JP2022066943A - Thin-film deposition source for vacuum-film deposition equipment - Google Patents

Abstract

To provide a vapor deposition source for a vacuum deposition device that can prevent the temperature rise of a target substrate or a mask plate during vapor deposition.SOLUTION: A vapor deposition source DS for a vacuum deposition device is disposed in a vacuum chamber for vapor deposition of a target substrate. The vapor deposition source has a container 41 to be filled with vapor deposition material Vm, and heating means 43 for heating the vapor deposition material in the container. The container is provided with a release part 44 that allows the release of the vapor deposition material vaporized or sublimated in the container due to heating. The heating of the vapor deposition material by the heating means involves heating container portions 41a, 44a, 44b, which then radiate heat rays to the target substrate, the container portions 41a, 44a, 44b provided with low-emissivity layers Le that are lower in emissivity than the base material of the container.SELECTED DRAWING: Figure 2

Description

The present invention relates to a vapor deposition source for a vacuum vapor deposition apparatus that is arranged in a vacuum chamber and for vapor deposition on a substrate to be processed. More specifically, the temperature rise of the substrate to be processed or a mask plate during vapor deposition is suppressed. About what you did.

A vacuum vapor deposition apparatus provided with this type of vapor deposition source is known, for example, in Patent Document 1. In this, a vapor deposition source is arranged at the bottom of the vacuum chamber, and the vapor deposition source includes a container filled with the vapor deposition material and a heating means for heating the vapor deposition material in the container. On the upper surface of the container, a plurality of discharge nozzles (discharge portions) capable of discharging the vaporized or sublimated vaporized material are provided in a row at predetermined intervals in one direction. Then, in a vacuum chamber with a vacuum atmosphere, the vaporized material in the container is heated to sublimate or vaporize, and the sublimated or vaporized vaporized material is discharged from each discharge nozzle according to a predetermined chord rule, and is relative to the vapor deposition source. A predetermined thin film is deposited (deposited) by adhering to and depositing on a moving substrate to be processed. At this time, a heating means such as a sheath heater is usually arranged around the upper surface of the container or around each discharge nozzle, and the discharge nozzle is also heated to prevent nozzle clogging during vapor deposition as much as possible. Further, at the time of vapor deposition, a plurality of mask plates (that is, openings penetrating in the plate thickness direction) are formed between the vapor deposition source and the substrate to be processed in a predetermined mask pattern to limit the adhesion range of the vapor-deposited substance to the substrate to be processed. It has also been conventionally known to deposit a film on a substrate to be processed in a predetermined film formation pattern by interposing the above.

Here, when the container or the discharge nozzle is heated, the substrate to be processed or the mask plate may also be heated by the radiation of heat rays, and the substrate to be processed and the mask plate may thermally expand. At this time, if there is a difference in the amount of thermal expansion, there is a problem that accurate vapor deposition cannot be performed with a predetermined film formation pattern (the positions of the openings are displaced with respect to the substrate to be processed). Therefore, the inventors of the present application have arranged a heat shield plate having a through hole through which the discharge nozzle is inserted so as to face the upper surface of the container so that only the discharge nozzle serves as a heat source, and the substrate to be treated during vapor deposition. And it is proposed to suppress the heating of the mask plate (see, for example, Patent Document 2).

By the way, in recent years, the film forming pattern to be vapor-deposited on the substrate to be processed has been further miniaturized, and along with this, the width of the opening formed in the mask plate has become even narrower (the opening width is several). μm or less). In such a case, when the mask plate is heated by the radiation of heat rays, each opening formed in the mask plate may be distorted, which may prevent vapor deposition with high accuracy (in other words, without so-called mask blur). There is. Therefore, how to suppress the temperature rise of the substrate to be processed and the mask plate during vapor deposition has become an important issue.

Japanese Unexamined Patent Publication No. 2014-77193 Japanese Unexamined Patent Publication No. 2019-167593

In view of the above points, it is an object of the present invention to provide a vapor deposition source for a vacuum vapor deposition apparatus capable of suppressing a temperature rise of a substrate to be processed or a mask plate during vapor deposition as much as possible. be.

