JPH11200018A - Vacuum deposition method by electron gun heating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for recovering the reduction of the efficiency of vapor deposition caused by the formation of a dent on the surface of a vapor depositing material in a crucible applied with electron beam irradiation in the field of electron beam vacuum deposition technology of high m.p. metals or the like and to provide a device therefor. SOLUTION: This method includes a stage in which vapor deposition treatment is executed while a dent 22 caused by an electron beam 30, of an evaporating material 2 is a crucible 21 is monitored by a dent detecting method and a stage in which the vapor deposition treatment is discontinued, and the dent on the surface of the evaporating material in the crucible is flattened by electron beam irradiation, and the dent detecting method is the one in which the electric current of an electron gun filament 3 is regulated for obtaining a certain film thickness speed according to the data of a film thickness gauge 5, and the filament electric current is compared with the set electric current value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of electron beam vacuum deposition of high melting point metals and the like, and a method for recovering a reduction in deposition efficiency due to the formation of a depression on the surface of a deposition material in a crucible irradiated with an electron beam. And its equipment.

[0002]

2. Description of the Related Art Vacuum deposition by electron beam irradiation is widely used in the field of semiconductor device manufacturing and the like as a method for depositing a thin film of a high melting point metal on a surface of a substrate or the like.
This method irradiates an electron beam onto the surface of an evaporating material such as a metal held in a water-cooled copper crucible in a vacuum vessel, deposits vapor evaporated from the molten surface of the evaporating material on the surface of the object, and forms a film. It is what forms.

[0003] When the vapor deposition is continued by this method, the irradiation material of the crucible melts and evaporates strongly in the electron beam irradiation area, and the surrounding area is cooled by the crucible wall. When the depression occurs, the evaporation rate of the metal material from the depression decreases, so that a constant film thickness rate cannot be controlled. For this reason, when the dent becomes large, in order to secure a film forming speed or a film forming speed, the vapor deposition process is temporarily interrupted, and the surface is melted and flattened while being swept by an electron beam, or the surface dent of the evaporation material is made. , And re-dissolve it to make the surface uniform. After the surface is made uniform, the deposition process is restarted. In this way,
Conventionally, the deposition process and the evaporation material surface uniformization process have been manually and alternately switched.

[0004] In the prior art, regarding the surface dents of the evaporation material in the crucible, Japanese Patent Application Laid-Open No. Hei 3-14659 discloses that as the molecular beam intensity measured on the filament side decreases,
It is disclosed that a material on a crucible or a container is sequentially tilted forward, that is, toward the electron beam side, so that the electron beam is always irradiated with a shallow surface dent and evaporated at a constant film thickness rate. In this example, a quartz oscillator sensor is used as a film thickness meter, and tilt control is performed by the sensor so that the molecular beam intensity is always constant.

In the prior art, Japanese Patent Laid-Open No. 5-339714.
Japanese Patent Laid-Open Publication No. 2000-171873 discusses an electron beam evaporation method, in which an electron beam irradiating the surface is deflected in a diametric direction through a center of rotation and is swung right and left with respect to an evaporating material source in a rotating crucible. In some cases, a special deflection magnetic pole is arranged so that the irradiation intensity is increased in the peripheral portion where the intensity is large.

[0006]

If the irradiation of the electron beam is continued, the surface of the metal material in the crucible is depressed, and the evaporation rate from the depressed portion is reduced. Therefore, the filament current is increased in order to increase the power of the electron beam. However, the heating conditions of the evaporation source change,
There has been a problem that the quality and uniformity of the film thickness formed by vapor deposition on the object are reduced. Regarding such a problem, in order to automate the repair of the dent, it is necessary to automatically and accurately detect the size of the dent.

[0007] The above-mentioned other prior arts have the advantage that, during the vapor deposition process, the electron beam is continuously evaporated by deflection of the electron beam or tilting of the crucible, and the film growth rate can be kept constant. However, the above-mentioned JP-A-3-
The method disclosed in Japanese Patent No. 146659 is not suitable for a large-area deposition process or a batch-type deposition process for a large number of wafers because the crucible is tilted. In addition, the above-mentioned Japanese Unexamined Patent Publication No.
In the electron beam evaporation method disclosed in 339714, it is necessary to dispose a large deflection magnetic pole above the evaporation source, and to perform the evaporation process in which the beam diameter to the evaporation source needs to be narrowed, for example, during the lift-off process, The above method of deflecting the electron beam is not preferable because the position of the evaporation point relative to the film forming substrate is displaced. Furthermore, in general, the method of rotating a crucible during a deposition process is difficult to apply to a crucible having a plurality of evaporation sources for multilayer deposition.

