JPH0244719A - Structure of copper wiring, manufacture thereof and device for manufacturing same - Google Patents

Abstract

PURPOSE:To suppress reaction of Si or polysilicon with Cu or Cu alloy and to further improve the adhesive properties of a Cu film to an SiO2 film or an interlayer insulating film by interposing transition metal as the base of copper wiring. CONSTITUTION:Metal for suppressing reaction of Si 4 with Cu 1 and enhancing the adhering strength of Cu 1 to an SiO2 film 3 such as Mo2 is interposed on an Si substrate 4 formed with bipolar emitter 5, base 6, collector 7, and Cu-wired. That is, the electrode leads of the emitter 5, base 6, collector 7 of a bipolar element are opened, and covered with the Mo 2. Thereafter, it is covered with the Cu 1 in the same device without oxidizing the Mo 2, both are patterned, and annealed to ohmically connect the bipolar electrode lead to the Cu wiring. Thus, the Mo 2 interposed between the Si 4 and the Cu 1 suppresses the reaction of both and mutual diffusion and enhances the adhering strength of the film 3 to the Cu 1.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the structure, manufacturing method, and manufacturing equipment of copper interconnects, and in particular suppresses reactions in contact areas of semiconductor devices and improves the reliability of copper interconnects. It is something.

[Conventional technology]

A conventional device is a device in which a metal wire is wire-bonded to an electrode pad portion of a wiring made of an aluminum film on a semiconductor element for sealing, as described in JP-A-62-120037. A structure has been proposed in which copper (Cu) or a Cu alloy is coated thereon with a metal silicide layer interposed therebetween. It has been proposed that this structure prevents the diffusion of both the aluminum film and Cu and improves the wire bonding properties of the Cu wire.

[Problem to be solved by the invention]

The above conventional technology is a technology for forming wire bonding, and the temperature applied after that is 200% in reliability tests.
The temperature is low, below .degree. C., at which no reaction occurs between Si and Cu in the silicide.

The present invention is an essential technology when applying Cu instead of poly-Si or An wiring and when annealing at 300° C. to 600° C. is required to make ohmic contact with electrodes of MOS or bipolar elements. An object of the present invention is to suppress the reaction between Si or poly-Si and Cu or Cu alloy when wiring is formed using Cu or Cu alloy, and to suppress the reaction between Si or poly-Si and Cu or Cu alloy.
A structure that increases the adhesion between the u film and the S i 02 film or interlayer insulating film.

Our objective is to provide manufacturing methods and manufacturing equipment.

[Means to solve the problem]

The feature of the present invention that achieves the above object is that Si or polySi
This is achieved by depositing a transition metal between Cu and Cu or a Cu alloy to a thickness that can suppress the reaction between the two.

Another feature of the present invention is that, in order to manufacture the above structure, a manufacturing method and apparatus are proposed in which copper wiring is continuously deposited on the above transition metal.

Further features of the invention will become apparent from the description below.

[Effect]

The metal interposed between Si or poly-Si and Cu or Cu alloy acts to stop the diffusion of Si into Cu and the diffusion of Cu into Si or poly-Si. This suppresses the reaction in the contact area, and since the intervening metal does not react with both Si and Cu, the substrate Si
It does not cause deterioration of elements formed in the same way. Moreover, since the intervening metal can also improve the adhesion between Cu and the insulating film, peeling of the Cu film can be prevented.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1st
The figure shows 81 substrate 4 with bipolar, emitter 5, base 6,
This is a cross-sectional view in which Cu wiring is formed on a Si substrate 4 on which a collector 7 is formed, with a metal such as Mo2 interposed therein to suppress the reaction between Si4 and Cu and to increase the adhesive strength between Cu1 and Si02 film 3.

Emitter of bipolar element 5. The electrode extension portions of the base 6 and the collector are opened, and M o 2 is deposited on, for example, 500 people using, for example, a sputtering device. Then M
For example, deposit 5,000 Cul in the same apparatus to avoid O2 oxidation. After that, M o 2 and Cul are patterned. At this time, the 5iOz film 3 and Cul are Mo2
Since they are in contact with each other through the bonding layer, the adhesive strength is increased, and peeling of Cul can be prevented during patterning. Next, annealing is performed, for example, at 450° C. for 1 hour to establish an ohmic connection between the bipolar electrode extension portion and the Cu wiring portion.

