-n-butoxysilane, dimethyl-di-sec-butoxysilane, dimethyl-di-tert-butoxysilane, dimethyldiphenoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyl-di-n
-Propoxysilane, diethyl-di-iso-propoxysilane, diethyl-di-n-butoxysilane, diethyl-di-sec-butoxysilane, diethyl-di-te
rt-butoxysilane, diethyldiphenoxysilane,
Di-n-propyldimethoxysilane, di-n-propyldiethoxysilane, di-n-propyl-di-n-propoxysilane, di-n-propyl-di-iso-propoxysilane, di-n-propyl-di -N-butoxysilane, di-n-propyl-di-sec-butoxysilane,
Di-n-propyl-di-tert-butoxysilane, di-n-propyl-di-phenoxysilane, di-iso-
Propyldimethoxysilane, di-iso-propyldiethoxysilane, di-iso-propyl-di-n-propoxysilane, di-iso-propyl-di-iso-propoxysilane, di-iso-propyl-di-n-butoxy. Silane, di-iso-propyl-di-sec-butoxysilane, di-iso-propyl-di-tert-butoxysilane, di-iso-propyl-di-phenoxysilane, di-n-butyldimethoxysilane, di-n -Butyldiethoxysilane, di-n-butyl-di-n-propoxysilane, di-n-butyl-di-iso-propoxysilane, di-n-butyl-di-n-butoxysilane, di-n-butyl -Di-sec-butoxysilane, di-n-
Butyl-di-tert-butoxysilane, di-n-butyl-di-phenoxysilane, di-sec-butyldimethoxysilane, di-sec-butyldiethoxysilane, di-sec-butyl-di-n-propoxysilane, The-s
ec-butyl-di-iso-propoxysilane, di-s
ec-butyl-di-n-butoxysilane, di-sec-
Butyl-di-sec-butoxysilane, di-sec-butyl-di-tert-butoxysilane, di-sec-butyl-di-phenoxysilane, di-tert-butyldimethoxysilane, di-tert-butyldiethoxysilane, Di-tert-butyl-di-n-propoxysilane, di-tert-butyl-di-iso-propoxysilane, di-tert-butyl-di-n-butoxysilane, di-tert-butyl-di-sec-butoxy Silane, di-tert-butyl-di-tert-butoxysilane, di-tert-butyl-di-phenoxysilane,
Diphenyldimethoxysilane, diphenyl-di-ethoxysilane, diphenyl-di-n-propoxysilane, diphenyl-di-iso-propoxysilane, diphenyl-di-n-butoxysilane, diphenyl-di-sec-
Butoxysilane, diphenyl-di-tert-butoxysilane, diphenyldiphenoxysilane, divinyltrimethoxysilane and the like;

Preferably, methyltrimethoxysilane,
Methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-iso-propoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane,
Vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane. These are 1 or 2
More than one species may be used simultaneously.

Compound (2): In the above general formula (2), examples of the monovalent organic group include the same organic groups as in the above general formula (1). Specific examples of the compound represented by the general formula (2) include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane, tetra-n-butoxylan and tetra-sec-butoxysilane. , Tetra-t
Examples include ert-butoxysilane and tetraphenoxysilane. These may be used either individually or in combination of two or more.

