JP2003003253A - Vapor deposition system and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively provide a continuous automatic vapor deposition system which is capable of realizing the uniform heating over the entire part of substrates by minimizing the temperature difference between a substrate holder and the segments of the substrates inclusive of lenses in contact with the substrate holder as far as possible, improves lens performance and is high in productivity. SOLUTION: This vapor deposition system has a plurality of heating and slow cooling chambers 2 in which the lenses 9 being the substrates are housed and which are respectively independently capable of controlling the atmospheres and temperatures in the chambers under the atmosphere pressure, a heat insulting chamber 16 which is connectable to both of the heating and slow cooling chambers 2 and makes exhausting and pressurizing to the atmosphere possible between the atmospheric pressure and a desired vacuum degree while preventing the escape of heat of the transferred and heated lenses 9, a deposition chamber 31 which deposits the films 9 by vapor deposition in the vacuum and a conveying chamber 24 which has a temperature controlled substrate conveying robot 25 and of which the substrate conveying robot 25 is capable of conveying the lenses 9 between the heat insulating chamber 16 and the deposition chamber 31 in the vacuum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor deposition apparatus capable of uniform heating and uniform cooling when a substrate mounted on a substrate holder is heated or cooled, and more particularly, when the substrate is Ca.
The present invention relates to a continuous automatic vapor deposition device for heating and gradually cooling a single crystal substrate such as F ₂ which is very weak against heat.

[0002]

2. Description of the Related Art An automatic vapor deposition apparatus that has been widely and conventionally used includes a load lock chamber, a transfer chamber, a film forming chamber,
It consists of an unload chamber, and multiple substrates are put into the load lock chamber to improve the performance such as vacuum evacuation, film absorption, film density (refractive index), and film adhesion. The process of heating the substrate is performed, and the substrate heated in the load lock chamber is transferred in a vacuum state in the transfer chamber and is transported between the film formation chamber and the unload chamber. A film is formed, and in the unload chamber, the formed substrate is gradually cooled and the pressure is restored to discharge the substrate. As a method of heating the substrate, since it is necessary to heat the film before or during film formation, the substrate holder to which the substrate such as the lens is attached is held in vacuum, and the film is formed by a heat source such as a sheath heater or halogen lamp. A method of heating the surface, the back surface of the film formation, or both surfaces is generally used.

Further, as a method for achieving uniform heating,
A method of supplying a gas such as He in the gap between the heater surface and the back surface of the substrate as disclosed in JP-A-10-41378, and electrostatic discharge as disclosed in JP-A-07-263530. It has been proposed that the chuck and the heater are integrated to improve the efficiency and uniformity of heating.

[0004]

However, a method of bringing a heater into contact with a substrate such as a sheath heater which has been widely used in the past, or a vacuum heater in a non-contact state with a heater using a heat source such as a halogen lamp is used. When a single crystal CaF ₂ lens is formed by the method of heating and gradually cooling, there are the following problems in addition to the problem that the lens is scratched by the contact method. 1. Uniform heating and uniform slow cooling are difficult 2. Larger and more expensive vapor deposition equipment such as heating / cooling chambers 3. Low productivity 1. The problem is that the heating without contact with the heater and the gradual cooling process generally require preheating in the preliminary exhaust chamber before film formation and heating during film formation. Heating / slow cooling is performed. Therefore, the heating mechanism is mostly heating by radiation, not by heat conduction or convection. Since the absorption efficiency of radiant heat is different between the lens made of different materials and the lens holder that holds the lens, the temperature rising and cooling characteristics differ between the two, and the part that contacts the lens holder of the lens and the other part Since there is a temperature difference between them, there is a problem with uniform heating / slow cooling.

2. In particular, in the heating / slow cooling process for a single-crystal CaF ₂ lens, in order to avoid problems such as surface shape change due to the influence of heat, a gradient such as several degrees Celsius to several tens of degrees Celsius / hour is very high. A heating / cooling process that uses a gradual temperature rise / fall curve is required, and a load lock chamber with the function of an in-line type continuous processing furnace is required to process multiple lenses for a large number of batches as before. In the structure of the unload chamber, the load lock chamber / unload chamber must be increased in size due to the long residence time, and thus the price has been increased.

Further, in order to function as an automatic vapor deposition apparatus corresponding to various lens shapes, a large vacuum storage chamber capable of storing various film thickness correction plates in vacuum is required.

3. However, in order to realize uniform film formation corresponding to various lens shapes, two types of correction masks corresponding to the lens shapes on both sides and a lens reversing mechanism are required.
Without the mechanism for transporting the correction mask and the lens reversing mechanism, the lens formed on one surface must be subjected to the temperature raising, film forming, and temperature lowering processes, and then turned over to perform the same process again. In particular, in single crystal high performance CaF ₂ lenses used in next-generation ArF and F ₂ semiconductor exposure equipment,
Above 1. CaF ₂ lens surface change, homogeneity change, crystal slip, etc. occurred due to the temperature difference of
The lens performance after coating such as an antireflection film is deteriorated.

