JP2018150581A - Vapor deposition apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology of grasping a residual quantity of a vapor deposition material in a storage part such as a melting pot by grasping temperature of a heating part or storage part for the vapor deposition material.SOLUTION: In a process for controlling a vapor deposition rate of a vapor deposition apparatus to be constant, for example, a storage part such as a melting pot 3 having a shape in which an evaporation area of a vapor deposition material 2 decreases as the vapor deposition material 2 reduces is used. A residual quantity of the vapor deposition material 2 is grasped from a relationship between the evaporation area grasped in advance and temperature of a heating part 5 or storage part 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vapor deposition apparatus such as a vacuum vapor deposition apparatus for depositing a film on a substrate, a method for detecting the remaining amount of vapor deposition material in the vapor deposition apparatus, and the like.

  A vacuum deposition apparatus is an apparatus that forms a film by evaporating a deposition material in a vacuum furnace and depositing it on a deposition object such as a substrate held in the vacuum furnace. The vapor deposition material is vaporized by heating a vapor deposition material container containing the vapor deposition material such as a crucible, if necessary, with a heating means provided around the vapor deposition material. Since the vapor deposition material in the container is consumed by the vapor deposition process, it is necessary to replenish the vapor deposition material at an appropriate timing when the vapor deposition material reaches a desired remaining amount. This is because if the remaining amount of the vapor deposition material is lower than expected, the vapor deposition rate may become unstable, or the crucible may be damaged due to abnormal heating. Therefore, it is important to properly grasp the state of the vapor deposition material in the crucible. However, in some cases, the crucible is provided with a lid for controlling the flow of vapor, and the vapor deposition material is completely covered by the lid. In such a case, since the vapor deposition material cannot be seen from the outside, it is difficult to grasp the remaining amount of the vapor deposition material in the crucible. Therefore, even when the vapor deposition material is completely covered with the crucible or the lid, it is required to appropriately grasp the remaining amount of the vapor deposition material in the crucible.

  Patent Document 1 describes a vacuum deposition apparatus that performs the following processing when the measurement result of the deposition rate and the power of the heating means satisfy predetermined conditions. In patent document 2, it describes about the vacuum evaporation system which grasps | ascertains the residual amount of the vapor deposition material in a crucible by measuring the mass of a crucible with a mass meter.

JP 2009-161842 A Japanese Patent Laid-Open No. 8-129982

  However, in the technique of Patent Document 1, it is possible to grasp the change in the vapor deposition material in the crucible when the crucible is broken, but it is impossible to accurately grasp the remaining amount of the vapor deposition material.

  In the technique of Patent Document 2, the remaining amount of the vapor deposition material in the crucible is indirectly grasped by a mass meter, but the vaporized vapor deposition material is deposited on the surface of the crucible or a lid mounted on the crucible. The effect of doing so cannot be considered. Therefore, the remaining amount of the vapor deposition material cannot be accurately grasped.

  A vapor deposition apparatus according to an aspect of the present invention includes a storage unit that stores a vapor deposition material, a heating unit that heats the storage unit or the vapor deposition material, and a heating monitor unit that detects a temperature of the heating unit or the storage unit. A vapor deposition rate detection unit that detects the vapor deposition rate, and a control unit that controls the heating unit based on the temperature detected by the heating monitor unit so that the vapor deposition rate detected by the vapor deposition rate detection unit is constant. And a vapor deposition apparatus. And the said accommodating part has the shape where the area of the cross section perpendicular | vertical to a depth direction changes in at least one part, The said heating part or the said accommodating part related to the evaporation area of the vapor deposition material in the said accommodating part From the temperature, the remaining amount of the vapor deposition material in the housing portion is detected.

  According to the present invention, the remaining amount of the vapor deposition material in the storage unit such as the crucible can be determined by determining the temperature of the heating unit or the storage unit.