In order to solve the above problems, the vapor deposition source for the vacuum vapor deposition apparatus of the present invention, which is arranged in a vacuum chamber and for vapor deposition on a substrate to be processed, is a container filled with a vapor deposition material and a container in the container. It is provided with a heating means for heating the vapor-deposited material, and the container has a discharge portion capable of releasing the vaporized material vaporized or sublimated in the container by heating, and is heated with the heating of the vapor-deposited material by the heating means. This is characterized in that a low emissivity layer having a lower emission rate than the base material of this container is provided in the container portion that radiates heat rays to the substrate to be processed. In the present invention, when the discharge portion is composed of a discharge nozzle projecting from the upper surface of the container facing the substrate to be processed and is provided with another heating means for heating the discharge nozzle, the container portion is discharged. It is possible to adopt a configuration in which a low emissivity layer is provided on the inner surface of the discharge nozzle.

Here, the present inventors have repeated diligent research, and tentatively, a heat shield plate having a through hole through which the discharge nozzle is inserted is arranged so as to face the upper surface of the container so that only the discharge nozzle serves as a heat source. However, it has been found that the influence of heat radiation from the inner surface and the outer surface of the discharge nozzle cannot be ignored for the heating of the substrate to be treated and the mask plate. Therefore, in the present invention, a low emissivity layer is provided on the container portion such as the inner surface and the outer surface of the discharge nozzle and the upper surface of the container, which mainly radiates heat rays to the substrate to be treated, and the heat rays are directed toward the substrate to be treated and the mask plate. By adopting a configuration that reduces the amount of heat radiated from the surface, it is possible to suppress the temperature rise of the substrate to be processed and the mask plate during vapor deposition as much as possible. In this case, the low emissivity layer can be formed of a gold film formed directly on the surface of the container portion. According to this, since the gold film has excellent heat resistance and poor reactivity with the vapor-deposited material, a low emissivity layer having excellent durability can be obtained. On the other hand, the low emissivity layer may be formed by processing the surface of the container to have a surface roughness within a predetermined range. According to this, the emissivity of only the surface of the container portion that radiates heat rays can be made lower by using the same base material (metal) as the container and the discharge nozzle.

(A) is a partial perspective view showing a partially sectional view of the vacuum vapor deposition apparatus including the vapor deposition source according to the embodiment of the present invention, and (b) is a partial sectional view of the vacuum vapor deposition apparatus viewed from the front side. Enlarged sectional view of the vapor deposition source of this embodiment. The figure which shows the temperature distribution of the heat shield plate of a thin film deposition source. The figure which shows the temperature distribution of the heat shield plate of the modification of the vapor deposition source.

Hereinafter, referring to the drawings, the substrate to be processed is a glass substrate having a rectangular outline and a predetermined thickness (hereinafter referred to as “substrate Sw”), and a predetermined thin film is deposited on one side of the substrate Sw by a vacuum vapor deposition method. An embodiment of a vapor deposition source for a vacuum vapor deposition apparatus of the present invention will be described by taking the case of (depositing) as an example. In the following, terms indicating directions such as "up" and "down" will be described with reference to FIG.

With reference to FIGS. 1 (a) and 1 (b), Dm is a vacuum vapor deposition apparatus including the vapor deposition source DS of the present embodiment. The vacuum vapor deposition apparatus Dm includes a vacuum chamber 1, and a vacuum pump is connected to the vacuum chamber 1 via an exhaust pipe, although not particularly illustrated, and can be evacuated to a predetermined pressure (vacuum degree) and held. It has become like. Further, a substrate transfer device 2 is provided above the vacuum chamber 1. The substrate transfer device 2 has a carrier 21 that holds the substrate Sw in a state where the lower surface as a film forming surface is open, and the carrier 21 and thus the substrate Sw are predetermined in one direction in the vacuum chamber 1 by a drive device (not shown). It is designed to move at speed. Since a known substrate transfer device 2 can be used, further description thereof will be omitted. Further, in the following, the relative movement direction of the substrate Sw with respect to the vapor deposition source DS is defined as the X-axis direction, and the width direction of the substrate Sw orthogonal to the X-axis direction is defined as the Y-axis direction.

A plate-shaped mask plate 3 is provided between the substrate Sw transported by the substrate transport device 2 and the vapor deposition source DS described later. The mask plate 3 is made of a thin plate made of metal such as thin film, aluminum, alumina, stainless steel, or resin such as polyimide, and a plurality of openings 31 penetrating in the plate thickness direction are formed in a predetermined mask pattern (this). As a result, during vapor deposition, the adhesion of the vapor deposition material Vm to the substrate Sw is restricted at a position where there is no opening 31, so that a predetermined thin film is vapor-deposited on the substrate Sw with a film formation pattern corresponding to the mask pattern). The mask plate 3 is attached integrally with the substrate Sw and is conveyed together with the substrate Sw by the substrate transfer device 2, but it can also be fixedly arranged in the vacuum chamber 1 in advance. A thin-film deposition source DS is provided on the bottom surface of the vacuum chamber 1 so as to face the substrate Sw to be conveyed.