Therefore, in the heating process of the continuous automatic vapor deposition apparatus for forming an optical thin film, an object of the present invention is to perform a plurality of atmosphere-controlled atmospheric pressure heating furnaces, which are different from the conventional ones, and to perform vacuum exhaust / recovery pressure. By using a vapor deposition apparatus having a heat-retaining chamber and an inversion chamber for forming a film on the back surface of the lens, the temperature difference between the lens holder and the lens portion in contact with the lens holder is suppressed as much as possible, and the CaF
₍₂₎ By realizing uniform heating of the entire lens, performance deterioration such as surface change during film formation is prevented, lens performance is further improved, and a high-performance anti-reflection film can be coated. To provide at low cost.

[0009]

A vapor deposition apparatus according to the present invention for achieving the above object is a vapor deposition apparatus for depositing a film on a substrate in a vacuum, and the substrate is housed under atmospheric pressure. It is also possible to connect multiple heating / slow cooling chambers, each of which can control the atmosphere and temperature in the room independently, and to escape the heat of the transferred heated substrate. A greenhouse chamber capable of exhausting and restoring pressure between atmospheric pressure and a desired degree of vacuum while preventing it, a film forming chamber for forming a film on a substrate by vacuum evaporation, and a temperature-controlled substrate transfer Have a mechanism,
The substrate transfer mechanism is provided with a transfer chamber capable of transferring the substrate between the greenhouse and the film forming chamber to which the substrate is connected in vacuum.

Further, in order to form a film on the back surface of the substrate having one surface formed in the film forming chamber, an inversion chamber for inverting the substrate in vacuum is provided, and the substrate transfer mechanism in the transfer chamber is a substrate transfer mechanism. It may be possible to transfer the film to the reversing chamber, and in the heating / slow cooling chamber and the warming chamber, one or two correction plates for correcting the film thickness distribution of the substrate at the time of film formation are provided at the same time as the substrate. Holding means for heating / slow cooling and heat retention may be provided.

This vapor deposition apparatus is particularly effective when this substrate is a CaF ₂ single crystal lens. The vapor deposition method according to the present invention is a vapor deposition method for forming a film on a substrate in a vacuum, and a substrate and a correction plate are provided in each of a plurality of heating / slow cooling chambers placed under atmospheric pressure. Arrange the trays that are held, control the atmosphere and temperature in the room according to a specified program, and connect the heating / slow cooling room that has reached the specified atmosphere and temperature to the greenhouse that has the specified atmosphere and temperature. Then, the tray holding the substrate and the correction plate is transferred to the greenhouse, and the inside of the greenhouse is evacuated and connected to the transfer chamber and the film forming chamber which have a predetermined degree of vacuum. When the substrate and the correction plate are transferred to the film forming chamber by the substrate transfer mechanism of the transfer chamber, and a predetermined film is formed on the substrate by vapor deposition in vacuum, and when the film is also formed on the back surface of the substrate, In vacuum, the substrate transfer mechanism moves the substrate to the reversal chamber, reverses it, and returns it to the film formation chamber. Replace the correction plate and again form a predetermined film on the substrate by vapor deposition in vacuum.The substrate after film formation is returned to the greenhouse by the substrate transport mechanism in vacuum, and the inside of the greenhouse is heated to the specified atmosphere and temperature. After re-pressurizing, transfer to a connected heating / slow cooling chamber controlled to a predetermined atmosphere and temperature, and control the temperature in the heating / slow cooling chamber according to a predetermined program to gradually cool and process. It is characterized by terminating. In the vapor deposition apparatus of the present invention, the heating and slow cooling of the substrate is performed by controlling a predetermined atmosphere and temperature under a condition of atmospheric pressure in a plurality of heating / slow cooling chambers for each substrate. The temperature difference between the substrate and the substrate holder that holds the substrate is small, so there is no temperature difference between the part of the substrate that contacts the substrate holder and the other part, and uniform heating. And cooling becomes possible. In addition, heating / slow cooling is not performed in the load lock chamber and unload chamber in which multiple substrates can be stored in a vacuum state, but in multiple heating / slow cooling chambers under atmospheric pressure conditions. The heating / slow cooling chamber is connected to the greenhouse, the substrate is transferred to the greenhouse, the vacuum is maintained in the greenhouse to connect to the vacuum film forming chamber for film formation, and the heating / slow cooling is performed by the same heating.・ Since it is performed in the slow cooling room, the scale of the equipment can be reduced and the equipment cost can be reduced.

Further, since the reversing chamber is provided under the same vacuum condition as the film forming chamber, it is not necessary to reverse the film formation after cooling once to form the film on the opposite surface even in the case of double-sided film formation. The required space can be saved.

Further, since the correction plate is combined with the substrate to simultaneously perform heating, cooling and heat retention, a vacuum storage for the correction film and a transfer device therefor are not required.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a vapor deposition apparatus embodying the present invention will be described. In the following description, the substrate will be described as a single crystal CaF ₂ lens that is most vulnerable to heat and is extremely weak against heat, but the present invention is not limited to this, and deposition of films for all substrates including a single crystal substrate that is weak against heat. Applicable to

Although the vapor deposition apparatus is not particularly limited to the automatic continuous vapor deposition apparatus, it can be easily understood by those skilled in the art that the structure of the present invention is applied to the automatic continuous vapor deposition apparatus. Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic plan layout view of a vapor deposition device according to an embodiment of the present invention.

