JPH0677334A - Manufacture and processor of electrode wiring - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To form a highly reliable contact hole wiring with a sufficient coverage in a contact hole portion with a high aspect ratio by a simple process. [Structure] Substrate 1 having an opening 41 or a groove-shaped recess
On top of the aluminum or aluminum alloy film 23
While applying pressure of 1 atm or more,
The temperature is maintained above / 2Tm (Tm is the melting point of the material expressed in absolute temperature) or above, or is maintained above 1 / 2Tm in the absence of surface oxide film contaminants. [Effect] The cavity of the aluminum alloy film in the opening can be removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode wiring of a semiconductor device or the like, and more particularly to a method of manufacturing an electrode wiring suitable for forming a vertical connection hole wiring having a high aspect ratio.

[0002]

2. Description of the Related Art In order to cope with high integration of semiconductor devices, a method of forming wiring in multiple layers is adopted. The aspect ratio (depth / diameter ratio) of the connection hole between the layers in the multilayer wiring and the connection hole with the connection electrode with the active portion formed in the semiconductor substrate is increased as the integration degree is increased. It is difficult to form a film with sufficient coverage in such a high aspect ratio contact hole by the sputtering method, which is the current typical metal film forming method, and some new methods or conventional methods have been improved. The methods have been studied and are being applied. The representative ones are listed below.

Formation of Blanket Tungsten or Aluminum Film by CVD Method Formation of Plug Electrode Wiring by Selective CVD Method (Tungsten or Aluminum) Filling of Cavity by Bias or High Temperature Sputtering Method (Aluminum Alloy) Cavity of Cavity by High Temperature Treatment After Film Formation Embedded (aluminum alloy)

[0004]

However, these new and improved technologies are not universal and have many problems. For each technology, (1) adhesive layer required, high resistance (tungsten), large surface undulation, (2) narrow range of conditions for selective deposition, small process margin, limited base material, (3) difficult bias control ( There are problems such as deterioration of film quality), poor embedding characteristics, and (4) poor embedding characteristics. Also, the above is the embedding characteristics (how high the aspect ratio holes can be embedded)
Is relatively good, but process controllability is poor. The process itself is relatively simple, but the embedding characteristics are low, and there are advantages and disadvantages.

An object of the present invention is to solve the above-mentioned problems, and to provide a method for manufacturing an electrode wiring which has a simple process, good controllability, and good burying characteristics.

[0006]

In order to achieve the above object, according to the present invention, a step of forming a metal, particularly aluminum having a low melting point or an alloy film containing aluminum as a main component under vacuum or reduced pressure, and a subsequent high temperature treatment. The electrode wiring is formed in the concave portion of the substrate surface by pressure treatment. At that time, particularly by removing the surface oxide film or the contaminant region, it is possible to lower the processing temperature and lower the pressure.

[0007]

[Function] A metal, particularly aluminum having a low melting point or an alloy film containing aluminum as a main component, exhibits a certain degree of fluidity even if the temperature is lower than the melting point (especially in a vacuum) and enters a concave portion of the substrate surface if kept at a sufficiently high temperature. And so on, the surface changes to become smooth. A guideline for temperature is 1 / of the melting point expressed in absolute temperature.
It is 2 or more. It is known that above this temperature, most metals undergo remarkable mass transfer due to diffusion. At this time, if a pressure is applied to the film from the outside of the substrate, the effect of pushing a part of the film into the concave portion of the substrate surface is significantly improved, and the temperature required at that time can be lowered. Further, the effect is further enhanced by removing the surface oxide film and the contaminant layer which hinder the movement of the metal.

[0008]

EXAMPLE 1 FIG. 1 to FIG. 3 are views of a wiring system of a silicon semiconductor device showing an example of the present invention. A wiring system was manufactured through steps in the order of FIG. 1 to FIG.

This wiring system was prepared by the following ordinary silicon semiconductor device manufacturing process and the process of the present invention. That is, after forming an active portion on the surface of the silicon substrate 11, the polycrystalline silicon electrode wiring 21 and the tungsten wiring 22 are formed with the insulating film layer interposed therebetween, and the base insulating film 32 for forming the wiring of the present invention is formed. Then, the connection hole 41 with the lower layer was opened. Subsequently, an aluminum-1% Si alloy film was formed by the sputtering method. Since the step coverage is low in the sputtering method, as shown in FIG. 1, the inside of the connection hole was not filled and a cavity remained. Subsequently, the substrate was subjected to pressure treatment. First, the chamber containing the substrate was filled with an inert high-purity argon gas, and a predetermined pressure was applied. After heating the substrate in this state and maintaining it at a predetermined temperature for a certain time (10 minutes in this case), it is cooled to room temperature, and the argon gas is exhausted under reduced pressure.
The substrate was taken out (Fig. 2).