In view of the above problems, the present invention provides a vacuum for automatically repairing and automatically detecting a surface dent of a vapor deposition material in a crucible generated in a vacuum vapor deposition process of an electron gun heating method. It is intended to provide a vapor deposition method. An object of the present invention is to provide a vacuum deposition apparatus having an automatic control device capable of detecting and repairing a surface dent of a deposition material in a crucible generated in a vacuum deposition process.

[0009]

According to the vacuum vapor deposition method of the present invention, a vapor deposition process is performed while monitoring a dent of an evaporating material in a crucible by an electron beam by a dent detection method, and a dent is detected by the dent detection method. A process of interrupting the deposition process and flattening the dents on the surface of the evaporating material in the crucible by electron beam irradiation, and a vacuum deposition method of an electron gun heating method, the feature of which is that the dents The detection method is to control the electron gun filament current for a constant film thickness rate based on the data of the film thickness meter, and to detect a dent when the filament current reaches a set value.

[0010] A film thickness meter broadly refers to a device capable of directly or indirectly measuring a vapor-deposited film, and is capable of detecting an evaporation rate of particles vaporized and dissipated by an electron beam irradiation from an irradiation portion of an evaporation material in a crucible. Measuring devices are also included.

According to the present invention, the amount of evaporation starts to decrease when a dent starts to be formed during the vapor deposition process, and the film thickness speed, and thus the evaporation speed, can be kept constant by the data from the film thickness meter for detecting this. The electron gun filament current is increased, thereby increasing the amount of the electron beam from the electron gun, that is, the electron beam current, and increasing the heat input to the recess to secure the evaporation amount. If the electron gun filament current becomes larger than a preset current value during such feedback control, a signal that detects a dent is output, the vapor deposition process is interrupted, and the process shifts to a process of automatically flattening the dent. It is.

In the present invention, another dent detection method can be employed, including a method of detecting a dent by a laser beam reflected from a surface of an evaporation material in a crucible irradiated with a laser beam. Laser light is irradiated to the electron beam irradiation position, the reflected light is detected, and from the output of the reflected laser light,
This is a method for detecting the size of the dent.

In the vacuum deposition method of the present invention, the above-mentioned dents are flattened after the dents are detected. In the dent flattening method, the irradiation position of the electron beam is fixed and the crucible is moved substantially horizontally in one direction. Or, it includes moving in two directions.

As a method of flattening a dent, a method of fixing a crucible and deflecting or moving or scanning an electron beam on the surface of the evaporation material in the crucible to fill the dent and flatten as in the prior art is also employed. Instead of, or in addition to, the flattening method of filling the depressions with the electron beam, the evaporation material is additionally added to the depressions, and the surface is averaged by electron beam irradiation.

The electron gun heating type vacuum evaporation method of the present invention also includes a method of avoiding the occurrence of dents during the evaporation process and continuing the evaporation. In other words, in this method, the evaporation position is performed while the irradiation position of the electron beam on the surface of the evaporating material in the crucible is fixed to the apparatus and the crucible is moved substantially horizontally in one or two directions.

Since the irradiation area of the electron beam is constantly updated by the movement of the crucible, the evaporation rate can be kept constant. Thereby, in particular, since the irradiation position of the electron beam on the evaporation material is fixed with respect to the object to be evaporated, for example, a film-forming substrate, there is an advantage that the evaporation direction with respect to the substrate can always be kept constant. As described above, since the relative position of the evaporation point with respect to the film forming substrate is not displaced, this evaporation method can be suitably used for evaporation processing in which the beam diameter to the evaporation source needs to be reduced, for example, a lift-off process. it can.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 First, in the vacuum deposition method of the present invention, which is divided into a vapor deposition process and a concave flattening process, in the vapor deposition process, the vapor deposition material in the crucible is monitored while monitoring the concave by the electron beam by the concave detection method. In the process of flattening, when a dent is detected by the dent detection method, the evaporation process is interrupted, and the dent on the surface of the evaporation material in the crucible is flattened by electron beam irradiation. When the planarization is completed, the process returns to the vapor deposition process, and the dent detection can be continued.

The apparatus which can be used in the vacuum deposition method of the present invention utilizing the control of the electron gun filament current is described below.
FIG. 1 shows a vacuum deposition apparatus of the present invention and a control system diagram thereof.
The substrate supporting member 1 for fixing the substrate 11 to be deposited is
In this example, a crucible 21 (usually a water-cooled copper crucible) containing the evaporating material 2 is disposed below and is disposed above the substrate 11 so as to face the substrate 11.
0 is maintained at a required degree of vacuum by a vacuum system (not shown).

