JP2000160322A - Method and device for sputtering - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate moisture contamination at the inside of the device and moreover to reduce the peeling of a thin film from the boundary between a substrate and the thin film without executing plasma treatment. SOLUTION: Before a sputtering device is charged with a substrate, it is treated in a dry nitrogen atmosphere, in the case of the opening of a gate 4 on the atmospheric side of a vacuum spare chamber 2, dry gaseous nitrogen is flowed from the inside of the vacuum spare chamber 2, and, in the case of the exhaust of the vacuum spare chamber 2, it is exhausted at an exhausting rate at which water vapor gas is not liquified by a valve 7 with a movable mechanism for slow exhaust, and it is heated at about 80 to 120 deg.C in a high vacuum of <=1×10-3 Torr before sputter film formation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering method and an apparatus used for forming a thin film in the production of electronic devices and surface treatments.

[0002]

2. Description of the Related Art When a thin film is formed on a substrate surface by a sputtering device, when the substrate is introduced into the sputtering device while moisture in the air is adsorbed on the substrate surface, the thin film is peeled off from the interface between the substrate and the thin film. Phenomena. Therefore, conventionally, in order to remove moisture adhering to the substrate surface, the substrate surface is subjected to a plasma treatment such as a reverse sputtering method or a bias sputtering method.

FIG. 4 shows processing steps in a conventional sputtering apparatus. Using a vacuum preparatory chamber C-1 ', a substrate plasma processing chamber C-2', and a sputtering apparatus C 'having a sputter film forming chamber C-3', the vacuum preparatory chamber C-1 '
After the substrate A has been charged, the substrate A is transported to the plasma processing chamber C-2 ′ for pretreatment, and the substrate surface is subjected to plasma processing in a vacuum, and then the substrate A is placed in the sputtering film forming chamber C-3 ′. It is transported to form a sputter film.

Further, when the substrate A having water adsorbed on the surface is brought into each of the vacuum chambers (C-1 ', C-2', C-3 '), water and the like adhere to the inside thereof. In order to remove this, Japanese Patent Application Laid-Open No. H10-60622
It is necessary to perform processing in a vacuum chamber as disclosed in Japanese Patent Application Laid-Open Publication No. Hei.

[0005]

However, in the above-described conventional configuration, the device surface is subjected to plasma processing, which may damage the device and degrade device characteristics. In addition, the inside of the vacuum chamber may be contaminated with moisture or the like, so that device characteristics may change over time. Furthermore, the removal step in the vacuum chamber requires a new unit for removing moisture adsorbed on the substrate and the chamber, and additional steps such as introduction and removal of dry nitrogen add equipment cost. This causes problems such as an increase in processing time and a decrease in processing tact.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, the present invention eliminates internal water contamination by introducing a substrate without adhering atmospheric moisture to the surface of the substrate, and allows the substrate to be connected to a thin film without plasma treatment. It is an object of the present invention to provide a sputtering method and an apparatus capable of reducing the peeling of a thin film from an interface.

[0007]

According to the present invention, there is provided a sputtering method and apparatus for forming a thin film on a surface of a substrate, the method comprising: The substrate is handled in a dry nitrogen atmosphere until the substrate is put into the equipment.Introducing the substrate without adhering atmospheric moisture to the substrate surface eliminates internal water contamination and eliminates substrate contamination without plasma treatment. Of the thin film from the interface between the film and the thin film can be reduced. Note that in the case where there is a heating step such as a heat treatment in a pre-step up to the film formation step, the substrate may be handled in an environment under a dry nitrogen atmosphere immediately after that.

When the substrate is loaded by opening the atmospheric side gate of the vacuum preparatory chamber, a means for flowing a dry nitrogen atmosphere from the vacuum preparatory chamber is provided. At the time of loading, a dry nitrogen atmosphere may flow from the pre-vacuum chamber. It is desirable that the flow rate of the dry nitrogen gas be equal to or higher than the flow rate at which the atmosphere enters the vacuum preparatory chamber.

Further, when the substrate is carried into the vacuum preparatory chamber of the sputtering apparatus and evacuated, the vapor gas containing moisture in the vacuum preparatory chamber may be evacuated at an exhaust speed that does not liquefy.

A means for heating the substrate to about 80 to 120 ° C. in a high vacuum of 1 × 10 ⁻³ Torr or less is provided.
In a high vacuum of 10 ^-3 Torr or less, the substrate is
A heat treatment at about ° C may be performed. When the substrate material is a resin or the like, the temperature may be 80 ° C. or less.

