JPH036024A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To simplify the production process by a method wherein a part other than an arbitrary part is covered with an organic film provided with a heat- resistant property which can endure a temperature during a selective vapor growth operation. CONSTITUTION:When a high-melting metal 6 is vapor-grown selectively only in an arbitrary part on a semiconductor substrate 5 and/or a metal interconnection 1, a part other than the arbitrary part is covered with an organic film 3 provided with a heat-resistant property which can endure a temperature during a selective vapor growth operation. When the high-melting metal 6 is vapor- grown selectively at a high temperature, the organic film 3 is not melted and sufficiently functions as a selective mask. In addition, the mask acts, on the basis of a characteristic of the organic film 3, in such a way that the high- melting metal 6 does not adhere and is not grown; a process to remove the high-melting metal 6 which has adhered to the part other than the arbitrary part is lot required. Thereby, the production process can be simplified.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a technique that is effective when applied to a method of manufacturing a semiconductor device, for example, a technique that is effective when applied to a technique for filling connection holes. It is something.

[Prior Art] Conventionally, the filling of contact holes such as contact holes that contact a diffusion layer on the surface of a semiconductor substrate or through holes that contact a metal scrap wiring with a conductor M has been performed by, for example, depositing and patterning a metal such as aluminum on the entire surface. It was done by doing. However, when the connection hole is filled by such a method, the coverage of the metal filled in the connection hole is not very good, so there is a risk that poor conduction or the like may occur in the connection hole. Moreover,
Recently, with the demand for higher integration, the connection holes have become smaller, and this fear is becoming more and more common.

Therefore, in recent years, instead of simply depositing metal on the entire surface to fill connection holes such as contact holes and through holes, selective vapor deposition of high melting point metals such as tungsten has been used to solve the above problems. I was trying to deal with the points.

This selective vapor phase growth method for high melting point metals is a process in which high melting point metals are vapor phase chemically deposited by controlling gas conditions (e.g., at a temperature of 300 to 350'C). grows only on certain substances, 5
Since tungsten has the characteristic that it is not formed on surfaces such as i02, this characteristic can be used to form tungsten only on silicon (semiconductor substrate) or aluminum (metal wiring) exposed through connection holes from an inorganic insulating film made of Sin, etc. This method involves growing a high-melting point metal such as, for example, by putting the high-melting point metal into a connection hole and growing it, which has the advantage of extremely good coverage compared to the above-mentioned conventional technology.

[Problems to be Solved by the Invention] However, the inventors of the present invention have discovered the following problems with semiconductor devices manufactured using such selective vapor phase epitaxy of high melting point metals.

In other words, when selectively vapor phase growing a high melting point metal,
It has been discovered that the high melting point metal may occasionally adhere to an inorganic insulating film made of 5i02 or the like, which was thought not to be attached to the high melting point metal. Leaving the refractory metal attached to the inorganic insulating film poses a quality problem, so this refractory metal must be removed from the inorganic insulating film, but additional etching steps are required. This makes the manufacturing process complicated and undesirable.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing a semiconductor device in which the manufacturing process is simplified.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for Solving the Problems] Representative inventions disclosed in this application will be summarized as follows.

In other words, when selectively vapor-depositing a high-melting point metal only on an arbitrary part on a semiconductor substrate and/or metal wiring, parts other than the above-mentioned arbitrary parts must have heat resistance that can withstand the temperature during selective vapor-phase growth. It is covered with an organic film having a

[Function] According to the above-described means, the high melting point metal is applied to the semiconductor substrate and/or
Alternatively, when performing selective vapor phase growth only on an arbitrary part of the gold wiring, parts other than the above-mentioned arbitrary parts are covered with an organic film having heat resistance that can withstand the temperature during selective vapor phase growth. Therefore, during high-temperature selective vapor phase growth of high-melting point metals, the organic film does not melt and fully functions as a selective mask. This effect eliminates the need for the step of removing high melting point metals that have adhered to areas other than this arbitrary area, thereby achieving the above-mentioned objective of simplifying the manufacturing process.

