JP2004131832A - Apparatus and method for depositing film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To deposit a thin film without causing damage to a film depositing objective material. <P>SOLUTION: In a film depositing apparatus 1, the surrounding of a vapor-depositing source 6 and an EB (electron beam) gun 3, is covered with a deposit-preventive member 16 having an opening part 9 and under state of closing a shutter 15, this opening part 9 is covered with a plate part 12 of the shutter 15. Since the portion near the opening part 9 of the deposit-preventive member 16 is surrounded with a projected line 13 of the shutter 15, when the electron beam 25 is radiated under state of closing the shutter 15, even in the case of leaking energy ray developed by radiating the electron beam 25 from the interval between the plate part 12 and the edge part of the opening part 9, a substrate 11b as the film-depositing objective material does not receive the damage because the energy ray is shut off with the projected line 13. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technical field of a method of forming a thin film, and more particularly to a technique of forming an electrode film of an organic EL device or a semiconductor device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a method for forming a metal film such as an electrode film, a vapor deposition method is used in which a vapor deposition material is heated to generate vapor and the vapor reaches a film formation target.
Among the vapor deposition methods, an EB (Electron Beam) vapor deposition method in which a vapor is generated by irradiating an electron beam to the vapor deposition material has a higher heating capability than other heating methods such as a resistance heating method. There are various advantages such as many types, high mass productivity, and a high purity thin film.
[0003]
However, when the film is formed by the EB evaporation method, during the film formation, in addition to the vapor, a recoil electron having a very high energy of several keV, a secondary electron having an energy of several eV or more, an ion, In addition, various energy rays such as ultraviolet rays and X-rays generated by irradiating the material with electrons are generated.
[0004]
Therefore, when an electrode film of an organic EL device or a semiconductor device is formed by the EB evaporation method, the device body may be damaged during the film formation due to the above-described energy rays such as charged particles and electromagnetic waves.
[0005]
[Problems to be solved by the invention]
The present invention has been made to solve the above problems, and an object of the present invention is to provide a technique for forming a thin film without damaging a device main body.
[0006]
[Means for Solving the Problems]
The inventors of the present application have examined the film forming rate of the conventional EB vapor deposition, and found that the film forming rate does not immediately become zero even after the time A when the EB irradiation was stopped as shown in the graph of FIG. all right. Investigation of the reason revealed that the generation of steam continued due to residual heat.
[0007]
Therefore, if EB irradiation is performed in a state where the evaporation source is surrounded by a deposition-preventing member having an opening and the opening is covered with a shutter, energy rays such as charged particles and electromagnetic waves generated by the EB irradiation can reach the film formation target. In addition, if the shutter is opened after stopping the electron beam, the vapor reaches the film formation target, so that the film formation can be performed without being damaged.
[0008]
The invention according to claim 1, which has been made based on the above knowledge, has a deposition source, an EB gun, a substrate holder, and a shutter, and the deposition source and the periphery of the EB gun have openings. Covered with a member, the substrate holder is disposed above the opening, the shutter is attached to a moving device, and is movable between a position between the opening and the substrate holder and a position separated from the opening. In the state where the shutter is arranged at a position between the opening and the substrate holder, the EB gun irradiates an electron beam to the deposition material of the deposition source to generate a vapor of the deposition material, A film forming apparatus configured such that the vapor is blocked by a shutter and does not reach the substrate holder, wherein the shutter is attached to a plate-shaped plate portion larger than the opening and a bottom surface of the plate portion. The moving device is configured to be able to move the shutter up and down, and when the shutter is lowered over the opening, a portion near the opening of the attachment-preventing member is surrounded by the projecting ridge. This is a film forming apparatus configured to be operated.
According to a second aspect of the present invention, the vapor deposition material is irradiated with an electron beam to generate vapor of the vapor deposition material, and the vapor reaches a film formation target disposed above the vapor deposition material, and the vapor deposition is performed. A film forming method for forming a thin film on a surface of an object, comprising irradiating the electron beam with a shutter disposed above the vapor deposition material, starting emission of the vapor, and then irradiating the electron beam. Is stopped, and then the shutter is retracted from a position above the vapor deposition material to a retracted position that does not prevent the vapor from reaching the film formation target, and the film reaches the film formation target. Is the way.
