JPH0584666B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a semiconductor device and a method for manufacturing the same, and particularly to improvements in multilayer wiring technology thereof.

[Conventional technology]

FIG. 4 is a sectional view showing, for example, a conventional semiconductor device, and FIG. 5 is a diagram showing its manufacturing flow. In the figure, 1 is a silicon (Si) substrate, 2 is an impurity diffusion layer formed on the silicon substrate 1,
3 is a base insulating film formed on the silicon substrate 1;
Reference numeral 4 designates a first layer of aluminum wiring connected to the impurity diffusion layer 2, and reference numeral 5 designates an interlayer insulating film that covers the aluminum wiring 4. Reference numeral 6 denotes a second layer of aluminum wiring, which is connected to the first layer of aluminum wiring 4 through a through hole, which is an opening in the interlayer insulating film 5 .

Next, the manufacturing method will be explained.

First, as shown in Figure 5, silicon (Si)
An impurity diffusion layer 2 is formed on a substrate 1 using photolithography, ion implantation, or the like. Next, a base insulating film 3 for protecting the Si interface is deposited, and a contact hole is formed in the base insulating film 3 on the impurity diffusion layer 2 for electrical contact with the outside. Thereafter, a first layer aluminum wiring 4 is formed in the contact hole and on the base insulating film 3, and patterned.

Next, as shown in FIG. 5, an interlayer insulating film 5 is deposited over the entire surface of the base insulating film 3 and the aluminum wiring 4. Then, as shown in FIG. Next, as shown in FIG.
Next, a through hole for making electrical contact with the first layer aluminum wiring 4 is made using photolithography.

Next, as shown in FIG. 5, an aluminum film is deposited on the entire surface of the through hole and interlayer insulating film 5 by sputtering, and patterned using photolithography to form a second layer aluminum wiring 6.

[Problem to be solved by the invention]

Conventional semiconductor devices are manufactured using the process described above, so as through holes become smaller and the aspect ratio (ratio of contact hole depth to contact diameter) increases, aluminum is Particles cannot penetrate deep into the through-hole, and the step coverage of the second layer aluminum wiring at the steep through-hole step becomes insufficient.Therefore, the wiring current density at the through-hole step increases rapidly. There were problems that caused electromigration.

This invention was made to solve the above problems, and has good step coverage.
The objective is to obtain a highly reliable semiconductor device that does not cause electromigration.

[Means to solve the problem]

A semiconductor device and a method for manufacturing the same according to the present invention include providing a metal other than aluminum, silicide, or a semiconductor in a through hole forming portion of a multilayer wiring, and then forming an interlayer insulating film made of aluminum hydrated oxide around the through hole. It is something.

[Effect]

In this invention, a metal other than aluminum, silicide, or semiconductor is provided in the through hole forming part, and then an interlayer insulating film made of aluminum hydrated oxide is formed around the through hole. A multilayer interconnect with a completely buried structure can be formed.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a semiconductor device according to an embodiment of the present invention, and FIG. 3 is a diagram showing its manufacturing flow. In the figure, the same reference numerals as those in FIGS. 4 and 5 indicate the same or corresponding parts, and 7 is a silicide layer in a through-hole forming part, and 8 is an aluminum hydrated oxide layer serving as an interlayer insulating film.

Next, the manufacturing method of this embodiment will be explained using the manufacturing flow shown in FIG.

The process up to the formation of the first layer aluminum wiring 4 is the same as that of the conventional semiconductor device, and will be omitted (FIG. 3).

Next, a silicide layer 7 is deposited over the entire surface by sputtering, and is removed by etching except for the through-hole forming portion using photolithography (FIG. 3).

Next, after sputter etching the entire surface, the surface is treated in heated pure water or water vapor at 40°C or higher, so that aluminum water is applied to the first layer aluminum wiring 4 and the base insulating film 3 using the silicide layer 7 as a mask. A layer 8 of oxidized oxide is selectively formed (FIG. 3).

Next, an aluminum film is deposited over the entire surface by sputtering and patterned by photolithography to form the second layer aluminum wiring 6 (FIG. 3).

As described above, according to this embodiment, the silicide layer 7 is formed in the through-hole formation portion on the first layer of aluminum wiring 4, and then the aluminum hydrated oxide layer 8 is formed around the through-hole, and then the second layer is formed. Since the aluminum wiring 6 is formed in a low temperature range, it is possible to obtain a structure in which the inside of the through hole is completely buried by processing in a low temperature region, which improves the step coverage of the wiring in the through hole. A semiconductor device that does not cause electromigration or the like can be obtained.

FIG. 2 is a cross-sectional view of a semiconductor device according to another embodiment of the present invention. In the figure, the same reference numerals as in FIG. It is an insulating film.

In the above-mentioned embodiment, only the aluminum hydrated oxide layer 8 was used as the interlayer insulating film, but if the insulation strength is weak when only the aluminum hydrated oxide layer 8 is used, the method shown in FIG. As shown in
It may also have a two-layer structure with an insulating film 9 formed by SOG (Spin On Glass) or CVD method.

In addition, in the above embodiment, the silicide layer 7 was used in the through-hole forming portion, but this may be made of conductive metals other than aluminum such as titanium (Ti), tungsten (W), or chromium (Cr), or silicon (Si). ) etc. may be used.

〔Effect of the invention〕

As described above, according to the semiconductor device and the manufacturing method thereof according to the present invention, a layer of a conductive metal other than aluminum, silicide, or semiconductor is provided in the through hole forming portion, and then a layer of a conductive metal other than aluminum, silicide, or a semiconductor is provided around the through hole as an interlayer insulating film. Since the aluminum hydrated oxide layer is grown selectively, the through-hole can be completely filled, and the second layer of the through-hole can be completely filled.
Wiring coverage is improved, and electro-
This has the effect of making it possible to obtain a highly reliable semiconductor device that does not cause migration or the like.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a semiconductor device according to an embodiment of the present invention, FIG. 2 is a sectional view showing a semiconductor device according to another embodiment of the invention, and FIG. 3 is a fabrication of the semiconductor device shown in FIG. 1. 4 is a sectional view showing a conventional semiconductor device, and FIG. 5 is a diagram showing a manufacturing flow of the semiconductor device of FIG. 4. In the figure, 1 is a silicon (Si) substrate, 2 is an impurity diffusion layer, 3 is a base insulating film, 4 is a first layer aluminum wiring, 6 is a second layer aluminum wiring, 7 is a silicide layer, and 8 is an aluminum hydrated oxide. layer,
9 is an insulating film. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A first wiring and a second wiring are separated by an interlayer insulating film, and the first wiring and the second wiring are connected through a through hole opened in the interlayer insulating film. A semiconductor device characterized in that the inside of the through hole is filled with a metal other than aluminum, silicide, or a semiconductor, and a part or all of the interlayer insulating film is made of aluminum hydrated oxide. 2 A step of providing a layer of a conductive metal other than aluminum, silicide, or semiconductor in the through-hole formation area on the first wiring, and an aluminum hydrated oxide layer in the interlayer insulating film formation area around the through-hole. A method for manufacturing a semiconductor device, comprising the steps of: forming the semiconductor device by adding water; and forming the second wiring so as to be connected to the through-hole portion.