JPH06124950A - Method of manufacturing semiconductor device - Google Patents

Abstract

PURPOSE:To make it difficult to separate an extension insulation layer covering a wiring layer from the wiring layer by a method wherein the wiring layer is formed as a laminated body forming a layer composed of Mo or a layer composed of MoSi or WSi. CONSTITUTION:On a layer 6 composed of Mo, having higher stress migration strength and electro-migration strength than a layer composed of Al, a wiring layer 5 is formed as a laminated body forming a layer 10 composed of W or MoSi or WSi, having the higher stress migration and electro-migration strength than the layer composed of Al. Thus, even if an extension insulation layer 7 covering the wiring layer 5 is formed, thereafter further heat treatment is performed, or acid washing is performed, the insulation film is almost never separated from the wiring layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device having a structure in which a wiring layer is formed on a semiconductor substrate and an insulating layer extending over the wiring layer is formed. .

[0002]

2. Description of the Related Art Conventionally, a method of manufacturing a semiconductor device has been proposed which has the following steps with reference to FIGS.

That is, there is prepared a semiconductor substrate 1 on which a semiconductor element or a semiconductor region 2 constituting the semiconductor element, electrodes (not shown), etc. are formed and a subsequent wiring layer 5 is connected to the semiconductor region 2 (FIG. 6A). ).

Then, an insulating layer 4 made of, for example, silicon oxide having a window 3 for exposing the semiconductor region 2 to the outside is formed on the semiconductor substrate 1 (FIG. 6B).

Next, a wiring layer 5 which extends through the window 3 to reach the semiconductor region 2 and is connected to the insulating layer 4 is formed in a desired pattern (FIG. 6C).

In this case, the wiring layer 5 is formed as a layer 6 made of Mo.

Next, an insulating layer 7 made of, for example, silicon oxide is formed on the insulating layer 4 so as to cover and extend the wiring layer 5 (FIG. 7A).

Next, a window 8 for exposing the wiring layer 5 to the outside at a desired position is formed in the insulating layer 7 (FIG. 7B).

Then, another wiring layer 9 which extends through the window 8 to reach the wiring layer 5 and is connected to the insulating layer 7 is formed in a desired pattern (see FIG. 7
C).

The above is the conventionally proposed method for manufacturing a semiconductor device.

According to such a conventional method for manufacturing a semiconductor device, the wiring layer 5 is formed on the semiconductor substrate 1, and the insulating layer 7 extending over the wiring layer 5 is formed. A semiconductor device having the above structure can be manufactured.

Further, according to the conventional method for manufacturing a semiconductor device shown in FIGS. 6 and 7, the wiring layer 5 is made of Mo which has higher stress migration resistance and electromigration resistance than a layer made of Al. Since the wiring layer 5 is formed of the layer 6 made of Al, the wiring layer 5 can be formed as a wiring layer having excellent characteristics as compared with the case of being formed of a layer of Al. .

[0013]

However, in the case of the conventional semiconductor device manufacturing method shown in FIG. 3, the insulating layer 7 is formed on the wiring layer in contact with the layer 6 composed of Mo. Therefore, the insulating layer 7 is formed as having a low adhesion to the wiring layer 5.

Therefore, in the step of forming the insulating layer 7 and the heat treatment step in which the heat treatment step is performed after the step of forming the insulating layer 7, the insulating layer 7 becomes the wiring layer 5.
There was a risk of peeling from above.

In order to avoid such a possibility, a layer made of Mo oxide is formed on the surface of the wiring layer 5 after the step of forming the wiring layer 5 and before the step of forming the insulating layer 7. Is being attempted.

However, in this case, since the Mo oxide layer is water-soluble and is easily dissolved in a solution of hydrofluoric acid, ammonia or the like, after the step of forming the window 8 in the insulating layer 7, water is added. In a step of forming a wiring layer 9 after the step of performing a cleaning process using Al2O3 or removing the region of the Mo oxide insulating layer 7 facing the window 8 with a solution of hydrofluoric acid, ammonia, or the like. When the layer 9 is satisfactorily connected to the wiring layer 5, the layer made of Mo oxide is dissolved under the insulating layer 7,

Therefore, also in this case, the insulating layer 7 may be peeled off from the wiring layer 5.

Therefore, the present invention does not have the above-mentioned drawbacks.
It proposes a new manufacturing method of a semiconductor device.