The invention according to claim 3 is the film forming method according to claim 2, wherein the step of arranging the shutter at a position above the vapor deposition material and irradiating an electron beam, and retracting the shutter to the retracted position. And forming a thin film on the substrate surface by repeating the step of causing the vapor to reach the object to be film-formed without irradiating the electron beam.
[0009]
The present invention is configured as described above, and the plate portion of the film forming apparatus of the present invention has a planar shape larger than the opening, so that when the shutter is arranged over the opening, the opening is covered with the plate portion. It has become.
Also, since the ridges are arranged on the back surface of the plate portion, the shutter is arranged above the opening, and the shutter is lowered in a state where the ridges are arranged above the opening, the vicinity of the opening of the attachment-preventing member is reduced. Are surrounded by ridges.
[0010]
If a film of an X-ray absorbing material such as lead is formed at least in the portion covering the opening of the shutter, or if the thickness of the plate portion is made sufficiently large, not only ultraviolet rays but also X-rays and γ-rays High energy rays can be shielded.
[0011]
Next, the film forming method of the present invention will be described.
When the electron beam is irradiated, the temperature of the deposition material rises, and the temperature of the entire deposition material rises at the end. Therefore, as the irradiation time of the electron beam becomes longer, the deposition rate increases. On the other hand, when the irradiation of the electron beam is stopped, the temperature decreases, and the film forming speed gradually decreases.
[0012]
When the shutter is opened and the film formation is started after the irradiation of the electron beam is stopped, the film formation speed is large immediately after the start of the film formation, and the film formation speed gradually decreases with time. When the film forming speed becomes lower than a certain speed, the thin film no longer grows, so that the shutter is closed to terminate the film forming operation.
[0013]
The time from when the shutter is opened to when it is closed is the film formation time. Generally, the film formation time is set in advance according to the conditions of the apparatus or the like. The higher the deposition rate, the better.
[0014]
The relationship between the type of deposition material and the amount of power supplied to the EB gun to be used, and the change in the deposition rate when irradiating an electron beam is measured in advance, and a thin film having a desired thickness can be formed at a set deposition time. The film formation speed at the time of opening the shutter to obtain the thickness can be obtained in advance by measurement or calculation. Therefore, a thin film having a desired film thickness can be obtained by irradiating the electron beam for the irradiation time obtained in advance.
[0015]
In addition, if a film thickness sensor is arranged above the opening and near the substrate holder and film formation is performed while measuring the film thickness with the film thickness sensor, the film formation time and the film formation speed are obtained in advance. A thin film having a desired film thickness can be obtained without performing the above.
[0016]
When a thin film having a large thickness is formed, the film thickness of the thin film formed by opening and closing the shutter once is obtained in advance, and the film is formed by repeatedly opening and closing the shutter on one substrate. A thin film having a desired thickness can be obtained. Also in this case, if the irradiation time is determined in advance, a thin film having a predetermined thickness can be formed in a constant film formation time without measuring the film formation rate.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Reference numeral 1 in FIG. 1 indicates an example of a film forming apparatus of the present invention. The film forming apparatus 1 includes a vacuum chamber 2, an evaporation source 6, an EB gun 3, a deposition prevention member 16, a shutter 15, and a substrate holder 7.
[0018]
The deposition-inhibiting member 16 is formed by forming a thin metal plate into a cylindrical shape, and is installed on the bottom wall of the vacuum chamber 2 with the center axis of the cylinder being vertical. That is, one opening of the attachment member 16 is directed toward the ceiling, and the other is in close contact with the bottom wall.
Reference numeral 9 in FIG. 1 denotes an upper opening, and the vicinity of the upper opening 9 of the deposition-inhibiting member 16 is smaller in diameter than the center.
[0019]
A vacuum pump 19 and a moving device 17 are provided outside the vacuum chamber 2. A rod-shaped pointing shaft 14 is vertically and airtightly inserted into the vacuum chamber 2, and the lower end thereof is attached to the moving device 17. Installed.