The basic structure of the vapor deposition apparatus according to the embodiment shown in FIG. 1 is that the temperature of an oven unit 1 in which a plurality of movable heating / slow cooling chambers 2 are arranged and the temperature of heated lenses are kept constant. Meanwhile, a greenhouse chamber 16 that can evacuate from the atmosphere or evacuate or restore pressure from the atmosphere to the atmosphere; It is composed of a film forming chamber 31 for forming a multilayer film on the lens and an inversion chamber 41 for inverting the film formed lens.

The oven unit 1 has a plurality of heating / slow cooling
Room 2 is stored, and heating / slow cooling room 2 is a multi-storey car park.
You can move while circulating. Inside the heating / slow cooling chamber 2
N to prevent organic contamination on the lens surface₂Introductory pipe
6 to N₂Introduce gas and N ₂Controlled by the atmosphere
It The temperature of each heating / slow cooling chamber 2 is controlled independently.
The heating method is heating with the heater 3 and the temperature controller 4.
・ N in the slow cooling room₂Heat the gas and use fan 5 from top to bottom
It forms a circulating flow into.

A filter 7 is disposed downstream of the fan 5 for removing dust and contaminated organic substances of 0.1 μm or more that are wound up by circulation in the heating / slow cooling chamber.

A detachable tray 8 is housed inside the heating / slow cooling chamber 2, and the tray 8 has a substrate holder 10 holding a CaF ₂ lens 9 and two correction plates 11 and 1.
2 and are stored. Due to the transport mechanism of the vapor deposition apparatus, the substrate holder 10 is made of SUS304 whose outer shape and outer dimensions are standardized, and the CaF ₂ lens 9 is dropped into the stepped hole at the center of the substrate holder 10. , C
The outer peripheral part of the aF ₂ lens 9 is sandwiched by a lens holding ring made of SUS304 having a stepped hole similar to the stepped part of the substrate holder 10 and held by the substrate holder, and the correction plate 11 is made of CaF ₂ during vapor deposition. The upper surface side of the lens 9 (R
The correction plate 12 is a correction plate that makes uniform the film unevenness in the shape of one surface), and the correction plate 12 is a correction plate 12 that makes the film unevenness in the shape of the back surface (R2 surface) of the lens uniform during vapor deposition, and each of them is a tray 8. Is set to. As described above, in the heating / slow cooling process of the single crystal CaF ₂ lens in the vapor deposition method, in order to avoid problems such as surface change due to the influence of heat,
It is necessary to use a temperature rising / falling curve having a very gentle slope such as several degrees centigrade to several tens of degrees centigrade / hour, and therefore it is necessary to form a film by a uniform heating process that requires several tens of hours per batch. The heating process of the vapor deposition apparatus of the present invention is different from the conventional heating method in which heating by radiation is the main, and forcibly convects the atmosphere and the temperature-controlled heating medium at atmospheric pressure and makes contact with the heating medium. The object is heated by the so-called heat conduction heating method. For this reason, as in the conventional heating mechanism in which radiation is mainly used, the temperature difference occurs in the member to be heated due to the difference in absorption rate and reflectance rate of near-infrared rays, infrared rays, and far-infrared rays depending on the vacuum components and substrate materials used. The problem was avoided. For example, in the conventional method, a lens made of a CaF ₂ material is attached to a substrate holder made of a vacuum material of SUS304 which is generally used because the material emits less gas. In this case, the substrate holder with high absorption rate of near-infrared ray, infrared ray, and far-infrared ray is heated quickly, but near-infrared ray is transmitted by the CaF ₂ lens whose absorption edge on the long wavelength (infrared ray) side is about 10 microns. Therefore, the heating efficiency is poor, and the temperature difference occurs because the heating is not performed so much. In the method of interposing the heating medium of the present invention, the heating medium is the substrate holder 10.
Since heat is transferred by contacting the or CaF ₂ lens 9, uniform heating can be realized even with different materials. He gas, which has a large specific heat, is most preferable as the heating medium, but is expensive. Therefore, in the present invention, it is practically preferable to use inexpensive N ₂ gas. Further, it is necessary to consider the surface treatment of the furnace inner member, the installation of the filter 7 and the like in order to prevent the organic substance contamination on the surface of the CaF ₂ lens 9 during heating.

A gate valve 13 for loading and unloading the tray 8 is provided outside the heating / slow cooling chamber, and the heating / slow cooling chamber after the heating process is circulated and moved inside the oven unit 1 to keep a greenhouse. Sixteen gate valves 15 are connected to each other, and N ₂ gas heated to a set temperature is introduced into the gap between the connected gate valves 13 and 15 through the N ₂ introducing pipe 14 to replace N ₂ .

A rotary drive unit 19 for rotating the tray 8 for the purpose of making the temperature uniform is disposed inside the greenhouse 16, and the heated lens 9 and the correction plate 1 are provided.
The entire inside of the greenhouse 16 is surrounded by a heater 17 so that the heat of 1 and 12 does not escape, and the heater 17 is controlled by a temperature controller 18. The side heater 17 is provided with a drive system 20 for rotating a part of the heater 17 in order to prevent interference with the heater surrounded by the entire surface when the tray 8 and lenses are conveyed.