Below the crucible 21 is disposed a filament 3 of an electron gun (not shown) for an electron beam, and a magnetic pole (not shown) for forming a deflection magnetic field H so as to cross the path of the electron beam 30. (Illustration) is arranged, and the deflection magnetic field is adjusted so that the electron beam generated from the electron gun is deflected by the deflection magnetic field H and irradiated onto the evaporation material on the crucible.

First, in the first dent detection method of the electron gun heating type vacuum evaporation method, the vacuum evaporation apparatus uses the film thickness meter 5 to detect the evaporated metal in the vicinity of the substrate 11 by using a quartz vibrating element. A current controller 61 fixed to a possible position and controlling the electron gun filament current is provided. The current controller 61 receives a data signal from the film thickness meter 5 during the vapor deposition process and inputs the data signal to the current controller 61. The current controller 61 controls the current of the electron gun filament 3 so that the thickness speed measured by the film thickness meter becomes uniform.

Further, the dent detecting means includes a current controller 61.
A current value monitor 62 for comparing the filament current data of the current setting device with the set current data of the current setting device 63 is provided. The current value monitor 62 includes a comparator for comparing the filament current data with the set current data. When it is detected that the current data is larger than the set current data, the dent detection signal, that is, the flattening signal is sent to the flattening means 6.
4, which interrupts the deposition process and transitions to a planarization process.

In the process of vacuum deposition with such an apparatus,
The electron beam 30 is irradiated from the electron gun with the initial electron beam current, and the irradiated portion of the crucible 21 with the evaporation material is heated and evaporates sequentially. Accordingly, a depression 22 is formed at the electron beam irradiation site, and usually, the evaporation rate is reduced. Therefore, the evaporation rate, that is, the film thickness rate is detected by the film thickness meter 5, and the data of the film thickness rate is sent to the current controller 61 as appropriate.
The current controller increases the filament current, and under a constant applied voltage between the filament and the crucible, the electron beam current increases, the dent of the irradiation site becomes hotter, and the evaporation rate from the dent becomes almost constant. Can be maintained.

Furthermore, when the filament current is increased, there is a possibility that the properties of the deposited film on the substrate 11 may be changed or abnormal due to the deposition of the material from the recess 22. Therefore, a filament current that shifts from the vapor deposition process to the flattening process is set in advance in the current setting device 63. When the set filament current exceeds a certain current value, the property of the deposited film on the substrate 11 changes. And an appropriate current value before an abnormality occurs.

The current value monitor 62 monitors the filament current from the power supply controller and compares it with the set filament current. When the actual filament current exceeds the set current, a dent detection signal, that is, a flattening signal Flattening means 6
4 to temporarily suspend the vapor deposition process and shift to a flattening process.

Further, an optical sensor is used as the second dent detecting method according to the present invention. As shown in FIG. 2, this method corresponds to the dent on the surface of the evaporation material 2 in the crucible 21. Irradiator 51 that irradiates laser beam 53 to the part
And a light receiver for receiving the reflected laser beam 53 from the concave corresponding portion is fixed in the vacuum chamber 90 to constitute a concave detector. When the concave in the concave corresponding portion is formed and becomes deep, the concave bottom portion is formed. The arrangement is preferably such that the reflected laser light at the above is obstructed by the concave edge so that the reflected light does not reach the light receiver. Thereby, the dent detection signal is output to the flattening means by the light receiver.

Next, the mechanism of the flattening method or flattening means of the present invention is shown in FIG. As a first dent flattening method, the one shown in FIG. 3 (A) sweeps the surface of the evaporation material 2 in the crucible 21 while controlling the deflection magnetic field H while irradiating the electron beam 30 with the surface. Dent 22
The recesses are filled with a molten material to flatten them. In this case, an operation of sweeping the irradiation position of the electron beam 30 by fixing the crucible and adjusting the deflection magnetic field H is performed. This operation is started by the dent detection signal, but can be performed by controlling the magnet current by a magnet current controller (not shown) for the deflection magnetic field H as a smoothing means.

In this flattening process, prior to the operation,
The shutter 7 shuts off the space between the crucible 21 and the substrate holding member 1. After the process of flattening the recess, the process of the vapor deposition process can be performed again in the same manner.

As a second flattening method, FIG.
Is another flattening means. The irradiation position of the evaporating material 2 in the crucible 21 is moved by reciprocating the crucible with the irradiation position of the electron beam 30 substantially fixed, thereby The recess 22 is filled with a molten material to make it flat. The crucible 21 is fixed to a moving table (not shown), and reciprocates the moving table in one horizontal direction. In particular, the crucible 21 moves forward, backward, left and right in two directions.