[0020]
The shutter 15 has a disk-shaped plate portion 12, and the plate portion 12 is horizontally attached to the tip of the arm portion 21. A ridge 13 is disposed at a position along the edge of the lower surface of the plate portion 12. That is, the ridge 13 has a ring shape. The plate portion 12 is a disk having a larger diameter than the opening 9, and the inner diameter of the ring of the ridge 13 is made larger than the opening 9.
[0021]
The moving device 17 is configured to rotate or raise and lower the support shaft 14 based on a signal from a control device (not shown), move the support shaft 14 upward, and make the shutter 15 After the shutter 15 is positioned above the opening 9 by rotating the support shaft 14 and then the shutter 15 is lowered, the opening 9 is covered with the plate portion 12 and the opening 9 is closed with the shutter 15. Become loose. In this state, the opening 9 is closed by the shutter 15, and a portion near the opening 9 of the deposition-inhibiting member 16 is surrounded by the ridge 13.
[0022]
The evaporation source 6 and the EB gun 3 are arranged inside the deposition-inhibiting member 16, and the EB gun 3 is connected to a power supply (not shown) arranged outside the vacuum chamber 2.
The vacuum pump 19 is connected to both the space surrounded by the deposition prevention member 16 of the vacuum chamber 2 and the space outside the deposition prevention member 16, and starts the vacuum pump 19 to be surrounded by the deposition prevention member 16. After evacuating both the space and the outer space to a predetermined pressure, the power supply is activated and the EB gun 3 emits an electron beam.
[0023]
FIG. 3 shows a state in which the electron beam 25 is emitted. The electron beam 25 is irradiated on the vapor deposition material 5 arranged in advance on the vapor deposition source 6, and the vapor deposition material 5 is heated. When the temperature of the vapor deposition material 5 rises to a temperature equal to or higher than a certain temperature determined by its physical properties, vapor of the vapor deposition material 5 is generated.
[0024]
The evaporation source 6 is disposed immediately below the opening 9, and the generated vapor is discharged toward the opening 9. During irradiation with the electron beam 25, energy rays such as ultraviolet rays, X-rays and electromagnetic waves are also emitted. However, if the opening 9 is closed with the shutter 15, the energy rays are absorbed or reflected by the plate portion 12. You. Further, even when the energy ray leaks from the plate portion 12 and the end of the opening 9 of the attachment member 16, the energy beam is blocked by the ridge 13, so that it does not enter the space above the shutter 15.
[0025]
From the state in which the shutter 15 is closed, the support shaft 14 is moved upward by the moving device 17 until the ridge 13 is positioned above the opening 9. FIG. 4 shows this state. Next, the support shaft 14 is rotated so that the plate portion 12 is completely retracted from above the opening 9, and is moved to a retracted position where the opening 9 is not blocked by the plate portion 12.
[0026]
FIG. 5 is a relative sectional view showing a positional relationship between the shutter 15 and the opening 9 in this state. In this state, the shutter 15 is opened, and the generated steam flies from the opening 9 toward the ceiling.
The substrate holder 7 is disposed right above the opening 9. When the substrate to be formed is held by the substrate holder 7 with the film formation surface facing the opening 9, the substrate holder 7 is moved from the opening 9. The released vapor reaches the substrate, and a thin film grows on the surface.
[0027]
When the shutter 15 is opened, the irradiation of the electron beam 25 is stopped, so that no energy rays are generated and the substrate is not damaged. A process of continuously forming a film on a plurality of substrates using the film forming apparatus 1 will be described.
[0028]
Reference numeral 11a in FIG. 2 indicates a substrate on which a film forming process has been completed in a later-described step, and reference numeral 22a in FIG. 2 indicates a thin film formed on the surface of the substrate 11a.
A not-shown carry-in / out chamber is connected to the vacuum chamber 2, and a vacuum atmosphere of a predetermined pressure is formed in advance in the vacuum chamber 2 and the carry-in / out chamber, and a film is formed by a transfer robot (not shown) arranged in the carry-in / out chamber. The completed substrate 11a is transported from the substrate holder 7 to the loading / unloading chamber, replaced with an unprocessed substrate in the loading / unloading chamber, the substrate is loaded into the vacuum chamber 2, and the substrate holder is placed in a state where the film formation surface faces downward. 7 is held.
