JP7240963B2 - Vacuum deposition equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vacuum vapor deposition apparatus, and more particularly, to a vapor deposition apparatus that heats a vapor deposition material with an appropriate temperature rise profile to stably vaporize or sublimate the vapor deposition material for vapor deposition.

For example, in the manufacturing process of an organic EL element, there is a process of sublimating or evaporating an organic material to deposit a predetermined thin film on the surface of a substrate such as a glass substrate as an object to be deposited in a vacuum atmosphere. A vacuum deposition apparatus is widely used for this (see, for example, Patent Document 1). Such a vacuum deposition apparatus is equipped with a vacuum chamber in which the substrate moves in one direction at a predetermined speed. A vapor deposition source is provided in the lower part of the vacuum chamber so as to face the substrate moving in the X-axis direction, with the moving direction of the substrate being the X-axis direction and the width direction of the substrate perpendicular to the X-axis direction being the Y-axis direction. there is

The deposition source has a storage box that stores a solid (for example, powdered) deposition material (organic material). A plurality of cylindrical ejection openings (injection nozzles) for ejecting vapor deposition materials are arranged at intervals in the Y-axis direction (so-called linear source). Then, in a vacuum chamber with a vacuum atmosphere, the storage box is heated by a heating means such as a sheath heater or a halogen heater attached to the storage box, so that the vapor deposition material is heated by heat transfer from the storage box and radiant heat from the wall surface. Then, the sublimated or vaporized vapor deposition material is discharged from each discharge opening according to a predetermined cosine law, and adhered to and deposited on a substrate that moves relative to the vapor deposition source in the X-axis direction, thereby forming a predetermined thin film. vapor-deposited.

By the way, since organic EL elements have advantages such as better visibility and power saving compared to liquid crystal display elements, they are being improved day by day, and along with this, new organic materials are being developed one after another. It is When such a novel organic material is deposited using the above conventional vacuum deposition apparatus, its decomposition temperature, vaporization temperature, or sublimation temperature is often unknown. In some cases, it is unclear whether the organic material is vaporizable, or organic material is sublimable, which transitions from the solid phase to the gas phase. At this time, in the process of increasing the temperature of the vapor deposition material from the start of heating until the vapor deposition material can be vapor-deposited on the substrate surface at a predetermined vapor deposition rate, if the vapor deposition material is heated more than necessary, the vapor deposition material becomes sublimable organic material. In the case of a material, for example, the organic material decomposes or thermally deteriorates in the storage box, which causes a problem that a thin film having a desired film quality that determines the performance of the device cannot be deposited. On the other hand, in the case of a vaporizable organic material, for example, bumping occurs and the vapor deposition material is wasted, or uneven melting occurs and the vapor deposition rate becomes unstable.

Conventionally, based on the operator's experience, the heating temperature for the storage box is gradually and gradually increased, and the sublimation or vaporization of the vapor deposition material is estimated (identified) based on the measurement results of the film thickness monitor provided in the vacuum chamber, After that, the heating temperature was controlled by the heating means so as to obtain a predetermined vapor deposition rate based on the measurement result of the film thickness monitor. For this reason, it takes a lot of labor and time to heat the vapor deposition material with an appropriate temperature rise profile during the temperature rise process. For this reason, early development of a vacuum deposition apparatus capable of heating organic materials developed one after another with an appropriate temperature elevation profile and stably vaporizing or sublimating deposition materials is desired.

JP 2014-77193 A

SUMMARY OF THE INVENTION In view of the above points, an object of the present invention is to provide a vacuum vapor deposition apparatus having a configuration capable of vapor deposition by heating a vapor deposition material with an appropriate temperature rise profile.