FIG. 3 (C) shows a third method of flattening a dent.
Shows that the further flattening means 64 comprises a small container 8 for material replenishment and its moving means. Container 8
A small amount of evaporating material 20 is placed in the container 8 in advance, which is arranged on a moving means (not shown) that can move directly above the crucible 21 in the vacuum chamber. When a flattening signal is input, the vapor deposition process is temporarily interrupted, the container 8 is moved onto a crucible (the left diagram in FIG. 3C), and then the evaporation material 20 in the container 8 is dropped into the recess 22. Then, after the container is retracted, the electron beam is irradiated to start vapor deposition.

However, after the evaporating material 20 is dropped from the container 8 into the recess 22 and replenished, the first or second flattening method (the method shown in FIGS. 3A and 3B) is used. The recess 22 may be flattened by irradiating the replenished evaporation material 20 with an electron beam. Such a method of replenishing the evaporation material can be used together with the first or second flattening method of flattening by electron beam irradiation as described above.

The third dent flattening method has the advantage that the height of the surface of the evaporation source is always made uniform and the uniformity of the film quality is improved by automatic replenishment of the evaporated metal material.

(Embodiment) The first or second dent detection method described above can be combined with any of the first to third dent flattening methods. Examples will be described below.

Embodiment 1 As Example 1, preferably,
First dent detection method (FIG. 1) and first planarization method (FIG. 3)
(A)) is used. That is, during the deposition process, the filament current is controlled by the data from the film thickness meter, and when the filament current exceeds the set current, the current monitor outputs a flattening signal, shuts off the shutter, and sets the deflection magnetic field for the electron beam. By automatically adjusting H, the electron beam is swept around the dent while filling the dent to flatten the material surface. When the planarization is completed, the shutter is opened again, the deflection magnetic field H for the electron beam is fixed, the electron beam is irradiated at a predetermined position, and the vapor deposition is performed while measuring the molecular beam velocity with a film thickness meter. Do. This method has an advantage that the flattening process can be easily automated simply by adjusting the deflection magnetic field H for the electron beam.

Embodiment 2 FIG. As the second embodiment, there is a combination of the first dent detection method (FIG. 1) and the second flattening method (FIG. 3B). That is, the filament current is controlled based on the data from the film thickness meter, and when the filament current exceeds the set current, the current monitor outputs a flattening signal, shuts off the shutter, and fixes the electron beam while holding the moving stage of the crucible. Is automatically moved back and forth and left and right in two directions by the drive device,
The surface of the material is flattened by filling the depression on the surface of the material while dissolving the electron beam around the depression. When flattening is finished,
The shutter is opened again, the crucible is fixed at a predetermined position in the same manner as in Example 1, an electron beam is irradiated at a predetermined material surface position, and vapor deposition is performed while measuring a molecular beam velocity with a film thickness meter. . According to this method, the irradiation position of the electron beam is fixed almost always, and the flattening can be performed while monitoring the movement of the crucible.

Embodiment 2 In another embodiment of the present invention, the vacuum evaporation method is to move the crucible substantially horizontally in one or two directions by fixing the irradiation position of the electron beam on the surface of the evaporation material in the crucible with respect to the apparatus. This is a method in which the vapor deposition process is continuously performed while being performed. The device for this is
The flattening means shown in FIG. 3B can be applied as it is. Therefore, in this method, the irradiation position of the evaporating material 2 in the crucible 21 is moved by reciprocating the crucible with the irradiation position of the electron beam 30 substantially fixed, thereby forming a deep recess 22 on the surface. It heats and vapor-deposits, without forming. The crucible 21 is fixed to a moving table (not shown), and the moving table can be reciprocated in one horizontal direction. The moving table may be moved in two orthogonal directions.

The vacuum deposition method of this embodiment has an advantage that the irradiation position of the electron beam on the evaporation material is fixed with respect to the film-forming substrate, so that the direction of vapor deposition on the substrate can always be kept constant. Therefore, according to this vapor deposition method, the dent can be avoided while the vapor deposition is continued, and since the relative position of the vaporization point with respect to the film forming substrate is not displaced, the vapor deposition processing in which the beam diameter to the vapor deposition source needs to be narrowed is required. For example, it can be suitably used for a lift-off process.