After that, a target wiring pattern as shown in FIG. 3 was processed by photoetching.

When the temperature and the pressure are within the proper ranges in the above pressurizing and high temperature treatment, the connection holes are filled as shown in FIG.
High reliability can be realized. Table 1 below shows the temperature and pressure ranges.
And shown in Table 2.

[0012]

[Table 1]

[0013]

[Table 2]

As can be seen from the above two tables, a temperature of 300 ° C. and a pressure of about 100 atm are required to maintain sufficient reliability, but if the temperature is raised to 400 ° C. or higher, the embedding can be performed at about 30 atm. It was

This experiment was conducted using an aluminum-1% Si alloy film, but pure aluminum and aluminum-C were used.
A u (-Si) alloy or the like can be embedded under almost the same conditions. Further, alloys having a very low eutectic temperature (424 ° C.) such as aluminum-Ge can be embedded at a temperature lower than the above conditions. Further, even with the same material, the lower the specific resistance film formed after the device was sufficiently evacuated to reach the high vacuum state, the better the embedding characteristics and yield tended to be. Although there are some variations depending on the material and film forming conditions,
With an alloy containing aluminum as a main component, this treatment method enables filling with sufficient reliability.

Further, a material having a melting point higher than that of an aluminum alloy can be similarly applied as long as there is no problem such as influence on the base substrate. For example, with copper, a similar effect could be obtained at 400 to 500 ° C. or higher.

<Embodiment 2> FIGS. 1 and 4 to 6 are views of a wiring system of a silicon semiconductor device showing an embodiment of the present invention. A wiring system was manufactured through steps in the order of FIG. 1 (same as Example 1) → FIG. 4 → FIG. 5 → FIG.

This wiring system was created by the following ordinary silicon semiconductor device manufacturing process and the process of the present invention. That is, after forming an active portion on the surface of the silicon substrate 11, the polycrystalline silicon electrode wiring 21 and the tungsten wiring 22 are formed with the insulating film layer interposed therebetween, and the base insulating film 32 for forming the wiring of the present invention is formed. Then, the connection hole 41 with the lower layer was opened. Subsequently, an aluminum-1% Si alloy film was formed by the sputtering method. Since the step coverage is low in the sputtering method, as shown in FIG. 1, the inside of the connection hole was not filled and a cavity remained.

Then, by a normal photoetching method, as shown in FIG.
The wiring pattern was processed into the intended wiring pattern as shown in. In order to perform this treatment, an oxide film is formed on the surface of the aluminum alloy film pattern as a result of removing the substrate from a vacuum or decompression container and exposing it to the atmosphere and various chemicals. Contaminants are attached. FIG. 4 shows this situation, where the oxide film or contaminant layer 51 covers the surface. In the case of aluminum alloy, the thickness of the oxide film is several nm ~
It is 10 nm. In this situation, a sufficient filling effect cannot be obtained even if the same process as in Example 1 is performed, so the oxide film removing process described below is performed.

The substrate was mounted on an electrode in a vacuum chamber, an argon gas was introduced, a high frequency voltage was applied, and so-called sputter cleaning was performed. It is more difficult to remove the oxide film and the contaminant layer on the side of the pattern than on the surface of the pattern. When the sputter cleaning treatment was performed until the layer of about 100 nm was removed on the surface, the layer of 10 nm could be removed on the side surface, and a nearly clean surface was exposed (FIG. 5).

This substrate was subsequently subjected to heat treatment without being exposed to the atmosphere. First, the chamber containing the substrate was filled with an inert high-purity argon gas, and a predetermined pressure was applied.
In this state, the substrate was heated and kept at a predetermined temperature for a certain period of time (10 minutes in this case), then cooled to room temperature, the argon gas was exhausted under reduced pressure, and then the substrate was taken out (FIG. 6).

When the temperature and the pressure are within the proper range in the above-mentioned pressurizing and high temperature treatment, the connection hole is filled as shown in FIG.
High reliability can be realized. The range of temperature and pressure is shown in Table 3 below.
And shown in Table 4.