[0029]
FIG. 3 shows a state where the unprocessed substrate 11 b is held by the substrate holder 7.
At this time, the electron beam 25 is irradiated while the shutter 15 is closed, and the deposition material 5 is heated.
[0030]
The relationship between the irradiation time and the film formation rate is obtained in advance, and when irradiation is performed until the preset irradiation time elapses from the start of irradiation of the electron beam 25, a predetermined amount of vapor is released. Since the shutter 15 is closed while the electron beam 25 is being irradiated, the vapor does not reach the substrate 11b.
[0031]
When the irradiation of the electron beam 25 is stopped and the shutter 15 is opened after the elapse of the irradiation time, the vapor reaches the substrate 11b and a thin film grows on the surface thereof. The relationship between the growth rate of the thin film and the time is determined in advance, and the shutter 15 is closed when the predetermined film forming time has elapsed from the time when the shutter 15 was opened and the amount of vapor emission has decreased, and the electron beam The irradiation of 25 is restarted.
[0032]
The electron beam 25 is irradiated for a certain time, and when a predetermined amount of vapor is released from the vapor deposition material 5, the irradiation of the electron beam 25 is stopped, the shutter 15 is opened, and a film is formed. While the substrate 11b is kept at the same position, the film formation is repeated while the irradiation with the electron beam 25 is stopped as described above. When the number of times to reach the desired film thickness is completed, the shutter 15 is closed and the electron beam 25 is closed. , The substrate 11b is carried out of the vacuum chamber 2 to the carry-in / out room.
[0033]
While the deposition material 5 is being heated by the electron beam 25, the unprocessed substrate is carried into the vacuum chamber 2 and held by the substrate holder 7, and when a predetermined amount of vapor is released by heating, the electron beam 25 is discharged. After stopping, the shutter 15 is opened, and film formation is started on a new unprocessed substrate. By repeatedly processing the substrates one by one as described above, a thin film having a desired thickness can be continuously formed on a plurality of substrates.
[0034]
FIG. 4 shows the relationship between the time at which the irradiation with the electron beam 25 is started, the time at which the irradiation with the electron beam is stopped, and the film forming speed in the above-described film forming process.
Symbols S ₁ , S ₂ , and S _{3 in} FIG. 6 indicate irradiation start times at which electron beam irradiation has started, and symbols E ₁ , E ₂ , and E ₃ indicate irradiation end times at which electron beam irradiation has ended. .
[0035]
After the irradiation end times E ₁ , E ₂ , and E ₃ , the amount of released steam is reduced, and the deposition rate is reduced. If the deposition rate is reduced to some extent, even if the deposition is continued further, the growth of the thin film becomes extremely slow, and the deposition efficiency is reduced. If the time before the film formation rate becomes zero is defined as irradiation start times S ₁ , S ₂ , and S ₃ and heating is started, the irradiation time can be shortened, and the overall work time can be shortened.
[0036]
Although the case where the shutter 15 is opened for a very short time after stopping the irradiation of the electron beam 25 has been described above, the present invention is not limited to this. After a lapse of time, the shutter 15 can be opened after the energy rays have completely disappeared.
[0037]
The case where the shutter 15 is closed and the irradiation of the electron beam 25 is started in a very short time has been described above. However, the present invention is not limited to this. After the is completely closed, the irradiation of the electron beam 25 can be started.
[0038]
Further, the case where the irradiation of the electron beam 25 is started before the substrate 11b on which the film formation has been completed is carried out from the substrate holder 7 has been described above, but the present invention is not limited to this. Starts the irradiation of the electron beam 25 when unloading the substrate 11b from the substrate holder 7, starts the irradiation of the electron beam 25 when unloading the unprocessed substrate, or holds the unprocessed substrate in the substrate holder 7. After that, irradiation of the electron beam 25 can be started.
