JPH0756866B2 - Method for manufacturing semiconductor integrated circuit device - Google Patents

Description

The present invention relates to a method for manufacturing a semiconductor integrated circuit device, and more particularly,
The present invention relates to a method for manufacturing a semiconductor integrated circuit device having high performance.

[Conventional technology]

Conventionally, this type of semiconductor integrated circuit device has the lowest layer resistance value on the surface of the impurity diffusion layer or the surface of the electrode wiring made of polycrystal silicon to speed up the operation of the device. A titanium silicide film having a low specific resistance value has been used.

[Problems to be Solved by the Invention]

In the above-described conventional semiconductor integrated circuit device, the silicon oxide film remaining on the titanium silicide film 202 when the titanium silicide film 202 is contacted with the wiring metal by forming the contact hole 204 as shown in FIG. The treatment with hydrofluoric acid was carried out in order to remove. However, at this time, the titanium silicide film exposed in the contact hole portion
Since 202 is also removed by this etching solution, there is a problem that the contact between the wiring metal and the titanium silicide film 202 cannot be sufficiently obtained, and the contact resistance value becomes high.

[Means for Solving the Problems]

According to the method of the present invention, after a tungsten film, a molybdenum film, or a cobalt film is formed on the surface of a titanium silicide film, ions heavier than Ti atoms, such as As ions and BF ₂ ions, are added to the tungsten film, the molybdenum film, the cobalt film, and the titanium film. It is driven into the interface with the silicide film so that there is a range, and then heat treatment is performed in a nitrogen gas or a mixed gas of nitrogen and hydrogen or a hydrogen gas atmosphere, and the tungsten film, molybdenum film or cobalt film is replaced with a tungsten silicide film. Or a step of forming a molybdenum silicide film or a cobalt silicide film.

The reason why the above metal film is transformed into a metal silicide film is
After the tungsten film, molybdenum film, or cobalt film is formed on the surface of the titanium silicide film, ions heavier than Ti atoms are driven into the interface between the tungsten film, molybdenum film, or cobalt film and the titanium silicide film so that there is a range. Therefore, mixing between these metal films and the titanium silicide film occurs at the interface, and the subsequent heat treatment facilitates diffusion of Si atoms from the titanium silicide film to the upper metal film, and the tungsten silicide film or molybdenum film is formed on the titanium silicide film. This is because the silicide film or the cobalt silicide film is formed in a self-aligned manner.

By the way, since the tungsten silicide film, the molybdenum silicide film, or the cobalt silicide film has hydrofluoric acid resistance, when the silicide film is connected to the wiring metal, the hydrofluoric acid is used for the purpose of removing the silicon oxide film on the silicide film. Even if the treatment is performed, the silicide film is not removed, and there is an effect that a good contact between the silicide film and the wiring metal can be formed and a semiconductor integrated circuit device having good element characteristics can be obtained.

Further, according to the finding of the inventor of the present invention, the titanium silicide film is covered with the tungsten silicide film, the molybdenum silicide film, or the cobalt silicide film, so that the titanium seen when the heat treatment of 900 ° C. or more is applied. Non-uniformity of resistivity of silicide film (Reference, V-MIC Conf. Proceeding 1987 pp470-47)
9) is not seen, and a thermally stable and low resistance silicide film is obtained.

Therefore, 90 is added when manufacturing a semiconductor integrated circuit device.
Even if the heat treatment is performed at 0 ° C. or higher, the specific resistance of the titanium silicide film is low and stable, so that a high-speed semiconductor integrated circuit device with less variation in element characteristics can be obtained.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a vertical sectional view of a diffusion layer portion of a semiconductor integrated circuit device which is a first embodiment of the present invention. 10 is a P-type Si substrate, 11
Is a silicon oxide film for element isolation, 12 is an N ⁺ diffusion layer, 13 is a titanium silicide film, 14 is a tungsten silicide film, 15
Is an interlayer insulating film made of a silicon oxide film, 16 is a titanium tungsten film, and 17 is a silicon-containing aluminum film.

In the semiconductor integrated circuit device thus configured,
After forming a contact hole in a part of the interlayer insulating film 15, the tungsten silicide film 14 is not removed even if hydrofluoric acid treatment is performed in order to remove the silicon oxide film remaining on the tungsten silicide film 14. Good contact with tungsten silicide 14,
A semiconductor integrated circuit device having excellent element characteristics can be obtained.

In addition, 900 is added when manufacturing this semiconductor integrated circuit device.
Even if the heat treatment is carried out at a temperature of ° C, there is no variation in the specific resistance value of the titanium silicide film 13, and a semiconductor integrated circuit device with little variation in element characteristics can be obtained.

Next, a manufacturing method for realizing the first embodiment of the present invention will be described. FIGS. 2A to 2H are process drawings for explaining the method for manufacturing the semiconductor integrated circuit device according to the first embodiment of the present invention.