Compound (3): In the above general formula (3), examples of the monovalent organic group include the same organic groups as in the above general formula (1). R in the general formula (3)
Examples of compounds in which ⁷ is an oxygen atom include hexamethoxydisiloxane, hexaethoxydisiloxane, hexaphenoxydisiloxane, 1,1,1,3,3-pentamethoxy-3-methyldisiloxane, 1,1,1,3 , 3-pentaethoxy-3-methyldisiloxane, 1,1,1,
3,3-pentaphenoxy-3-methyldisiloxane,
1,1,1,3,3-pentamethoxy-3-ethyldisiloxane, 1,1,1,3,3-pentaethoxy-3-
Ethyldisiloxane, 1,1,1,3,3-pentaphenoxy-3-ethyldisiloxane, 1,1,1,3,3
-Pentamethoxy-3-phenyldisiloxane, 1,
1,1,3,3-pentaethoxy-3-phenyldisiloxane, 1,1,1,3,3-pentaphenoxy-3-
Phenyldisiloxane, 1,1,3,3-tetramethoxy-1,3-dimethyldisiloxane, 1,1,3,3-
Tetraethoxy-1,3-dimethyldisiloxane, 1,
1,3,3-tetraphenoxy-1,3-dimethyldisiloxane, 1,1,3,3-tetramethoxy-1,3-
Diethyldisiloxane, 1,1,3,3-tetraethoxy-1,3-diethyldisiloxane, 1,1,3,3-
Tetraphenoxy-1,3-diethyldisiloxane,
1,1,3,3-tetramethoxy-1,3-diphenyldisiloxane, 1,1,3,3-tetraethoxy-1,
3-diphenyldisiloxane, 1,1,3,3-tetraphenoxy-1,3-diphenyldisiloxane, 1,
1,3-trimethoxy-1,3,3-trimethyldisiloxane, 1,1,3-triethoxy-1,3,3-trimethyldisiloxane, 1,1,3-triphenoxy-
1,3,3-trimethyldisiloxane, 1,1,3-trimethoxy-1,3,3-triethyldisiloxane,
1,1,3-triethoxy-1,3,3-triethyldisiloxane, 1,1,3-triphenoxy-1,3,3
-Triethyldisiloxane, 1,1,3-trimethoxy-1,3,3-triphenyldisiloxane, 1,1,3
-Triethoxy-1,3,3-triphenyldisiloxane, 1,1,3-triphenoxy-1,3,3-triphenyldisiloxane, 1,3-dimethoxy-1,1,
3,3-tetramethyldisiloxane, 1,3-diethoxy-1,1,3,3-tetramethyldisiloxane, 1,
3-diphenoxy-1,1,3,3-tetramethyldisiloxane, 1,3-dimethoxy-1,1,3,3-tetraethyldisiloxane, 1,3-diethoxy-1,1,
3,3-tetraethyldisiloxane, 1,3-diphenoxy-1,1,3,3-tetraethyldisiloxane,
1,3-dimethoxy-1,1,3,3-tetraphenyldisiloxane, 1,3-diethoxy-1,1,3,3-
Tetraphenyldisiloxane, 1,3-diphenoxy-
1,1,3,3-tetraphenyldisiloxane etc. can be mentioned.

Of these, hexamethoxydisiloxane, hexaethoxydisiloxane, 1,1,3,3-tetramethoxy-1,3-dimethyldisiloxane, 1,
1,3,3-tetraethoxy-1,3-dimethyldisiloxane, 1,1,3,3-tetramethoxy-1,3-diphenyldisiloxane, 1,3-dimethoxy-1,1,
3,3-tetramethyldisiloxane, 1,3-diethoxy-1,1,3,3-tetramethyldisiloxane, 1,
Preferred examples include 3-dimethoxy-1,1,3,3-tetraphenyldisiloxane and 1,3-diethoxy-1,1,3,3-tetraphenyldisiloxane.