In order to solve the above-mentioned problems, the present invention includes a storage box that is arranged in a vacuum chamber and stores a solid vapor deposition material, and heating means that heats the vapor deposition material in the storage box. In the chamber, the vapor deposition material in the container is heated to sublimate or vaporize the vapor deposition material, and the sublimated or vaporized vapor deposition material is discharged from the discharge opening of the container to be deposited on the object in the vacuum chamber. In a vacuum vapor deposition apparatus for vapor deposition at a preset vapor deposition rate, in a vacuum atmosphere, a storage box filled with a vapor deposition material is heated at a predetermined temperature rise rate by a heating means, and the temperature is measured in an equivalent vacuum atmosphere. A temperature difference measuring means for measuring the temperature difference by comparing the temperature of an empty reference storage box with the temperature when the reference storage box is heated at the same rate of temperature increase; a thermogravimetric measuring means for measuring a weight change, and heating the containing box based on the temperature difference measured by the temperature difference measuring means until the deposition material in the containing box starts sublimation or vaporization. The means is controlled to specify sublimation or vaporization of the vapor deposition material in the storage box based on the weight change measured by the thermogravimetric measurement means, and then the storage box based on the amount of weight change per unit time determined from the deposition rate. It is characterized in that the heating means for heating the is configured to be controlled. In this case, until the vapor deposition material in the storage box starts to vaporize, the heating means is operated based on the weight change measured by the thermogravimetry means in addition to the temperature difference measured by the temperature difference measuring means. A controlled configuration may be employed.

Further, in the present invention, the vacuum chamber further includes a vacuum gauge, and the pressure measured by the vacuum gauge is used until the vapor deposition material in the storage box starts to sublimate or vaporize. A configuration may be adopted in which heating means for heating the box and the housing box are respectively controlled.

According to the above, if a case where a reference storage box having the same structure as the storage box is arranged in the vacuum chamber as an example (at this time, the reference storage box contains the deposition material sublimated or vaporized at the time of deposition). (Although it is installed in a vacuum chamber so as not to adhere, it can also be placed in a separate vacuum chamber), first, the deposition material to be deposited on the surface of the object to be deposited is placed in a storage box in a vacuum chamber in an atmospheric atmosphere. is filled at a predetermined filling rate. On the other hand, the reference storage box is left empty without being filled with the vapor deposition material. Then, the vacuum chamber is evacuated, and when the inside of the vacuum chamber reaches a predetermined pressure (eg, 1×10 ⁻⁵ Pa), the heating means arranged around the storage box is activated to start heating the storage box. , the heating temperature is increased at a predetermined temperature increase rate (for example, a constant temperature gradient) (that is, the amount of heat applied to the housing box by the heating means is increased at a constant temperature gradient). As a result, the vapor deposition material is heated by heat transfer from the containing box and radiant heat from the wall surface thereof. At the same time, the heating means for the reference storage box having the same configuration as the above starts heating the storage box, and the heating temperature is increased at the same rate of temperature rise.

As the heating temperature is increased, the gas adhering to the wall surface of the storage box and the gas contained in the vapor deposition material filled therein are released first. Therefore, when the pressure measured by the vacuum gauge changes beyond a predetermined range, the temperature rise is temporarily stopped, and deposition is performed at the heating temperature at that time (that is, the amount of heat applied to the container by the heating means is kept constant). Continue to heat the material. At this time, the temperature rise of the reference storage box is also temporarily stopped. Then, when the amount of pressure change per unit time falls within a predetermined range, the heating of the containing box is restarted, and the heating temperature is increased at the same rate of temperature rise as above. At the same time, the heating of the reference storage box is resumed. As a result, it is possible to suppress deterioration of the film quality due to contamination of the film deposited on the substrate surface with impurities.

Next, when the heating temperature is further increased at a constant heating rate, the temperature difference measuring means continuously or periodically measures the temperature difference between the storage box and the reference storage box. From the temperature difference measured in this way, heat such as red heat, transition (melt temperature in the case of vapor deposition material), decomposition, melting, oxidation, etc., caused by heating of the deposition material in the storage box, heat generation, etc. The amount of change can be measured (that is, endothermic and exothermic behaviors are acquired as data). For example, if the temperature difference measured by the temperature difference measuring means increases beyond a predetermined range during the temperature rise, the heat applied to the vapor deposition material by the heating means through the storage box will cause the vapor deposition material to Since it can be determined that the material is used for phase transition, it can be specified that the vapor deposition material is a vaporizable material. At this time, if a configuration is adopted in which weight change is measured by the thermogravimetric measurement means in addition to the measurement of the temperature difference by the temperature difference measurement means, for example, bumping occurs and the vapor deposition material is wasted. Alternatively, the heating means can be controlled to lower the heating temperature, or the heating temperature can be temporarily stopped before an excessive heat load is applied to the vapor deposition material. For example, after increasing the amount of heat applied to the storage box by a heating means at a predetermined temperature gradient, the amount of heat is maintained for a certain period of time. is further increased at a predetermined temperature gradient and held at that heat amount for a certain period of time at least once to heat the vapor deposition material. After that, if the heating temperature is gradually increased while measuring the amount of heat change and the amount of weight change, it is possible to prevent uneven melting of the vapor deposition material in the storage box.