In addition, two or more of the above methods and means may be combined. At that time, it is preferable to select the combination according to the substrate material and device content, and to optimize the apparatus cost and the processing tact.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of a sputtering method and apparatus according to the present invention will be described below with reference to FIG.

This embodiment relates to a method for sputtering an optical disk, and FIG. 1 is a conceptual view of the process. The substrate A manufactured by resin molding is stored in the N ₂ atmosphere management unit B immediately after being taken out of the molding apparatus. By storing and managing the substrate A immediately after molding in a dry nitrogen atmosphere at a relatively high temperature in this step, adsorption of moisture in the air to the resin is prevented. Thereafter, by introducing the substrate A into the sputtering device C, it is possible to prevent moisture from adhering to the substrate surface and to prevent the introduction of moisture into the vacuum device.

(Second Embodiment) Next, a second embodiment of the sputtering method and apparatus of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

FIG. 2 shows the operation of the sputtering apparatus used in the present embodiment in a pre-vacuum chamber. In FIG. 2, 1 is a main body of the sputtering apparatus, 2 is a vacuum auxiliary chamber, 3 is a gate between the main body 1 and the vacuum auxiliary chamber 2, and 4 is a gate of the vacuum auxiliary chamber 2 on the atmosphere side. The vacuum spare chamber 2 is connected to a vacuum exhaust device 5 via a main exhaust valve 6 and a slow exhaust valve 7 with a variable mechanism arranged in parallel, and a gas inlet 8 for introducing N ₂ gas. I have. 9 is a substrate.

The pre-vacuum chamber 2 has a gas inlet 8 after evacuation.
N ₂ gas (dry nitrogen) is introduced from the above and purged to above atmospheric pressure. Thereafter, the gate 4 is opened as shown in the figure with the gate 3 and the valves 6 and 7 closed, and N ₂ gas is introduced from the gas inlet 8. In this state, the substrate 9 is put into the vacuum preparatory chamber 2 from the atmosphere side, and
Is closed, and the introduction of N ₂ gas is also stopped.

By performing such an operation, when the gate 4 is opened, the moisture in the atmosphere that is going to be mixed or diffused into the vacuum preparatory chamber 2 from the atmosphere side is caused to flow in the gate 4 by the flow of the introduced N ₂ gas. Returned inside. For this reason, the amount of water mixed into the pre-vacuum chamber 2 can be reduced.

Thereafter, the inside of the pre-vacuum chamber 2 is evacuated
Is evacuated. Usually, in order to reduce the generation of particles and the like, the air is slowly exhausted from the atmospheric pressure only by the slow exhaust valve 7 and then exhausted by the main exhaust valve 6.

At this time, in the case of the conventional example as shown in FIG. 4, the substrate surface and the moisture in the atmosphere are evacuated while being brought into the pre-vacuum chamber 2. As a result, the steam gas containing moisture is rapidly adiabatically expanded at the start of evacuation or at the moment of switching from slow exhaust to main exhaust, and the moisture is liquefied and the surface of the substrate 9 or the vacuum preliminary chamber 2 Adsorb to the chamber wall inside. Therefore, a phenomenon occurs in which the thin film formed on the substrate 9 is separated.

In the present embodiment, by adjusting the exhaust speed at the start of the exhaust and the exhaust time until the main exhaust by the slow exhaust valve 7 with a variable mechanism, the vapor gas in the vacuum preparatory chamber 2 is not liquefied. The gas can be removed by the evacuation device 5 in a gas state.

(Third Embodiment) Next, a third embodiment of the sputtering method and apparatus of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

FIG. 3 is a conceptual view showing the steps of the sputtering method according to this embodiment. The substrate A is handled by the N ₂ atmosphere management unit B described in the first embodiment, or is directly loaded into the pre-vacuum chamber C-1 after the previous process. At this time,
After the operation shown in FIG. 2 of the second embodiment, it is introduced into the main body 1 of the sputtering apparatus.

Next, prior to the sputter deposition, the wafer is transferred to a high vacuum / preheating chamber C-2. Here, 1 × 10 ⁻³ To
The substrate A is heated at a temperature of about 80 to 120 ° C. in a high vacuum evacuation state of not more than rr (preferably not more than 10 ⁻⁴ Torr). At this time, the moisture adsorbed on the substrate A evaporates due to the high temperature and is exhausted, so that the moisture on the substrate A can be removed without plasma damage. However,
When the substrate A is made of a material such as a resin substrate such as an optical disk, the material can be removed even if the temperature is lowered to 80 ° C. or less. Thereafter, the substrate A is carried into the sputter film forming chamber C-3 from the high vacuum / preheating chamber C-2, and a predetermined sputter film is formed.