In this way, Cu wiring with excellent reliability can be formed.

According to this example, Mo2 interposed between Si4 and Cul
suppresses the reaction and mutual diffusion between the two, and the SiO2 film 3 and Cu
The adhesive strength of l can also be increased. In this example, Mo
Although the reaction between Cu and Si can be suppressed, other transition metals other than MO can also be used with Cu or Cu alloy and Si or poly-Si.
reaction is also suppressed. Furthermore, Cu or Cu alloy and 5i
Adhesion strength with other insulating films other than the Oz film can also be increased.

FIG. 2 shows an embodiment in which the present invention is applied to multilayer wiring. 8
Mo2 is deposited on the SiO2 film 3 formed on the first substrate 4 to form a first layer Cul, and then an interlayer insulating film such as the SiO2 film 3 is formed. Thereafter, a through-hole portion is opened, and the first layer Cu and the second layer Cu5 are ohmically connected to that portion, and in order to improve reliability, for example, 5000 layers of Mo2 are applied to the lever. Thereafter, the second layer of Cu5 is subjected to revertaning, for example, by 5,000 deposits. At this time, Mo2 was coated only on the through hole part, but C
It may be deposited on the entire surface where u and the SiO2 film are in contact. Furthermore, in this example, an example of two-layer wiring of Cu was shown, but three
A layer and a four-layer wiring can also be formed in the same manner as the structure of this embodiment.

Table 1 Table 1 shows the results of examining the resistance change when 500 transition metals were deposited on a Si substrate, and after 8000 Cu deposits, hydrogen annealing was performed at 450°C for 1 hour. . From the table, the sheet resistance is 2 when no transition metal is involved.
It rises from 8mΩ/mouth to 530mΩ/mouth, and Cu and S
It can be seen that i is responding. In addition, MO5iz (molybdenum silicide), which is effective as a barrier metal for AI2 wiring, reacts with Cu and the sheet resistance increases from 28 mΩ/hole to 3
It has a value of 70mΩ/mouth and cannot be used for Cu or Cu alloy wiring. However, transition metals, especially Group VIA Cr, Mo
, W has no change in resistance and can be said to be a metal that suppresses the reaction between Cu and Si.

FIG. 3 shows that when a multilayer wiring is formed using Cu or a Cu alloy, the Cu or Cu alloy is used for forming other films such as Si.

This shows a structure in which everything in contact with poly-Si, SiO2, or other insulating films is covered with a transition metal. This structure also increases the adhesive strength of the side walls of the wiring and prevents the formation of cavities.
can prevent oxidation and corrosion.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an apparatus according to an embodiment of the present invention, and FIG.
The figure is a sectional view showing another embodiment of the invention, and FIG. 3 is a structural sectional view showing still another embodiment of the invention. 1- Cu, 2- Mo, 3- Si○2 film, 4-
Si substrate, 5... emitter, 6... base, 7
···collector. 8... First layer Cu, 9... Second layer Cu.

Claims (1)

[Claims] 1. A copper wiring structure containing at least copper, characterized in that a transition metal is interposed as a base of the copper wiring. 2. The copper wiring structure according to claim 1, wherein the transition metal is a group VIA of the periodic table. 3. The copper wiring structure according to claim 1, wherein the transition metal has a thickness in the range of 200 Å to 5000 Å. 4. A method for manufacturing a copper wiring containing at least copper, characterized in that the annealing temperature after forming the copper wiring is in the range of 300°C to 600°C. 5. A method for manufacturing a copper wiring, characterized in that an additive of up to 5% is added to the copper wiring to prevent oxidation and corrosion and to increase adhesive strength with an insulating film. 6. An apparatus for manufacturing a copper wiring, characterized in that the apparatus for manufacturing a wiring containing at least copper has an apparatus capable of continuously depositing the transition metal and the copper wiring.