JPH11204637A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily remove a spacer film formed beforehand and increase the degrees of freedom in designing by forming an aerial interconnection which has supports formed on a first and a second terminal formed on a semiconductor substrate and has through-holes in areas other than those where supports are formed. SOLUTION: This semiconductor device is constituted such that elements 2a, 2b, 2c are formed on a semiconductor substrate 2 and a first terminal (the terminal of the element 2a) and a second terminal (the terminal of the element 2b) respectively are connected by an aerial interconnection 5. In the aerial interconnection 5, a plurality of through-holes 12 are formed in areas other than those where supports 5a, 5b are formed. Due to this structure, a spacer film preliminarily formed under the aerial interconnection 5 can be removed easily via the through-holes 12. Since a plurality of through-holes 12 are formed, the dead weight of the aerial interconnection 5 is lighter than that of the conventional, thereby preventing it from being brought into contact with other elements, signal lines and the like due to its bending. Furthermore, there is no need for forming many supports an the reduction in the degrees of freedom in designing can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor device having an aerial wiring and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, semiconductor devices having aerial wiring have been developed. Since the aerial wiring has a high propagation speed of a high-frequency signal, it is used particularly as a transmission line of a high-frequency semiconductor device.

[0003]

When manufacturing a semiconductor device having such an aerial wiring, it is necessary to remove the spacer film formed below the aerial wiring after the formation of the aerial wiring. Therefore, there is a problem that it takes time to remove the spacer film when forming an aerial wiring having a large area.

[0004] In addition, large-area aerial wirings bend under their own weight and come into contact with elements or signal lines under the aerial wirings,
Poor contact may occur. To avoid this contact failure, it is necessary to provide a large number of support columns,
In this case, there is a problem that the degree of freedom in design is greatly reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a semiconductor device having an aerial wiring capable of easily removing a spacer film formed in advance and having as large a design freedom as possible, and its manufacture. The aim is to provide a method.

[0006]

A semiconductor device according to the present invention has support columns provided on first and second terminals formed on a semiconductor substrate, and a through-hole is formed in a region other than the support columns. Is provided.

It is preferable that the through holes have a hexagonal shape and are arranged in a honeycomb shape.

[0008] The aerial wiring may be composed of a multilayer metal wiring layer.

Further, the method of manufacturing a semiconductor device according to the present invention comprises a step of forming a spacer film having an opening on the first and second terminals on a semiconductor substrate on which the first and second terminals are formed. Forming a metal film on the entire surface of the substrate, forming a photoresist pattern having a columnar photoresist on the metal film, and forming metal wiring by plating using the photoresist pattern as a mask. Forming a hole in the metal wiring by removing the photoresist pattern; patterning the metal film using the metal wiring as a mask to make the opening a through hole; And removing the spacer film using the above method.

Further, the method of manufacturing a semiconductor device according to the present invention comprises the steps of: forming a spacer film having an opening on the first and second terminals on a semiconductor substrate on which the first and second terminals are formed; Filling the opening with a first metal film, forming a second metal film on the entire surface of the substrate, and forming a photoresist pattern having a columnar photoresist on the second metal film. Forming a metal wiring by plating using the photoresist pattern as a mask, forming an opening in the metal wiring by removing the photoresist pattern, and using the metal wiring as a mask. A step of patterning a second metal film to make the opening a through hole; and a step of removing the spacer film using the through hole. To.

[0011]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of the first embodiment of the semiconductor device according to the present invention. In the semiconductor device of the first embodiment, elements 2a, 2b, and 2c are formed on a semiconductor substrate 2, and terminals of the element 2a and terminals of the element 2b are connected by an aerial wiring 5. . In the drawings, the element and the terminal of the element are denoted by the same reference numerals. The aerial wiring 5 is provided with a plurality of through holes 12 in a region except for the pillar portions 5a and 5b. The aerial wiring 5 is formed so as to straddle the element 2c.

According to the semiconductor device of the first embodiment configured as described above, since the plurality of through-holes 12 are provided in the aerial wiring 5, a spacer film formed beforehand under the aerial wiring 5 ( Not shown (the photoresist pattern 4 in a second embodiment described later) can be easily removed through the through hole 12.

Further, since the plurality of through holes 12 are provided, the own weight of the aerial wiring 5 itself is reduced as compared with the conventional case, and it is prevented from contacting with other elements or signal lines due to bending. can do. Furthermore, by reducing the weight of its own, there is no need to provide many support columns,
It is possible to prevent the degree of freedom of design from being reduced as much as possible.