Schematic which shows an example of the vapor deposition apparatus in this invention. Schematic which shows the example of the crucible shape mounted in the vapor deposition apparatus of this invention. The graph which shows the relationship table of the residual amount of vapor deposition material, and the temperature of a heat source. The flowchart which shows an example of the process at the time of implementing this invention.

  In the present invention, in a process in which the deposition rate is controlled to be constant, for example, using an accommodating portion having a shape in which the evaporation area of the deposition material decreases as the deposition material decreases, The remaining amount of the vapor deposition material is grasped from the temperature relationship related to the vapor deposition material. The method of grasping the remaining amount of the vapor deposition material is to detect the remaining amount of the vapor deposition material by knowing the evaporation area from the detection of the temperature of the heating unit or the accommodation unit, and knowing the height in the vapor deposition material accommodation unit.

  An embodiment of the present invention will be described with reference to FIGS. First, the configuration of a vacuum deposition apparatus (hereinafter referred to as the present apparatus) of the present embodiment will be described with reference to FIG. This apparatus includes a crucible 3 (a unified description of the crucible in the following description), a support table 4 for supporting the crucible 3, and a crucible 3 around the crucible 3, which is a container for storing the vapor deposition material 2. A heating source 5 that is a heating unit for heating from a temperature sensor, and a temperature sensor 6 that is a heating monitor unit that measures the temperature of the heating source 5. The temperature sensor 6 may measure the temperature of the crucible 3 as long as the information related to the temperature of the vapor deposition material 2 in the crucible 3 can be grasped. Further, a substrate 7 on which the vapor deposition material is deposited, a substrate holding unit 8 that holds the substrate 7, a shutter 9 that is disposed between the crucible 3 and the substrate 7, and a side portion in the vacuum vessel 1. The vapor deposition rate detection part 10 which detects a vapor deposition rate, and the control part 11 are included. The control unit 11 is connected to the heating source 5, the temperature sensor 6, and the vapor deposition rate detection unit 10 by wires, and controls the amount of power supplied to heat the crucible 3. In addition, the apparatus includes a vacuum pump (not shown) for exhausting the vacuum container 1 to reduce the pressure.

  The vapor deposition material 2 is preferably in the form of granules in consideration of ease of melting. The crucible 3 is preferably made of a metal or ceramic having high heat resistance and high corrosion resistance to the vapor deposition material 2. For example, molybdenum or tungsten is suitable for metals, and PBN, silicon carbide, nitrogen carbide, or the like is suitable for ceramics.

  It is preferable to use a ceramic having a low thermal conductivity so that the support table 4 has heat resistance and heat is difficult to escape through the support table 4. For example, zirconia or alumina is used. The heating source 5 may be a system that indirectly heats the vapor deposition material 2 by heating the crucible 3 or may directly heat the vapor deposition material 2 by high frequency induction heating using a spiral heating coil. Although the temperature sensor 6 detects the temperature of the heating source 5, as described above, the temperature of the crucible 3 may be detected.

  The substrate holding part 8 is arranged in the upper part in the vacuum container 1. A substrate 7 is held on the lower surface of the substrate holding portion 8. In this apparatus, a rotation unit that rotates the substrate holding unit 8 together with the substrate 7 around a rotation axis parallel to the normal direction of the substrate holding unit 8 using a motor or the like may be provided. The shutter 9 is driven in the horizontal direction by a drive mechanism (not shown).

  The vapor deposition rate detector 10 is disposed between the crucible 3 and the substrate 7. The deposition rate detection unit 10 uses, for example, a quartz vibration type. The vapor deposition rate of the vapor deposition material 2 deposited on the substrate 7 can be predicted or detected based on the measurement result of the vapor deposition rate detector 10. The measurement result of the deposition rate detector 10 is fed back to the controller 11. That is, the control unit 11 controls the heating source 5 so that the deposition rate is constant, and the control unit 11 confirms that the deposition rate is constant through the measurement result of the deposition rate detection unit 10. At this time, the control unit 11 also monitors temperature information detected by the temperature sensor 6.

