JPH039524A - Semiconductor device - Google Patents

Abstract

PURPOSE:To improve unstability existing in a contact part between different kind of materials by constituting contact connection at the contact part of multilayer wirings by using the same kind of materials. CONSTITUTION:A first conductor layer 2 constituted of multilayer formed on a substrate 1, and a second conductor layer 3 constituted of multilayer formed via an insulating film 3 are provided. At the connection part of the conductor layer 2 and the conductor layer 4, said layers are connected by using the same kind of materials 2A, 4A. As a result, the contact can be formed by not different kind of materials but the same kind of materials. Thereby, the movement of impurity and the discontinuity of interface can be improved, and reliability is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to contact with a conductor layer having a stacked structure in a semiconductor device.

The purpose is to improve problems such as impurities moving through contacts between different materials, and contact resistance becoming high and fluctuating due to discontinuous interfaces.

It has a first conductor layer formed on a substrate and made of a single layer or a multilayer, and a second conductor layer made of a single layer or a multilayer with an insulating film interposed between the first conductor layer and the first conductor layer. At the connection portion between the two conductor layers, the first conductor layer and the second conductor layer are connected by the same kind of material.

[Industrial application field]

The present invention relates to a contact with a conductor layer having a stacked structure in a semiconductor device.

In recent years, as semiconductor devices have become more highly integrated and faster, a laminated structure has been used for conductor layers forming two interconnections, but when making contact with the upper conductor layer, there are cases where contact is made between different materials. was unstable.

[Conventional technology]

FIG. 3 is an explanatory diagram showing a conventional example.

In the figure, 13 is the substrate, 14 is the first conductor layer, 15
16 is an insulating film, 16 is a second conductor layer, 17 is a substrate, 18
is a first conductor layer, 19 is an insulating film, and 20 is a second conductor layer.

As shown in FIG. 3(a).

An insulating film 15 is formed on a first conductor layer 14 having a laminated structure formed on a substrate 13 .

Next, the insulating film 15 in the area to be contacted is removed by etching, and then the second conductive layer 16 is formed.

Here, the lower layer part 14A of the first conductor layer 14 is made of the same material as the second conductor layer 16, and the upper layer part 14B of the first conductor layer 14 is made of the same material as the second conductor layer 16.
is made of a material different from that of the second conductor layer 16.

In this case, the upper layer portion 14B of the first conductor layer 14 and the second conductor layer 16 are in contact, resulting in contact between different materials.

Also, as shown in FIG. 3(b).

An insulating film 1 is formed on the first conductor layer 18 formed on the substrate 17.
form 9.

Next, the insulating film 19 in the area to be contacted is removed by etching, and then the second conductor layer 20 is formed.

Here, the upper layer part 20B of the second conductor layer 20 is made of the same material as the first conductor layer 18, and the lower layer part 20A of the second conductor layer 20 is made of the same material as the first conductor layer 18.
is made of a material different from that of the first conductor layer 18.

In this case, since the first conductor layer 18 and the lower layer portion 2OA of the second conductor layer 20 are in contact with each other, this also results in contact between different materials.

[Problems to be Solved by the Invention] Therefore, the resistance of the contact 1 may become high due to the influence of impurities moving through the contact between different materials or discontinuity of the interface.

This caused problems such as variations.

The present invention aims to improve the above-mentioned problems.

[Means to solve the problem]

FIG. 1 is a diagram explaining the principle of the present invention.

In the figure, 1 is a substrate, 2 is a first conductor layer, 3 is an insulating film, and 4 is a second conductor layer.

As shown in FIG. 1, the present invention includes a first conductor layer 2 formed on a substrate l, which is a single layer or a multilayer, and a second conductor layer 2, which is a single layer or a multilayer, with an insulating film 3 interposed therebetween. 4, and at the connection portion between the first conductor layer 2 and the second conductor layer 4, the first
The conductor layer 2 and the second conductor N4 are connected by the same kind of material.

