JPH06188321A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To completely prevent a problem that Al is ionized and flows out into a liquid and that a wiring defect is caused when an Al interconnection is formed on an Si substrate, it is ashed and cleaned. CONSTITUTION:A contact hole is opened in an insulating layer on a substrate, tungsten 2 is filled into the contact hole, a polisilicon pad 3 is formed on its surface, a first-layer interconnection 4 is then formed independently of the substrate, an interlayer film 6 is deposited, a via hole 5j is opened in it, and a second-layer interconnection 7 is coupled to the substrate and to the first-layer interconnection 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and its manufacturing method.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, ashing is performed when a photoresist is removed after etching, and the ashing residue is washed with an amine-based organic cleaning agent. When forming the Al wiring on the substrate, the Si substrate and the Al wiring form an electric circuit in the cleaning liquid in the steps of the amine-based organic cleaning and the pure water cleaning, and Al is ionized and flows out into the liquid.

This phenomenon may be accelerated by the influence of light, etc., and Al may be rapidly eluted to cause defects in Al at the Al wiring portion and at the bottom of the via contact hole. In this case, disconnection of the first-layer wiring portion occurs, and when the second interlayer film is sputtered, the interlayer film does not easily enter the contact hole.
A disconnection occurs between the first layer and the second layer.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to prevent the wiring material from being lost in the cleaning process and to securely connect the wiring. That is, it is an object to prevent wiring open defects due to organic cleaning after Al wiring formation and via open defects due to organic cleaning after via hole etching.

[0005]

According to the present invention, a first wiring formed on a substrate independently of a substrate is provided with a second wiring located above the first wiring and coupled to the substrate. The semiconductor device is characterized by being connected. Such a semiconductor device has a contact hole opened in an insulating layer on a substrate,
A conductive metal is buried in this contact hole, a pad is formed on the upper surface of the contact hole, then a wiring of the first layer is formed independently of the substrate, an interlayer film is deposited, a via hole is opened in this, and a second layer of the second layer is formed. It can be manufactured by combining the wiring with the wiring of the substrate and the first layer.

[0006]

The Al wiring of the first layer and the Si substrate are normally connected via a contact hole, but they are not connected in the present invention. Then, an interlayer film is formed, a via hole is opened in this, and then the Al wiring of the second layer is connected to the substrate. Since the first-layer wiring is not connected to the Si substrate, the first-layer wiring and Si
No electric circuit is formed between the substrates via the solution. As a result, no Al elution (corrosion) occurs in the Al wiring due to the organic cleaning after the Al etching and the via hole portion due to the organic cleaning after the via etching, and the wiring open defect can be prevented.

The semiconductor device manufactured in this manner is
It is an excellent semiconductor device having a special wiring structure and having no broken state of Al wiring.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the manufacturing process of a semiconductor device of the present invention will be described with reference to FIG. (A) A contact hole is opened, and a conductive metal such as tungsten 2 is embedded in this contact hole. Further, a pad 3 is formed on the tungsten 2 by using, for example, polysilicon. (B) The first layer wiring 4 is formed. At this time, the first-layer wiring 4 is formed on the insulating coating without being connected to the substrate. (C) After depositing the second interlayer film 6, the via hole 5 is opened. (D) The second layer wiring 7 is formed.

When the wiring is formed in this manner, since the first layer wiring 4 is not connected to the Si substrate in the cleaning process, Al does not leach into the cleaning liquid and a sound wiring can be formed. . FIG. 2 is a plan view of an essential part of the semiconductor device of the present invention manufactured as described above. The first wiring (first layer wiring) 4 is formed independently of the substrate.
The second wiring (second layer wiring) 7 is connected to the substrate via the tungsten 2, the polysilicon pad 3, and the via hole 5. Then, the first wiring 4 is coupled to the second wiring 7. Such a semiconductor device has no wiring open defect.

[0010]

EFFECTS OF THE INVENTION When an Al wiring is formed on a Si substrate and washed after ashing, Al is ionized and flows out into the liquid, causing a wiring defect. The present invention completely prevents this. It became possible to do.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram of an example.

FIG. 2 is a plan view of the embodiment.

[Explanation of symbols]

1 Gate 2 Tungsten 3 Pad 4 First Layer Wiring 5 Via Hole 6 Second Interlayer Film 7 Second Layer Wiring

Claims (2)

[Claims] 1. A semiconductor characterized in that a second wiring, which is located above the first wiring and is coupled to the substrate, is connected to a first wiring formed on the substrate independently of the substrate. apparatus. 2. A contact hole is opened in an insulating layer on a substrate, a conductive metal is buried in the contact hole, a pad is formed on the upper surface of the contact hole, and a wiring for the first layer is formed independently of the substrate. Deposit a film, open a via hole in it,
A method of manufacturing a semiconductor device, characterized in that the wiring of the second layer is combined with the wiring of the substrate and the wiring of the first layer.