In the first embodiment, the provision of the through holes 12 reduces the area through which the current flowing through the aerial wiring 5 passes, thereby increasing the electric resistance. However, since the high-frequency current flows through the surface of the wiring 5, as shown in FIG.
By increasing the film thickness d ₂ of the aerial line 5 than _1, the surface area of the aerial wiring 5, no aerial wire through holes it is possible to increase than the surface area of the (see FIG. 4 (b)), the high-frequency Can be reduced as compared with the case where the through hole 12 is not provided.

The through holes 12 provided in the aerial wiring 5
Is formed in a honeycomb shape as shown in FIG. 2, the strength of the aerial wiring 5 is higher than in the case where the shape of the through-hole 12 is another shape.

The aerial wiring 5 of the first embodiment is:
You may comprise so that it may consist of a multilayer wiring layer.

In the first embodiment, the aerial wiring 5 connects the element 2a and the element 2b. However, the aerial wiring 5 may connect the element and a signal line.
A signal line may be connected to another signal line.

When the aerial wiring 5 is L-shaped as shown in FIG. 3, it is preferable to provide a through hole 12 at a corner.

Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment relates to a method of manufacturing a semiconductor device, and FIG.

First, a photoresist having a thickness of 2.5 μm is applied on the semiconductor substrate 2 on which the elements 2a, 2b, 2c are formed, and then patterned to pattern the elements 2a, 2b.
A photoresist pattern (also referred to as a spacer film) 4 having openings 4a and 4b is formed on the terminal (FIG. 5A).
reference). In the drawings, elements and their terminals are denoted by the same reference numerals. Thereafter, the corners of the photoresist pattern 4 are rounded by heat treatment. This is to prevent disconnection of the Au film 6 serving as a base electrode in an electrolytic plating method described later.

Next, an Au film 6 having a thickness of, for example, 0.5 μm is deposited on the entire surface of the substrate by using an electron beam evaporation method (see FIG. 5B). Subsequently, a photoresist is applied to the entire surface of the substrate, and then patterned to form a photoresist pattern 8 having a plurality of columnar photoresists (see FIG. 5B).

Next, a wiring layer 10 made of an Au film having a thickness of 3 μm is formed by an electrolytic plating method using the photoresist pattern 8 as a mask and using the Au film 6 as a base electrode.
The photoresist pattern is removed (see FIG. 5C). As a result, an opening 11 is formed in the trace of the photoresist pattern 8 of the wiring layer 10 (see FIG. 5C).

Next, the Au film 6 is processed by ion milling using the wiring layer 10 as a mask, so that the opening 11 is formed.
Is formed in the through hole 12 (see FIG. 5D). At this time, the Au film 6 has the same contour as the wiring layer 10. Subsequently, the resist pattern 4 is ashed by the asher method, and the through holes 12 are formed.
And so on. As a result, a semiconductor device including the aerial wiring 5 having the plurality of through holes 12 is completed (FIG. 5).
(D)).

It goes without saying that the semiconductor device manufactured by the manufacturing method of the second embodiment also has the same effect as that of the first embodiment.

In the second embodiment, if the columnar photoresist is arranged in a honeycomb pattern as a columnar pattern having a hexagonal cross section, the formed aerial wiring 5 can be formed.
Can be configured to be arranged in a honeycomb shape.

Next, a third embodiment of the present invention will be described with reference to FIG. The third embodiment relates to a method of manufacturing a semiconductor device, and FIG. 6 is a sectional view showing the manufacturing process.

First, a W film 22 having a thickness of 150 nm is formed on the semiconductor substrate 2 on which the elements 2a, 2b and 2c are formed (see FIG. 6A). In the drawings, elements and their terminals are denoted by the same reference numerals. Subsequently, a film thickness of 2.5 is formed on the W film 22.
A photoresist pattern 24 (also referred to as a spacer film) having openings on the terminals of the elements 2a and 2b is formed by patterning after forming a μm photoresist film (see FIG. 6A). Using this photoresist pattern 24 as a mask, a film thickness of 2 μm is formed on the elements 2a and 2b.
The m Au films 26a and 26b are formed by plating (see FIG. 6A). Thereafter, the corners of the photoresist pattern 24 are rounded by performing a heat treatment. this is,
This is to prevent disconnection of the Ti film 28 and the W film 30 which serve as base electrodes in the electrolytic plating method described later.

Next, a film thickness of, for example, 50
nm Ti film 28 and 150 nm thick W film 30
Are sequentially formed on the entire surface of the substrate (see FIG. 6B). Subsequently, a photoresist is applied on the W film 30 and then patterned to form a photoresist pattern 32 having a plurality of columnar photoresists (FIG. 6B).
reference).

Next, using a photoresist pattern 32 as a mask, a wiring layer 34 made of an Au film having a thickness of, for example, 3 μm is formed by an electrolytic plating method using the W film 30 and the Ti film 28 as underlying electrodes. Photoresist pattern 3
2 is removed using an organic solvent (see FIG. 6C). As a result, an opening 35 is formed in the trace of the photoresist pattern 32 of the wiring layer 34 (see FIG. 6C).

