JPH0555225A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To provide the manufacture of a semiconductor device, in which a metallic wiring layer can be formed with an excellent coverage while the metallic wiring layer can be buried uniformly into a contact hole and the metallic wiring layer, which is made fine and changed into multilayers, can be formed stably. CONSTITUTION:Foundation layers 14 composed of the quality of material constituting a metallic wiring layer are formed through a sputtering method while cooling a semiconductor substrate 1, surface layers 16, 16a consisting of the quality of material organizing the metallic wiring layer are shaped onto the foundation layers 14 through the sputtering method while heating the semiconductor substrate 1, and the metallic wiring layers 18, 18a are constructed by the foundation layers 14 and the surface layers 16, 16a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for forming a metal wiring layer made of aluminum or the like.

[0002]

2. Description of the Related Art A semiconductor substrate that constitutes a semiconductor device is
A metal wiring layer made of aluminum may be laminated in multiple layers with an interlayer insulating film layer interposed therebetween. For example, as shown in FIG. 3, the interlayer insulating film layer 2 is formed on the semiconductor substrate 1,
A first metal wiring layer 4 made of aluminum is laminated thereon.

An interlayer insulating film layer 6, a planarizing film layer 8 and an interlayer insulating film layer 10 are laminated on the first metal wiring layer 4.
A contact hole 12 facing the first metal wiring layer 4 is formed in the insulating film layers 6 and 10 and the flattening film layer 8, and a second metal wiring layer 14 is formed inside the contact hole 12 from above the insulating film layer 10. It is formed to enter.

The second metal wiring layer 14 is formed, for example, by sputtering aluminum. However, since there is a possibility that wedge-shaped voids may be generated in ordinary sputtering, semiconductor substrates of 200 to 3 have been recently used.
Sputtering is performed while heating at a temperature of 00 ° C. Further, since the inside of the contact hole 12 is completely filled with the second metal wiring layer 14 made of aluminum, the semiconductor substrate 1 may be sputtered while being heated at a temperature of 500 to 550 ° C.

[0005]

However, when the second metal wiring layer 14 is formed by sputtering the semiconductor substrate 1 while heating the semiconductor substrate 1, the SOG (which constitutes the planarization film layer 8 remaining in the contact hole 12) is formed. SPIN O
N GLASS) and degassing from residual moisture in the wet treatment before the sputtering process occur, resulting in poor coverage in the contact hole 12 as shown in FIG. There is. If the coverage is poor, problems such as disconnection of the metal wiring layer 14 due to electromigration may occur.

The present invention has been made in view of such circumstances, and it is possible to form the metal wiring layer with good coverage and to uniformly embed the metal wiring layer in the contact hole. An object of the present invention is to provide a method of manufacturing a semiconductor device capable of stably forming a metal wiring layer that is miniaturized and multilayered.

[0007]

In order to achieve the above object, a method of manufacturing a semiconductor device according to the present invention comprises forming an underlayer of a material forming a metal wiring layer by a sputtering method while cooling a semiconductor substrate, Next, a surface layer of a material forming the metal wiring layer is formed on the underlayer by a sputtering method while heating the semiconductor substrate, and the metal wiring layer is formed by the underlayer and the surface layer. To do.

[0008]

In the method of manufacturing a semiconductor device according to the present invention, first, the underlayer made of the material forming the metal wiring layer is formed by the sputtering method while cooling the semiconductor substrate. Alternatively, prevent degassing from residual moisture. Then, the surface layer sputtered while heating the semiconductor substrate is formed on the underlayer with good coverage.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A semiconductor device manufacturing method according to an embodiment of the present invention will be described in detail below with reference to the drawings.
1 is a schematic sectional view showing a method for manufacturing a semiconductor device according to an embodiment of the present invention, and FIG. 2 is a schematic sectional view showing a method for manufacturing a semiconductor device according to another embodiment of the present invention.

In the embodiment shown in FIG. 1, an interlayer insulating film layer 2 is formed on a semiconductor substrate 1, and a first metal wiring layer 4 made of aluminum is laminated thereon. The interlayer insulating film layer 4 is composed of, for example, a phosphorus-doped silicon oxide film (PSG film), although not particularly limited.

An interlayer insulating film layer 6, a planarizing film layer 8 and an interlayer insulating film layer 10 are laminated on the first metal wiring layer 4.
The interlayer insulating film layers 6 and 8 are not particularly limited, but for example, C
It is composed of a silicon oxide film or the like formed by the VD method.
Although not particularly limited, the flattening film layer 8 is composed of an SOG film (a film for applying a liquid silica-based compound for flattening). Contact holes 12 facing the first metal wiring layer 4 are formed in the insulating film layers 6 and 10 and the flattening film layer 8 by a photolithography process.

