JP5202250B2 - Film forming apparatus and film forming method - Google Patents

Description

  The present invention relates to a technique for forming a compound film, and more particularly to a film forming apparatus for forming an MgO film suitable for a protective film of a plasma display panel and a film forming method therefor.

Conventionally, a metal oxide film such as MgO is formed as a protective film on a glass substrate used in a plasma display panel.
An oxygen gas is introduced into the vacuum chamber, an MgO evaporation source is arranged in the vacuum chamber to release MgO vapor, a glass substrate is carried in, and the glass substrate is moved while MgO is moved to the glass substrate surface. A film is formed.
JP 2004-055180 A

  However, the MgO film formed on the glass substrate has low (111) crystal orientation strength on both sides parallel to the direction in which the glass substrate is moved by the transport mechanism (transport direction), and the film density is also low. Variations occurred and the distribution was poor.

In order to solve the above problems, the present invention provides a film forming chamber, a film forming material chamber connected to the film forming chamber and communicated with the inside through an opening, an evaporation source disposed in the film forming material chamber, A reaction gas introduction system for introducing a reaction gas into the film formation chamber, allowing vapor released from the evaporation source to enter the film formation chamber through the opening , with one side of the rectangular film formation target as the head A film forming apparatus that moves while facing the opening in the film forming chamber and forms a compound film on the surface of the film forming object, wherein the film forming object heats the film forming object in the film forming chamber. room heater is provided, the deposition chamber heater, among four sides of the film-forming target that faces the opening, than the top of one side perpendicular double sides, sandwiched between the two sides This is a film forming apparatus for heating the center to a high temperature.
The present invention further includes a heating chamber connected to the film formation chamber via a vacuum valve, and the film formation target is moved from the heating chamber to the film formation chamber by opening the vacuum valve. In the film forming apparatus configured as described above, a heating chamber heater for heating the film forming object is provided in the heating chamber, and the heating chamber heater is provided from the two sides of the film forming object. Is a film forming apparatus configured to heat the center sandwiched between the two sides to a high temperature.
Further, the present invention is a film forming apparatus, wherein the evaporation source is configured to release MgO vapor, and the reactive gas includes oxygen gas.
Further, the present invention introduces a reactive gas into the vacuum chamber, allows film forming material vapor released from an evaporation source to enter the vacuum chamber through an opening , and makes the vacuum with one side of a rectangular film-forming target at the top. moving the internal vessel, the a film forming method for forming a compound film allowed to reach the film-forming material vapor deposition target surface, among four sides of the film-forming target that facing the opening , than the top of one side perpendicular double sides, is a film forming method for forming a central sandwiched between the two sides allowed to reach the film forming material vapor while heating to a high temperature.
Further, the present invention is a film formation method, before the film-forming material vapor on the film-forming target is reached in advance, out of four sides of the film-forming target, than before Symbol two sides, the In this film forming method, the center sandwiched between two sides is heated to a high temperature.
In addition, the present invention is a film forming method that releases MgO vapor from the evaporation source and uses the reaction gas containing oxygen gas.

  The center of the two sides is heated to a higher temperature than the edge part of two sides perpendicular to the first side of the film formation target, and more reaction to the edge part of the two sides of the film formation target than the center part. By performing the film formation while blowing the gas, the (111) crystal orientation strength is improved, the difference in the (111) crystal orientation strength of the MgO film is reduced, and the dispersion in distribution is reduced. Further, the film density distribution of MgO Was also improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a panel manufacturing apparatus (film forming apparatus) according to an embodiment of the present invention.
The panel manufacturing apparatus 1 includes a carry-in chamber 11, a heating chamber 12, a process chamber 13, a cooling chamber 15, and a carry-out chamber 16.
The carry-in chamber 11, the heating chamber 12, the process chamber 13, the cooling chamber 15, and the carry-out chamber 16 are connected in this order via a vacuum valve 18, and a transfer mechanism is provided inside. Yes.

Here, the structure of the heating chamber 12 and the process chamber 13 of this invention is shown in FIG. 2 and FIG.
As shown in FIG. 2, the heating chamber 12 and the process chamber 13 are each composed of a vacuum chamber 21. The process chamber 13 has a film forming chamber 22 and a film forming material chamber 23.
The film forming chamber 22 has an elongated shape, and has an inlet and an outlet by a vacuum valve 18 at one end and the other end. The film forming material chamber 23 is located below the film forming chamber 22, and the ceiling of the film forming material chamber 23 and the bottom surface of the film forming chamber 22 are connected.

