JPH04162652A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent generation of let-go of an upper part conductive layer by setting a ratio a/b between a length a in longer side direction of a contact hole which is provided for electrically connecting the upper part conductive layer and a lower part conductive layer and length b in short side direction to 0<a/b<3. CONSTITUTION:An upper part conductive layer 4b and a lower part conductive layer 3b of a contact region are connected at a part of three square-shaped contact holes 1. No contact hole with a ratio a/b between a length a in longer side direction of the contact hole and a length b in shorter side direction exceeding 3 is owned. Also, when increasing a contact area between the upper part conductive layer and the lower part conductive layer, the contact hole is divided and a plurality of contacts with a/b<3 are provided at a same contact region, thus preventing let-go of the upper part conductive layer from occurring easily even if a force in a direction which is vertical to the longer side direction of the contact hole is applied from side direction and enabling yield of a semiconductor device to be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device, and particularly to the shape of a contact hole provided for electrically connecting a lower conductive layer and an upper conductive layer.

[Conventional technology]

In the conventional semiconductor device, FIG. 4(a).

As shown in (b), since no special consideration has been given to the ratio a/b between the length a in the long side direction of the contact hole and the length b in the short side direction, the contact hole with a large value is It existed. However, when a force F is applied to the upper conductive layer 4b of the contact region having such a shape as shown in FIG. In severe cases, the upper conductive layer may be completely peeled off.

[Problem to be solved by the invention]

In the conventional semiconductor device described above, the ratio of the length a in the long side direction of the contact hole to the length b in the short side direction is a / b
If a force in the direction perpendicular to the long side of the contact hole is applied from the side to the upper conductive layer where there is a large contact hole, the upper conductive layer will be deformed, and in severe cases, the upper conductive layer will be deformed. There was a problem in that the layers peeled off.

[Means to solve the problem]

The semiconductor device of the present invention does not have a contact hole in which the ratio a/b of the length a in the long side direction and the length b in the short side direction of the contact hole is greater than 3. In addition, when increasing the contact area between the upper conductive layer and the lower conductive layer, the contact hole is divided so that a/b <
In this method, a plurality of contacts of 3 are provided in the same contact area.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1(a) is a plan view showing a first embodiment of the present invention, and FIG. 1(b) is a sectional view taken along the line A--A in FIG. 1(a).

The upper conductive layer 4b and the lower conductive layer 3b in the contact region are connected through a portion of three square contact holes.

FIG. 2 is a diagram showing the correlation between the peeling probability $P of the upper conductive layer and the shape (a/b) of the contact hole.

However, this is a characteristic diagram in which the upper conductive layer is an A1 film with a thickness of 1 μm, and a silicon oxynitride film with a thickness of 1.1 μm is provided as a cover insulating film. 0kua/b<3
At this time, the peeling probability P becomes almost 0.

FIG. 3(a) is a plan view showing a second embodiment of the present invention, and FIG. 3(b) is a sectional view taken along the line B--B in FIG. 3(a).

The difference from the first embodiment is that the contact hole has an elliptical shape. If the shape of the contact hole is circular or oval rather than square or rectangular, the probability that the upper conductive layer will peel off is further reduced.

〔Effect of the invention〕

As explained above, in the semiconductor device of the present invention, the ratio a of the length a in the long side direction of the contact hole to the length b in the short side direction is
By not providing a contact hole with / b greater than 3, by not providing a contact hole in the upper conductive layer, the upper conductive layer can be maintained even if a force in a direction perpendicular to the long side of the contact hole is applied from the side to the upper conductive layer. This has the effect that layer peeling is less likely to occur and the yield of semiconductor devices is improved.

[Brief explanation of the drawing]

FIG. 1(a) is a plan view showing the first embodiment of the present invention, FIG. 1(b) is a sectional view taken along line A-A in FIG. 1(a), and FIG. 2 is a peeling of the upper conductive layer. Probability P and contact hole shape a
Figure 3 (a) is a plan view showing the second embodiment, Figure 3 (b) is a diagram showing the correlation between
-B sectional view, FIG. 4(a) is a plan view showing the conventional example, FIG. 4(b) is a C-C sectional view of FIG. 4(a), and FIG. 5 is peeling of the upper conductive layer. It is a sectional view showing a state. 1... Contact hole, 2... Interlayer insulating film, 3a
... lower conductive layer (wiring region), 3b ... lower conductive layer, 4a ... upper conductive layer (wiring region), 4b ... upper conductive layer (contact region), 5. one substrate.

Claims (1)

[Claims] 1. In a contact hole provided for electrically connecting an upper conductive layer and a lower conductive layer of a semiconductor device,
A semiconductor device characterized in that a ratio a/b of the length a in the long side direction and the length b in the short side direction of the contact hole satisfies 0<a/b<3 for all the contact holes. 2. The semiconductor device according to claim 1, wherein a plurality of contact holes where 2,0<a/b<3 are provided in the same contact region.