On the other hand, for example, if the temperature difference measured by the temperature difference measuring means is always maintained within a predetermined range within a predetermined time during temperature rise, the vapor deposition material is a sublimable material because there is no phase transition. It can be specified that In such a case, while the heating temperature can be increased at a constant temperature increase rate, if the amount of heat change changes beyond the allowable range that does not cause deterioration of the vapor deposition material, etc., the accommodation The heating means for heating the box is controlled (the deposition material is heated in the same manner as described above). As a result, regardless of the operator's experience, the storage box and, in turn, the vapor deposition material can be automatically heated at a constant rate of temperature increase, and in such a temperature rising process, more heat than necessary is applied to the vapor deposition material. can be prevented.

Next, the heating temperature is further increased at a constant rate of temperature rise, and when a certain temperature is reached, the vapor deposition material inside the storage box begins to sublimate or vaporize. At this time, the weight of the vapor deposition material in the container decreases. Therefore, the sublimation or vaporization of the vapor deposition material inside the storage box can be identified from the weight change measured by the thermogravimetry means. After the deposition material sublimes or vaporizes, the heating means for heating the storage box is controlled based on the amount of weight loss per unit time (that is, the thickness of the film to be deposited on the substrate surface and the deposition time If the amount of weight reduction per unit time is specified based on the above, and the heating temperature is set so that the amount of weight reduction is a predetermined value, vapor deposition can be performed at a constant vapor deposition rate). At this time, in addition to measuring the weight change by the weight measuring means, if the temperature difference measuring means also measures the temperature difference, decomposition and thermal deterioration of the vapor deposition material can be prevented. can specify the upper limit of the amount of heat applied to the vapor deposition material (in other words, the vapor deposition rate according to the vapor deposition material), and the relative movement speed of the substrate can be controlled accordingly.

As described above, in the present invention, in the process of raising the temperature of the deposition material, the temperature difference measuring means measures the temperature difference between the storage box and the reference storage box, and the thermogravimetric measurement means measures the weight change of the deposition material in the storage box. Therefore, regardless of the operator's experience and regardless of the filling rate of the deposition material in the storage box, the deposition material is heated with an appropriate temperature rise profile while reliably grasping the temperature at which the deposition material sublimes or vaporizes. vapor deposition becomes possible. Here, even if there is a difference in the filling rate of the vapor deposition material in the storage box (when vapor deposition is performed using the same vapor deposition material), or if the storage box is additionally filled with the vapor deposition material at the same filling rate, the temperature rise profile However, even in such a case, it is possible to heat the vapor deposition material with an appropriate temperature rise profile for vapor deposition.

By the way, when using a vapor deposition source having a plurality of cylindrical discharge openings (injection nozzles) arranged in a row on the upper surface of a storage box, the discharge openings are also heated to a temperature equivalent to the vaporization or sublimation temperature during vapor deposition. If not heated, vapor deposition material passing through the discharge openings will adhere and solidify, causing problems such as clogging of the nozzles. For this reason, in the case of having the first heating means for heating the portion of the containing box filled with the vapor deposition material and the second heating means for heating the discharge opening of the containing box, the object to be vapor deposited is When stopping vapor deposition, the first heating means is controlled to lower the temperature of the storage box at a predetermined cooling rate based on the weight change amount per unit time measured by the thermogravimetric measuring means, and this weight change amount is A configuration can be employed in which each of the first and second heating means is stopped when a predetermined value is reached. This advantageously avoids nozzle clogging at the end of production.