On the bottom surface in the film forming material chamber 23, an MgO evaporation source 31 is arranged at a position directly below a portion where the film forming material chamber 23 and the film forming chamber 22 are connected. The MgO evaporation source 31 has a crucible, and granular MgO is disposed inside the crucible.
An electron gun 32 is provided in the film forming material chamber 23. When the electron gun 32 is operated, MgO in the crucible is irradiated with an electron beam and MgO vapor is emitted.

  A restricting plate 27 is disposed at a connection portion between the film forming chamber 22 and the film forming material chamber 23, and an opening 28 is formed in the restricting plate 27 at a position directly above the MgO evaporation source 31. Accordingly, the vapor of MgO released from the MgO evaporation source 31 enters the film forming chamber 22 through the opening 28.

The film forming chamber 22 is provided with a transport mechanism 29, and a holding unit 30 is attached to the transport mechanism 29. The glass substrate 10, which is a processing object held by the holding means 30, is configured to move from the inlet toward the outlet while passing through the position directly above the opening 28 and facing the opening 28.
The process chamber 13 has two gas ejection pipes.

Reference numerals 33a and 33b in FIGS. 2 and 3 denote gas ejection pipes, respectively.
The gas ejection pipes 33 a and 33 b are provided closer to the film forming material chamber 23 than the transport mechanism 29 in the film forming chamber 22. Further, the gas ejection pipes 33a and 33b are located outside the opening 28 and on the upstream side and the downstream side of the upstream end of the opening 28 on the transport path of the glass substrate 10 by the transport mechanism 29. Further, they are arranged on the downstream side, so that the vapor of MgO released from the opening 28 is not prevented from entering the film forming chamber 22.

Each gas ejection pipe 33a, 33b is pipe-shaped and is directed in a direction perpendicular to the direction (conveyance direction) in which the glass substrate 10 is moved by the conveyance mechanism 29.
The gas ejection pipes 33a and 33b are connected to the reaction gas introduction system 35, and the gas ejection pipes 33a and 33b are each provided here with a plurality of gas ejection holes 34 arranged in a direction perpendicular to the transport direction. Has been. The reaction gas introduced from the reaction gas introduction system 35 into the gas ejection pipes 33 a and 33 b is configured to be ejected from the gas ejection holes 34.

  Each gas ejection pipe 33a, 33b is positioned between the glass substrate 10 moved by the transport mechanism 29 and the opening 28, and each gas ejection hole 34 faces the glass substrate 10 to be moved. It is configured. The reaction gas ejected from each gas ejection hole 34 is blown to the glass substrate 10 to be moved.

  Here, the glass substrate 10 has a quadrangular shape, and among the four sides, two sides are parallel to the transport direction and two sides are oriented perpendicular to the transport direction. When the two sides parallel to the transport direction are defined as the sides, the edge portions on both sides of the glass substrate 10 are set so that a relatively large amount of reaction gas can be sprayed onto the central portion. The opening 28 is configured to be larger than the glass substrate 10.

  Therefore, while the glass substrate 10 is facing the opening 28, more reactive gas is blown onto the edge portions on both sides of the glass substrate 10, so that the MgO vapor is applied to the edge portions on both sides of the glass substrate 10. More reactive gas than the central portion reaches, while the central portion of the glass substrate 10 reaches MgO vapor in the reactive gas atmosphere. Therefore, the crystallinity of MgO is improved at the edge portions on both sides of the glass substrate 10.

  A heater 36 is provided on the back side of the glass substrate 10 that is moved by the transport mechanism 29 in the heating chamber 12 and the process chamber 13, and the heater 36 has a plurality of elongated heaters 36 a. Here, the elongated heaters 36a are oriented in a direction parallel to the transport direction, and are arranged in a direction orthogonal to the transport direction.

The length of the elongated heater 36a in the longitudinal direction is the same as or larger than that of the opening 28, and the elongated heaters 36a at both ends are arranged outside the moving glass substrate 10.
Moreover, although not shown in figure, the heater 36 of the heating chamber 12 is provided with an auxiliary heater in order to heat and heat the glass substrate 10 and control the temperature distribution.

  Each elongate heater 36a has a uniform temperature distribution, and the elongate heaters 36a at both ends in the direction orthogonal to the transport direction are set to have a relatively lower temperature than the elongate heater 36a at the center. . Therefore, the glass substrate 10 is heated with a temperature difference so that the temperature of both side portions of the glass substrate 10 is relatively lower than the temperature of the central portion.