The greenhouse 16 includes an exhaust unit 21 for exhausting the interior of the greenhouse and a leak valve 2 for restoring the pressure inside the greenhouse.
2 and. After the CaF ₂ lens 9 is conveyed to the greenhouse 16 by moving the uniformly heated heating / slow cooling chamber 2, the inside of the greenhouse 16 is evacuated. At this time, if the inside of the greenhouse 16 is exhausted all at once, heat is taken from the surroundings by adiabatic expansion, so it is necessary to perform slow exhaust at the initial stage of exhaust. After slow exhaust, exhaust at once. The greenhouse 16 has a structure in which the entire surface is surrounded by a heater, and is devised to suppress the heat input / output from the contact portion of the substrate holder 10 and suppress the temperature change of the heated CaF ₂ lens 9.

The greenhouse 16 is connected to the transfer chamber 24 via a gate valve 23. Inside the transfer chamber 24, a transfer robot 25 that transfers the lens 9 and the correction plates 11 and 12, a heater 27 that prevents a temperature decrease during the transfer, and a temperature controller 28 are installed. A transfer table 26 for picking up and transferring the substrate holder 10 and the correction plates 11 and 12 is attached to the tip of the robot 25, and the substrate holder 10 can be transferred to the greenhouse 16, the film forming chamber 31, and the reversing chamber 41. it can. In addition, the transfer chamber 24 has a reversal chamber 4
1 is connected, and an exhaust unit 29 for exhausting the inside of the two chambers is attached.

Inside the reversing chamber 41, there are provided a rotary table 42, a reversing drive unit 43, a heater 44 and a temperature controller 45 for preventing the temperature of the lens from decreasing during the reversing operation.

A film forming chamber 31 is connected to the transfer chamber 24 via a gate valve 30. Inside the film forming chamber 31, C
The substrate holder 10 on which the aF ₂ lens 9 ′ is set is transported by the transport robot 25 and set on the dome 32. The substrate holder 10 thus set performs a so-called revolving motion in which the revolving drive unit 33 revolves around its own axis. Between the substrate holder 10 set on the CaF ₂ lens 9 ′ and the evaporation source 38, the correction plate 11 ′ or the correction plate 12 ′ that matches the shape of the lens surface to be formed is conveyed by the conveyance robot 25 and fixed. Will be placed. Further evaporation source 3
A shutter plate 36 that is opened and closed by a shutter drive unit 37 is arranged near the front surface of the shutter 8. The evaporation source 38 contains an evaporation material, and the evaporation power source 39 melts the evaporation material to form a film on the lens. A heater 34 for heating the lens and a temperature controller 35 are arranged above the dome 32 to prevent the temperature of the lens from decreasing. In addition, the film forming chamber 31
An exhaust unit 40 for exhausting the inside of the film forming chamber 31 is attached to the. After the greenhouse is evacuated, the CaF ₂ lens 9 and the substrate holder 10 are transferred to the film forming chamber 31 by the transfer robot 25 in the transfer chamber 24 to perform film formation,
Further, the reversing chamber 4 is moved by the transfer robot 25 in the transfer chamber 24.
After being inverted, the robot is transported to the film forming chamber 31 again by the transport robot 25 after being inverted, and film formation is performed on the back surface. After these processing steps are finished, the robot is transported to the greenhouse 16 again. After being transported to the greenhouse 16, a leak operation for introducing heated N ₂ gas is started. This time,
Since heat is taken away by the same adiabatic expansion as during exhaust operation, a slow leak that slowly leaks is performed. After the leak operation, the coated lens 9 is conveyed to the heating / slow cooling chamber 2 by the operation opposite to the above, and the slow cooling process is started. When the slow cooling process is completed, the series of processes is completed. Therefore, several degrees to several tens of degrees C
A uniform heating process using the temperature rising and falling curves can be achieved, and a temperature difference occurs between the substrate holder 10 and the CaF ₂ lens 9 during the rising / falling and constant value states, and C
It has been possible to solve the technical problems that occur in the conventional process such as the surface change of the aF ₂ lens 9, the change of homogeneity, the slip of crystals, and the like, which deteriorates the lens performance.

The outline of the vapor deposition method has been described together with the above description of the vapor deposition apparatus. Next, the actual steps of the vapor deposition method using the vapor deposition apparatus of the present invention will be described. CaF ₂ lens 9
After setting the substrate holder 10 on which is set and the correction plates 11 and 12 of the R1 surface and the R2 surface on the tray 8, the substrate holder 10 is conveyed to the heating / slow cooling chamber 2 and heated / slow cooling chamber via the gate valve 13. Place inside 2. After the placement, N ₂ introduction pipe 6 to N
₂ gas is introduced to replace the inside of the heating / slow cooling chamber 2 with N ₂ gas. At this time, the oxygen concentration is detected by an oxygen concentration meter inside the heating / slow cooling chamber 2 to confirm the N ₂ substitution state. When the oxygen concentration meter becomes 100 ppm or less, the amount of N ₂ gas introduced is reduced to keep the oxygen concentration meter at 100 ppm or less.