  The control unit 11 has a temperature control mode for controlling the temperature of the heating source 5 and a vapor deposition rate control mode for controlling the vapor deposition rate, and can be switched under desired conditions. In the vapor deposition rate control mode, as described above, the power supplied to the heating source 5 is controlled so that the measurement result of the vapor deposition rate detector 10 becomes the set vapor deposition rate. Based on the measurement result of the temperature sensor 6 from the relationship table between the remaining amount of the vapor deposition material 2 in the crucible 3 and the temperature of the heating source 5 input in advance, the controller 11 deposits the vapor deposition material in the crucible 3. 2 has a function of displaying the remaining amount. More specifically, this relationship table is a relationship table between a distance from the upper end of the crucible and a temperature correction coefficient, which will be described later.

  Moreover, when the measurement result of the temperature sensor 6 exceeds a predetermined value, the power supplied to the heating source 5 may be stopped. Further, the crucible 3 may have a function of exchanging the crucible 3 with another crucible containing the vapor deposition material by a mechanism (not shown), or a mechanism for introducing a new vapor deposition material into the crucible 3 may be provided. . For example, a place where another crucible is stored and a support 4 on which the crucible 3 is installed are connected by a rail mechanism or the like so that both can be exchanged. Further, the place where the container containing the vapor deposition material is stored and the place where the crucible 3 is installed are connected by a rail mechanism or the like, and the container is moved to the crucible 3 to supply the crucible 3 with the vapor deposition material. To do.

  Next, details of the crucible 3 will be described with reference to FIG. As shown in FIG. 2A, the crucible 3 of the present embodiment has a cross-sectional area perpendicular to the depth direction of a part (here, the bottom portion) having a different shape in the depth direction. In other words, at least part of the shape has a portion in which the evaporation area of the vapor deposition material 2 changes as the vapor deposition material 2 stored in the crucible 3 decreases. In the example of FIG. 2A, the evaporation area is constant from the upper surface of the crucible 3 to a predetermined position, and the evaporation area changes (decreases in this case) from the predetermined position to the lower part. The shape may change the evaporation area from the upper end. Moreover, the crucible 3 may be covered with a lid on which slits or the like are formed, instead of a shape in which the upper end is completely opened as shown.

  In addition to the crucible 3 having a spherical lower portion as shown in FIG. 2A, the crucible 3 may have a circular shape at the lower portion of the crucible 3 as shown in FIG. As shown in FIG. 2 (c), a part (three in this case) inside the crucible 3 may have a convex portion. The cross-sectional shape in the direction perpendicular to the depth direction of the crucible 3 can be various, such as a circular shape, an elliptical shape, and a polygonal shape. In order to accurately grasp the remaining amount, it is preferable that the crucible 3 has a unique relationship between the area of the cross section and the depth at least at the bottom.

  Next, a method for grasping the remaining amount of the vapor deposition material 2 using the shape of the crucible 3 as described above will be described. In a process in which the vapor deposition rate is controlled to be constant, if the evaporation area of the vapor deposition material 2 changes, the evaporation amount of the vapor deposition material 2 coming out of the crucible 3 changes, which affects the vapor deposition rate. However, by adjusting the evaporation amount of the vapor deposition material 2 per unit area by changing the temperature of the vapor deposition material 2, the vapor deposition rate can be controlled to be constant. Since the relationship between the temperature of the vapor deposition material 2 and the evaporation amount of the vapor deposition material 2 per unit area is determined by the vapor deposition material, it can be grasped in advance, and based on this, the temperature is controlled according to the change in the evaporation area. Thus, the deposition rate can be controlled to be constant.