When the production is finished with the vapor deposition material remaining in the storage box, if the operation of the first and second heating means is stopped as described above, depending on the vapor deposition material, abrupt solidification may occur. There is a risk of material deterioration. For this reason, it is preferable to control so that the first and second heating temperatures are gradually lowered based on the temperature difference measured by the temperature difference measuring means in the temperature lowering process. At this time, if the vapor deposition material is a vaporizable material, if the temperature difference is also measured by the temperature difference measuring means, the phase transition from the liquid phase to the solid phase can be specified. It can be converted back to solid phase.

1(a) is a partially cross-sectional partial perspective view illustrating a vacuum deposition apparatus according to an embodiment of the present invention, and FIG. 1(b) is a partial cross-sectional view of the vacuum deposition apparatus viewed from the front side. 2 is a graph for explaining the profile of temperature rise and temperature drop from the start of heating to the end of heating of the vapor deposition material, (a) when the vapor deposition material is a vaporizable material, and (b) when the vapor deposition material is a sublimable material. is.

Hereinafter, with reference to the drawings, the object to be vapor-deposited is a glass substrate having a rectangular outline and a predetermined thickness (hereinafter referred to as “substrate Sw”), the vapor deposition material is a polymeric organic material Om, and an organic An embodiment of the vacuum deposition method of the present invention will be described by taking the case of depositing (depositing) a film as an example. Hereinafter, terms such as "up" and "down" are based on the attitude of the vacuum deposition apparatus shown in FIG.

Referring to FIG. 1, DM is the vacuum deposition apparatus of this embodiment. The vacuum deposition apparatus DM includes a vacuum chamber 1, which is connected to a vacuum pump through an exhaust pipe (not shown and described), and can be evacuated to and maintained at a predetermined pressure (degree of vacuum). It's like A vacuum gauge Vg such as a Pirani vacuum gauge, an ionization vacuum gauge, or a Penning vacuum gauge is provided at a predetermined position in the vacuum chamber 1 to measure the internal pressure. A substrate transfer device 2 is also provided above the vacuum chamber 1 . The substrate transfer device 2 has a carrier 21 that holds the substrate Sw with its lower surface as a vapor deposition surface open. to move. Since a known device can be used as the substrate transfer device 2, further explanation is omitted. Also, hereinafter, the direction of relative movement of the substrate Sw with respect to the vapor deposition source Ds, which will be described later, is defined as the X-axis direction, and the width direction of the substrate Sw perpendicular to the X-axis direction is defined as the Y-axis direction.

A plate-like mask plate 3 is provided between the substrate Sw transported by the substrate transport device 2 and the vapor deposition source Ds. In this embodiment, the mask plate 3 is attached integrally with the substrate Sw and transported together with the substrate Sw by the substrate transport device 2 . The mask plate 3 can also be fixedly arranged in the vacuum chamber 1 in advance. A plurality of openings 31 are formed through the mask plate 3 in the plate thickness direction, and the adhesion range of the organic material Om to the substrate Sw is limited at positions where there are no openings 31, so that the organic material Om adheres to the substrate Sw in a predetermined pattern. vapor-deposited. The mask plate 3 may be made of metal such as invar, aluminum, alumina or stainless steel, or made of resin such as polyimide. A storage box Ds as a vapor deposition source is provided on the bottom surface of the vacuum chamber 1 so as to face the substrate Sw that is moved in the X-axis direction.

The storage box Ds includes an outer container 41 and an inner container 42 having an open top, which is installed in the outer container 41. The inner container 42 accommodates a powdery (solid) organic material Om. A first heating means 43a such as a sheath heater is provided inside the outer container 41 so as to surround the wall surface of the inner container 42 . When the inner container 42 is heated by the first heating means 43a, the organic material Om is heated by heat transfer from the wall surface of the inner container 42 and radiation from the upper surface (the surface facing the substrate Sw) 41a of the outer container 41, thereby sublimating or Vaporize. On the upper surface 41a of the outer container 41, a plurality of discharge openings (injection nozzles) 44, which are cylindrical bodies having a predetermined height, are arranged at predetermined intervals in the Y-axis direction (six in this embodiment). The vapor deposition material Om sublimated or vaporized within the outer container 41 is discharged into the space within the vacuum chamber 1 according to a predetermined cosine law. In addition, the upper surface (the surface facing the substrate Sw) 41a of the outer container 41 is covered with a shielding plate 45 formed with openings 45a through which the discharge openings 44 are inserted. , a second heating means 43b such as a sheath heater is provided. The discharge openings 44 are mainly heated by the second heating means 43b to prevent the organic material Om passing through the discharge openings 44 from adhering and solidifying during vapor deposition and causing nozzle clogging.