Next, the heating process is started. In the heating process, the program temperature controller 4 heats the inside of the heating / slow cooling chamber 2 up to 300 ° C. at a heating rate of several ° C. to several tens of ° C./hour. After the heating process is completed, the heating / slow cooling chamber 2 is moved to dock the gate valve 13 of the heating / slow cooling chamber 2 and the gate valve 15 of the greenhouse 16 and the N ₂ gas heated to 300 ° C. ₂ Gate valve 13 and gate valve 1 introduced from the inlet pipe 14
The air between 5 and 5 is replaced with N ₂ gas. At this time, it is preferable to perform the substitution operation while confirming the concentration with an oxygen concentration meter.

After the replacement operation is completed, the supply of the heated N ₂ gas is stopped and the gate valves 15 and 12 are opened. At this time, the inside of the greenhouse 16 is preliminarily replaced with N ₂ gas and heated to 300 ° C. by the heater 17. A part of the heater 17 is rotated by the drive system 20 of the greenhouse 16 to open the tray carry-in port and keep the tray 8
Transport to. After the transfer, both gate valves 13 and 15 are closed, a part of the heater 17 is further rotated by the drive system 20 to close the tray carry-in port, and then the exhaust unit 21 performs slow exhaust. When the inside of the greenhouse is 100 Pa or less, rapid evacuation is performed until it reaches 10E-4 Pa or less.
At this time, the tray 8 is continuously rotated by the rotation driving unit 19 to achieve uniform temperature.

After the evacuation of the greenhouse 16 is completed, the gate valves 23 and 30 are opened, and at the same time, a part of the heater 17 is rotated to open the tray carry-in port, and the carrier table 26 of the carrier robot 25 holds the substrate holder 10 in place. Scoop and hold greenhouse 16
To the film forming chamber 31.

In the film forming chamber 31, the transported substrate holder 10 is set on the dome 32. Similarly, the correction plate 11 for the R1 surface is transferred from the warming room 16 by the transfer robot 25 and set in the film forming chamber 31. After transportation is completed, gate valve 2
Close tray inlets for heaters 3 and 30 and heater 17.

In the film forming chamber 31, the substrate holder 10 is caused to perform a so-called revolving motion in which the substrate holder 10 revolves while rotating on its own axis. Next, the evaporation material inside the evaporation source 38 is melted by resistance heating of the evaporation power source 39, and after the gas release and evaporation of the evaporation material is stabilized, the shutter plate 36 is opened to form a film on the lens 9. Desired optical characteristics can be obtained by depositing several layers of such a vapor deposition operation with a desired material and film thickness.

After the film forming process is completed, the gate valves 23 and 30 and the tray carrying inlet of the heater 17 are opened and the substrate holder 10 of the lens 9 coated by the carrying robot 25 is placed in the reversing chamber 41 in the reversing chamber 41 as described above. The correction plate 11 is conveyed to the original tray 8 of the greenhouse 16.

In the reversing chamber 41, the turntable 42 is reversed by the reversing drive unit 43 to perform the reversing operation of the lens 9. After the inversion operation is completed, the substrate holder 10 and the R2 correction plate 12 in the greenhouse 16 which have been inverted again are transported to the film forming chamber 31 to form a film.

After the film formation on both sides is completed, the substrate holder 1
0 and the correction plate 12 are transported to the greenhouse 16 by the transport robot 25 and returned to the tray 8. After that, the gate valves 23, 3
0 and the tray carry-in port of the heater 17 are closed, and the pressure recovery operation in the greenhouse 16 is started.

In the leak operation, the leak valve 22 is slightly opened and N ₂ gas heated to 300 ° C. is introduced. When the pressure inside the greenhouse is 1000 Pa or more, the leak valve 22 is fully opened. After completion of the recompression operation and the N ₂ replacement operation between the gate valves 13 and 15, the gate valves 15 and 13 and the heater 1
The tray 7 is opened to transfer it to the heating / slow cooling chamber 2 inside the greenhouse 16 to which the tray 8 having the film-formed lenses 9 mounted thereon is connected. The gate valves 15 and 13 are closed, the heating / slow cooling chamber 2 is separated from the greenhouse 16, and the oven unit 1 is moved. The new heating / slow cooling chamber 2 after the heat treatment is again connected to the greenhouse 16, and the above steps are repeated.

The heating / slow cooling chamber in which the film formation is completed enters a slow cooling step, and the heater 3 and the temperature controller 4 set a temperature curve of several to several tens of degrees Celsius / hour for several tens of hours. Slowly cool over.

As described above, in order to improve productivity, the heating / slow cooling process, which requires a very long time, has a plurality of independent heating.
This can be achieved by efficiently carrying and moving the slow cooling chamber 2 or by adding the reversing chamber 41 to realize coating on both sides in a depressurized state. In addition, by transporting the correction plates corresponding to the shapes on both sides of the lens at the same time as the lenses, a large chamber for storing the correction plates in a vacuum and a drive system are not required, and an inexpensive automatic vapor deposition apparatus is obtained.