[0019]

A method of manufacturing a semiconductor device according to the present invention includes a step of forming a wiring layer on a semiconductor substrate, as in the case of the conventional method of manufacturing a semiconductor device described above with reference to FIGS. And a step of forming an insulating layer on the semiconductor substrate, the insulating layer covering and extending the wiring layer.

However, in the method for manufacturing a semiconductor device according to the present invention, in the step of forming the wiring layer in the method for manufacturing the semiconductor device, the wiring layer is formed on the layer made of Mo by W.
(Tungsten) or MoSi (molybdenum silicide) or WSi (tungsten silicide).

[0021]

According to the method of manufacturing a semiconductor device of the present invention, as in the conventional method of manufacturing a semiconductor device described above with reference to FIGS. 6 and 7, a wiring layer is formed on a semiconductor substrate and its wiring is formed. It is possible to manufacture a semiconductor device having a structure in which an insulating layer extending over the layers is formed.

According to the method of manufacturing a semiconductor device of the present invention, the wiring layer is formed on the Mo layer having a higher stress migration resistance and electromigration resistance than the Al layer, and Is formed as a laminated body in which a layer made of W or MoSi or WSi having higher stress migration resistance and electromigration resistance than a layer made of Al is formed. As in the case of the conventional semiconductor device manufacturing method described above with reference to FIGS. 6 and 7,
It can be formed as one having excellent characteristics as a wiring layer as compared with the case where it is formed as a layer made of Al.

However, in the case of the method for manufacturing a semiconductor device according to the present invention, the insulating layer is formed on the wiring layer in contact with the W or MoSi or Mo layer forming the insulating layer, and therefore the insulating layer is formed. However, it has a higher adhesiveness as compared with the case where it is formed on the wiring layer in contact with the Mo layer constituting the wiring layer by the conventional method for manufacturing a semiconductor device described above with reference to FIGS. 6 and 7. Formed.

Therefore, there is almost no risk of the insulating layer peeling off from the wiring layer in the step of forming the insulating layer or in the heat treatment step in which the heat treatment step is performed after the step of forming the insulating layer.

From the above, according to the method of manufacturing a semiconductor device according to the present invention, a semiconductor device having a higher reliability than that of the conventional method of manufacturing a semiconductor device described with reference to FIGS. , Can be easily manufactured.

[0026]

First Embodiment Next, a first embodiment of the semiconductor device according to the present invention will be described with reference to FIGS.

1 and 2, parts corresponding to those in FIG. 3 are designated by the same reference numerals.

The method for manufacturing the semiconductor device according to the present invention shown in FIGS. 1 and 2 has the following sequential steps.

That is, a semiconductor element or a semiconductor region 2 constituting the semiconductor element, electrodes (not shown), etc. are formed in the same manner as in the conventional method for manufacturing a semiconductor device described above with reference to FIGS. A semiconductor substrate 1 to which the subsequent wiring layer 5 is connected to 2 is prepared (FIG. 1A).

Then, for example, silicon oxide SiO ₂ having a window 3 for exposing the semiconductor region 2 to the outside is formed on the semiconductor substrate 1 as in the case of the conventional semiconductor device manufacturing method described above with reference to FIGS. 6 and 7. 2) is formed by applying, for example, a known atmospheric pressure CVD method, a lithographic method, and a reactive etching method (FIG. 1B).

Next, as in the case where the wiring layer is formed as the layer 6 made of Mo in the conventional semiconductor device manufacturing method described above with reference to FIGS. 6 and 7, the insulating layer 4 is formed on the insulating layer 4. A layer 6 of Mo extending through the window 3 to reach the semiconductor region 2 of the semiconductor substrate 1 and connected thereto.
To the desired pattern, for example, by applying the sputtering method known per se and the ECR etching method (FIG. 1C).

Next, on the outer surface of the layer 6 made of Mo, the layer 10 made of W and, for example, a material gas known per se is used as WF.
₂ and H ₂ , temperature is 420 ° C, pressure is 0.17T
By the thermal CVD method with orr, the thickness of 500A,
Layer 6 formed by selective growth and thereby made of Mo
The wiring layer 5 is formed as a laminated body on which the layer 10 made of W is formed (FIG. 1D). Next, as shown in FIG.
In accordance with the conventional method for manufacturing a semiconductor device described above with reference to FIG. 7, the insulating layer 7 made of, for example, silicon oxide, which extends to cover the wiring layer 5, is formed by a known method such as the bias ECR method. (Fig. 2A).