Also with reference to FIG. 2, the vapor deposition source DS has a metal container 41 that houses the vapor deposition material Vm. A metal crucible 42 is stored in the container 41, and the vapor deposition material Vm is filled in the crucible 42. A sheath heater 43 as a heating means is provided between the crucible 42 and the container 41 so as to cover the outer wall surface of the crucible 42 over the entire surface thereof, and the vaporized material Vm is vaporized or sublimated to the vaporization temperature or the sublimation temperature via the crucible 42. Can be heated. As the vapor deposition material Vm, a metal material or an organic material is appropriately selected according to the thin film to be formed on the substrate Sw, and a granular or tablet-like material is used. On the upper surface (the surface facing the substrate Sw) 41a of the container 41, a plurality of discharge nozzles 44 (8 in this embodiment) as discharge portions are arranged at predetermined intervals in the Y-axis direction.

A sheath heater 45 as another heating means is provided around each discharge nozzle 44. Then, the vaporized material Vm vaporized or sublimated in the container 41, which is heated to the vaporization temperature or the sublimation temperature by the sheath heater 43, is discharged from each discharge nozzle 44 according to a predetermined cosine rule. At this time, by heating each discharge nozzle 44 by the sheath heater 45, it is possible to prevent the vaporized or sublimated vaporized material Vm from reattaching to the inner surface 44a of the discharge nozzle 44 and condensing or solidifying. The number of discharge nozzles 44, the nozzle diameter of each discharge nozzle 44, and the height from the upper surface 41a to the tip of the discharge nozzle 44 are determined in consideration of, for example, the film thickness distribution in the Y-axis direction when vapor-deposited on the substrate Sw. It can be set as appropriate.

Further, on the upper surface 41a of the container 41, a heat shield plate 5 that covers the entire surface of the container 41 via a prismatic support frame 5a is arranged so as to face each other. The heat shield plate 5 is made of a material having high heat resistance, for example, stainless steel. The heat shield plate 5 is provided with a through hole 51a that penetrates in the plate thickness direction and allows the insertion of each discharge nozzle 44, and each discharge nozzle is attached to the upper surface 41a of the container 41. The tip of the 44 is slightly projected from the upper surface of the heat shield plate 5. Further, in the space between the upper surface 41a of the container 41 and the lower surface of the heat shield plate 5, two reflector plates 61 and 62 are provided at intervals in the vertical direction and are radiated from the upper surface 41a of the container 41. It is possible to prevent the heat shield plate 5 from being heated by reflecting the heat rays. In this case, a cooling means may be arranged below the heat shield plate 5 so that the heat shield plate 5 is maintained at a predetermined temperature or lower. In this embodiment, the one provided with the heat shield plate 5 and the reflector plates 61 and 62 will be described as an example, but the heat shield plate 5 and the reflector plates 61 and 62 themselves may be omitted.

When a predetermined thin film is deposited on the lower surface of the substrate Sw by the vacuum vapor deposition apparatus Dm, the vacuum chamber 42 is filled with the vapor deposition material Vm in the air atmosphere in the vacuum chamber 1, and then a predetermined pressure is applied by a vacuum pump (not shown). Vacuum exhaust until. Next, when the sheath heater 43 is operated to heat the vaporized material Vm, the vaporized material Vm is vaporized or sublimated to form a vaporized atmosphere or a sublimated atmosphere in the container 41, and each discharge nozzle is formed by the pressure difference from the vacuum chamber 1. The vaporized or sublimated vaporized material Vm is released from 44 according to a predetermined chord rule. At the same time, the substrate Sw is transported in the X-axis direction by the substrate transport device 2. As a result, the vaporized or sublimated vapor-filmed material Vm discharged from each discharge nozzle 44 according to a predetermined cosine rule adheres and is deposited on the lower surface of the substrate Sw that moves relative to the container 41 in the X-axis direction, and is deposited to be a predetermined organic substance. The film is vapor-deposited (deposited). At this time, since each discharge nozzle 44 is heated by the sheath heater 45, the substrate Sw and the mask plate 3 are prevented from being heated as much as possible by the heat radiated from the inner surface 44a and the outer surface 44b of the discharge nozzle 44. You need to keep it.

