JPS63208249A - Manufacture of multilayer interconnection structure - Google Patents

Abstract

PURPOSE:To prevent the decrease in volume of a film between resin layers when photoresist is removed and to obtain a highly reliable multilayer interconnection structure characterized by the high yield rate, by making a photoresist film to remain on a piller, and using a specified polyimide film including an SiO component for an interlayer film. CONSTITUTION:Metal layers on first metal wirings 106 and 106' are made to be piller shaped metal pieces 108 and 108' for electrical conduction with second metal wirings 111 and 111' by selective etching using photoresist films 109 and 109'. A polyamide acid/silicon intermediate is formed by mixing and reacting aromatic tetracarboxylic acid dianhydride shown in the Formula 1, diamine shown in the Formula 2 and aminosilicon compound shown in the Formula 3. Solution including said intermediate is applied on the entire surface. A resin film 110 is formed on the entire surface by heat treatment. The resin film 110 and photoresist films 109 and 109' are removed. The resin film 110 is further heat-treated. Second metal wirings 111 and 111' are formed. Thus the manufacturing yield rate of the multilayer interconnection structure having a flat interlayer insulating film can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a semiconductor device having multilayer wiring, and particularly to a method for manufacturing a multilayer wiring structure having fine contacts.

[Conventional technology]

Conventionally, as a technique for forming this type of multilayer wiring structure, there is a pillar method using a polyimide resin film.

To briefly explain the conventional pillar method, first, Figure 2 (a)
As shown in FIG. 1, an aluminum film and a barrier metal 303 having different etching rates are formed on the first aluminum wiring 302. The same figure (bl
A second aluminum film 304 is formed as shown in FIG.
Pillar 305t- is formed by leaving the aluminum film only in the portion where electrical conduction is established between pillars 2 and 304. Next, a polyimide resin film 306 is spin-coated, and after a heat treatment step, the polyimide resin film is etched in oxygen plasma until the surface of the pillar 305 appears as shown in FIG. As shown in FIG. 3, an M2 aluminum wiring 307 is formed by a known method.

[Problem that the invention seeks to solve]

However, in the conventional method described above, when the polyimide film 306 on the pillar 305 is etched until the pillar surface appears, the part without the pillar 305 is also etched to the same thickness, resulting in non-uniform interlayer insulation properties. However, as a result, there is a drawback that the yield rate becomes poor.

An object of the present invention is to solve the above-mentioned problems and provide a method for manufacturing a multilayer wiring structure having a flat interlayer insulating film, thereby improving the manufacturing yield.

[Means for solving problems]

The method for manufacturing a multilayer wiring structure of the present invention includes the steps of forming a first metal wiring on one main surface of a semiconductor substrate, forming a metal layer on the first metal wiring, and applying a photoresist to the metal layer. A step of forming a columnar metal selectively provided on the first metal wiring in order to establish electrical continuity with the second metal wiring by selective etching using a film, and a photoresist film on the columnar metal. An aromatic tetracarboxylic dianhydride represented by the following formula (11), a diamine represented by the formula (2), and an amine silicon compound represented by the formula (3) are mixed and reacted while leaving the A solution containing the polyamic acid silicon type intermediate formed by this process is applied to the entire surface, and a resin film is formed on the entire surface by heat treatment at a temperature of 0 to 200°C for 150 cm. a step of uniformly removing the resin film by chemical ion etching under conditions where the etching rates of the resin film and the photoresist are equal until the entire surface of the photoresist on the columnar metal is exposed; a step of removing the photoresist film under conditions where the etching rate is higher than the etching rate of the resin film, followed by a step of heat-treating the resin film at a temperature of 300° C. to 450° C., and forming a second metal wiring. It includes the process.

NH, -R-NH, ... Mountain... (2) Formula (1) ~
In (3), R represents a tetravalent carbocyclic aromatic group, R2 is an aromatic aliphatic group having 6 to 30 carbon atoms, or a carbocyclic aromatic group having 6 to 30 carbon atoms, R3 and R4 is independently an alkyl group or phenyl group having 1 to 6 carbon atoms, and K has a value of 1≦ and ≦3.

〔Example〕

Next, the present invention will be explained in detail using the drawings. In this example, P-aminophenyltrimethoxysilane represented by CHa was used as the amino silicon compound, diaminodiphenyl ether was used as the diamine, and benzophenonetetracarboxylic dianhydride was used as the aromatic tetracarboxylic dianhydride. The molar concentration of P-aminofurtrimethoxysilane was set to 40%. Further, dimethylacetamide was used as the solvent, and the viscosity of this solution was set to 300 cm-poise.

[Example 1] FIGS. 1A to 1H are process cross-sectional views for forming a two-layer aluminum wiring structure according to the first example of the present invention.

In FIG. 1(a), a semiconductor element active part is formed,
Further, on the surface of the element substrate 101 on which polysilicon electrodes 103, 103' are formed via a phosphorus glass film 102 formed by chemical vapor deposition, a phosphorus glass film 1 formed by chemical vapor deposition is applied.
04, and by known lithography and dry etching), as shown in FIG.
03, 103' and the first aluminum wiring 106, 106' formed thereon are provided with openings 105, 105', and then, by sputtering, an opening with a thickness of approximately 1 μm is formed. An aluminum film is formed, and a titanium-gold JAM with a thickness of about 0.2 μm is formed as a barrier metal by sputtering, followed by photolithography.

By dry etching, first aluminum wirings 106, 106' having barrier metals 107, 107'i on their surfaces are formed as shown in FIG.

Next, an aluminum film with a thickness of about 1 μm is formed by sputtering, and then photolithography and dry etching are applied to the first aluminum wirings 106, 106' and on top of them, as shown in FIG. The second formed
A photoresist 109,
Pillars 108, 108' having 109' are formed.