First, as shown in FIG. 2 (a), by a selective oxidation method or the like,
A device isolation silicon oxide film 11 is formed on a P-type Si substrate 10. Next, the natural oxide film in the diffusion layer formation area is removed by a hydrofluoric acid solution, and then a titanium film is formed on the entire surface of the semiconductor substrate by sputtering to a thickness of 600 to 800 Å, followed by heat treatment in a nitrogen atmosphere (lamp 600 ℃ ~ 700 ℃ by annealing)
Are heat-treated at a temperature of 1 to form a titanium silicide film 13 in the diffusion layer formation region and unreacted titanium on the element isolation silicon oxide film 11. Next, in order to remove the unreacted titanium, a treatment is carried out with a mixed solution of ammonia water, hydrogen peroxide water and water, and as shown in FIG. 2 (b), only in the region where the diffusion layer is formed. The titanium silicide film 13 is formed. At this stage, the layer resistance of the titanium silicide film 13 is 6
Has a value of ~ 10Ω / □ and 750 to further reduce the layer resistance.
Performs heat treatment at ~ 800 ° C with a lamp annealing device,
A layer resistance value of 2-3 Ω / □ is finally obtained.

Next, as shown in FIG. 2C, a tungsten film 20 is formed to a thickness of 300 to 400 Å by the sputtering method.

Next, the As ions are added to the tungsten film 20 at an accelerating voltage of 70 to 100 KeV and a dose amount of 5 × 10 ¹⁵ to 1 × 10 ¹⁶ cm ^-2 so that a range is reached at the interface between the tungsten film 20 and the titanium silicide film 13. Drive into. Then, heat treatment (lamp anneal) in a hydrogen atmosphere is performed at a temperature of 600 ° C. to 800 ° C. to form a tungsten silicide film 14 only on the titanium silicide film 13, and then ammonia water, hydrogen peroxide, and water are added. The unreacted tungsten is removed by the mixed solution of, and a tungsten silicide film 14 covering the titanium silicide film 13 is formed as shown in FIG. 2 (d).

Next, as shown in FIG. 2 (e), the As ions for forming the N ⁺ diffusion layer have an acceleration voltage of 70 to 150 KeV and a dose of 10 ¹⁶ cm ^-2.
It is driven into the semiconductor substrate under the condition of.

Next, an interlayer insulating film 15 made of a silicon oxide film is formed to a film thickness of 7000Å by the CVD method, and then a heat treatment is applied at a temperature of 900 to 950 ° C to activate the As atoms that have been previously implanted. , The diffusion layer 12 is formed, as shown in FIG. 2 (f).

Next, as shown in FIG. 2 (g), contact holes are formed to connect the tungsten silicide film 14 and the metal wiring.
22 is formed by a photoetching method.

Next, in order to make a good connection between the metal wiring and the tungsten silicide film 14, the silicon oxide film remaining on the tungsten silicide film 14 exposed in the contact hole 22 is removed by a hydrofluoric acid solution, and then titanium tungsten is used. Membrane 16
And the silicon-containing aluminum film 17 are formed to a film thickness of 1000 Å and a film thickness of 5000 Å by the sputtering method, respectively, and then patterned by the photoresist and processed by the RLE method to form the metal wiring as shown in FIG. 2 (h). Is formed. In this way, the semiconductor integrated circuit device as shown in FIG. 1 is obtained.

FIG. 3 is a vertical sectional view of a diffusion layer portion of a semiconductor integrated circuit device manufactured by the method according to the second embodiment of the present invention. Ten
0 is a P-type Si substrate, 101 is a silicon oxide film for element isolation, 102
Is an N ⁺ diffusion layer, 103 is a titanium silicide film, 104 is a tungsten silicide film, 105 is an interlayer insulating film made of a silicon oxide film, 106 is a tungsten film selectively grown by CVD of a silane reduction method, and 107 is silicon-containing. It is an aluminum film.

In this embodiment, the contact hole is filled with the tungsten film 106 selectively grown on the tungsten silicide film 104 by using the CVD of the silane reduction method. Therefore, it is impossible to bury the metal by the sputtering method. There is an advantage that a semiconductor integrated circuit device having contacts can be realized.

Next, a method of manufacturing the semiconductor integrated circuit device according to the second embodiment of the present invention will be described. 4 (a) and 4 (b) are process drawings for explaining a method for manufacturing a semiconductor integrated circuit device according to the second embodiment of the present invention.

FIG. 4 (a) is a process diagram for explaining the manufacturing method of the first embodiment, and after the structure shown in FIG. 2 (f) is obtained,
The contact hole (110), which is finer than the contact used in the example of FIG.
The structure after being formed by etching by (Reactive Ion Etching) is shown.