In the present embodiment, a low emissivity layer having a lower emissivity than the base material (metal) of the container 41 over the entire inner surface 44a and outer surface 44b of the discharge nozzle 44 and over the entire upper surface 41a of the container 41. Le was provided (see FIG. 2). As the low emissivity layer Le, for example, a thin film of a metal or a metal compound selected from Au, Cu, TiN and the like (thickness is, for example, 1 to 20 μm) can be used, and more preferably, it is directly formed. A filmed gold film is used. Since the gold film has excellent heat resistance and poor reactivity with the vapor deposition material Vm, it is possible to obtain a low emissivity layer Le with excellent durability. As a film forming method for the low emissivity layer Le, a physical film forming method such as a plating method, a vacuum vapor deposition method or a sputtering method, or a CVD method can be used. On the other hand, as the low emissivity layer Le, the inner surface 44a and outer surface 44b of the discharge nozzle 44 and the surface of the upper surface 41a of the container 41 are processed (polished) to have a surface roughness within a predetermined range (for example, Ra 3 μm or less). You can also do it. In this case, the same base material (metal) as the container 41 and the discharge nozzle 44 can be used to lower the emissivity of only the surface of the container portion that radiates heat rays. As a surface roughness processing method, a polishing method such as an electrolytic polishing method or a chemical polishing method or a cutting process can be used.

According to the above embodiment, the low emissivity layer Le is provided over the entire inner surface 44a and outer surface 44b of the discharge nozzle 44 and the upper surface 41a of the container 41 as the container portion that radiates heat rays to the substrate Sw. The amount of heat radiation of the heat rays toward the substrate Sw and the mask plate 3 is reduced, and the temperature rise of the substrate Sw and the mask plate 3 during vapor deposition can be suppressed as much as possible.

In order to confirm the above effect, the following evaluation was performed using the vacuum vapor deposition apparatus Dm. That is, Alq ₃ : Tris (8-hydroxyquinolinate) aluminum was filled in the pit 42 as the vapor-deposited substance Vm, the inside of the vacuum chamber 1 was evacuated to a predetermined pressure ( ^10-5 Pa), and then the sheath heaters 43 and 45 were used. The temperature was raised to the vapor deposition temperature (about 400 ° C.), and the temperature distribution of the heat shield plate 5 was evaluated by simulation. In this case, the container 41 in which the discharge nozzle 44 is formed is made of titanium, and a conventional product is obtained by only blasting using particles having a predetermined particle size, and the inner surface 44a, outer surface 44b and outer surface 44b of the conventional product discharge nozzle 44. A low emissivity layer Le over the entire upper surface 41a of the container 41, in which a gold film was previously formed with a film thickness of 150 nm by a physical film forming method, and a TiN film was physically formed with a film thickness of 20 nm. The product that was previously film-formed by the film-forming method was designated as Invention 2.

FIG. 3 shows the temperature distribution of the surface of the heat shield plate 5 facing the substrate Sw. According to this, in the conventional product, as shown in FIG. 3C, the central region along the longitudinal direction of the heat shield plate 5 where the discharge nozzle 44 is present becomes relatively high temperature (the temperature at the midpoint is 94 ° C.). It was confirmed that a temperature difference of 40 ° C. or more was generated between the outer peripheral edge and the outer peripheral edge. Such a temperature difference between the central region and the outer peripheral edge portion is caused by an increase in the amount of heat radiation of the heat rays radiated from the emission nozzle 44 itself. On the other hand, in the invention product 1, as shown in FIG. 3A, the temperature at the midpoint is 57 ° C., the surface temperature is about 40 ° C. lower than that of the conventional product, and the heat shield plate 5 is in the longitudinal direction. It was confirmed that the temperature difference between the central region along the line and the outer peripheral edge thereof can also be reduced. Similarly, in the invention product 2, as shown in FIG. 3 (b), the temperature at the midpoint is 69 ° C., the surface temperature is about 25 ° C. lower than that of the conventional product, and similarly, the longitudinal direction of the heat shield plate 5 It was confirmed that the temperature difference between the central region along the line and the outer peripheral edge thereof can also be reduced. That is, in the invention product 1 and the invention product 2, it is shown that the amount of heat radiation of the heat rays radiated from the emission nozzle 44 itself is small. From these results, the low emissivity layer Le was provided over the entire inner surface 44a and outer surface 44b of the emission nozzle 44 and the upper surface 41a of the container 41 as the container portion for radiating heat rays to the substrate Sw. It can be seen that the amount of heat radiation of the heat rays toward the mask plate 3 was reduced, and the temperature rise of the substrate Sw and the mask plate 3 during vapor deposition could be suppressed as much as possible.