[Effect]

In the present invention, as shown in FIG. 1, contact connections can be made using the same type of material in the contact portions of multilayer wiring.

Therefore, the instability found in contacts between dissimilar materials is eliminated.

(Example〕 FIG. 2 is a schematic cross-sectional view of an embodiment of the present invention in the order of steps.

In the figure, 5 is a Si substrate, 6 is a poly-Si film, and 7 is a WS
ix film, 8 is a resist, 9 is a SiO□ film, 10 is a resist, 11 is a poly-Si film, and 12 is a -5i2 film.

As shown in FIG. 2(a).

Sila 7 (Sit14) is formed on the Si substrate 5 by CVD method.
Gas flow 150cc/11in, vacuum degree 0.2Torr
, the poly-Si film 6 was heated at 2,0°C under the reaction temperature of 625°C.
Formed to a thickness of 0.00 people.

Subsequently, SiH4 gas flow rate 1,000cc/min,
WFi gas flow it 8cc/min, vacuum degree QJTo
WSi2 film 7 is laminated to a thickness of 2,000 wafers under conditions of rr and reaction temperature of 360°C.

As shown in FIG. 2(b).

The resist 8 is patterned, and using the resist 8 as a mask, the -Si2 film 7 is patterned to a size wider than the contact hole.
Open by etching.

This means that the sides of the contact hole are also made of a different material (WSi*).
This is to prevent the film 7) from being exposed.

Furthermore, a resist (not shown) is patterned, and using the resist as a mask, the WSi2 film 7 and the poly-Si film 6 are patterned to form a lower wiring pattern.

As shown in FIG. 2(c), a film 9 of Sin was formed by the CVO method at a reaction temperature of 800°C.

Coat to a thickness of 4.000 people.

As shown in FIG. 2(d).

The resist 10 is patterned, and a contact hole is opened in the SiO□ film 9 by etching using the resist 10 as a mask.

As shown in FIG. 2(e), a poly-Si film 11 was formed on the SiO□ film 9 and the contact hole by the CVO method under the conditions of a 51g4 gas flow ff150cc/min, a degree of vacuum of 0.2 Torr, and a reaction temperature of 625°C. Formed to a thickness of 2.000 people, followed by
SiH4 gas flow rate L, 000cc/min, WF
a gas flow! J, 8cc/min, degree of vacuum Q, 2 Tor
r.

Under the condition of reaction temperature 360°C, 2.0
Formed by laminating to a thickness of 0.00 people.

As a result, in the contact hole, the upper layer polyS
The i film II and the underlying poly S4 film 6 are in direct contact.

Then, a resist (not shown) is patterned, and the WSiz film 12 and the poly-Si film 11 are patterned using the resist as a mask to form an upper layer wiring pattern.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to make contact not between different materials, but between materials of the same type, which improves the movement of impurities and discontinuities at the interface, improving the reliability of the contact. It greatly contributes to improvement.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the principle of the present invention. FIG. 2 is a schematic cross-sectional view of an embodiment of the present invention in the order of steps. FIG. 3 is an explanatory diagram of a conventional example. In fig. 1 is the board. 3 is an insulating film. 5 is a Si substrate. 7 is -3i2 membrane. 9 is a SiO□ film. 11 is a poly-Si film. 2 is the first conductor layer 4 is the second conductor layer 6 is a poly-Si film. 8 is resist 10 is resist 12 is WSi2 film 7! , Understanding the principles of invention Z jth threshold Toki 2z

Claims (1)

[Claims] A first layer consisting of a single layer or multiple layers formed on a substrate (1).
a conductor layer (2), and a second conductor layer (4) consisting of a single layer or multiple layers, with an insulating film (3) interposed between the first conductor layer (2) and the second conductor layer (4). At the connection part of the conductor layer (4),
A semiconductor device characterized in that the first conductor layer (2) and the second conductor layer (4) are connected by the same kind of material.