A weight measuring device 46 composed of an electronic balance or the like is provided on the bottom surface of the outer container 41, and substantially changes in weight (weight per unit time) associated with sublimation or vaporization of the organic material Om contained in the inner container 42 decrease) can be measured. A side wall of the inner container 42 is provided with a temperature measuring device 47a composed of a thermocouple or the like. Also provided on the bottom surface of the vacuum chamber 1 is a reference storage box Bs having the same configuration as the storage box Ds, offset in the Y-axis direction with respect to the substrate Sw moved in the X-axis direction. Similarly, the side wall of the inner container 42 is provided with a temperature measuring device 47b composed of a thermocouple or the like. In this case, an anti-adhesion plate 5 is provided around the reference container Bs so that the organic material Om discharged from the discharge opening 44 of the container Ds does not adhere.

The vacuum deposition apparatus DM includes a well-known control unit Cu including a microcomputer, a memory element, a sequencer, and the like. Then, the control unit Cu centrally controls each component such as a vacuum pump (not shown) and the substrate transfer device 2 . The control unit Cu also receives outputs from the vacuum gauge Vg, the weight measuring device 46, and the temperature measuring devices 47a and 47b. 2 heating means 43a and 43b. In this case, the weight measuring device 46, the temperature measuring devices 47a and 47b, and the control unit Cu constitute the temperature difference measuring means and thermogravimetric measuring means of this embodiment. A vapor deposition (film formation) method on the substrate Sw using the vacuum vapor deposition apparatus DM will be described below with reference to FIGS. 2(a) and 2(b).

In the vacuum chamber 1 in the atmosphere, the inner container 42 of the storage box Ds is filled with the organic material Om at a predetermined filling rate. At this time, the inner container 42 of the reference container Bs is left empty without being filled with the organic material Om. When the organic material Om is filled, the vacuum chamber 1 is evacuated by a vacuum pump, and when the inside of the vacuum chamber 1 reaches a predetermined pressure (for example, 1×10 ⁻⁵ Pa), the storage box Ds and the reference storage box Bs are evacuated. The first and second heating means 43a and 43b are operated to start heating the storage box Ds and the reference storage box Bs, and the heating temperature is increased at a predetermined temperature increase rate (a constant temperature gradient) (that is, storage The storage box Ds and the reference storage box Bs are heated while increasing the amount of heat applied to the box Ds and the reference storage box Bs by the first and second heating means 43a and 43b at a constant temperature gradient. At this time, in the storage box Ds, the organic material Om is heated by heat transfer from the side wall of the inner container 42 and radiant heat from the upper wall of the outer container 41 .

As the heating temperature is increased, the gas adhering to the wall surface of the storage box Ds and the gas contained in the organic material Om filled in the storage box Ds are released. When the pressure measured by the vacuum gauge Vg changes beyond a predetermined range, the control unit Cu temporarily stops raising the temperature of the storage box Ds and the reference storage box Bs by the first and second heating means 43a and 43b, The heating of the organic material Om is continued at the heating temperature at that time (that is, the amount of heat applied to the storage box Ds and the reference storage box Bs is kept constant) (the degassing step indicated by section A in FIG. 2). Then, when the amount of pressure change per unit time falls within a predetermined range, the first and second heating means 43a and 43b resume heating of the storage box Ds and the reference storage box Bs, and the temperature rise rate is the same as above. to increase the heating temperature. As a result, it is possible to prevent impurities from entering the film deposited on the surface of the substrate Sw and degrading the film quality.