Further, in the general formula (3), as the compound in which d is 0, hexamethoxydisilane, hexaethoxydisilane, hexaphenoxydisilane, 1,1,1,
2,2-pentamethoxy-2-methyldisilane, 1,
1,1,2,2-pentaethoxy-2-methyldisilane, 1,1,1,2,2-pentaphenoxy-2-methyldisilane, 1,1,1,2,2-pentamethoxy-2
-Ethyldisilane, 1,1,1,2,2-pentaethoxy-2-ethyldisilane, 1,1,1,2,2-pentaphenoxy-2-ethyldisilane, 1,1,1,2,2
-Pentamethoxy-2-phenyldisilane, 1,1,
1,2,2-pentaethoxy-2-phenyldisilane,
1,1,1,2,2-pentaphenoxy-2-phenyldisilane, 1,1,2,2-tetramethoxy-1,2-
Dimethyldisilane, 1,1,2,2-tetraethoxy-
1,2-dimethyldisilane, 1,1,2,2-tetraphenoxy-1,2-dimethyldisilane, 1,1,2,2
-Tetramethoxy-1,2-diethyldisilane, 1,
1,2,2-tetraethoxy-1,2-diethyldisilane, 1,1,2,2-tetraphenoxy-1,2-diethyldisilane, 1,1,2,2-tetramethoxy-1,
2-diphenyldisilane, 1,1,2,2-tetraethoxy-1,2-diphenyldisilane, 1,1,2,2-
Tetraphenoxy-1,2-diphenyldisilane, 1,
1,2-trimethoxy-1,2,2-trimethyldisilane, 1,1,2-triethoxy-1,2,2-trimethyldisilane, 1,1,2-triphenoxy-1,2,2
-Trimethyldisilane, 1,1,2-trimethoxy-
1,2,2-triethyldisilane, 1,1,2-triethoxy-1,2,2-triethyldisilane, 1,1,2
-Triphenoxy-1,2,2-triethyldisilane,
1,1,2-trimethoxy-1,2,2-triphenyldisilane, 1,1,2-triethoxy-1,2,2-triphenyldisilane, 1,1,2-triphenoxy-
1,2,2-triphenyldisilane, 1,2-dimethoxy-1,1,2,2-tetramethyldisilane, 1,2-
Diethoxy-1,1,2,2-tetramethyldisilane,
1,2-diphenoxy-1,1,2,2-tetramethyldisilane, 1,2-dimethoxy-1,1,2,2-tetraethyldisilane, 1,2-diethoxy-1,1,2,
2-tetraethyldisilane, 1,2-diphenoxy-
1,1,2,2-tetraethyldisilane, 1,2-dimethoxy-1,1,2,2-tetraphenyldisilane,
Examples thereof include 1,2-diethoxy-1,1,2,2-tetraphenyldisilane and 1,2-diphenoxy-1,1,2,2-tetraphenyldisilane.

Of these, hexamethoxydisilane,
Hexaethoxydisilane, 1,1,2,2-tetramethoxy-1,2-dimethyldisilane, 1,1,2,2-tetraethoxy-1,2-dimethyldisilane, 1,1,
2,2-tetramethoxy-1,2-diphenyldisilane, 1,2-dimethoxy-1,1,2,2-tetramethyldisilane, 1,2-diethoxy-1,1,2,2-tetramethyldisilane, 1,2-dimethoxy-1,1,
Preferred examples include 2,2-tetraphenyldisilane and 1,2-diethoxy-1,1,2,2-tetraphenyldisilane.

