JPH0249430A - Semiconductor device - Google Patents

Abstract

PURPOSE:To hold the function of the circuit of a semiconductor device by a by-pass wiring layer even if a disconnection is generated in a wiring layer by a method wherein an insulating layer is formed on the wiring layer and the by-pass wiring layer having a pattern configuration identical with that of the wiring part is formed on the insulating layer. CONSTITUTION:An SiO2 film is deposited on a second-layer wiring layer 4 and an insulating layer 11 is formed. A by-pass wiring layer 12 having a pattern configuration identical with that of the wiring layer 4 is formed on this layer 11. The wiring layers 4 and 12 are electrically connected to each other through contact holes 13 bored in the layer 11. Accordingly, even if the wiring layer 4 is cut at a stepped part 4a where a disconnection is easy to generate, an electrical signal is made to flow through the wiring layer 4, the hole 17, the wiring layer 12, the hole 13 and the wiring layer 4 and the function of a circuit of a semiconductor device is never damaged.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a semiconductor device, and particularly to a wiring structure in a semiconductor device.

(Prior Art) In a semiconductor device, after functional elements are formed, wiring is provided between these elements to electrically connect each element to obtain a desired circuit function. At this time, if wiring is performed in only a single layer, manufacturing becomes difficult because the degree of integration of the elements increases and the wiring becomes complicated, approaching the limit of thinning. Therefore, in order to reduce the area occupied by wiring as ICs become more highly integrated, multilayer wiring in which wiring is arranged in multiple layers has been used.

゛Multilayer wiring is achieved by interposing an interlayer insulating film between each element region formed in the substrate and the first layer wiring, and between the wirings, and connecting the wiring through contact holes drilled in predetermined areas. It is formed by electrically connecting wires in different layers.

That is, for example, as shown in FIG.
A first layer wiring 2 made of aluminum metal or the like is formed in a band shape in the front and back directions of the figure so as to be connected to the element isolation region 1a. An interlayer insulating film 3 is deposited on the wiring 2, a thin aluminum film is further deposited, and this is patterned by photolithography, and unlike the first layer wiring 2, it has a pattern shape that is band-shaped in the left and right direction in the figure. A second layer of wiring 4 is formed. If it is necessary to connect wiring 2 and wiring 4,
Contact holes (not shown) were formed in the interlayer insulating film 3 at desired locations to connect the two.

(Problem to be Solved by the Invention) In the multilayer wiring structure as described above, the arrangement of the first layer! 2 and the second layer wiring 4 intersect,
Since the interlayer insulating film 3 is deposited on the wiring 2 formed on the element isolation region 11a, a steep height difference is generated on the surface thereof. Therefore, a step is created in the second layer wiring 4 deposited on the interlayer insulating film 3, and as shown in FIG.
There was a problem that the wire breakage 5 was likely to occur in the wiring a4 and the semiconductor circuit function would stop.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wiring structure that can improve the reliability of a semiconductor device having a multilayer wiring structure.

(Means for Solving the Problems) In order to solve the above problems, a semiconductor device according to the present invention includes a semiconductor device in which wiring is formed on an interlayer insulating film, in which an insulating layer is formed on the wiring, and an insulating layer is formed on the insulating layer. The invention is characterized in that a bypass wiring having the same pattern shape as the wiring is formed, and the wiring and the bypass wiring are electrically connected through a contact hole drilled in the insulating layer.

(Function) According to the present invention, since the bypass wiring is formed having the same pattern shape as the wiring, even if a disconnection occurs in the wiring, the circuit function of the semiconductor will not be impaired due to the signal flowing through the bypass wiring. do not have.

(Example) An example of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional explanatory diagram of a semiconductor device having a multilayer wiring structure according to an embodiment of the present invention. The first layer wiring 2 is formed in a band shape in the front and back directions of the figure. An interlayer insulating film 3 is deposited on the wiring 2, an aluminum thin film is further deposited, and this is patterned by photolithography to form a second layer wiring 4 having a pattern shape different from that of the first layer wiring 2. has been done.

In FIG. 1, parts with the same reference numerals as in FIG. 2 have the same configuration.

A film of 5tO2 is deposited on the second wiring layer 4 to form an insulating layer 1.
1 is formed. A bypass wiring 12 having the same pattern shape as the wiring 4 is formed on this insulating layer 11. The wiring 4 and the bypass wiring 12 are electrically connected through a contact hole 13 formed in the insulating layer 11. As shown in FIG. 1, the contact hole 13 is formed in the insulating layer 11 on both sides of the steep step 4a, and connects the wiring 4 above and below the step 4a to the bypass wiring. 12 can be connected.

Next, the manufacturing process of the semiconductor device of this example will be explained.

First layer wiring 21 interlayer insulation v! on silicon substrate 1! 3
．． An insulating layer 1 is formed by depositing SiO on the entire surface of the wiring 4 of the semiconductor device as shown in FIG. 2 in which the second layer wiring 4 is sequentially formed.
form 1. A contact hole 1 is formed in a predetermined location of the insulating layer 11.
Drill 3. Contact holes 13 are formed by forming a resist pattern (not shown) having openings at predetermined locations on insulating layer 11, performing anisotropic etching, and then removing the resist pattern.

A film of aluminum is deposited on the insulating layer 11 in which the contact hole 13 is formed, and a bypass wiring 12 having the same pattern shape as the wiring 4 is formed by photolithography.

Therefore, even if the wiring 4 is cut at the stepped portion 4a where disconnection is likely to occur, the electrical signal will not be transmitted to the wiring 4. Contact hole 13. Bypass wiring 12. The contact hole 13 flows with the wiring 4, so that the circuit function is not impaired.

In this embodiment, a two-layer wiring has been described, but the present invention can also be applied to a multilayer wiring of three or more layers.

(Effects of the Invention) As described above, in the present invention, the bypass wiring having the same button shape as the wiring is connected to the wiring, so even if a disconnection occurs in the wiring, the electrical signal can bypass the bypass wiring and flow. Therefore, the circuit function of the semiconductor is not impaired, and the reliability of the semiconductor can be improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional explanatory diagram of a semiconductor device according to an embodiment of the present invention, and FIG.
The figure is an explanatory cross-sectional view of a conventional semiconductor device, and FIG. 3 is an explanatory cross-sectional view when a disconnection occurs in the same semiconductor device. ...Silicon substrate...Wiring...Interlayer insulating film...Wiring...Insulating layer...Bypass wiring...・・・Contact hole

Claims (1)

[Scope of Claims] In a semiconductor device in which wiring is formed on an interlayer insulating film, an insulating layer is formed on the wiring, a bypass wiring having the same pattern shape as the wiring is formed on the insulating layer, and the wiring is and a bypass wiring are electrically connected to each other through a contact hole drilled in the insulating layer.