[0037]

According to the present invention, there is provided an electron gun heating type evaporation method.
The method for detecting the dent of the evaporating material in the crucible during the vapor deposition process, controlling the electron gun filament current for a constant film thickness speed by the data of the film thickness meter, and comparing the filament current with the set current value, When a dent is detected, the evaporation process is interrupted, and a process of flattening the dent on the surface of the evaporating material in the crucible by electron beam irradiation is provided. ,
Moreover, it is possible to accurately grasp the properties of the deposited film until it changes,
Therefore, the deposition process and the planarization process can be completely automated.

In the electron gun heating type vapor deposition method of the present invention, the above-described dent detection method is a method of detecting the dent by the reflected laser light from the surface of the evaporation material in the crucible irradiated with the laser beam. Since the detection can be performed optically in a non-contact manner and while the electron beam is stopped during the vapor deposition process, the vapor deposition process and the planarization process can be more completely automated.

In the vapor deposition method using an electron gun heating method according to the present invention, in particular, the flattening method flattens the surface of the evaporating material in the crucible by sweeping the irradiation area of the electron beam.
An electron beam irradiation site can be easily flattened by using a deflection magnetic field.

When the flattening method of the present invention is a method of fixing the irradiation position of the electron beam and moving the crucible in one direction or two directions substantially horizontally to flatten the surface, the movement control of the crucible is performed. Thereby, there is an advantage that the position of the crucible with respect to the irradiation site can be confirmed. In particular, there is an advantage that unexpected accidents such as melting of the crucible due to erroneous irradiation can be prevented.

When the evaporation material is replenished as the flattening method of the present invention, the automatic replenishment of the evaporated metal material has the advantage that the height of the surface of the evaporation source is always uniform and the uniformity of the film quality is improved. is there.

In the vapor deposition method of the electron gun heating method of the present invention, the vapor deposition process is performed while the irradiation position by the electron beam is fixed to the apparatus and the crucible is moved in one direction or two directions substantially horizontally. The irradiation position of the electron beam on the material is fixed with respect to the film-forming substrate, so that the direction of vapor deposition on the substrate can be kept constant. For small film-forming substrates, the direction of vapor deposition on the substrate should be parallel. There are advantages that can be. As described above, this vapor deposition method can avoid a dent while continuing vapor deposition, and moreover, the vapor deposition is preferably used for a vapor deposition process in which a beam diameter to a vapor deposition source needs to be reduced, for example, a lift-off process. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view and a control system diagram showing an electron gun heating type vapor deposition apparatus of the present invention.

FIG. 2 is a view similar to FIG. 1, showing another electron gun heating type vapor deposition apparatus of the present invention.

FIG. 3 is a schematic cross-sectional view showing a vapor deposition apparatus in the process of flattening a dent according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate holding member 2 Evaporation material 21 Crucible 22 Depression 3 Electron gun filament 30 Electron beam 5 Film thickness meter 51 Laser irradiator 52 Laser receiver

Claims (6)

[Claims] In a vacuum deposition method using an electron gun heating method, a step of performing a deposition process while monitoring a dent of an evaporation material in a crucible due to an electron beam by a dent detection method, and detecting a dent by the dent detection method. Interrupting the deposition process and flattening the dents on the surface of the evaporating material in the crucible by irradiating an electron beam. The electron gun heating type vacuum deposition method is a method of controlling the electron gun filament current and comparing the filament current with a set current value. 2. A vacuum vapor deposition method using an electron gun heating method, wherein a vapor deposition process is performed while monitoring a dent of an evaporating material in a crucible by an electron beam by a dent detection method, and when a dent is detected by the dent detection method. Interrupting the deposition process and flattening the dents on the surface of the evaporating material in the crucible by electron beam irradiation. A vacuum deposition method using an electron gun heating method, which is a method for detecting a dent by reflected laser light. 3. The electron gun heating method according to claim 1, wherein said method of flattening the dents includes sweeping an electron beam irradiation site on a surface of the evaporation material in the crucible to flatten the surface. Vacuum deposition method. 4. The flattening method according to claim 1, wherein the irradiation position of the electron beam is fixed and the crucible is moved horizontally in one direction or two directions.
3. An electron gun heating type vacuum deposition method according to claim 1, further comprising the step of moving the surface to flatten the surface. 5. The electron gun heating type vacuum deposition method according to claim 1, wherein the method of flattening the dents replenishes and adds an evaporating material to the dents and averages the surface by electron beam irradiation. 6. A vacuum evaporation method using an electron gun heating method, wherein the irradiation position of the electron beam on the surface of the evaporation material in the crucible is fixed with respect to the apparatus, and the crucible is moved substantially horizontally in one or two directions. A vacuum deposition method of an electron gun heating method including performing a deposition process.