[Embodiment 1] Hereinafter, embodiments of the method for manufacturing a semiconductor device according to the present invention will be described with reference to the drawings.

FIG. 1 shows a semiconductor device obtained by applying a first embodiment of the method for manufacturing a semiconductor device according to the present invention.

In the semiconductor device of this first embodiment, a through hole that contacts any position of a metal wiring 1 made of, for example, aluminum is formed by selective vapor deposition using a high melting point gold made of, for example, tungsten. Filling (growth)
In the semiconductor device of the first embodiment, the parts other than the through hole have heat resistance that can withstand the temperature during selective vapor phase growth, and the above-mentioned high melting point gold @6
An organic film 3 made of, for example, polyimide resin (P i Q (trademark)), which does not adhere or grow, is coated in an intermediate process.

Hereinafter, an example of the method for manufacturing the semiconductor device of the above embodiment will be explained in the second example.
This will be explained based on FIG. 2(a) to FIG. 2(f).

First, on the entire surface of the semiconductor substrate 5 made of silicon, for example, an inorganic interlayer insulating film 2,400 made of, for example, Sin is formed.
An organic film 3 made of, for example, a polyimide resin having heat resistance up to 450°C, and a Si-containing photoresist 4 having resistance to reactive ion etching are sequentially applied in that order to form a film. Through development, a through hole pattern at an arbitrary position on the metal wiring 1 is formed using Si.
The photoresist 4 is then transferred to the containing photoresist 4 to form the state shown in FIG. 2(a).

Next, the above Si was etched using 02 reactive dry etching technology.
The pattern on the containing photoresist 4 is transferred to the underlying organic film 3, resulting in the state shown in FIG. 2(b).

Next, the Si-containing photoresist 4 is removed using a resist removal solution.
is peeled off to obtain the state shown in FIG. 2 (Q).

Next, using a reactive ion etching technique in CF4 gas using the organic film 3 as a processing mask.

The above-mentioned through-hole pattern is formed in the inorganic interlayer insulating film 2 to form the state shown in FIG. 2(d).

Next, with the organic film 3 remaining, that is, parts other than the through hole pattern covered with the organic film 3, selective vapor phase growth of a high melting point metal such as tungsten is performed at a temperature of about 300 to 350°C. Then, tungsten is selectively grown only in the through holes, resulting in the state shown in FIG. 2(e). Here, since the heat resistant temperature of the polyimide resin 3 is 400 to 450°C as described above, the polyimide resin 3 does not melt during selective vapor growth,
Moreover, since tungsten 6 does not adhere or grow on the polyimide resin 3 due to its characteristics, tungsten 6
Selectivity between the aluminum 1 and the polyimide resin 3 can be ensured favorably.

Next, the organic film 3 is etched away using a mixed solution of hydrazine hydrogen chloride and ethylene diamine to form the state shown in FIG. 2(f), and the electrode 7 is formed to obtain the semiconductor device shown in FIG. Become.

As a result, according to the method of manufacturing a semiconductor device of the first embodiment, the following effects can be obtained.

That is, when selectively vapor-depositing a high-melting point metal made of tungsten only on an arbitrary part (inside the through-hole) on the metal interconnection IjAl made of aluminum, a part other than the above-mentioned arbitrary part (inside the through-hole) is Since it is covered with an organic film 3 made of a polyimide resin having heat resistance that can withstand the temperature during selective vapor phase growth, the organic film 3 will not melt during selective vapor phase growth at high temperatures of high melting point metals. In addition to fully functioning as a selective mask, the high melting point metal does not adhere to or grow on the mask due to the characteristics of the organic film 3, so that it does not adhere to any part other than this arbitrary part (inside the through hole). This eliminates the need for the process of removing high-melting point metals, which has been previously used, making it possible to simplify the manufacturing process.