Next, the insulating layer 7 is provided with a window 8 for exposing the wiring layer 5 to the outside at a desired position according to the conventional method for manufacturing a semiconductor device described above with reference to FIGS. 6 and 7. It is formed by applying a known lithography method and etching method (FIG. 2B).

Then, after performing a cleaning treatment using, for example, a 0.5% hydrofluoric acid solution, the insulating layer 7 is subjected to a cleaning treatment in accordance with the conventional semiconductor device manufacturing method described above with reference to FIGS. , Another wiring layer 9 consisting of a layer of W which extends through the window 8 of the insulating layer 7 to reach the wiring layer 5 and is connected to it.
The layer 10 made of W of the wiring layer 5 is formed on a desired pattern by a known method per se (FIG. 2C).

The above is the method of manufacturing a semiconductor device according to the present invention.

According to the method of manufacturing a semiconductor device according to the present invention, the wiring layer 5 is formed on the semiconductor substrate 1 as in the conventional method of manufacturing a semiconductor device described above with reference to FIGS. 6 and 7. It is possible to manufacture a semiconductor device having a structure in which the insulating layer 7 extending over the wiring layer 5 is formed.

Further, according to the method of manufacturing a semiconductor device of the present invention shown in FIGS. 1 and 2, the wiring layer 5 is Mo which has higher stress migration resistance and electromigration resistance than a layer made of Al. On the layer 6 made of Al, which has a higher stress migration than the layer made of Al.
Since the wiring layer 5 is formed as a laminated body in which the layer 10 made of W having the resistance to ionization and the resistance to electromigration is formed, the wiring layer 5 is formed as shown in FIGS.
As in the case of the conventional semiconductor device manufacturing method described above in
It can be formed as a layer having excellent characteristics as a wiring layer as compared with the case where it is formed as a layer made of l.

However, in the method of manufacturing the semiconductor device according to the present invention shown in FIGS. 1 and 2, the insulating layer 7 is replaced by the wiring layer 5.
The insulating layer 7 is formed on the wiring layer 5 by the conventional semiconductor device manufacturing method described above with reference to FIGS. As compared with the case where it is formed in contact with the layer 6 made of Mo, which forms it, it is formed with high adhesion.

Therefore, there is almost no possibility that the insulating layer 7 will be separated from the wiring layer 5 in the step of forming the insulating layer 7 or in the case where a heat treatment step is performed after the step of forming the insulating layer 7, etc. I don't have it.

After the step of forming the window 8 in the insulating layer 7,
Before the step of forming another wiring layer 9 on the insulating layer 7,
Although a cleaning process using a hydrofluoric acid solution is performed, in the process, the layer 10 of W forming the wiring layer 5 does not dissolve even in the region of the insulating layer 7 facing the window 8. The insulating layer 7 does not have a risk of peeling from the wiring layer 5.

Further, in the step of forming the insulating layer 7, by forming the insulating layer in a heated oxygen atmosphere, even if the W layer 10 forming the wiring layer 5 is oxidized, Or W whose surface is inert to water
Since only the oxide layer is formed, the insulating layer 7 will not be peeled off from the wiring layer even if the cleaning process is performed.

From the above, the method of manufacturing a semiconductor device according to the present invention shown in FIGS. 1 and 2 has higher reliability than the conventional method of manufacturing a semiconductor device described with reference to FIGS. 6 and 7. A semiconductor device can be easily manufactured with a high yield.

[0043]

Second Embodiment Next, a second embodiment of the semiconductor device according to the present invention will be described with reference to FIGS.

3 to 5, parts corresponding to those in FIGS. 1 and 2 are designated by the same reference numerals.

The method of manufacturing the semiconductor device according to the present invention shown in FIGS. 3 to 5 has the following sequential steps.

That is, a semiconductor element or a semiconductor region 2 constituting the semiconductor element, electrodes (not shown), etc. are formed in the same manner as in the method of manufacturing a semiconductor device according to the present invention described above with reference to FIGS. A semiconductor substrate 1 in which the subsequent wiring layer 5 is connected to the region 2 is prepared (FIG. 3A).