A process of forming the MgO film using the panel manufacturing apparatus 1 will be described.
The chambers 11 to 13, 15, and 16 of the panel manufacturing apparatus 1 are connected to an evacuation system 19. The evacuation system 19 is operated and the chambers 12, 13, 15, and 16 other than the carry-in chamber 11 are operated. Evacuate and leave a vacuum atmosphere inside. Further, the heaters 36 in the heating chamber 12 and the process chamber 13 are heated to a predetermined temperature.
After the glass substrate 10 is attached to the holding means 30 and carried into the carry-in chamber 11, the inside of the carry-in chamber 11 is evacuated to a predetermined pressure.

Next, the vacuum valve 18 is opened, and the holding means 30 holding the glass substrate 10 is moved into the heating chamber 12 by the transport mechanism 29.
The glass substrate 10 moved into the heating chamber 12 is stopped, and the glass substrate 10 is heated with a temperature difference so that the temperature on both sides of the glass substrate 10 is relatively lower than the temperature of the central portion. And raise the temperature inside.

After the inside of the glass substrate 10 reaches a predetermined temperature, the vacuum valve 18 is opened, and the holding means 30 holding the glass substrate 10 is moved to the process chamber 13 by the transport mechanism 29.
In addition, a reaction gas of oxygen and water (H ₂ O) is introduced from the reaction gas introduction system 35 into the gas ejection pipes 33a and 33b, and the reaction gas is ejected from the gas ejection holes 34, thereby forming the film forming chamber 22 and the film forming material. The inside of the chamber 23 is kept in an atmosphere of reaction gas.

While the glass substrate 10 heated to a predetermined temperature is moved into the film forming chamber 22 by the transport mechanism 29 and moved to a position above the MgO evaporation source 31, the glass substrate 10 is heated by the heater 36.
MgO vapor is released from the MgO evaporation source 31.
The glass substrate 10 carried into the film forming chamber 22 is moved by the transport mechanism 29 so as to face the opening 28.

  While the glass substrate 10 and the opening 28 are facing each other, the reaction gas ejected from the gas ejection hole 34 is blown onto the glass substrate 10, and is also discharged from the MgO evaporation source 31 and from the opening 28 into the film forming chamber 22. The MgO vapor that has entered the glass reaches the surface of the glass substrate 10, and an MgO film is formed on the surface of the glass substrate 10. The glass substrate 10 faces the opening 28 while moving, and the vapor of MgO reaches the entire surface of the glass substrate 10. At this time, the glass substrate 10 is heated by the heater 36 in a state where a temperature difference is provided so that the temperature of both side portions of the glass substrate 10 is relatively lower than the temperature of the central portion. As a result of forming the MgO film in the process chamber 13, the average value of the (111) crystal orientation strength of the MgO film formed on the glass substrate 10 is increased, and the strength distribution and film of the (111) crystal orientation are further increased. The density distribution was improved compared to the conventional one.

When the MgO film having a predetermined thickness is formed on the surface of the glass substrate 10, the glass substrate 10 is moved to the cooling chamber 15 by the transport mechanism 29, cooled, and then moved to the carry-out chamber 16.
When the glass substrate 10 is carried into the carry-out chamber 16, the vacuum valve 18 between the cooling chamber 15 is closed, the exhaust of the carry-out chamber 16 is stopped, and the atmosphere is introduced to make the inside an atmospheric atmosphere. Then, when it takes out from the carrying-out chamber 16 in air | atmosphere, the glass substrate 10 in which the MgO film | membrane was formed can be obtained.

As for the reaction gas blown to the glass substrate 10, oxygen and water (H ₂ O) of each gas jet pipe 33a, is introduced into 33b was to be ejected from the gas ejection holes 34, limits the gas jet pipe plate 27 Further, oxygen may be introduced from one side and water from the other side may be introduced by the gas ejection pipe above the restriction plate 27 and the gas ejection pipe below the restriction plate 27.

  Further, in the present embodiment, each gas ejection pipe 33a, 33b is provided in a direction orthogonal to the transport direction, but as shown in FIGS. 4 and 5, two gas ejection pipes 33a, 33b may be provided, and reactive gas may be sprayed to the edge portions on both sides of the glass substrate 10, or four gas ejection pipes may be used in both the direction orthogonal to the transport direction and the direction parallel to the transport direction. You may arrange. Moreover, although the several gas ejection hole 34 was formed in each gas ejection pipe | tube 33a, 33b, the reactive gas should just be sprayed on the both sides of the glass substrate 10, and it is not limited to the said embodiment.