Further, in the general formula (3), R ⁷ is −
(CH _{2) n} - Examples of the compound group represented by bis (trimethoxysilyl) methane, bis (triethoxysilyl) methane, bis (tri -n- propoxy) methane, bis (tri -i- propoxy Silyl) methane, bis (tri-n-butoxysilyl) methane, bis (tri-s)
ec-butoxysilyl) methane, bis (tri-t-butoxysilyl) methane, 1,2-bis (trimethoxysilyl) ethane, 1,2-bis (triethoxysilyl) ethane, 1,2-bis (tri- n-propoxysilyl) ethane, 1,2-bis (tri-i-propoxysilyl) ethane, 1,2-bis (tri-n-butoxysilyl) ethane, 1,2-bis (tri-sec-butoxysilyl) Ethane, 1,2-bis (tri-t-butoxysilyl) ethane, 1- (dimethoxymethylsilyl) -1- (trimethoxysilyl) methane, 1- (diethoxymethylsilyl)
-1- (triethoxysilyl) methane, 1- (di-n-
Propoxymethylsilyl) -1- (tri-n-propoxysilyl) methane, 1- (di-i-propoxymethylsilyl) -1- (tri-i-propoxysilyl) methane,
1- (di-n-butoxymethylsilyl) -1- (tri-
n-butoxysilyl) methane, 1- (di-sec-butoxymethylsilyl) -1- (tri-sec-butoxysilyl) methane, 1- (di-t-butoxymethylsilyl)
-1- (tri-t-butoxysilyl) methane, 1- (dimethoxymethylsilyl) -2- (trimethoxysilyl)
Ethane, 1- (diethoxymethylsilyl) -2- (triethoxysilyl) ethane, 1- (di-n-propoxymethylsilyl) -2- (tri-n-propoxysilyl) ethane, 1- (di-i -Propoxymethylsilyl) -2-
(Tri-i-propoxysilyl) ethane, 1- (di-n
-Butoxymethylsilyl) -2- (tri-n-butoxysilyl) ethane, 1- (di-sec-butoxymethylsilyl) -2- (tri-sec-butoxysilyl) ethane, 1- (di-t-butoxy Methylsilyl) -2- (tri-t-butoxysilyl) ethane, bis (dimethoxymethylsilyl) methane, bis (diethoxymethylsilyl)
Methane, bis (di-n-propoxymethylsilyl) methane, bis (di-i-propoxymethylsilyl) methane,
Bis (di-n-butoxymethylsilyl) methane, bis (di-sec-butoxymethylsilyl) methane, bis (di-t-butoxymethylsilyl) methane, 1,2-bis (dimethoxymethylsilyl) ethane, 1, 2-bis (diethoxymethylsilyl) ethane, 1,2-bis (di-n-propoxymethylsilyl) ethane, 1,2-bis (di-i-propoxymethylsilyl) ethane, 1,2-
Bis (di-n-butoxymethylsilyl) ethane, 1,2
-Bis (di-sec-butoxymethylsilyl) ethane,
1,2-bis (di-t-butoxymethylsilyl) ethane, 1,2-bis (trimethoxysilyl) benzene,
1,2-bis (triethoxysilyl) benzene, 1,2
-Bis (tri-n-propoxysilyl) benzene, 1,
2-bis (tri-i-propoxysilyl) benzene,
1,2-bis (tri-n-butoxysilyl) benzene,
1,2-bis (tri-sec-butoxysilyl) benzene, 1,2-bis (tri-t-butoxysilyl) benzene, 1,3-bis (trimethoxysilyl) benzene,
1,3-bis (triethoxysilyl) benzene, 1,3
-Bis (tri-n-propoxysilyl) benzene, 1,
3-bis (tri-i-propoxysilyl) benzene,
1,3-bis (tri-n-butoxysilyl) benzene,
1,3-bis (tri-sec-butoxysilyl) benzene, 1,3-bis (tri-t-butoxysilyl) benzene, 1,4-bis (trimethoxysilyl) benzene,
1,4-bis (triethoxysilyl) benzene, 1,4
-Bis (tri-n-propoxysilyl) benzene, 1,
4-bis (tri-i-propoxysilyl) benzene,
1,4-bis (tri-n-butoxysilyl) benzene,
Examples thereof include 1,4-bis (tri-sec-butoxysilyl) benzene and 1,4-bis (tri-t-butoxysilyl) benzene.

Of these, bis (trimethoxysilyl) methane, bis (triethoxysilyl) methane, 1,
2-bis (trimethoxysilyl) ethane, 1,2-bis (triethoxysilyl) ethane, 1- (dimethoxymethylsilyl) -1- (trimethoxysilyl) methane, 1-
(Diethoxymethylsilyl) -1- (triethoxysilyl) methane, 1- (dimethoxymethylsilyl) -2-
(Trimethoxysilyl) ethane, 1- (diethoxymethylsilyl) -2- (triethoxysilyl) ethane, bis (dimethoxymethylsilyl) methane, bis (diethoxymethylsilyl) methane, 1,2-bis (dimethoxymethyl) (Silyl) ethane, 1,2-bis (diethoxymethylsilyl) ethane, 1,2-bis (trimethoxysilyl) benzene, 1,2-bis (triethoxysilyl) benzene, 1,3-bis (trimethoxysilyl) )benzene,
1,3-bis (triethoxysilyl) benzene, 1,4
Preferred examples include -bis (trimethoxysilyl) benzene and 1,4-bis (triethoxysilyl) benzene. These may be used either individually or in combination of two or more.