Next, when the heating temperature is further increased at a constant heating rate, the control unit Cu controls the inner container 42 of the storage box Ds and the inner container of the reference storage box Bs based on the outputs received from the temperature measuring devices 47a and 47b. 42 continuously or periodically, and based on the output received from the weight measuring device 46, the storage box Ds, and thus the weight change of the organic material Om filled in the inner container 42 is continuously measured. Or measure regularly. From the temperature difference measured in this way, red heat, transition (melt temperature in the case of a vaporizable organic material), decomposition, melting, oxidation, etc., caused by heating of the organic material Om in the storage box Ds, endothermic heat generation, etc. The amount of heat change can be measured (that is, endothermic and exothermic behaviors are acquired as data). Further, from the measured temperature difference, dehydration due to heating of the organic material Om in the storage box Ds can be identified. Therefore, in such a case, the degassing step may be performed again. For example, when the temperature difference measured by the temperature measuring devices 47a and 47b exceeds a predetermined range during temperature rise, the first and second heating means 43a and 43b Since it can be determined that the heat applied to the organic material Om through the storage box Ds is used for the phase transition, it can be determined (specified) that the organic material Om is a vaporizable material.

Once determined to be a vaporizable material, the control unit Cu also continuously or periodically measures the weight change of the organic material Om, e.g. , the first heating means 43a is controlled such that an excessive heat load is applied to the organic material Om. For example, in FIG. 2(a), as in the temperature raising step indicated by section B, after increasing the amount of heat applied to the housing box Ds by a predetermined temperature gradient by the first and second heating means 43a and 43b, the amount of heat is maintained for a certain period of time, and if the amount of heat change is maintained within the allowable range, the amount of heat applied to the storage box Ds is further increased by a predetermined temperature gradient, and this amount of heat is maintained for a certain period of time. This is repeated more than once to heat the organic material Om. Along with this, the first and second heating means 43a and 43b for heating the reference container Bs are similarly controlled. Gradually raising the heating temperature in this manner can prevent uneven melting of the organic material Om in the storage box Ds during the temperature raising process.

On the other hand, for example, when the temperature difference measured by the temperature measuring devices 47a and 47b is always maintained within a predetermined range within a predetermined time during the temperature rise, the phase transition does not occur and the organic material Om is It can be identified as a sublimable material. In such a case, for example, the heating temperature can be increased at a constant rate of temperature increase, as in the temperature increase step indicated by section B in FIG. 2(b). If the temperature difference changes beyond the predetermined range, for example, the temperature rise is temporarily interrupted as soon as possible, and after the elapse of a predetermined time, the heating is resumed at a slower temperature rise rate than the above. . Along with this, the first and second heating means 43a and 43b for heating the reference container Bs are similarly controlled. The allowable range in this case is appropriately set experimentally, for example. In addition, in the temperature rising step indicated by section B in FIG. 2B, for example, the second When the amount of heat applied to the storage box Ds by the first and second heating means 43a and 43b is increased with a predetermined temperature gradient, and then the amount of heat is maintained for a certain period of time, and the amount of heat change is maintained within the allowable range. In this case, the organic material Om can be heated by increasing the amount of heat applied to the storage box Ds at a predetermined temperature gradient and maintaining the amount of heat for a certain period of time at least once. As a result, regardless of the experience of the operator, the storage box Ds and, by extension, the organic material Om can be automatically heated at a constant temperature increase rate. can be prevented from being added to

Furthermore, the heating temperature is increased at a constant rate of temperature rise, and when a certain temperature is reached, the organic material Om in the inner container 42 begins to sublimate or vaporize. At this time, since the weight of the organic material Om decreases, the control unit Cu identifies the sublimation or vaporization of the organic material Om, and after the vapor deposition material sublimes or vaporizes, the weight change (that is, the weight per unit time amount of decrease), the first and second heating means 43a and 43b of the storage box Ds and the reference storage box Bs are controlled so as to achieve a preset deposition rate (indicated by section C in FIG. 2 evaporation process). When the preset vapor deposition rate is reached, the substrate conveying device 2 conveys one substrate Sw in the X-axis direction. As a result, the organic material Om emitted from each emission opening 44 according to a predetermined cosine law adheres and accumulates on the lower surface of the substrate Sw, which moves relative to the deposition source Ds in the X-axis direction, and a predetermined thin film is deposited. be. While vapor deposition is performed on a plurality of substrates Sw in this manner, the first and second heating means for the storage box Ds and the reference storage box Bs are heated based on the change in weight so that the deposition rate is always the same. 43a and 43b are appropriately controlled. At this time, since the decomposition of the organic material Om can be determined from the temperature difference measured by the temperature measuring devices 47a and 47b, the upper limit of the amount of heat applied to the organic material Om (in other words, the upper limit of the deposition rate) can be specified. Therefore, when the vapor deposition rate is less than the vapor deposition rate required for vapor deposition onto the substrate Sw, the relative movement speed of the substrate Sw can be controlled accordingly.