Further, although the heater 36 is provided only on the back side in the heating chamber 12, it may be provided on the front side of the glass substrate 10.
In this embodiment, the electron gun 32 is used for vapor deposition, but a method such as ion plating may be used.

<Gas introduction experiment>
2 and 3, an MgO film was formed on a glass substrate for PDP having an effective film thickness range of 1300 mm × 1100 mm by a vacuum deposition method of about 800 nm (8000 mm).
At this time, two electron guns 32 are used and charged at 10 kW each, the dynamic rate is 400 nm · m / min (4000 mm · m / min), the temperature of the glass substrate 10 is about 250 ° C., and the pressure in the film forming chamber 22 is 4. 0.0 × 10 ⁻² Pa.

The reaction gas was oxygen gas, and 135 sccm of oxygen was introduced from the reaction gas introduction system 35. The diameter of the gas ejection holes 34 was 0.5 mm, and they were arranged at 15 mm intervals. The angle at which the reactive gas was sprayed onto the glass substrate 10 was 45 °.
The relationship between the flow rate of the reactive gas sprayed and the position of the glass substrate 10 is shown in FIG. The horizontal axis indicates the position on the glass substrate 10 in the direction perpendicular to the transport direction, and the vertical axis indicates the reactive gas when the point where the amount of reactive gas blown is the largest is 1.0. The flow rate ratio is shown.

As shown in FIG. 6, a relatively larger amount of reaction gas is sprayed on both side portions of the glass substrate 10 than on the central portion.
The (111) crystal orientation strength of the MgO film formed under the above conditions was examined by X-ray diffraction. The (111) crystal orientation strength distribution is shown in FIG.

Further, the refractive index of the MgO film formed under the above conditions was measured to obtain the film density. The film density distribution is shown in FIG.
As a comparative example, an MgO film was formed by introducing oxygen gas into the process chamber 13 so that no reactive gas was blown onto the glass substrate 10 under the above conditions. FIG. 12 shows the (111) crystal orientation strength distribution of the MgO film thus formed, and FIG. 13 shows the film density distribution.

  7 and FIG. 12, the (111) crystal orientation strength distribution of the comparative example was 2784 cps ± 28.3%, but the (111) crystal orientation strength distribution of this example was 3484 cps ± 16.3. The (111) crystal orientation strength of the MgO film is improved as compared with the comparative example, and the (111) crystal orientation strength of both side portions of the glass substrate 10 is improved. Differences were reduced and distribution variation was improved.

  8 and FIG. 13, the film density of the comparative example was 85.9% at the highest and 82.3% at the lowest, which was a difference of 3.6 points. The film density was 82.9% at the highest and 81.9% at the lowest, and the difference was improved to 2.0 points.

<Heating temperature difference experiment>
Next, using the process chamber 13 of FIGS. 2 and 3, oxygen gas is introduced into the process chamber 13 so that the reaction gas is not blown onto the glass substrate 10, and the temperature of the elongated heater 36 a is set to the temperature of the glass substrate 10. The MgO film was formed by changing the position. Eleven elongated heaters 36a are provided, and the temperature distribution of the glass substrate 10 is 200 ° C. on the both sides of the glass substrate 10 during the MgO film formation, and the maximum temperature portion is 250 ° C. as shown in FIG. As described above, the temperature of each elongated heater 36a was set.

The conditions other than setting the temperature on both sides of the elongated heater 36a low and introducing the reactive gas so as not to blow on the glass substrate 10 were the same as the conditions of the gas introduction experiment.
FIG. 10 shows the (111) crystal orientation strength distribution of the MgO film formed under the above conditions, and FIG. 11 shows the film density distribution.

  Also in this experiment, each of the elongated heaters 36a is uniformly set to the same temperature and introduced so as not to spray the reaction gas onto the glass substrate 10, and other conditions are compared with the MgO film formed under the same conditions as in this embodiment. Use as an example to compare.

  10 and FIG. 12, the (111) crystal orientation strength distribution of the comparative example was 2784 cps ± 28.3%, but the (111) crystal orientation strength distribution of this example was 3047 cps ± 13.7. %, The (111) crystal orientation strength of the MgO film was improved as compared with the comparative example, and the difference in (111) crystal orientation strength was reduced, thereby improving the distribution variation.