Next, as shown in FIG. 4B, after the contact hole 110 is formed, the silicon oxide film remaining on the tungsten silicide film 104 is removed by a hydrofluoric acid solution, and then SiH ₄ gas is added.
A tungsten film 106 is selectively formed on the tungsten silicide film 104 by a silane reduction CVD method using WF ₆ gas, and the contact hole 110 is buried.

Next, as shown in FIG. 4 (c), a silicon-containing aluminum film 107 is formed on the entire surface of the semiconductor substrate by a sputtering method to a thickness of 5000Å, patterned by a photoresist, and then processed by RIE to form a metal wiring. Is formed. Thus, the semiconductor integrated circuit device according to the method of the second embodiment of the present invention is obtained.

〔The invention's effect〕

As described above, according to the present invention, a tungsten silicide film, a molybdenum silicide film, or a cobalt silicide film having hydrofluoric acid resistance is formed on the surface of the titanium silicide film formed on the surface of the gate polysilicon electrode, the polysilicon wiring, or the diffusion layer. By forming a contact hole in the interlayer insulating film made of a silicon oxide film that covers the titanium silicide film and making contact with the wiring metal, the titanium silicide film in the contact portion is left and the contact can be made. .

Therefore, a contact having a low resistance can be formed, so that a semiconductor integrated circuit device having excellent element characteristics can be obtained.

Further, according to the finding of the inventor of the present invention, the titanium silicide film was found to be covered with a tungsten silicide film, a molybdenum silicide film, or a cobalt silicide film, so that the titanium silicide film was subjected to heat treatment at 900 ° C. or higher. No unevenness of the specific resistance of the titanium silicide film is observed, and a thermally stable silicide film is obtained.

Therefore, it is added when manufacturing a semiconductor integrated circuit device.
The specific resistance of the titanium silicide film is stable even by the heat treatment at 900 ° C. or higher, and there is an effect that a semiconductor integrated circuit device with less variation in element characteristics can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a semiconductor integrated circuit device manufactured by the method of the first embodiment of the present invention, and FIGS. 2 (a) to 2 (h).
FIG. 3 is a process drawing for explaining the method for manufacturing a semiconductor integrated circuit device according to the first embodiment of the present invention, FIG. 3 is a longitudinal sectional view of a semiconductor integrated circuit device according to the method of the second embodiment of the present invention, Four
FIGS. 5A to 5C are process drawings for explaining a method for manufacturing a semiconductor integrated circuit device according to a second embodiment of the present invention, and FIG. 5 is a semiconductor integrated circuit for explaining problems in the conventional technique. It is a longitudinal cross-sectional view of an apparatus. 10 ... P-type Si substrate, 11 ... Silicon oxide film for element isolation, 12 ... N ⁺ diffusion layer, 13 ... Titanium silicide film, 14 ...
… Tungsten silicide film, 15 …… Interlayer insulating film made of silicon oxide film, 16 …… Titanium silicide film, 17 ……
Silicon-containing aluminum film, 20 …… tungsten film, 21 ……
As ion, 22 …… contact hole, 100 …… P type Si substrate, 1
01 …… Silicon oxide film for element isolation, 102 …… N ⁺ diffusion layer, 103 …… Titanium silicide film, 104 …… Tungsten silicide film, 105 …… Interlayer insulating film made of silicon oxide film, 106 …… Silane reduction Tungsten film grown by CVD, 107 ... Silicon-containing aluminum film, 110 ... Contact hole, 200 ... P type Si substrate, 201 ... N ⁺ diffusion layer, 202 ...
… Titanium silicide film, 203 …… Interlayer insulating film made of silicon oxide film, 204 …… Contact hole.

Claims (3)

[Claims] 1. A step of forming a titanium silicide film on the surface of an impurity diffusion layer or a surface of a polycrystalline silicon layer, a step of forming a tungsten film, a molybdenum film or a cobalt film on the surface of the titanium silicide film, and a titanium atom. A step of implanting heavier ions into the interface between the tungsten film, molybdenum film or cobalt film and the titanium silicide film with a range, and heat-treating the tungsten film, molybdenum film or cobalt film, and the surface of the titanium silicide film. And a step of forming a tungsten silicide film, a molybdenum silicide film, or a cobalt silicide film, in the method for manufacturing a semiconductor integrated circuit device. 2. The method for manufacturing a semiconductor integrated circuit device according to claim 2, wherein the ions implanted into the tungsten film, the molybdenum film or the cobalt film are As ions or BF ₂ ions. 3. A step of forming a silicon oxide film on the tungsten silicide film, the molybdenum silicide film or the cobalt silicide film, and a step of forming a depth of the silicon oxide film reaching the tungsten silicide film, the molybdenum silicide film or the cobalt silicide film. The method further includes the step of forming a contact hole and the step of forming a conductive film inside the contact hole, the conductive film being in contact with the tungsten silicide film, the molybdenum silicide film, or the cobalt silicide film exposed at the bottom of the contact hole. Item 3. A method for manufacturing a semiconductor integrated circuit device according to Item 1 or 2.