[0024]

According to the sputtering method and apparatus of the present invention, the substrate is handled in a dry nitrogen atmosphere until the substrate is put into the sputtering apparatus as described above, so that atmospheric moisture does not adhere to the substrate surface. The substrate can be introduced to eliminate moisture contamination inside, and the peeling of the thin film from the interface between the substrate and the thin film can be reduced without plasma treatment.

Further, when the substrate is carried in after opening the gate on the atmosphere side of the vacuum preparatory chamber of the sputtering apparatus, moisture contamination and thin film peeling of the substrate and the chamber can be prevented by flowing a dry nitrogen atmosphere from the vacuum preparatory chamber. it can.

Further, when the substrate is carried into the vacuum preparatory chamber of the sputtering apparatus and evacuated, the vapor gas containing water in the preliminary vacuum chamber is evacuated at an exhaust speed that does not liquefy, thereby preventing the vapor gas from being liquefied. , Moisture contamination and thin film peeling can be prevented.

Before the substrate is put into the film forming chamber of the sputtering apparatus, the substrate is subjected to a heat treatment at about 80 to 120 ° C. in a high vacuum of 1 × 10 ⁻³ Torr or less, thereby adhering to the substrate. It is possible to reliably remove the water thus removed, thereby preventing water contamination and thin film peeling.

Further, by combining the above two or more means, these effects can be obtained and water contamination and thin film peeling can be prevented.

[Brief description of the drawings]

FIG. 1 is a process conceptual diagram of a sputtering method according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation in a preliminary vacuum chamber of a sputtering apparatus according to a second embodiment of the present invention.

FIG. 3 is a process conceptual diagram of a sputtering method according to a third embodiment of the present invention.

FIG. 4 is a process conceptual diagram of a conventional sputtering method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sputtering apparatus main body 2 Vacuum reserve room 4 Atmospheric side gate 5 Vacuum exhaust device 6 Main exhaust valve 7 Slow exhaust valve with variable mechanism 8 Gas inlet 9 Substrate

Claims (10)

[Claims] 1. A sputtering method for forming a thin film on a substrate surface in a sputtering apparatus, wherein the substrate is handled in a dry nitrogen atmosphere until the substrate is put into the sputtering apparatus. 2. A sputtering method for forming a thin film on a substrate surface in a sputtering apparatus, wherein a dry nitrogen atmosphere is flown from a vacuum preparatory chamber when the substrate is carried in with a gate in the vacuum preparatory chamber being opened to the atmosphere. The sputtering method characterized by the above-mentioned. 3. In a sputtering method for forming a thin film on a substrate surface in a sputtering apparatus, when a substrate is carried into a vacuum preparatory chamber of the sputtering apparatus and evacuated, a vapor gas containing moisture in the vacuum preparatory chamber is not liquefied. A sputtering method characterized by evacuating at a speed. 4. In a sputtering method for forming a thin film on a substrate surface in a sputtering apparatus, before the substrate is put into a film forming chamber of the sputtering apparatus, 1 × 10 ⁻³ To.
A sputtering method comprising subjecting a substrate to a heat treatment at about 80 to 120 ° C. in a high vacuum of rr or less. 5. A sputtering method comprising combining two or more steps according to claim 1. 6. A sputtering apparatus for forming a thin film on a substrate surface, comprising means for handling a substrate in a dry nitrogen atmosphere and feeding the substrate into the apparatus. 7. A sputtering apparatus for forming a thin film on the surface of a substrate, wherein a means for flowing a dry nitrogen atmosphere from the vacuum preparatory chamber is provided when the substrate is carried in by opening the atmospheric side gate of the vacuum preparatory chamber. Sputtering equipment. 8. A sputtering apparatus for forming a thin film on a surface of a substrate, wherein the exhaust means of the pre-vacuum chamber is evacuated at an exhaust speed at which vapor gas containing water is not liquefied. 9. A sputtering apparatus for forming a thin film on a surface of a substrate, comprising means for heating the substrate to about 80 to 120 ° C. in a high vacuum of 1 × 10 ⁻³ Torr or less. . 10. A sputtering apparatus comprising a combination of two or more means according to claim 6.