When the vapor deposition on the plurality of substrates Sw is completed (end of production) and the organic material Om remains in the storage box Ds, the first and second heating means 43a and 43b of the storage box Ds and the reference storage box Bs are turned on. When stopping, first, the heating temperature of the storage box Ds and the reference storage box Bs by the first heating means 43a is lowered at a constant cooling rate (at this time, the second heating means 43b is maintained as it is). Here, when the organic material Om is a vaporizable material, the temperature difference measured by the temperature measuring devices 47a and 47b during the temperature drop indicates that part of the organic material Om undergoes a phase transition from the liquid phase to the solid phase. can be determined, as indicated by section D in FIG. After that, the heating temperature is lowered at a constant cooling rate, and at this time, based on the output received from the weight measuring device 46, the amount of weight reduction of the organic material Om per unit time is measured. The second heating means 43a, 43b are completely stopped. As a result, the organic material Om can be returned to the solid phase evenly while preventing the organic material Om from being abruptly solidified.

On the other hand, when the organic material Om is a sublimable material, it is heated by the first heating means 43a as shown in section D in FIG. The heating temperature is lowered stepwise, and at this time, the amount of weight reduction of the organic material Om per unit time is measured based on the output received from the weight measuring device 46. When the weight reduction ceases, the first and second Each heating means 43a, 43b is completely stopped. Note that the profile of the temperature rise and temperature drop of the first and second heating means 43a and 43b until the vapor deposition is performed by heating the organic material Om as described above and the heating is stopped and completed is determined by the control unit Cu When the same organic material Om is filled in the inner container 42 and vapor-deposited again, the first and second heating are performed based on the stored profile. The actuation of means 43a, 43b may be controlled.

According to the above embodiment, in the process of increasing the temperature of the organic material Om, by measuring the temperature difference between the storage box Ds and the reference storage box Bs and the weight of the organic material Om in the storage box Ds, the operator can Appropriate temperature rise profile and temperature drop profile for the organic material Om while reliably grasping the sublimation or vaporization temperature of the organic material Om regardless of experience and regardless of the filling rate of the organic material Om in the storage box Ds. can be performed by heating or lowering the temperature of the substrate Sw to vapor-deposit a predetermined organic film on the surface of the substrate Sw. Moreover, it is possible to reliably prevent the organic material Om passing through the discharge opening 44 from adhering and solidifying when the temperature is lowered, leading to nozzle clogging, or material deterioration due to rapid solidification. In the conventional vacuum deposition apparatus, the deposition rate was monitored by a film thickness monitor using a crystal oscillator in the vacuum chamber. Based on this, the first and second heating means 43a and 43b of the storage box Ds and the reference storage box Bs can be controlled so as to achieve a preset deposition rate, so there is no particular need for a film thickness monitor, Advantageous.

Although the embodiments of the present invention have been described above, various modifications are possible without departing from the scope of the technical idea of the present invention. In the above embodiment, the object to be vapor-deposited is the glass substrate Sw, and the vapor deposition is performed while the glass substrate Sw is conveyed by the substrate conveying device 2 at a constant speed. It is not limited to For example, the present invention can also be applied to an apparatus in which the material to be vapor-deposited is a sheet-like base material, and vapor deposition is performed on one side of the base material while moving the base material at a constant speed between the drive roller and the take-up roller. . Further, in the above-described embodiment, the storage box Ds of the deposition source, in which the inner container 42 is arranged in the outer container 41, is described as an example. In this case, the crucible of the same shape is also used for the reference storage box Bs. Also, the vapor deposition material is not limited to the organic material Om.