  It is assumed that the relationship between the evaporation area of the vapor deposition material 2 and the temperature of the heating source 5 for keeping the vapor deposition rate constant is grasped using the above-described characteristics. Then, when the crucible 3 in which the evaporation area of the vapor deposition material 2 is different in the depth direction is used, the evaporation area of the vapor deposition material 2 can be known from the temperature of the heating source 5, and the height of the vapor deposition material 2 in the crucible 3 is By knowing, it becomes possible to predict or detect the remaining amount of the vapor deposition material in the crucible. The relationship table between the remaining amount of the vapor deposition material 2 in the crucible 3 and the temperature of the heating source 5 may be obtained from experiments in advance, or the temperature of the heating source 5 is corrected based on the evaporation area of the vapor deposition material 2. You may acquire by doing. That is, you may acquire as a relationship table of a temperature correction coefficient and the residual amount of the vapor deposition material 2. FIG.

  Unlike this embodiment, when the function of predicting the remaining amount of the vapor deposition material 2 in the crucible 3 is not provided, the vapor deposition process is started and the vapor deposition process is stopped after a predetermined time has elapsed. become. In that case, the vapor deposition material 2 in the crucible 3 after the vapor deposition process may not reach a desired remaining amount due to the position of the vapor deposition rate detection unit 10 being shifted during maintenance. If a large amount of the vapor deposition material 2 remains, if the vapor deposition material 2 cannot be reused after the vapor deposition process and is discarded, the utilization efficiency of the vapor deposition material 2 is not good. Moreover, the vapor deposition material 2 in the crucible 3 may be lost during the vapor deposition process, and in this case, the crucible 3 may be damaged by abnormal heating.

  According to this embodiment, the amount of the vapor deposition material in the crucible is grasped from the temperature of the heating unit or the crucible. The reason is that, as described above, there is a relationship between the temperature of the heating unit or the crucible and the evaporation rate, and this relationship can be reproduced inherent to the vapor deposition material. In addition, when measuring temperature, it is more suitable for stable temperature measurement to measure the temperature of the heating part or the crucible rather than the vapor deposition material whose situation changes every moment. In this embodiment, the reason why the power of the heating unit is not used is that the integral value of the power is only the integration of the input, and due to the initial value of the temperature of the heating unit or the crucible and the influence of the surrounding heat dissipation, This is because they are not equivalent. In addition, when the integral value is used, if there is an offset error in the signal, the accumulated error becomes large. Moreover, the instantaneous value of electric power is not equivalent to the temperature of the heating part or the crucible. Therefore, in this embodiment, the amount of the vapor deposition material in the crucible can be grasped with high accuracy by grasping the temperature of the heating unit or the crucible.

  As an effect thereof, since the replenishment of the vapor deposition material can be performed at an appropriate timing, the time for opening the vacuum vessel can be optimized and the productivity can be improved. In addition, when replenishing the vapor deposition material, the remaining vapor deposition material may be discarded without being reused. Therefore, if the remaining amount of vapor deposition material can be accurately grasped, it is possible to minimize the vapor deposition material to be discarded. it can. As a result, the utilization efficiency of the vapor deposition material can be improved. Further, since the crucible is not unnecessarily heated after the vapor deposition material in the crucible is exhausted, it is possible to prevent the crucible from being damaged by heat.

  In the apparatus of one embodiment shown in FIG. 1, the crucible 3 has a thickness of 1 mm, an upper inner diameter of 20 mm, and a height of 30 mm. The lower part has a hemispherical shape, and the side part of the crucible 3 above the lower part of the hemispherical shape is a straight body (that is, a constant inner diameter of 20 mm). The vapor deposition material 2 is stored up to the upper end of the crucible 3. The shape of the support 4 in contact with the crucible 3 is the same as the curvature of the bottom of the crucible 3. The shutter 9 is installed between the crucible 3 and the substrate 7.