The molecular weight of the hydrolyzed condensate of the compounds (1) to (3) is a polystyrene-equivalent weight average molecular weight of usually 500 to 300,000, preferably 700 to 2
0,000, more preferably 1,000-100,
It is about 000.

Further, when each component of the compounds (1) to (3) is converted into a complete hydrolysis-condensation product, the compound (3) is added to the total amount of the compound (1), the compound (2) and the compound (3). On the other hand, it is 5 to 60% by weight, preferably 5 to 50% by weight, more preferably 5 to 40% by weight, and it is desirable that [weight of compound (1)] <[weight of compound (2)]. . When the compound (3) is less than 5% by weight of the total amount of the compound (1) to the compound (3) in the ratio of each component converted into a complete hydrolysis-condensation product, the mechanical strength of the obtained coating film decreases, while If it exceeds 60% by weight, the water absorption becomes high and the electrical characteristics deteriorate. If the weight of the compound (1) is more than the weight of the compound (2), the strength of the coating film obtained will be poor. In the present invention, the complete hydrolysis condensate is
The SiOR groups of the compounds (1) to (3) are 100% hydrolyzed to SiOH groups, and are further completely condensed to form a siloxane structure.

In the present invention, the inorganic insulating film layer is preferably formed by applying a coating solution prepared by dissolving the above-mentioned silane compound hydrolysis and condensation product in an organic solvent and heating. Examples of the organic solvent include at least one selected from the group consisting of alcohol solvents, ketone solvents, amide solvents, ester solvents and aprotic solvents. Among the organic solvents, alcohol solvents are preferable.
As a coating method of such a coating liquid, spin coating,
Examples include dipping and roller blades. The film thickness at this time is 0.0 as a dry film thickness.
About 5 to 1.5 μm, the thickness is 0.1 to 3 μm after double coating
A coating film of a certain degree can be formed. The thickness of the coating film to be formed is usually 0.2 to 20 μm.

As a heating method at this time, a hot plate, an oven, a furnace or the like can be used,
The heating atmosphere can be performed under the atmosphere, nitrogen atmosphere, argon atmosphere, vacuum, reduced pressure with controlled oxygen concentration, or the like. Further, in order to control the curing rate of the above-mentioned component (A), it is possible to heat stepwise and select an atmosphere such as nitrogen, air, oxygen, or reduced pressure, as required. The silica or siloxane-based film thus obtained has a relative dielectric constant of 1.5 to 3.2, preferably 1.5 to 3.0, more preferably 1.8 to 2.8, and a film density of Usually, 0.35 to 1.2 g / cm ³ , preferably 0.4 to 1.1 g / cm ³ , and more preferably 0.5.
Is about 1.0 g / cm ³ . Film density is 0.35g / cm ³
If it is less than 1, the mechanical strength of the coating film decreases, while 1.2 g
If it exceeds / cm ³ , a low dielectric constant cannot be obtained. In the present invention, the above-mentioned silane compound is used as C as the inorganic insulating film.
A film deposited by the VD method can also be used.

Metal Oxide Film In the present invention, B, Al, G are formed on the inorganic insulating film.
a, In, Tl, Ge, Sn, Pb, Ti, Zr, H
f, V, Nb, Ta, Cr, Mo, W, Mn, Zn, C
A silicon oxide compound film having a higher density than a metal oxide film or an inorganic insulating film having at least one kind selected from d, P, As, Sb, Bi and Ce as a constituent element (hereinafter, these are collectively referred to as “metal oxide”). (Referred to as FIG. 1).