Then, as in the case of the method for manufacturing the semiconductor device according to the present invention described above with reference to FIGS. 1 and 2, the semiconductor substrate 1 is provided with a window 3 for exposing the semiconductor region 2 to the outside, for example, silicon oxide SiO 2. _The insulating layer 4 consisting of ₂ ) is formed by, for example, a publicly known atmospheric pressure CVD method, a lithography method and a reactive etching method (FIG. 3B).

Then, through the window 3 of the insulating layer 4 in accordance with the case where the layer 6 made of Mo is formed on the insulating layer 4 in the method of manufacturing the semiconductor device according to the present invention described above with reference to FIGS. A layer 6'of Mo, which extends to reach the semiconductor region 2 of the semiconductor substrate 1 and is connected to it, is formed, for example, by a sputtering method known per se (FIG. 3).
C).

Next, a layer 11 'made of MoSi is formed on the layer 6'made of Mo by a sputtering method known per se, whereby M is formed on the layer 6'made of Mo.
A laminated body in which a layer 11 'made of oSi is formed is formed (FIG. 4A).

Next, the layered body in which the layer 11 'made of MoSi is formed on the layer 6'made of Mo is subjected to a known etching process using, for example, a chlorine-based gas as an etchant, so as to remove Mo. On the layer 6 '
From the laminated body in which the layer 11 'made of Si is formed,
A wiring layer 5 is formed which is a laminated body in which the layer 11 made of MoSi is formed on the layer 6 made of (3) and has a desired pattern (FIG. 4B).

Next, on the insulating layer 4, according to the method of manufacturing the semiconductor device according to the present invention described above with reference to FIGS. 1 and 2, the insulating layer made of, for example, silicon oxide is extended to cover the wiring layer 5. The layer 7 is known per se, for example a bias ECR
Formed by the method (FIG. 4C).

Next, in the insulating layer 7, a window 8 for exposing the wiring layer 5 to the outside at a desired position is provided in the insulating layer 7 according to the method for manufacturing the semiconductor device according to the present invention described above with reference to FIG. Are formed by applying a known lithography method and etching method (FIG. 5A).

Next, in the case of the method for manufacturing a semiconductor device according to the present invention described above with reference to FIGS. 1 and 2, linear processing using, for example, a 0.5% hydrofluoric acid solution is performed, and then the insulating layer 7 is formed. According to the method of manufacturing a semiconductor device according to the present invention described above with reference to FIGS. 1 and 2, the layer formed of W is extended through the window 7 to reach the wiring layer 5, and is connected to the wiring layer 5. The wiring layer 9 is formed in a desired pattern (FIG. 5B).

The above is the second embodiment of the method for manufacturing a semiconductor device according to the present invention.

According to the method of manufacturing the semiconductor device of the present invention, the wiring layer 5 is formed on the semiconductor substrate 1 as in the method of manufacturing the semiconductor device of the present invention described above with reference to FIGS. At the same time, it is possible to manufacture a semiconductor device having a structure in which the insulating layer 7 that extends to cover the wiring layer 5 is formed.

Further, according to the method of manufacturing a semiconductor device according to the present invention shown in FIGS. 3 to 5, the wiring layer 5 is Mo which has higher stress migration resistance and electromigration resistance than a layer made of Al. And a layer 11 made of MoSi having a higher stress migration resistance and electromigration resistance than the layer made of Al. Therefore, as in the case of forming the wiring layer 5 as a layer made of Al as in the case of the semiconductor device manufacturing method according to the present invention described above with reference to FIGS. It can be formed to have the following characteristics.

Further, in the case of the method for manufacturing the semiconductor device according to the present invention shown in FIGS. 3 to 5, the insulating layer 7 is formed in accordance with the method for manufacturing the semiconductor device according to the present invention described above with reference to FIGS.
On the wiring layer 5, the layer 1 made of MoSi constituting the wiring layer 5
Since it is formed in contact with 1, the insulating layer 7 has a high adhesiveness on the wiring layer 5, as in the case of the method for manufacturing a semiconductor device according to the present invention described above with reference to FIGS. It is formed.

Therefore, similar to the method of manufacturing a semiconductor device according to the present invention described above with reference to FIGS. 1 and 2, a step of forming the insulating layer 7 and a heat treatment step after the step of forming the insulating layer 7 are involved. In that case, there is almost no risk of the insulating layer 7 peeling from the wiring layer 5 in the heat treatment step or the like.