  Further, comparing FIG. 11 and FIG. 13, the film density of the comparative example was 85.9% at the highest and 82.3% at the lowest, and there was a difference of 3.6 points. The density was 84.3% at the highest and 82.1% at the lowest, and the difference was improved to 2.2 points.

  From these experimental results, in the case where the reaction gas was sprayed on the glass substrate 10 during film formation, and in the case where the temperature of the elongated heater 36a at both ends for heating during film formation was set relatively lower than the central portion, Compared to the comparative example, the (111) crystal orientation strength of the MgO film formed on the glass substrate 10 is improved, and the difference in the (111) crystal orientation strength is reduced, thereby reducing the variation in distribution. The film density distribution was also improved.

  From this, it is more effective to spray MgO on the glass substrate 10 at the time of film formation, and to set the temperature of the elongated heater 36a at both ends for heating at the time of film formation relatively lower than the central part, thereby making MgO more effective. It is considered that the (111) crystal orientation strength of the film and the film density distribution of the MgO film are improved.

  In this embodiment, an MgO single crystal is used as a film forming material, but the present invention can also be applied to film formation of a material containing MgO and other metal oxide films.

The figure for demonstrating the structure of the panel manufacturing apparatus of this invention Sectional drawing for demonstrating the structure of the heating chamber of this invention, and a process chamber The top view for demonstrating the structure of the heating chamber of this invention, and a process chamber Sectional drawing for demonstrating the structure of the heating chamber of another example of this invention, and a process chamber The top view for demonstrating the structure of the heating chamber of another example of this invention, and a process chamber In the gas introduction experiment, a graph showing the flow rate of the sprayed reaction gas to the position on the glass substrate Graph showing (111) crystal orientation strength distribution in gas introduction experiment Graph showing film density distribution in gas introduction experiment Graph showing temperature distribution of glass substrate in film formation chamber in heating temperature difference experiment Graph showing (111) crystal orientation strength distribution in heating temperature difference experiment Graph showing film density distribution in heating temperature difference experiment The graph which shows (111) crystal orientation intensity distribution of a comparative example Graph showing film density distribution of comparative example

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Glass substrate 12 ... Heating chamber 13 ... Process chamber 22 ... Deposition chamber 23 ... Deposition material chamber 31 ... MgO evaporation source 33a, 33b ... Gas ejection pipe 34 ... Gas ejection hole 35 ... ... Reactive gas introduction system 36 ... Heater 36a ... Elongated heater

Claims (6)

A deposition chamber;
A film forming material chamber connected to the film forming chamber and communicating with the inside through an opening;
An evaporation source disposed in the film forming material chamber;
A reaction gas introduction system for introducing a reaction gas into the film forming chamber;
Allowing the vapor released from the evaporation source to enter the film formation chamber through the opening;
One side of the rectangular film-forming target in the head is moved while facing the opening in said deposition chamber, a deposition apparatus for forming a compound film on the film-forming target surface,
In the film formation chamber, a film formation chamber heater for heating the film formation target is provided ,
The deposition chamber heater, among four sides of the film-forming target which faces the said aperture than said top of one side perpendicular double sides, heated central sandwiched between the two sides to a high temperature A film forming apparatus. A heating chamber connected to the film forming chamber via a vacuum valve is provided, and the film forming object is moved from the heating chamber to the film forming chamber by opening the vacuum valve. A membrane device,
In the heating chamber, a heating chamber heater for heating the film formation target is provided,
  2. The film forming apparatus according to claim 1, wherein the heating chamber heater is configured to heat a center sandwiched between the two sides to a higher temperature than the two sides of the film formation target. The evaporation source is configured to emit MgO vapor;
The film forming apparatus according to claim 1, wherein the reaction gas includes oxygen gas. Introduce reaction gas into the vacuum chamber, let the film forming material vapor released from the evaporation source enter the vacuum chamber through the opening ,
One side of the rectangular film-forming target in the first moving inside said vacuum chamber, said a deposition method for forming a compound film allowed to reach the film-forming material vapor deposition surface of the object,
Among four sides of the film-forming target which faces the said aperture than said top of one side perpendicular double sides, the film-forming material vapor while heating the central sandwiched between the two sides to a high temperature A film forming method for forming a film by reaching the surface. Heated prior to the film forming material vapor reaches the film-forming target in advance of the four sides of the film-forming target, than before Symbol two sides, the middle sandwiched by the two sides to a high temperature The film forming method according to claim 4 . Releasing MgO vapor from the evaporation source;
The film forming method according to claim 4, wherein the reaction gas containing oxygen gas is used.

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