Next, using the wiring layer 34 as a mask, RIE (Re
W film 30 and Ti film 2 using active ion etching)
8 is patterned to make the opening 35 a through hole 36.
(See FIG. 6D). At this time, the outlines of the W film 30 and the Ti film 28 become the same as the wiring layer 34. Subsequently, the resist pattern 24 is ashed using an asher method, and removed through the through holes 36 and the like. After that, CDE (Chemic
al Dry Etching) to remove the W film 22. At this time, the W film 22 is etched, but the Ti film 28 is not etched, so that the W film 30 on the Ti film 28 remains without being etched, thereby reinforcing the strength of the wiring layer 34. Thus, a semiconductor device including the aerial wiring 33 having the plurality of through holes 36 is completed (see FIG. 6D).

It goes without saying that the manufacturing method of the third embodiment also has the same effect as that of the second embodiment.

In the third embodiment, if the columnar photoresist is arranged in a honeycomb shape as a columnar pattern having a hexagonal cross section, the formed aerial wiring 33 is formed.
Of the through holes 36 may be arranged in a honeycomb shape.

The bridge connection distance between the case where the semiconductor device is manufactured using the manufacturing method of the second or third embodiment and the case where the semiconductor device is manufactured without providing a through hole in the aerial wiring as in the related art. FIG. 7 shows the manufacturing yield of the semiconductor device with respect to (μm). Here, the bridge connection distance is defined as the distance between the element 2a and the element 2b connected by aerial wiring in FIG. 5 or FIG.

As can be seen from FIG. 7, when the through hole is provided in the aerial wiring, that is, the manufacturing method of the second or third embodiment has a longer bridge connection distance than the conventional manufacturing method. Yields have not dropped much.

As a result, the production yield of the semiconductor device can be increased as compared with the conventional case, and the production cost can be reduced.

Further, since the through holes are provided, the time for removing the resist under the aerial wiring can be greatly reduced, and the manufacturing cost can be reduced.

[0037]

As described above, according to the present invention, the spacer film formed under the aerial wiring can be easily removed, and the degree of design freedom can be increased as much as possible. Can be.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the configuration of a first embodiment of the present invention.

FIG. 2 is a top view of a modified example of the first embodiment.

FIG. 3 is a top view showing another modification of the first embodiment.

FIG. 4 is an explanatory diagram illustrating an effect of the present invention.

FIG. 5 is a sectional view showing a manufacturing process of a semiconductor device manufactured by the manufacturing method according to the second embodiment of the present invention;

FIG. 6 is a sectional view showing a manufacturing process of a semiconductor device manufactured by the manufacturing method according to the third embodiment of the present invention.

FIG. 7 is a graph illustrating the effect of the manufacturing method of the present invention.

[Explanation of symbols]

 Reference Signs List 2 semiconductor substrate 2a, 2b, 2c element 4 photoresist pattern (spacer film) 4a, 4b opening 5 aerial wiring 6 Au film 8 photoresist pattern 10 Au film 11 opening 12 through hole 22 W film 24 photoresist pattern 26a, 26b Au Film 28 Ti film 30 W film 32 photoresist pattern 34 Au film 35 opening 36 through hole

Claims (5)

[Claims] 1. A semiconductor device comprising a support pillar provided on a first and a second terminal formed on a semiconductor substrate, and an aerial wiring provided with a through hole in a region other than the support pillar. A semiconductor device characterized by the above-mentioned. 2. The semiconductor device according to claim 1, wherein said through holes have a hexagonal shape and are arranged in a honeycomb pattern. 3. The semiconductor device according to claim 1, wherein said air wiring comprises a multilayer metal wiring layer. 4. A step of forming a spacer film having openings on the first and second terminals on the semiconductor substrate on which the first and second terminals are formed, and forming a metal film on the entire surface of the substrate. A step of forming a photoresist pattern having a columnar photoresist on the metal film; a step of forming a metal wiring by a plating method using the photoresist pattern as a mask; and removing the photoresist pattern. Forming an opening in the metal wiring, patterning the metal film using the metal wiring as a mask, making the opening a through-hole, and removing the spacer film using the through-hole. A method for manufacturing a semiconductor device, comprising: 5. A step of forming a spacer film having an opening on the first and second terminals on a semiconductor substrate on which the first and second terminals are formed; Embedding with a film; forming a second metal film on the entire surface of the substrate; forming a photoresist pattern having a columnar photoresist on the second metal film; masking the photoresist pattern Forming a metal wiring by plating, forming an opening in the metal wiring by removing the photoresist pattern, and patterning the second metal film using the metal wiring as a mask. A method of making the opening a through hole, and a step of removing the spacer film using the through hole.