Further, the present invention has solved the conventional problems as follows. 1) Miniaturization and cost reduction of vapor deposition equipment such as heating / slow cooling chamber For heating / slow cooling process that requires dozens of hours for processing time, multiple heating / slow cooling chambers can be independently controlled and movable. The heating / slow cooling chamber of this model realizes downsizing and price reduction. For example, each heating / cooling room moves horizontally / vertically like a multi-storey car park and connects to the greenhouse, and the tray with lenses etc. is transferred to the greenhouse and vacuum exhausted in the greenhouse. Therefore, the heating / slow cooling chamber is for atmospheric pressure atmosphere processing,
It is much cheaper than vacuum-compatible containers.

Further, in the prior art, a fully automatic vapor deposition apparatus corresponding to a plurality of lenses is provided with a correction plate for correcting the film thickness distribution of two kinds of front and back corresponding to the lens shape, corresponding to all the lens shapes to be coated. A large vacuum chamber stocked in a vacuum and a transfer system such as a robot were required.
In the present invention, since the CaF ₂ lens and the correction plate for correcting the film thickness distribution of the two types of the front and back that match the lens shape are processed at the same time, the vacuum chamber and a transfer system such as a robot are not required, and the vapor deposition apparatus is small.・ Lower prices. 2) Productivity improvement For productivity improvement, the heating / slow cooling process, which requires a processing time of several tens of hours, can be used as a plurality of heating / slow cooling chambers that can independently control the heating / slow cooling chamber. This is achieved by making good movement possible, and by providing a reversing chamber in the vapor deposition device, it is possible to perform processing in the same process on the front and back sides, and heating / slow cooling that requires a processing time of several tens of hours. There is no need to repeat the process again, improving productivity. As a comparative example of "Comparative Example" then uniformly heated, and when the heating in a vacuum substrate holder equipped with a CaF ₂ lens, using a vapor deposition apparatus of the embodiment shown in Figure 1 of the present invention N ₂ A comparison was made with the case of heating in an atmospheric pressure controlled atmosphere. In this comparative experiment, the same substrate holder was used to measure the temperature under the same conditions. The CaF ₂ lens used for temperature measurement has an uneven surface with an outer diameter of φ20.
A lens with a meniscus shape of 0 and a center wall thickness of about 40 mm is used. The thermocouple for temperature measurement has a minimum diameter sheath type φ to minimize the effect of heating the thermocouple itself.
0.5 for the central and peripheral parts of the lens and SU of φ420
It was installed by embedding it in an S substrate holder.

FIG. 2 shows the results of temperature measurement under the above conditions when heated in vacuum and at atmospheric pressure.

For heating in vacuum, the substrate holder and Ca
Due to the difference in the heat absorption efficiency of F ₂ , the temperature of the substrate holder becomes higher, and when the temperature of the CaF ₂ lens is 300 ° C., a temperature difference of about 110 ° C. occurs between the substrate holder and the center and the periphery of the lens. A temperature difference of about 30 ° C. was recognized. This is considered to be due to the conduction of heat from the substrate holder.

On the other hand, in the heating under the atmospheric pressure controlled by the N ₂ atmosphere, the substrate holder, the front and back surfaces of the central portion of the CaF ₂ lens, and the periphery are heated to substantially the same temperature, and the temperature rising curve also obtains desired characteristics. I was able to.

FIG. 3 shows the results of measuring the temperature characteristics of temperature increase and decrease by heating at atmospheric pressure. As can be seen from this graph, uniform heating and uniform gradual cooling were realized.

As described above, in the present embodiment, unlike the conventional vacuum heating method, the temperature of the substrate and the substrate holder is controlled by heating in the atmospheric pressure with controlled atmosphere, which provides excellent uniform heating characteristics. The difference can be reduced, and therefore the temperature difference between the substrate and the substrate holder in the contacting portion can be suppressed as much as possible, and uniform heating of the entire CaF ₂ lens can be realized.

Therefore, the object of the present invention is to prevent the lens performance from deteriorating during the film formation of the CaF ₂ lens, and further to form a uniform film over the entire CaF ₂ lens, thereby improving the film characteristics and providing high-performance reflection. It was possible to provide at low cost a highly productive fully automatic vapor deposition device capable of coating an anti-prevention film.

[0046]

As described above, the present invention has the following effects. That is, the effect that excellent uniform heating characteristics of the entire CaF ₂ lens, which could not be achieved by heating in vacuum used in the conventional vapor deposition heating process, can be achieved. This is because the temperature difference between the substrate and the substrate holder at the contacting portion was suppressed as much as possible by using the atmospherically controlled heating method at atmospheric pressure.
In addition, a highly efficient, compact, inexpensive vapor deposition apparatus can be obtained, and as a result, excellent CaF _{2 that} does not undergo surface change, crystal slip, and homogeneity change even after a film forming process such as vapor deposition or sputtering. The effect that an automatic vapor deposition apparatus that supplies lenses with high productivity can be provided at low cost was obtained. This is because a plurality of heating / slow cooling chambers, reversing chambers, and the lens and the correction plate are simultaneously conveyed, as compared with the conventional heating and slow cooling steps which require a very long time.