Similar to the method of manufacturing the semiconductor device according to the present invention described above with reference to FIGS. 1 and 2, another wiring layer 9 is formed on the insulating layer 7 after the step of forming the window 8 in the insulating layer 7. Before the step of performing the cleaning process, a cleaning process using a hydrofluoric acid solution is performed. In the process, the Mo forming the wiring layer 5 is processed.
Since the layer 11 made of Si does not dissolve even in the region of the insulating layer 7 that faces the window 8, the insulating layer 7 does not have a risk of peeling from the wiring layer 5.

Further, in the step of forming the insulating layer 7, even if the layer 11 of MoSi forming the wiring layer 5 is oxidized by forming the insulating layer in a heated oxygen atmosphere, However, since the surface of the insulating layer 7 is only a layer made of SiO2 which is inactive to water, the insulating layer 7 is not likely to be peeled off from the wiring layer even if the cleaning process is performed.

From the above, the manufacturing method of the semiconductor device according to the present invention shown in FIGS. 3 to 5 is similar to the manufacturing method of the semiconductor device according to the present invention described above with reference to FIGS. 1 and 2.
A semiconductor device having high reliability can be easily manufactured with a high yield.

[0062]

Third Embodiment Next, a third embodiment of the method for manufacturing a semiconductor device according to the present invention will be described.

The third embodiment of the method of manufacturing a semiconductor device according to the present invention is the same as the second embodiment of the method of manufacturing a semiconductor device according to the present invention described above with reference to FIGS. Is read as "layer 12 'of WSi",
In addition, in response to this, the “layer 11 made of MoSi” is changed to “WSi”.
The semiconductor device is manufactured by taking the sequential steps of reading "the layer 12".

The third embodiment of the method for manufacturing a semiconductor device according to the present invention is the same as the method for manufacturing a semiconductor device according to the present invention described above with reference to FIGS. Although not described, in the second embodiment of the method for manufacturing a semiconductor device according to the present invention described above with reference to FIGS. 3 to 5, the “layer 11 made of MoSi” is replaced with the “layer 1 made of WSi”.
2 ", which is the same as in the case of the second embodiment of the method for manufacturing a semiconductor device according to the present invention described above with reference to FIGS.

In the above description, only a few examples of the present invention are shown, and various modifications and changes can be made without departing from the spirit of the present invention.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view in a sequential process showing a first embodiment of a method for manufacturing a semiconductor device according to the present invention.

FIG. 2 is a schematic cross-sectional view in a sequential process showing a first embodiment of a method for manufacturing a semiconductor device according to the present invention.

FIG. 3 is a second and a third method of manufacturing a semiconductor device according to the present invention.
FIG. 6 is a schematic cross-sectional view in a sequential process showing the embodiment of FIG.

FIG. 4 is a second and a third method of manufacturing a semiconductor device according to the present invention.
FIG. 6 is a schematic cross-sectional view in a sequential process showing the embodiment of FIG.

FIG. 5 is a second and a third method of manufacturing a semiconductor device according to the present invention.
FIG. 6 is a schematic cross-sectional view in a sequential process showing the embodiment of FIG.

FIG. 6 is a schematic cross-sectional view in a sequential process showing a method for manufacturing a conventional semiconductor device.

FIG. 7 is a schematic cross-sectional view in sequential steps showing a method for manufacturing a conventional semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 semiconductor substrate 2 semiconductor region 3 window 4 insulating layer 5 wiring layer 6, 6'layer made of Mo 8 window 7 insulating layer 9 wiring layer 10 layer made of W 11, 11 'layer made of MoSi 12, 12' made of WSi layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masao Nagase 1-1-6 Uchiyuki-cho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corp. (72) Tetsuo Hosoya 1-1-6 Uchiyuki-cho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Misao Sekimoto 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Shuichi Kanamori 1-1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corp. (72) Inventor Hideo Oikawa 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corp. (72) Hideo Akiya 1-1-6 Uchisaiwai-cho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (1)

[Claims] 1. A method of manufacturing a semiconductor device, comprising: a step of forming a wiring layer on a semiconductor substrate; and a step of forming an insulating layer extending on the semiconductor substrate to cover the wiring layer. In the step of forming a layer, the wiring layer is
A method of manufacturing a semiconductor device, which is characterized in that the semiconductor device is formed as a laminated body in which a layer made of W or MoSi or WSi is formed on a layer made of o.