In this embodiment, the relationship table between the remaining amount of the vapor deposition material 2 and the temperature of the heating source 5 is calculated according to the following procedure.
First, the temperature correction coefficient α based on the evaporation area is calculated using the following equation (1).
(1) α = evaporation area 1 (straight body part) / evaporation area 2 (lower part of crucible 3) (1)
The temperature correction coefficient α of the heating source 5 at the position of the vapor deposition material 2 in the crucible 3 is as shown in FIG. The reason is as follows. Since the deposition rate is controlled to be constant, the temperature of the heating source 5 can be raised if the evaporation area decreases. The mode of the rise is specific to the vapor deposition material and is known in advance. Therefore, since the relationship between the evaporation area and the distance of the upper surface (evaporation surface) of the vapor deposition material 2 from the upper end of the crucible is known from the shape of the crucible, the change of the temperature correction coefficient α with respect to the distance from the upper end of the crucible is shown in FIG. ) As shown. As a result, it becomes as follows.
(2) Determine which of the temperature correction coefficients α of the heating source 3 calculated in (1) corresponds to the temperature of the heating source 3 at the target deposition rate. Thereby, as shown in FIG. 3B, a relationship table between the remaining amount of the vapor deposition material 2 in the crucible 3 (that is, the distance from the upper end of the crucible) and the temperature of the heating source 5 can be acquired.

  The relationship table between the remaining amount of the vapor deposition material 2 in the crucible 3 and the temperature of the heating source 5 obtained in (2) is input and stored in the control unit 11 before performing the vapor deposition process. In some cases, a relationship table as shown in FIG. 3A is stored, and the remaining amount of the vapor deposition material 2 (that is, the distance from the upper end of the crucible) is calculated from the respective temperatures. Also good. And the temperature of the heating source 5 which stops vapor deposition in a vapor deposition process is input.

The vapor deposition process according to this embodiment will be described with reference to FIG. At the start, the vacuum vessel 1 is evacuated by a vacuum pump (not shown) until it becomes 1.0 × 10 ⁻² Pa or less (S1). Next, the crucible 3 is heated by the heating source 5 supplied with power from the control unit 10 (S2). In order to prevent bumping of the vapor deposition material 2 and breakage of the crucible 3 due to a rapid temperature change, the heating source 5 is gradually heated (S3). Therefore, the control unit 11 controls the temperature rising gradient of the heating source 5 so as to increase at a constant rate. When the temperature of the heating source 5 reaches a predetermined value (predetermined value 1) (S4), the shutter 9 is driven to a position that does not affect the deposition of the vapor deposition material 2 on the substrate 7 (S5). When the driving of the shutter 9 is completed, the controller 11 switches from the temperature control mode to the vapor deposition rate control mode.

  Next, it is judged from the measurement result of the vapor deposition rate detector 10 whether the vapor deposition rate (predetermined value 2) is a predetermined value (S6). If the predetermined value has not been reached, the control unit 11 adjusts the power supplied to the heating source 5 (S7). If the vapor deposition rate reaches a predetermined value, the vapor deposition material 2 is deposited on the substrate 7 at a constant rate.

  Next, when it is determined in the heating monitoring step that the temperature of the heating source 5 has reached a predetermined value (predetermined value 3, for example, 510 ° C.) (S8), the shutter 9 is driven to the initial position (S9). Thereafter, power supply to the heating source 5 is stopped (S10). Thereafter, for example, after the temperature of the heating source 5 becomes a predetermined value or less, the vacuum vessel 1 is opened and the vapor deposition material 2 is put into the crucible 3. Here, if the predetermined value 3 is set to an appropriate temperature (for example, 680 ° C.) in the relationship table of FIG. 3B, a predetermined remaining amount (for example, from the upper end of the crucible on the upper surface of the remaining amount). The power supply is stopped at a distance of about 25 cm).

  By carrying out the present embodiment as described above, the vapor deposition material 2 in the crucible 3 after completion of the vapor deposition process can be made a desired remaining amount each time. Therefore, the amount of vapor deposition material 2 does not remain in the crucible 3 more than expected, and material utilization efficiency can be improved in the vapor deposition material 2 that cannot be reused and is discarded.