[0023]

[Table 3]

[0024]

[Table 4]

As can be seen from the above two tables, a temperature of about 300 ° C. and a pressure of about 30 atm are required to maintain sufficient reliability, but if the temperature is raised to 400 ° C. or higher, the filling can be performed even in vacuum.

This experiment was conducted using an aluminum-1% Si alloy film, but pure aluminum and aluminum-C were used.
A u (-Si) alloy or the like can be embedded under almost the same conditions. Further, alloys having a very low eutectic temperature (424 ° C.) such as aluminum-Ge can be embedded at a temperature lower than the above conditions. Further, even with the same material, the lower the specific resistance film formed after the device was sufficiently evacuated to reach the high vacuum state, the better the embedding characteristics and yield tended to be. Although there are some variations depending on the material and film forming conditions,
With an alloy containing aluminum as a main component, this treatment method enables filling with sufficient reliability.

Further, a material having a melting point higher than that of an aluminum alloy can be similarly applied if there is no problem such as an influence on the base substrate. For example, with copper, a similar effect could be obtained at 400 to 500 ° C. or higher.

[0028]

As described above, according to the present invention,
Since it is possible to fill the connection holes with a high aspect ratio by a simple treatment with an aluminum alloy and improve the reliability of the connection hole wiring, it is extremely useful for realizing various semiconductor devices with high integration density.

[Brief description of drawings]

FIG. 1 is a sectional view of a wiring portion according to an embodiment of the present invention.

FIG. 2 is a sectional view of a wiring portion according to an embodiment of the present invention.

FIG. 3 is a sectional view of a wiring portion according to an embodiment of the present invention.

FIG. 4 is a sectional view of a wiring portion according to an embodiment of the present invention.

FIG. 5 is a sectional view of a wiring portion according to an embodiment of the present invention.

FIG. 6 is a sectional view of a wiring portion according to an embodiment of the present invention.

[Explanation of symbols]

11 ... Silicon substrate, 21 ... Polycrystalline silicon electrode wiring,
22 ... Tungsten wiring, 23 ... Aluminum-1% S
i alloy wiring, 31, 32 ... Interlayer insulating film, 41 ... Connection hole part, 51 ... Oxide film or contaminant layer.

Claims (7)

[Claims] 1. A film-shaped or patterned metal region processed into a predetermined shape is formed on a substrate, and a melting point of the metal represented by an absolute temperature of 1 is applied while applying a pressure of 1 atm or more. A method for manufacturing an electrode wiring, which is characterized by holding at a temperature of / 2 or more. 2. A film-shaped or patterned metal region processed into a predetermined shape is formed on a substrate, and an oxide film or contaminants formed on the surface of this region is removed to obtain non-oxidizing or contamination. 1 / of the melting point expressed by the absolute temperature of the above metal (including vacuum) while keeping the atmosphere free from substances
A method for manufacturing an electrode wiring, which is characterized by holding at a temperature of 2 or more. 3. A film-shaped or patterned metal region processed into a predetermined shape is formed on a substrate, and an oxide film or contaminants formed on the surface of this region is removed to make it non-oxidizing or contaminating. A method for producing electrode wiring, which is characterized in that the temperature is maintained at ½ or more of the melting point expressed by the absolute temperature of the metal while applying a pressure of 1 atm or more in an atmosphere free from adhesion of substances. 4. A method of manufacturing an electrode wiring, wherein the metal region according to claim 1, 2 or 3 is aluminum or an alloy containing aluminum as a main component. 5. The aluminum or the region containing aluminum as a main component according to claim 4 completely covers at least one opening or groove-shaped recess on the surface of the substrate, and an aluminum cavity is provided inside. A method for manufacturing an electrode wiring, which is characterized by being left. 6. The medium according to any one of claims 1 to 5 to which a pressure of 1 atm or more is applied is an inert gas such as hydrogen, argon or nitrogen, or a liquid having low reactivity such as oil. The method for manufacturing the electrode wiring according to claim 1. 7. A portion having a function of removing an oxide film or a contaminant region existing on the surface of a film-shaped or patterned metal region formed on a substrate, a portion having a function of heating and pressing the substrate, And a substrate processing apparatus having a function of transporting the substrate between the two portions in a vacuum or a non-oxidizing atmosphere.