JP2000269204A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a semiconductor device, where an inter-wiring insulating film can be lessened in permittivity, and the semiconductor device can be manufactured through application of wet process. SOLUTION: A semiconductor device is equipped with wirings 2 insulated from each other by an insulating film on a board possessed of a circuit device which forms an electronic circuit, where the insulating film interposed between the wirings 2 comprises matrix materials 3 and hollow fine particles 4 dispersed in the matrix materials 3. The semiconductor device is capable of using an insulating film which contains close voids, is lessened in permittivity, and without moisture-resistance, and a wet process can be applied to the manufacturing method of the semiconductor device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a semiconductor device.

[0002]

2. Description of the Related Art A semiconductor device is formed on a substrate such as a silicon (Si) wafer or a gallium arsenide (GaAs) wafer.
Manufactures circuit elements, such as transistors, diodes, resistors, and capacitors, which constitute electronic circuits, and further includes SiO ₂ , Si ₃ N ₄ , and PSG (phospho Si).
Insulating resin film such as aluminum oxide, aluminum, copper, etc., and an insulating resin film for protecting the surface other than the electrode portion which becomes the terminal for external connection of the wiring. ing. The wiring of metals such as aluminum and copper is insulated by an insulating film, and when the design rule of a semiconductor device becomes smaller, the capacitance between wirings adjacent to each other becomes more problematic than between layers. It has been demanded. As a semiconductor insulating film having a low dielectric constant, an organic material such as polyimide, polyallyl ether, and polybenzoxazole, an inorganic material such as SiO ₂ , and a composite material such as polysiloxane and fluorine polymer have been proposed. Further, porous silica comprising solid fine particles of SiO ₂ has also been proposed.

[0003]

The dielectric constant of an organic material such as polyimide, polyallyl ether or polybenzoxazole is 3.4 to 2.5, and the dielectric constant of an inorganic material such as SiO ₂ is 4.0 to 3.0. 5. The dielectric constant of the composite material such as polysiloxane and fluoropolymer is 3.0 to 2.5, which is not sufficient to reduce the dielectric constant. Porous silica composed of solid fine particles of SiO ₂ is reliable as a material, and the dielectric constant can be increased to about 4.0 to 1.5 by changing the porosity.
It is hygroscopic, has low mechanical strength, and has many problems such as difficulty in applying a wet process as a semiconductor insulating film. The present invention provides a semiconductor device using a low dielectric constant semiconductor insulating film.

[0004]

According to the present invention, there is provided a semiconductor device comprising:
A semiconductor device provided with wiring insulated by an insulating film over a substrate having circuit elements constituting an electronic circuit, wherein at least the insulating film between the wirings is an insulating film including closed pores. The closed pores are preferably present in the matrix, and the area around the closed pores is preferably filled with a matrix material. The closed pores do not necessarily have to be spherical, in which case it is sufficient that the minimum size of the closed pores is shorter than the distance between the previous wirings. Further, it is preferable that at least a part of the closed pores is formed of hollow particles, and the average value of the average particle diameter of the hollow particles is preferably 5 to 50 nm.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The insulating film of the present invention contains closed pores, and preferably coexists with a matrix material. Further, the closed pores can be constituted by hollow particles.
Any low dielectric constant material can be used as the matrix material. For example, organic materials such as polyimide, fluorinated polyimide, polyallyl ether, and polybenzoxazole; inorganic-organic hybrid materials such as hydrogen silsesquioxene and methyl silsesquioxene; inorganic materials such as SiO2; organic SOG materials; Materials and the like can be used. In particular, including SiO _2, polymer material having a siloxane bond consisting of SiO-Si is preferable.
Closed pores need not necessarily be spherical. It is possible to maintain the size and shape along the spatial shape of the insulating region between the wirings. It is preferable that the hollow particles and the matrix material be densely filled in a part of the closed pores, particularly in an insulating region near the wiring portion. Further, an insulating film in which hollow particles are uniformly dispersed at high density throughout the matrix is preferable from the viewpoint of mechanical strength. The hollow particles are preferably air-tight, but may be somewhat air-permeable as long as the hollow particles are maintained in the matrix material. Hollow silica fine particles, soccer balls such as C60 and the like are used. The median diameter of the hollow particles is preferably 5 to 50 nm. The amount of closed pores or hollow particles in the matrix material can be appropriately determined according to the required dielectric constant. In the present invention, at least an insulating film between adjacent wirings is an insulating film including closed pores, and an insulating film between layers may be an insulating film including similar closed pores.

FIGS. 1 and 2 are cross-sectional views of essential parts of a semiconductor device according to the present invention, wherein 1 is a substrate having circuit elements constituting an electronic circuit, 2 is a wiring, 3 is a matrix material, and 4 is a matrix material. Hollow fine particles dispersed therein are large closed pores 5 existing in the insulating film between the wirings 2, and 6 is an interlayer insulating film.

[0007]

According to the semiconductor device of the present invention, since the insulating film between the wirings contains closed pores, the dielectric constant can be reduced, and the manufacturing method by a wet process without moisture absorption can be applied.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of a semiconductor device of the present invention.

FIG. 2 is a cross-sectional view of a main part of the semiconductor device of the present invention.

[Explanation of symbols]

 1: substrate having circuit elements constituting an electronic circuit 2: wiring 3: matrix material 4: hollow microparticles 5: closed pores 6: interlayer insulating film

Claims (6)

[Claims] 1. A semiconductor device having a wiring insulated by an insulating film on a substrate having circuit elements constituting an electronic circuit, wherein at least the insulating film between the wirings is an insulating film including closed pores. A semiconductor device characterized by the above-mentioned. 2. The semiconductor device according to claim 1, wherein the insulating film includes closed pores and a matrix. 3. The semiconductor device according to claim 1, wherein the closed pores are non-spherical and the minimum diameter thereof is smaller than the distance between wirings. 4. The semiconductor device according to claim 1, wherein a part or all of the closed pores are hollow particles. 5. The median average particle diameter of the hollow particles is 5 to 50.
The semiconductor device according to claim 4, wherein the thickness is in nm. 6. The semiconductor device according to claim 2, wherein the matrix includes a Si—O—Si bond.