In this first embodiment, the polyimide resin 3 is removed in case there is a mistake such as tungsten adhering to the polyimide resin 3. Of course, it is also possible to form the electrode 7 while leaving the polyimide resin 3 without removing it, and to obtain the semiconductor device shown in FIG. 3. In this case, since the polyimide resin 13 having excellent flatness is used as the interlayer film, it is possible to further improve the processability of the semiconductor device having a multilayer structure.

FIG. 4 shows a semiconductor device obtained by applying the second embodiment of the method for manufacturing a semiconductor device according to the present invention.

The semiconductor device of this second embodiment differs from that of the first embodiment in that the function of the inorganic insulating film 2 is given to an organic film 23 made of polyimide resin, that is, the inorganic insulating film 2 The point is that it is no longer necessary.

An example of the method for manufacturing the semiconductor device of this second embodiment is described in the fifth example.
This will be explained based on FIG. 5(a) to FIG. 5(c).

First, an organic film 23 made of, for example, a polyimide resin having heat resistance up to 400 to 450° C. is coated and formed on the entire surface of a semiconductor substrate 5 made of, for example, silicon, and then the film shown in FIG.
Set the state shown in a).

Next, Si with 02 reactive ion etching resistance
A Si-containing photoresist 14 is applied, exposed and developed using a well-known photolithography technique, and a through-hole pattern at an arbitrary position on the metal wiring 1 is transferred to the Si-containing photoresist 14.
The state shown in FIG. S(b) is established.

Next, the above Si
The pattern on the containing photoresist 14 is transferred to the underlying organic film 23.
After that, the Si-containing photoresist 14 is peeled off using a resist removal solution to obtain the state shown in FIG. 5(c).

Next, in this state, that is, with the parts other than the through hole pattern covered with the organic film 23, selective vapor phase growth of a high melting point metal such as tungsten is performed for about 30 to 35 minutes.
If tungsten 16 is selectively grown only in the 5-hole portion at a temperature of 0'C, the semiconductor device shown in FIG. 4 will be obtained.

In this way, the second embodiment also has the same effect as that achieved by the semiconductor device manufacturing method of the first embodiment, that is, the high melting point metal adhered to a region other than the arbitrary region (inside the through hole). This eliminates the need for the removal process, and the manufacturing process can be simplified.

As a third example, if the organic film 23 of the semiconductor device shown in FIG. 4 is etched away using a mixed solution of hydrazine hydrogen chloride and ethylene diamine, the columnar shape shown in FIG. 6 can be formed. .

Conventionally, the formation of this columnar shape was done by the lift-off method, which had the problem that it was difficult to mass-produce due to the adhesion of foreign matter, but if it is formed by the manufacturing method of this third embodiment, such a problem can be avoided. The advantage is that the problem is avoided.

FIG. 7 shows a semiconductor device obtained by applying the fourth embodiment of the method for manufacturing a semiconductor device according to the present invention.

In the semiconductor device of this fourth embodiment, a high melting point metal made of tungsten formed by selective vapor phase epitaxy protrudes from the upper surface of the semiconductor chip 15 and functions as a bonding pad 26.

To manufacture the semiconductor device of this fourth embodiment, first, for example, S
i O, inorganic interlayer insulating film 12.400-450
An organic film 33 made of, for example, a polyimide resin having a heat resistance of up to The through-hole pattern at the position is transferred to the Si-containing photoresist, and then the pattern on the Si-containing photoresist is transferred to the underlying organic film 33 using the 02 reactive dry etching technique. The photoresist contained therein is peeled off, and the inorganic interlayer #@edge film 12 is removed using reactive ion etching technology in CF and gases using the organic film 33 as a processing mask.
The above-mentioned through-hole pattern is penetrated, and then, with the above-mentioned organic film 33 remaining, that is, the parts other than the through-hole pattern are covered with the organic film 33, a selective vapor phase of a high melting point metal such as tungsten is applied. Growth about 300-3
The process is carried out at a temperature of 50'C, and tungsten is selectively grown only in the through-hole portions, resulting in the state shown in FIG.