  In the present embodiment, one crucible 3 in which the vapor deposition material 2 is accommodated is provided in the vacuum vessel 1, but a plurality of crucibles 3 in which the vapor deposition material 2 is accommodated are installed, and step S9 of the vapor deposition process is performed. After implementation, the crucible 3 may be replaced by a transport mechanism (not shown). The shape of the crucible 3 may be changed according to the vapor deposition material 2. Further, the vacuum vessel 1 may be provided with a vapor deposition material charging mechanism, and the vapor deposition material 2 may be charged into the crucible 3 after performing step S9 of the vapor deposition process. By doing so, since the frequency | count of opening the vacuum vessel 1 can be reduced, it is possible to improve productivity.

2: Vapor deposition material 3: Crucible (container)
5: Heating source (heating unit)
6: Temperature sensor (heating monitor)
10: Deposition rate detection unit 11: Control unit

Claims (12)

A storage unit for storing a deposition material, a heating unit for heating the storage unit or the deposition material, a heating monitor unit for detecting the temperature of the heating unit or the storage unit, and a deposition rate detection unit for detecting a deposition rate And a control unit that controls the heating unit based on the temperature detected by the heating monitor unit so that the deposition rate detected by the deposition rate detection unit is constant,
The accommodating portion has a shape in which an area of a cross section perpendicular to the depth direction changes at least in part,
The vapor deposition apparatus characterized by detecting the remaining amount of the vapor deposition material in the storage unit from the temperature of the heating unit or the storage unit related to the evaporation area of the vapor deposition material in the storage unit.   The vapor deposition apparatus according to claim 1, wherein a relationship between the area of the cross section and the depth of the accommodating portion is uniquely determined at least in part.   The vapor deposition apparatus according to claim 2, wherein the at least part includes a bottom portion.   The vapor deposition apparatus according to claim 2, wherein the at least part has a shape in which an evaporation area of the vapor deposition material decreases as the vapor deposition material in the housing portion decreases.   The said control part has the information showing the relationship between the temperature of the said heating part or the said accommodating part, and the residual amount of the vapor deposition material in the said accommodating part, The any one of Claim 1 to 4 characterized by the above-mentioned. The vapor deposition apparatus of description.   The vapor deposition apparatus according to claim 5, wherein information indicating the relationship acquired in advance is stored in the control unit.   The said control part is equipped with the function to stop the electric power supply to the said heating part, when the temperature of the said heating part or the said accommodating part exceeds a predetermined value, The any one of Claim 1 to 6 characterized by the above-mentioned. The vacuum evaporation apparatus as described in.   8. The mechanism according to claim 1, further comprising: a mechanism for exchanging the accommodating portion with a new accommodating portion in which the vapor deposition material is accommodated when the temperature of the heating unit or the accommodating portion exceeds a predetermined value. The vapor deposition apparatus as described in any one of Claims.   The vapor deposition according to any one of claims 1 to 7, further comprising a mechanism for introducing a new vapor deposition material into the accommodating portion when the temperature of the heating portion or the accommodating portion exceeds a predetermined value. apparatus. A housing step in which a vapor deposition material is accommodated or a heating step for heating the vapor deposition material, a heating monitor step for detecting a temperature related to the vapor deposition material, a vapor deposition rate detection step for detecting a vapor deposition rate of the vapor deposition material, and the vapor deposition A control step of controlling heating in the heating step based on the temperature detected in the heating monitor step so that the deposition rate detected in the rate detection step is constant,
The accommodating portion has a shape in which an area of a cross section perpendicular to the depth direction changes at least in part,
A vapor deposition method comprising: a remaining amount detecting step of detecting a remaining amount of the vapor deposition material in the storage unit from a temperature detected in the heating monitor step related to an evaporation area of the vapor deposition material in the storage unit.   The vapor deposition method according to claim 10, wherein the heating in the heating step is stopped when it is determined that the temperature detected in the heating monitoring step has reached a predetermined value.   12. The vapor deposition method according to claim 10 or 11, wherein, in the remaining amount detection step, detection is performed based on information representing a relationship between a temperature related to the vapor deposition material and a remaining amount of the vapor deposition material in the container. .

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