Furthermore, in the above-described embodiment, a single weight measuring device 46 is provided in the containing box Ds to substantially measure the change in weight of the organic material Om. A plurality of 46 may be provided to measure the weight change at a plurality of locations. In such a case, although not shown and described, the energization path to the sheath heater as the heating means provided in the storage box Ds is divided into a plurality of blocks, and the weight reduction per unit time measured by each weight measuring device 46 is calculated. It is also possible to control the sheath heater of each block according to the quantity. As a result, even when the storage box Ds has a large volume, the organic material Om filled in the storage box Ds can be sublimated or vaporized substantially uniformly from the upper surface thereof (in other words, the organic material Om in the storage box Ds can be Om can be prevented from being unbalanced), which is advantageous.

In addition, in the above-described embodiment, the case where the reference storage box Bs having the same structure as the storage box Ds is arranged in the vacuum chamber 1 has been described as an example. The box Bs may be provided in another vacuum chamber, and if the temperature change when heated by the first and second heating means 43a and 43b is calibrated, the reference storage box Bs does not need to have the same structure as storage box Ds, and the temperature measurement position is not limited to the above. In this case, the empty storage box Ds is heated by the first and second heating means 43a and 43b in a vacuum atmosphere, the temperature change at this time is experimentally determined in advance, and this is sent to the control unit Cu in advance. It may be stored and the temperature difference may be measured by comparison with this stored one.

Bs... Reference storage box, DM... Vacuum evaporation apparatus, Ds... Storage box, evaporation source, Om... Organic material (evaporation material), Sw... Substrate (object to be evaporated), Vg... Vacuum gauge, 1... Vacuum chamber, 43a... First heating means 43b Second heating means 44 Release opening 46 Weight measuring device (thermogravimetric measuring means) 47a, 47b Temperature measuring device (temperature difference measuring means) Cu Control unit ( thermogravimetric measuring means, temperature difference measuring means).

Claims (4)

A storage box arranged in a vacuum chamber to store a solid vapor deposition material, and a heating means for heating the vapor deposition material in the storage box, wherein the vapor deposition material in the storage box is heated in the vacuum chamber having a vacuum atmosphere. A vacuum vapor deposition apparatus that sublimes or vaporizes the vapor deposition material of the lever, discharges the sublimated or vaporized vapor deposition material from the discharge opening of the storage box, and vaporizes the vapor deposition material existing in the vacuum chamber at a predetermined vapor deposition rate. in
In a vacuum atmosphere, the temperature when the storage box filled with the vapor deposition material is heated at a predetermined temperature rise rate by a heating means is heated at the same temperature rise rate in an empty reference storage box in an equivalent vacuum atmosphere. temperature difference measuring means for measuring the temperature difference by comparing with the temperature when the vapor deposition material is held;
until the deposition material in the storage box starts sublimation or vaporization, the heating means for heating the storage box is controlled based on the temperature difference measured by the temperature difference measuring means,
Heating means for identifying the sublimation or vaporization of the vapor deposition material in the storage box based on the weight change measured by the thermogravimetric measuring means, and then heating the storage box based on the amount of weight change per unit time determined from the deposition rate. is controlled. The heating means is controlled based on the weight change measured by the thermogravimetric measuring means in addition to the temperature difference measured by the temperature difference measuring means until the deposition material in the storage box starts to vaporize. 2. The vacuum deposition apparatus according to claim 1, characterized in that it is constructed as follows. The vacuum chamber further includes a vacuum gauge, and the reference storage box and the storage box are separated based on the pressure measured by the vacuum gauge until the vapor deposition material in the storage box starts to sublimate or vaporize. 3. A vacuum vapor deposition apparatus according to claim 1, wherein said heating means for heating are controlled respectively. The vacuum deposition apparatus according to any one of claims 1 to 3, wherein the heating means includes first heating means for heating a portion of the storage box filled with the deposition material; and a second heating means for heating the emission opening,
When stopping vapor deposition on the object to be vapor-deposited, the first heating means is controlled to lower the temperature of the storage box at a predetermined temperature-lowering rate based on the amount of change in weight per unit time measured by the thermogravimetric measuring means. A vacuum vapor deposition apparatus characterized in that each of the first and second heating means is stopped when the amount of change reaches a predetermined value.

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