[0039]
The case where the substrate 11b on which film formation has been completed is carried out after the shutter 15 is closed has been described above. However, the present invention is not limited to this case. The substrate 11b may be carried out with the 15 open.
[0040]
In the above description, the case where the opening and closing of the shutter 15 and the irradiation of the electron beam are repeated while the substrate 11b is held in the substrate holder 7 and the film formation is repeated a plurality of times on one substrate 11b has been described. The present invention is not limited to this. If a sufficient film thickness can be ensured in one film forming step, the film forming step is completed by opening and closing the shutter 15 once, and the substrate 11 is removed from the vacuum chamber 2. It can also be carried out to The present invention also includes a case where the shutter 15 is spirally moved by simultaneously rotating the support shaft 14 up and down by the moving device 17.
[0041]
Various materials such as a metal material such as aluminum and a metal oxide such as magnesium oxide and calcium oxide can be used as the deposition material 5.
When an electron beam is emitted while supplying a reaction gas such as oxygen to a position near the deposition source 6, a thin film of an oxide of a deposition material can be formed.
[0042]
【The invention's effect】
With the use of the film forming apparatus of the present invention, energy rays such as ultraviolet rays can be shielded from a film formation target during film formation. Therefore, when an electrode film of an organic EL device, a protective film of a semiconductor, or the like is formed using the film forming apparatus of the present invention, the device is not damaged at the time of film formation due to ultraviolet rays, electromagnetic waves, or the like.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a film forming apparatus of the present invention. FIG. 2 is a cross-sectional view illustrating a state where a film forming process is completed. FIG. 3 is a cross-sectional view illustrating a state where an electron beam is irradiated. 4 is a cross-sectional view illustrating a state in which the shutter is moved upward. FIG. 5 is a cross-sectional view illustrating a state in which the shutter is moved in a horizontal plane. FIG. 6 is a time for starting irradiation of the electron beam and a time for stopping irradiation. FIG. 7 is a graph showing a relationship between a film forming speed and a film forming speed. FIG. 7 is a graph showing a relationship between a film forming speed and time in conventional EB vapor deposition.
DESCRIPTION OF SYMBOLS 1 ... Deposition apparatus 2 ... Vacuum tank 3 ... EB gun 5 ... Deposition material 6 ... Deposition source 7 ... Substrate holder 9 ... Opening 11 ... Deposition target (substrate) 12 ... Plate part 13... Protrusion 15... Shutter 16.

Claims (3)

An evaporation source, an EB gun, a substrate holder, and a shutter,
The vapor deposition source and the periphery of the EB gun are covered with a deposition prevention member having an opening,
The substrate holder is disposed above the opening,
The shutter is attached to a moving device, and is movable between a position between the opening and the substrate holder and a position separated from the opening,
In a state where the shutter is arranged at a position between the opening and the substrate holder, the EB gun irradiates the deposition material of the deposition source with an electron beam to generate vapor of the deposition material. A film forming apparatus configured to be blocked by a shutter and not reach the substrate holder,
The shutter has a plate-like plate portion larger than the opening, and a ridge attached to a bottom surface of the plate portion,
The moving device is configured to move the shutter up and down,
A film forming apparatus configured such that when the shutter moves down on the opening, a portion near the opening of the deposition-inhibiting member is surrounded by the ridge. The vapor deposition material is irradiated with an electron beam to generate vapor of the vapor deposition material, and the vapor reaches the film formation target disposed above the vapor deposition material, forming a thin film on the surface of the film formation target. Film forming method,
Irradiating the electron beam in a state where a shutter is disposed above the vapor deposition material, after starting the emission of the vapor, stopping the irradiation of the electron beam, and then moving the shutter from a position above the vapor deposition material, A film forming method in which the vapor is retracted to a retreat position that does not prevent the vapor from reaching the film formation target, and the vapor reaches the film formation target. The step of arranging the shutter at a position above the vapor deposition material and irradiating an electron beam, and retracting the shutter to the retracted position, in a state where the electron beam is not irradiated, and applying the vapor to the film-forming target. 3. The film forming method according to claim 2, wherein the step of reaching is repeated to form a thin film on the substrate surface.

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