Then, the organic film 33 is removed by etching with a mixed solution of hydrazine hydrogen chloride and ethylene diamine, and this removal causes the pad 2 made of tungsten to be exposed.
When the inner lead 30 is connected to 6, the semiconductor device shown in FIG. 7 is obtained.

In this way, the present invention can also be applied to the above-mentioned bonding technology.

Although the invention made by the present inventor has been specifically explained above based on examples, it goes without saying that the present invention is not limited to the above-mentioned examples, and can be modified in various ways without departing from the gist thereof. Nor.

For example, in each of the above embodiments, application examples are described exclusively to through holes that contact metal wiring 1, but the present invention is applicable to contact holes that contact diffusion layers formed on the surface of semiconductor substrate 5. The same applies to

Further, in each of the above embodiments, the high melting point metal is 6°16.
Although tungsten is used as 26, it is not limited to tungsten, and any high melting point metal that can perform selective vapor phase growth may be used.

Further, although the semiconductor substrate 5 is made of silicon and the metal wiring 1 is made of aluminum, the material is not limited to these, and any material may be used as long as it has good selective vapor phase growth properties of a high melting point metal.

Similarly, although the organic films 3, 13, 23, and 33 are made of polyimide resin, they are not limited to polyimide resins, and have heat resistance that can withstand the temperature during selective vapor phase growth of high melting point metals. Any ia film may be used as long as it does not allow attachment or growth of high melting point metals.

Furthermore, although the inorganic insulating films 2 and 12 are 5 in 2 in size, it is also possible to use a three-layer film of plasma oxide film or the like.

[Effects of the Invention] The effects obtained by the typical inventions disclosed in Suito are briefly described below.

In other words, when selectively vapor-depositing a high-melting point metal only on an arbitrary part on a semiconductor substrate and/or metal wiring, parts other than the above-mentioned arbitrary parts must have heat resistance that can withstand the temperature during selective vapor-phase growth. Since the organic film is covered with an organic film having a high melting point metal, it does not melt during selective vapor phase growth at high temperatures and functions as a selective mask without melting. The high melting point metal does not adhere or grow. As a result, the step of removing the refractory metal adhering to parts other than this arbitrary part becomes unnecessary, making it possible to simplify the manufacturing process.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a semiconductor device obtained by applying the first embodiment of the method for manufacturing a semiconductor device according to the present invention, and FIGS. FIG. 3 is a vertical cross-sectional view of a semiconductor device obtained by applying the first embodiment of the method for manufacturing a semiconductor device according to the present invention, and FIG. 5(a) to 5(c) are longitudinal cross-sectional views of a semiconductor device obtained by applying the second embodiment of the semiconductor device manufacturing method according to the above. 6 is a vertical cross-sectional view of a semiconductor device obtained by applying the third embodiment of the method for manufacturing a semiconductor device according to the present invention, and FIG. FIG. 8 is a longitudinal sectional view of a semiconductor device obtained by applying the fourth embodiment, and FIG. 8 is a process diagram of the fourth embodiment. 1...Metal wiring, 3,13,23.33...Organic film, 5...Semiconductor substrate, 6,16.26...
High melting point metal. Figure 2 (b) Figure 2 ((1) Figure Figure Figure +01

Claims (3)

[Claims] 1. When selectively vapor-depositing a high-melting point metal only on an arbitrary location on a semiconductor substrate and/or metal wiring,
A method for manufacturing a semiconductor device, characterized in that parts other than the arbitrary parts are covered with an organic film having heat resistance that can withstand temperatures during selective vapor growth. 2. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the organic film is made of polyimide resin. 3. 3. The method of manufacturing a semiconductor device according to claim 1, wherein the high melting point metal is tungsten.