The amine silicon compound, the diamine, and the aromatic tetracarboxylic dianhydride are mixed and reacted by incubation. 72: The coating solution is spin-coated at 2000 rpm for 30 seconds, and heat-treated at 200° C. for 30 minutes in a nitrogen gas atmosphere. In this way, a resin film 110 is formed as shown in tel of the figure.

Next, using reactive ion etching using a mixed gas of CF4 and 02, the flow rate of CF4 was 508 CCM.

The flow rate of 02 is 1108CC, and the pressure inside the chamber is 5.
pa, the applied power was 50 W, and the etching rate of the resin film 110 and the photoresist films 109, 109' was about 1000 A/min for 3 minutes under the same conditions.
The photoresist films 109, 109' and the resin film 110 were uniformly etched (FIG. 4(f)).

Next, the flow rate of CF4 is t-58CCM, and the flow rate of 02 is 58CCM.
5 SCCM, the chamber pressure is 5 pa, the applied power is 50 W, and the etching rate of the resin film 110 is 4.
00λ/min, photoresist 109, 10
The resin film 110 and the photoresist 109 were etched for 5 minutes under the condition that the etching rate of 9' was 1500 A/min.
゜109' is etched and the photoresist 109, 109' on 108, 108' is removed (g).
.

Subsequently, the resin film 110 is heated at 400° C. in a nitrogen gas atmosphere.
After applying heat treatment for 1 hour, an aluminum film with a thickness of approximately 1 μm is formed by sputtering, and the second aluminum wirings 111 and 111' are formed by photolithography and dry etching as shown in the same figure (hl). By forming, a two-layer aluminum wiring structure is formed.

[Example 2] Next, as a λ-th example, the method for manufacturing the multilayer wiring structure described in the first example is applied to a B i -CMUS super LS
An example applied to I will be explained. Bi-0MO8 super L
SI has three-layer KL wiring, and the wiring pitch is 2.5 μm in the first layer, 3.5 μm in the second layer, and 4.5 μm in the third layer.
It is m. Figure 1 fal ~ (1 by the manufacturing method shown in hl)
Interlayer film between layer wiring and second layer wiring and second layer wiring and 3
An interlayer film was formed between the wiring layers.

In order to demonstrate the effectiveness of the present invention, a Bi-CMOS VLSI formed by the multilayer wiring formation method of the present invention and a Bi-0MO8 VLSI formed by the conventional multilayer wiring formation method were created and compared. . Table 1 shows these two Bi-0MO
8 shows the yield of 9 and the non-defective rate after a 2000 hour reliability test for an 8-super LSI device. It can be seen that the manufacturing method according to the present invention is superior to the conventional method in both yield and quality. This is based on the advantage of the present invention, that is, the interlayer insulation properties are uniform during pillar formation.

〔Effect of the invention〕

As explained above, in the present invention, since a photoresist film remains on the pillar and a polyimide film containing an SiO component is used as an interlayer film, when the photoresist is removed,
It becomes possible to prevent the resin interlayer film from becoming thinner. Therefore,
It becomes possible to form a multilayer wiring structure with high yield and excellent reliability. That is, the present invention has a great effect on increasing the degree of integration of integrated circuit devices.

[Brief explanation of the drawing]

FIG. 1 (al to (hl) are process cross-sectional views when forming a two-layer aluminum wiring structure according to the first embodiment of the present invention. 101... Element substrate, 102... ...Phosphorus glass film, 103.103'...Polysilicon electrode, 104...Phosphorus glass film, 105,10
5'...Opening, 106.106'...
First aluminum wiring, 107.107'...
・Barrier metal, 108, 108'... Pillar, 109, 109'... Photoresist, 11
0... Resin film, 111, 111'...
Second aluminum wiring. 2(al) to (e) are process cross-sectional views when forming a two-layer aluminum wiring structure by the conventional pillar method. 301...Substrate, 302...... 1 aluminum wiring, 303...barrier metal/l/
, 304... Aluminum film, 305...
・・Pillar, 306・River・・Polyimide resin film, 307
...Second aluminum wiring.

Claims (1)

[Claims] A step of forming a first metal wiring on one main surface of a semiconductor substrate, forming a metal film on the first metal wiring, and selectively etching the metal film using a photoresist. selectively forming a columnar metal on the first metal wiring by etching, and an aromatic tetracarbon represented by the following formula (1) while leaving the photoresist film on the columnar metal. A solution containing a polyamic acid silicon type intermediate formed by a mixed reaction of an acid dianhydride, a diamine represented by formula (2), and an aminosilicon compound represented by formula (3) is applied. , 150℃
A process of forming a resin film on the entire surface by heat treatment at a temperature of ~200°C, and then reactive ion etching until the photoresist surface appears under conditions where the etching rate of the resin film and the photoresist is equal. etching the resin film and then removing the photoresist film by etching under conditions where the etching rate of the photoresist film is smaller than the etching rate of the resin film;
A method for manufacturing a multilayer wiring structure, comprising the steps of: heat-treating at a temperature of °C; and forming a second metal wiring on the resin film in contact with the surface of the columnar metal. ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・・・・
(1) NH_2-R^2-NH_2・・・・・・・・・(2) ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・・・・
(3) In formulas (1) to (3), R^1 represents a tetravalent carbocyclic aromatic group, and R^2 represents an aromatic aliphatic group having 6 to 30 carbon atoms, or an aromatic aliphatic group having 6 to 30 carbon atoms. 30 carbocyclic aromatic groups, R^
3 and R^4 are independently an alkyl group having 1 to 6 carbon atoms or a phenyl group, and K has a value of 1≦K≦3.