The metal oxide film in the present invention is preferably formed by applying a coating solution in which the (partial) hydrolysis-condensation product of the metal alkoxide of the above metal element is dissolved in an organic solvent and heating. The metal alkoxide of the starting material is preferably alkoxysilane. As the alkoxysilane, the same ones as the silane compound used for forming the inorganic insulating film can be mentioned. Examples of the organic solvent include at least one selected from the group consisting of alcohol solvents, ketone solvents, amide solvents, ester solvents and aprotic solvents. Among the organic solvents, alcohol solvents are preferable. In the present invention, the metal oxide film is usually obtained by coating and baking a (partial) hydrolysis-condensation product of a metal alkoxide. As a means for curing and insolubilizing the coating film,
A latent acid generator may be contained in the coating liquid system to accelerate the curing reaction in the film forming process. Examples of the acid generator used for such a purpose include a latent thermal acid generator and a latent photoacid generator. The above-mentioned latent thermal acid generator is usually 50 to 450 ° C., preferably 200 to 3
A compound that generates an acid when heated to 50 ° C., and an onium salt such as a sulfonium salt, a benzothiazolium salt, an ammonium salt, or a phosphonium salt is used,
The latent photoacid generator is usually a compound that generates an acid by irradiation with ultraviolet light of 1 to 100 mJ, preferably 10 to 50 mJ. The baking temperature of the coating film of the coating liquid containing the (partial) hydrolysis condensate of the metal alkoxide as the main component is 80 ° C to 450 ° C.
Is preferred. The firing atmosphere is usually under normal pressure nitrogen or under vacuum. The film after the film formation is 1 nm to 5
The range is 00 nm, but usually 10 nm to 200 nm
Used in the range of.

Method for Forming Copper Damascene Structure The method for forming a copper damascene according to the present invention is characterized in that a metal oxide film is formed on an inorganic insulating film forming a wiring and a via layer. The inorganic insulating layer is usually formed on the silicon nitride or silicon carbide based film formed by the plasma CVD method, which is an insulating film for preventing copper diffusion, by the above-mentioned method, and the metal oxide film is further formed by the above-mentioned method. A film is formed to form a laminated structure for forming copper damascene (see FIG. 1). In forming the copper damascene forming laminate structure, the metal oxide film layer is applied in a state where the inorganic insulating film layer is dried and partially cured (B stage), and dried and partially cured to form an inorganic insulating film layer. The metal oxide film layer and the metal oxide film layer can be baked and cured at the same time.
This method is preferable because it can reduce the heat balance of the entire wiring process. This copper damascene forming laminate structure is
Damascene trenches and / or via holes are formed through photolithography and etching processes, the trenches and / or via holes are covered with a barrier metal, and copper is embedded in the wiring trenches and / or via holes (see FIG. 2). The excessively laminated copper and the barrier metal laminated on the upper portion of the insulating layer are removed by the chemical mechanical polishing method (CMP). The metal oxide film layer is usually unfavorable as an insulating layer because it has a high dielectric constant and exhibits the properties of a conductor and a semiconductor. Therefore, it is preferable to remove the metal oxide film layer located under the barrier metal in the CMP process (see FIG. 3).

[0025]

EXAMPLES The present invention will be described more specifically below with reference to examples. However, the following description is a general description of example embodiments of the present invention, and the present invention is not limited to the description without particular reason. In addition, unless otherwise indicated, the part and% in an Example and a comparative example have shown that it is a weight part and weight%, respectively.

Synthesis Example 1 (Preparation of Coating Solution for Inorganic Insulating Film) 15 g of methyltrimethoxysilane (7.4 g in terms of complete hydrolyzed condensate) in a mixed solution of 5 g of 25% aqueous ammonia solution, 320 g of ultrapure water and 600 g of ethanol. ) And 20 g of tetraethoxysilane (5.
8 g) was added and reacted at 60 ° C. for 3 hours, and then maleic acid was added to adjust the pH to 2.5. 150 g of propylene glycol monopropyl ether was added to this solution and then concentrated under reduced pressure to obtain a composition solution having a solid content of 9%. The polystyrene-reduced weight average molecular weight of this hydrolysis-condensation product was 300,000. Here, the weight average molecular weight was measured by the GPC method and converted into polystyrene.