Next, the inner surface 44a, the outer surface 44b, and the upper surface 41a of the container 41 of the conventional discharge nozzle 44 are processed by an electrolytic polishing method to have a surface roughness Ra of 3 μm or less. An experiment was conducted. FIG. 4 shows the temperature distribution of the surface of the heat shield plate 5 facing the substrate Sw, including the discharge nozzle 44. According to this, the temperature at the midpoint is 76 ° C., the surface temperature is about 20 ° C. lower than that of the conventional product, and the temperature between the central region along the longitudinal direction of the heat shield plate 5 and the outer peripheral edge thereof. It was confirmed that the difference can be smaller than that of the conventional product. That is, the invention product 3 shows that the amount of heat radiation of the heat rays radiated from the discharge nozzle 44 itself is small, as in the invention product 1 and the invention product 2. From these results, the inner surface 44a and outer surface 44b of the discharge nozzle 44 and the upper surface 41a of the container 41 were processed by an electrolytic polishing method to have a surface roughness Ra of 3 μm or less, so that heat rays directed toward the substrate Sw and the mask plate 3 were obtained. It can be seen that the amount of heat dissipated is reduced, and the temperature rise of the substrate Sw and the mask plate 3 during vapor deposition can be suppressed as much as possible.

Although the embodiments of the present invention have been described above, various modifications are possible as long as they do not deviate from the scope of the technical idea of the present invention. In the above embodiment, as the container portion that radiates heat rays to the substrate Sw, the low emissivity layer Le is provided over the entire inner surface 44a and outer surface 44b of the discharge nozzle 44 and over the entire upper surface 41a of the container 41. Although the provided one has been described as an example, the container portion that radiates heat rays to the substrate Sw is not limited to these, and is limited to each portion of the inner surface 44a, the outer surface 44b, and the upper surface 41a of the container 41 of the discharge nozzle 44, or. , A low emissivity layer Le may be provided partially in each portion. Further, when the heat shield plate 5 and the reflector plates 61 and 62 are provided, a low emissivity layer Le may be provided on the upper surface of the heat shield plate 5 and the reflector plates 61 and 62 as a container portion for radiating heat rays to the substrate Sw. good.

Dm ... Vacuum vapor deposition equipment, DS ... Vapor deposition source, Le ... Low radiation layer, Sw ... Substrate (processed substrate), Vm ... Vapor deposition material, 1 ... Vacuum chamber, 41 ... Container, 41a ... Top surface of container (Processed substrate) (Container part that radiates heat rays to the substrate), 43 ... Sheath heater (heating means), 44 ... Discharge nozzle (discharge part), 44a ... Inner surface of the discharge nozzle (Container part that radiates heat rays to the substrate to be processed), 44b … Outer surface of the emission nozzle (container portion that radiates heat rays to the substrate to be treated), 45… sheath heater (other heating means).

Claims (4)

A vapor deposition source for a vacuum vapor deposition apparatus that is placed in a vacuum chamber to deposit on a substrate to be processed.
A container filled with a vapor-deposited material and a heating means for heating the vapor-deposited material in the container, and the container has a discharge portion capable of releasing the vaporized material vaporized or sublimated in the container by heating. In
It is characterized by providing a low emissivity layer with a lower emissivity than the base material of this container in the container part that radiates heat rays to the substrate to be treated by being heated by heating the vapor-filmed material by the heating means. A vapor deposition source for vacuum vapor deposition equipment. Another vapor deposition source for a vacuum vapor deposition apparatus according to claim 1, wherein the discharge portion is composed of a discharge nozzle projecting from the upper surface of the container facing the substrate to be processed, and heats the discharge nozzle. In those equipped with heating means,
A vapor deposition source for a vacuum vapor deposition apparatus, characterized in that the container portion is an inner surface of a discharge nozzle and a low emissivity layer is provided on the inner surface of the discharge nozzle. The vapor deposition source for a vacuum vapor deposition apparatus according to claim 1 or 2, wherein the low emissivity layer is composed of a gold film formed directly on the surface of the container portion. The vapor deposition source for a vacuum vapor deposition apparatus according to claim 1 or 2, wherein the low emissivity layer is formed by processing the surface of the container to a surface roughness within a predetermined range.

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