[Brief description of drawings]

FIG. 1 is a schematic plan layout view of a vapor deposition device according to an embodiment of the present invention.

FIG. 2 is a graph showing a comparison result of temperature characteristics between the conventional heating in vacuum and the heating in the atmospheric pressure controlled in the N ₂ atmosphere of FIG. 1 of the present invention.

FIG. 3 is a graph showing the results of temperature rising / falling characteristics according to the embodiment of the present invention.

[Explanation of symbols]

1 Oven unit 2 Heating / slow cooling chamber 3, 17, 27, 34, 44 Heater 4, 18, 28, 35, 45 Temperature controller 5 Fan 6, 14 N ₂ introduction pipe 7 Filter 8 Tray 9 CaF ₂ lens 10 Substrate Holders 11, 12 Correction plates 13, 15, 23, 30 Gate valve 16 Greenhouse 19 Rotation drive unit 20 Drive systems 21, 29, 40 Exhaust unit 22 Leak valve 24 Transfer chamber 25 Transfer robot 26 Transfer table 31 Film forming chamber 32 Dome 33 Auto-rotation drive unit 36 Shutter plate 37 Shutter drive unit 38 Vapor deposition source 39 Vapor deposition power source 41 Inversion chamber 42 Rotating table 43 Inversion drive unit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koji Teranishi             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F-term (reference) 2K009 AA02 BB04 DD03                 4K029 AA04 BB04 BC07 BD00 CA01                       DA00 DA08 KA01

Claims (9)