Synthesis Example 2 (Preparation of coating liquid for forming metal oxide film) (1) 106.4 g of tetramethoxysilane was dissolved in 298 g of propylene glycol monopropyl ether, and the mixture was stirred with a three-one motor to a solution temperature of 60. ℃
Stabilized to. Next, 50 g of ion-exchanged water in which 2.1 g of maleic acid was dissolved was added to the solution over 1 hour. Then, after reacting at 60 ° C. for 4 hours, the reaction solution was cooled to room temperature. After removing 90 g of a solution containing methanol from the reaction solution by evaporation at 50 ° C., 643 g of propylene glycol monopropyl ether was added to obtain a solution (A). (2) In the solution (A), as the component (B), bis (4-t
5 g of -butylphenyl) iodonium camphorsulfonate was added, and the mixture was filtered through a filter made of polytetrafluoroethylene (trade name: Teflon) having a pore size of 0.2 μm to obtain a coating liquid for forming a metal oxide film. Synthesis Example 3 In a separable flask made of quartz, 25.7 g of pentaethoxytantalum was dissolved in 258 g of propylene glycol monoethyl ether, and then stirred with a three-one motor to stabilize the solution temperature at 60 ° C. Next, 64.6 g of propylene glycol monoethyl ether containing 1.43 g of ion-exchanged water was added to the solution over 30 minutes. Then, after reacting at 60 ° C. for 30 minutes, the reaction solution was cooled to room temperature. A solution containing ethanol as a by-product was removed from the reaction solution at 50 ° C. by evaporation to remove 268 g of propylene glycol monoethyl ether 9
3.3 g was added and diluted, and filtered with a filter made of polytetrafluoroethylene (trade name: Teflon) having a pore size of 0.2 μm to obtain a coating liquid for forming a metal oxide film. Synthesis Example 4 Tetraisopropoxy titanium (49.8 g) was dissolved in propylene glycol monoethyl ether (235 g) in a quartz separable flask, and the mixture was stirred with a three-one motor to stabilize the solution temperature at 60 ° C. Next, 58.8 g of propylene glycol monoethyl ether containing 6.3 g of ion-exchanged water was added to the solution over 30 minutes. Then, after reacting at 60 ° C. for 30 minutes, the reaction solution was cooled to room temperature. At 50 ° C., 210 g of a solution containing by-product ethanol was removed from the reaction solution by evaporation, and propylene glycol monoethyl ether 17
5 g was added and diluted, and the mixture was filtered through a filter made of polytetrafluoroethylene (trade name: Teflon) having a pore size of 0.2 μm to obtain a coating liquid for forming a metal oxide film.

Example 1 A substrate on which a silicon nitride film having a thickness of 400 nm was formed on a silicon substrate by a usual plasma CVD method was coated with the coating liquid for an inorganic insulating film produced in Synthesis Example 1 by a spin coating method and was exposed to the atmosphere. Medium at 80 ° C for 1 minute, then under nitrogen at 200 ° C for 1 minute
Heated for minutes. The relative dielectric constant of this inorganic insulating film is 2.
3, the density was 1.2 g / cm ³ . Here, the relative permittivity and the density were calculated from the volume obtained from the film thickness of the film and the area of the film, and the weight of the film. Further, the coating liquid for forming a metal oxide film produced in Synthesis Example 2 was applied, and the coating liquid was applied at 80 ° C. in air at 1
It was heated for 1 minute at 200 ° C. in the air for 1 minute. Further, by heating under vacuum at 425 ° C. for 1 hour, a laminated structure composed of an inorganic insulating film layer having a film thickness of 500 nm and a metal oxide film layer having a film thickness of 30 nm was formed. The density of this metal oxide film layer was 1.6. Here, the density of this metal oxide layer was calculated from the volume obtained from the film thickness and the area of the film, and the weight of the film. Further, a TaN film, which is a barrier metal layer, was laminated by PVD method to a thickness of 100 nm to form a laminate structure for measuring adhesive strength. When the fracture toughness of the laminate structure for measuring the adhesive strength was measured by the 4-point bending method, it showed a high value of 4 J / m ² . The destruction was mainly in the cohesive failure mode of the inorganic insulating layer. On the other hand, when the fracture toughness of the laminate having a structure in which the metal oxide film layer was removed from the laminate structure for measuring adhesive strength was measured by the 4-point bending method, the fracture toughness value was 1.5 J / m ² . The breakdown mode was the interface between the inorganic insulating layer and the barrier metal layer. From the above experimental results, it was proved that the metal oxide film layer functions as an adhesive layer between the inorganic insulating layer and the barrier metal layer. Also,
The metal oxide film-forming coating liquid prepared in Synthesis Example 3 or Synthesis Example 4 was used in place of the metal oxide film-forming coating liquid prepared in Synthesis Example 2 to form a laminate structure for measuring the adhesive strength. However, in any of the films, the metal oxide film layer functions as an adhesive layer between the inorganic insulating layer and the barrier metal layer.