Then, the underlayer 1 is formed by sputtering aluminum, for example, on the insulating film layer 10.
4 is formed. The sputtering for forming the underlayer 14 is performed while cooling the semiconductor substrate 1.
The cooling temperature is not particularly limited, but is, for example, −150 to 0.
It is preferably about ° C. The thickness of the underlayer 14 is not particularly limited, but is about 1/4 to 1/2, preferably about 1/3 of the total thickness of the metal wiring layer 18 to be obtained. If the total thickness of the metal wiring layer to be obtained is 3000 to 4000 angstroms, the thickness of the underlayer 14 is 1000.
It is preferably about 1500 angstroms. Underlayer 1
4 is formed so as to enter the inside of the contact hole 12.

Since the substrate 1 is cooled during the sputtering for forming the underlayer 14, the degassing from the SOG remaining inside the contact hole 12 or the residual water content is avoided. It is possible to prevent the degassing of.

Next, the underlayer 14 is formed on the underlayer 14.
A surface layer 16 made of the same material as the above is formed by a sputtering method while heating the semiconductor substrate 1, and the underlayer 14 and the surface layer 1 are formed.
6 and 6 form a metal wiring layer 18. The heating temperature of the substrate 1 during sputtering for forming the surface layer 16 is
Although not particularly limited, it is about 200 to 300 ° C.
Further, the film thickness of the surface layer 16 is preferably about 1/2 to 3/4 of the total film thickness of the metal wiring layer 18, and specifically, 1000.
It is preferably about 3000 angstroms.

Since the surface layer 16 is formed by sputtering while heating the substrate 1, the surface layer 16 is formed with good coverage. In that case, the underlayer prevents degassing. Note that such two-step continuous sputtering is performed using a multi-chamber type sputtering device.

Next, another embodiment of the present invention will be described with reference to FIG. The embodiment shown in FIG. 2 is an embodiment in which the contact hole 12 is filled with the second metal wiring layer 18a to flatten the surface of the metal wiring layer 18a. Up to the formation of the underlayer 14, it is the same as the embodiment shown in FIG.
The heating temperature of the substrate 1 for forming the surface layer 16a is different.

In this embodiment, the heating temperature of the substrate 1 during the sputtering for forming the surface layer 16a is close to the melting point of aluminum forming the metal wiring layer 18a.
The temperature is set to a high temperature of about 00 to 550 ° C. By heating at such a temperature, the contact hole 12 can be uniformly filled with the metal wiring layer 18a. At that time, since the underlayer 14 is formed, degassing does not occur.

The present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention. For example, in the above-described embodiment, the case of forming the second metal wiring layer has been described, but the present invention is not limited to this, and is applicable to all cases of forming the metal wiring layer regardless of the number of layers. be able to. Further, although the underlayer 14 and the surface layers 16 and 16a in the above-described embodiment are formed by sputtering aluminum, they may be formed by sputtering metal other materials. The base layer 16 and the surface layers 16 and 16a are not necessarily made of the same material but may be made of different materials.

[0019]

As described above, according to the present invention, first, while cooling the semiconductor substrate, the underlayer made of the material forming the metal wiring layer is formed by the sputtering method. This underlayer can prevent degassing. Then, the surface layer sputtered while heating the semiconductor substrate is formed on the underlayer with good coverage. Therefore, it becomes possible to stably form a metal wiring layer that is miniaturized and multilayered.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a method for manufacturing a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a method for manufacturing a semiconductor device according to another embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view showing a method of manufacturing a semiconductor device according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 2 Interlayer insulating film layer 4 First metal wiring layer 6,10 Interlayer insulating film layer 8 Planarizing film layer 12 Contact hole 14 Underlayer 16, 16a Surface layer

Claims (1)

[Claims] 1. A contact hole formed in an interlayer insulating film layer laminated on a semiconductor substrate,
In a method of manufacturing a semiconductor device in which a metal wiring layer is laminated on an interlayer insulating film layer, an underlayer made of a material forming the metal wiring layer is formed by a sputtering method while cooling the semiconductor substrate, On the ground layer, a surface layer of a material forming the metal wiring layer is formed by a sputtering method while heating the semiconductor substrate, and a metal wiring layer is composed of the underlayer and the surface layer. Method.