[Claims] 1. A vapor deposition apparatus for depositing a film on a substrate in a vacuum, wherein a plurality of the substrates are housed and are capable of independently controlling the atmosphere and temperature in a room under atmospheric pressure. The heating / slow cooling chamber and the heating / slow cooling chamber can be connected to prevent the heat of the transferred and heated substrate from escaping, and to prevent the heat between the atmospheric pressure and the desired vacuum degree. It has a greenhouse chamber capable of exhausting and restoring pressure, a film forming chamber for forming a film on the substrate by vapor deposition in vacuum, and a temperature controlled substrate transfer mechanism, and the substrate transfer mechanism is in vacuum. A vapor deposition apparatus comprising: a transfer chamber capable of being transported between the greenhouse and the film forming chamber to which the substrate is connected. 2. A reversing chamber for reversing the substrate in a vacuum so as to form a film on the back surface of the substrate having one surface formed in the film forming chamber, further comprising: The vapor deposition apparatus according to claim 1, wherein the substrate transfer mechanism can transfer the substrate to the reversal chamber. 3. In the heating / slow cooling chamber and the greenhouse, a correction plate for correcting the film thickness distribution of the substrate during film formation is held simultaneously with the substrate for heating / slow cooling and heat retention processing. The vapor deposition apparatus according to claim 1, wherein means are provided. 4. The holding means includes a first correction plate for correcting the film thickness distribution on one side of the substrate during film formation and a second correction plate for correcting the film thickness distribution on the other side of the substrate. The vapor deposition apparatus according to claim 3, wherein and are held. 5. An oven unit in which a plurality of heating / slow cooling chambers which can be moved inside are arranged, and an exhaust unit between atmospheric pressure and a predetermined vacuum degree while keeping the temperature of a heated substrate constant. A greenhouse that can restore pressure, a deposition chamber that can form a multilayer film on the substrate, an inversion chamber that inverts the deposited lens, and the substrate that is the greenhouse, the deposition chamber, and the inversion. And a transfer chamber having a substrate transfer mechanism for transferring the chamber to the chamber, wherein the oven unit is provided with a plurality of heating / slow cooling chambers that are movable inside and desired heating / slow cooling chambers. The heating / slow cooling chambers are stored so that they can be connected to the greenhouse, and each of the heating / slow cooling chambers has a gas introducing pipe for introducing a heating medium gas, and a heater for controlling the internal temperature. , A fan for circulating heating medium gas can be connected to the greenhouse A gate valve is provided, and a tray holding the substrate and two correction plates corresponding to the substrate can be stored in and out freely, and the greenhouse is connected to the heating / slow cooling chamber. A gate valve for operating the transfer chamber, a gate valve for connecting to the transfer chamber, a rotary drive unit for rotating the loaded tray, a heater for keeping heat, an exhaust unit, and a leak valve. The transfer chamber is provided with a gate valve for connecting to the film forming chamber, a substrate transfer mechanism for transferring the substrate and the correction plate by a transfer table at the tip, a heater, and an exhaust unit. A revolving stage for reversing the substrate, a reversing drive unit, and a heater are provided in the reversing chamber connected to the transfer chamber, and the dome for accommodating the substrate in the film forming chamber. And the substrate Between a rotation and revolution drive unit for rotating and revolving, a correction plate holding portion, an evaporation source that stores an evaporation material for film formation, an evaporation power source for evaporating the evaporation material, and a correction plate and an evaporation source. The vapor deposition apparatus according to any one of claims 1 to 4, further comprising a shutter, a heater, and an exhaust unit provided in the. 6. The vapor deposition device according to claim 1, wherein the substrate is a CaF ₂ single crystal lens. 7. A vapor deposition method for forming a film on a substrate in a vacuum, wherein each of a plurality of heating / slow cooling chambers placed under atmospheric pressure,
A tray holding the substrate and the correction plate is arranged, the atmosphere and temperature in the room are controlled according to a predetermined program, and the heating / slow cooling chamber having the predetermined atmosphere and temperature is
The chamber is connected to a greenhouse which has a predetermined atmosphere and temperature, the tray holding the substrate and the correction plate is transferred to the greenhouse, and the interior of the greenhouse is evacuated to a predetermined vacuum. Connected to the transfer chamber and the film forming chamber, the substrate transfer mechanism of the transfer chamber transfers the substrate and the correction plate to the film forming chamber, and the substrate is vacuum-deposited on the substrate. When a predetermined film is formed and is also formed on the back surface of the substrate, the substrate is transferred to an inversion chamber by the substrate transfer mechanism in vacuum, inverted, and returned to the film formation chamber, and the correction plate is used. And again to form a predetermined film on the substrate by vapor deposition in a vacuum, and return the film-formed substrate to the greenhouse by the substrate transfer mechanism in a vacuum, and set a predetermined atmosphere in the greenhouse. And re-pressurized at temperature to control the connected atmosphere and temperature. And transferred to the serial heating and slow cooling chamber, and ends the processing temperature of the heating-gradual cooling chamber slowly cooled by controlling in accordance with a predetermined program,
A vapor deposition method characterized by the above. 8. A vapor deposition method for forming a film on a substrate in a vacuum, wherein the substrate and the correction plate are held on a tray, and then carried into a heating / slow cooling chamber and disposed.・ Introducing a heating medium gas into the slow cooling chamber to replace the inside of the heating / slow cooling chamber with the heating medium gas, and control the heater provided in the heating / slow cooling chamber to control the internal heating medium gas by a predetermined program. After the heating process is completed, the heating / slow cooling chamber is moved to connect the gate valve of the heating / slow cooling chamber and the gate valve of the greenhouse to heat the air between both gate valves. After the replacement operation is completed, both gate valves are opened, and the tray is conveyed to the greenhouse which is replaced with the heating medium gas and heated to a predetermined temperature in advance, and both gate valves are opened. Close and exhaust the inside of the greenhouse with an exhaust unit. When the internal degree of vacuum reaches a predetermined value, the gate valve between the greenhouse and the transfer chamber, which has been previously depressurized to a predetermined vacuum degree, and the transfer chamber and the transfer chamber, which are depressurized to a predetermined vacuum degree, are depressurized. And a gate valve between the film forming chamber and a transfer chamber of the substrate transfer mechanism of the transfer chamber to transfer the substrate from the tray of the greenhouse to the film forming chamber, It is installed in a dome, and the correction plate is conveyed from the tray of the greenhouse to be installed at a predetermined position of the film forming chamber, and the gate valve and the transfer between the greenhouse and the transfer chamber are installed. A gate valve between the mounting chamber and the film forming chamber is closed, and while rotating the substrate installed on the dome, the evaporation material inside the evaporation source in the film forming chamber is heated and melted, Provided between the substrate and the evaporation source after the gas release or evaporation of the evaporation material is stabilized The shutter plate is opened to form a film on the substrate, and the vapor deposition operation is repeated to obtain desired optical characteristics to form several layers on the substrate with a desired material and film thickness. If the gate valve between the transfer chamber and the gate valve between the transfer chamber and the film formation chamber are opened, and film formation is not performed on the opposite surface of the substrate, the substrate transfer mechanism is used for one surface. When the substrate on which the film has been formed and the correction plate of the film forming chamber are returned to the tray of the greenhouse and the film is formed on the opposite surface of the substrate, the film formed on one surface by the substrate transfer mechanism is The substrate is transferred to an inversion chamber and placed on a turntable, the correction plate of the film forming chamber is returned to the tray of the greenhouse, and the other correction plate of the tray of the greenhouse is set in the film forming chamber. Arranged at a predetermined position, the rotary table of the reversal chamber is rotated to invert the substrate,
The inverted substrate is transferred to the film forming chamber by the substrate transfer mechanism and installed in the dome, and a gate valve between the greenhouse and the transfer chamber, the transfer chamber, and the film forming chamber are provided. After closing the gate valve between and and forming the desired film,
The gate valve between the warming room and the transfer chamber and the gate valve between the transfer chamber and the film formation chamber are opened, and the substrate formed on both sides by the substrate transfer mechanism and the growth film. The correction plate of the film chamber is returned to the tray of the greenhouse, the gate valve between the greenhouse and the transfer chamber is closed, and the heating medium gas heated to a predetermined temperature is stored in the greenhouse. After introducing and repressurizing, after repressurizing, open the gate valve between the greenhouse and the heating / slow cooling chamber, transfer the tray to the heating / slow cooling chamber, and The vapor deposition method according to claim 7, wherein a gate valve between the slow cooling chamber and the heating / slow cooling chamber is closed, and the interior of the heating / slow cooling chamber is gradually cooled according to a predetermined program. 9. The vapor deposition method according to claim 7, wherein the substrate on which the film is formed is a CaF ₂ single crystal lens.