[0029]

According to the present invention, the structure of such a laminated body eliminates the mismatch of the mechanical characteristics between the copper diffusion preventing insulating layer and the inorganic insulating layers used for the wiring layer and the via layer, thereby damascene. Problems such as peeling and cracking that occur during the CMP process or heat cycle in the formation can be completely solved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a copper damascene forming laminate structure before laminating a barrier metal layer and copper in the present invention.

FIG. 2 is a configuration diagram showing an example of a copper damascene structure before CMP in the present invention.

FIG. 3 is a configuration diagram showing an example of a copper damascene structure after CMP according to the present invention.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hidefumi Miyajima             8th Shinsugita Town, Isogo Ward, Yokohama City, Kanagawa Prefecture             Ceremony company Toshiba Yokohama office F term (reference) 5F033 HH11 JJ01 JJ11 KK11 MM01                       MM02 MM12 MM13 NN06 NN07                       QQ48 RR01 RR03 RR06 RR09                       RR25 SS11 SS15 SS22 TT02                       WW09 XX14 XX17                 5F058 BA20 BD01 BD02 BD05 BF07                       BF46 BH04 BJ02

Claims (8)

[Claims] 1. In the production of a copper damascene structure, when chemical mechanical polishing of copper and / or a barrier metal layer provided on an inorganic insulating film, B, Al, and Ga, In, Tl, Ge, Sn, P
b, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo,
W, Mn, Zn, Cd, P, As, Sb, Bi and C
A method for manufacturing a copper damascene structure, characterized in that an oxide layer of at least one metal selected from e is present. 2. The metal oxide layer comprises B, Al, Ga,
In, Tl, Ge, Sn, Pb, Ti, Zr, Hf,
V, Nb, Ta, Cr, Mo, W, Mn, Zn, Cd,
The copper according to claim 1, which is formed by applying a solution of a precursor of an oxide of at least one metal selected from P, As, Sb, Bi and Ce onto an inorganic insulating film and heating the solution. Damascene structure manufacturing method. 3. The inorganic insulating film has a relative dielectric constant of 1.5 to 3.2.
The method for manufacturing a copper damascene structure according to claim 1 or 2, which is the siloxane-based insulating film. 4. The method for producing a copper damascene structure according to claim 3, wherein the siloxane-based insulating film having a relative dielectric constant of 1.5 to 3.2 has a hydrocarbon group. 5. In the production of a copper damascene structure, when the copper and / or the barrier metal layer provided on the inorganic insulating film is chemically mechanically polished, the inorganic insulating film is formed on the inorganic insulating film. A method of manufacturing a copper damascene structure, characterized in that a silicon oxide layer having a higher density than the film is present. 6. The inorganic insulating film has a relative dielectric constant of 1.5 to 3.2.
6. The method for manufacturing a copper damascene structure according to claim 5, which is the siloxane-based insulating film. 7. The method for manufacturing a copper damascene structure according to claim 6, wherein the siloxane insulating film having a relative dielectric constant of 1.5 to 3.2 has a hydrocarbon group. 8. A copper damascene structure formed by the method according to claim 1.