JP7316877B2 - Vacuum process equipment and method for cooling process object in vacuum process equipment - Google Patents

Description

The present invention relates to, for example, a semiconductor manufacturing apparatus. It relates to the cooling method.

Many microfabrication and thin film forming techniques are applied to the manufacturing process of semiconductor devices.
These devices are also collectively called vacuum process devices, and utilize physical and chemical phenomena in a vacuum.

Electric discharge, ionization, sputtering phenomena, etc. can be mentioned as physical and chemical processing principles produced by vacuum.
These phenomena are applied to plasma etching, plasma chemical vapor deposition (CVD), ion implantation, sputtering deposition, and the like.

In the vacuum process equipment to which these phenomena are applied, heat sources such as so-called plasma sources and heater sources are used during the process. phenomenon occurs.

For example, in vacuum deposition, the temperature of the vapor deposition material and the temperature of the crucible containing the vapor deposition material become high in order to vaporize the vapor deposition material.
Then, the substrate is placed above the hot crucible in order to deposit the vapor deposition material onto the substrate, which is the process object.
During deposition, the temperature of the substrate rises mainly for the following reasons.
The temperature of the substrate also rises due to radiant heat from the high-temperature crucible and the surface of the molten vapor deposition material.

Therefore, in vacuum process equipment, a cooling device (cooling system) is employed to control the temperature of the process object (for example, a substrate) in order to suppress warping and material deterioration in the process object (for example, a substrate) due to temperature rise ( For example, see Patent Document 1).

The cooling device disclosed in Patent Document 1 is provided in a vacuum chamber, and a cooled roll that guides movement of a substrate, which is a process object, and a space in the vacuum chamber around the roll are used as a first vapor deposition apparatus. It has a separation part separating into a pressure chamber and a second pressure chamber having a predetermined pressure higher than that of the first pressure chamber, the roll winds the substrate in the second pressure chamber, and a gas layer is formed between the substrate and the roll. to form
In this cooling device, when the substrate is wound around the roll in the second pressure chamber having a predetermined pressure, gas of a predetermined pressure is present around the portion where the substrate and the roll start to come into contact with each other. A gas layer is formed by naturally entraining gas in minute gaps.
This gas layer contributes to heat transfer and provides a cooling effect for the substrate.

That is, in this cooling device, the cold roll functions as a cooling plate, and in a vacuum, gas accumulates between this cooling plate and the substrate as the object to be processed. It functions as a coolant and dissipates the heat of the substrate as the process object to the roller as the cooling plate.
This cooling method can be called a gas refrigerant cooling method or a contact cooling method.

JP 2006-89782 A

However, adopting the so-called gas refrigerant cooling method as described above makes it difficult to maintain the seal and the degree of process vacuum.

In addition, in a vacuum process apparatus for mass production, it is necessary to rotate or move the object in the process at high speed in the vacuum chamber in order to improve the distribution yield and shorten the time.
At that time, however, applying the generally conceived contact cooling method significantly reduces the efficiency.

INDUSTRIAL APPLICABILITY The present invention can easily maintain a seal and maintain a process vacuum, can be efficiently applied even when a process object rotates or moves at high speed in a vacuum chamber, and can achieve efficient cooling. An object of the present invention is to provide a vacuum process apparatus and a method for cooling an object to be processed in the vacuum process apparatus.

A vacuum process apparatus according to a first aspect of the present invention comprises: a vacuum chamber; A process object having a surface facing the process material supply unit, a process material supplied with the process material to form a predetermined object, a first surface and a second surface, and the vacuum chamber. a cooling plate disposed such that the first surface faces a non-processed surface of the process object opposite to the processable surface; and a heat radiation sheet disposed on the first surface of the cooling plate. and

Preferably, the heat radiation sheet is attached to the first surface of the cooling plate with an adhesive.

Preferably, the cooling plate is formed with a coolant circulation path through which a coolant circulates.

Preferably, the cooling plate holds a plurality of objects to be processed so that the surface to be processed faces the process material supply unit, has a disk shape, and rotates around the center of the disk. It is axially sealed to the vacuum chamber so as to be rotatable.

Also preferably, the cooling plate is provided on the first surface of the process object so that a gap is formed between the non-process object surface of the process object and the heat radiation sheet surface. It has a holding portion that holds the outer edge of the.

A second aspect of the present invention is a vacuum chamber; a process object arranged to face a material supply unit side, and to which the process material is supplied to form a predetermined process object, the cooling method for a process object in a vacuum process apparatus comprising: A cooling plate having a surface and a second surface, with a thermal radiation sheet attached to the first surface, is placed in the vacuum chamber so that the first surface is on the opposite side of the object to be processed from the surface to be processed. The heat radiation sheet arranged to face the surface to be processed and attached to the first surface of the cooling plate absorbs at least the radiant heat of the object to be processed and radiates the heat toward the cooling plate, thereby Cool the process object.

INDUSTRIAL APPLICABILITY According to the present invention, it is easy to maintain the seal and the degree of process vacuum, it can be efficiently applied even when the process object rotates or moves at high speed in the vacuum chamber, and efficient cooling is realized. becomes possible.

FIG. 1 is a configuration diagram schematically showing an ion beam assisted vacuum deposition apparatus, which is a vacuum film forming apparatus employing the vacuum process apparatus according to the first embodiment of the present invention. FIG. 2 is a diagram schematically showing one configuration example of a cooling system for a process object in a vacuum vapor deposition apparatus employing the vacuum process apparatus according to the first embodiment. FIG. 3 is a diagram showing the result of theoretical calculation of the cooling effect with and without the heat radiation sheet in the cooling system for the process object. FIG. 4 is a diagram schematically showing a configuration example of a cooling system for a process object in a vacuum vapor deposition apparatus employing the vacuum process apparatus according to the second embodiment. FIG. 5 is a diagram schematically showing an arrangement example of a plurality of process objects and a plurality of heat sources circularly held on the outer peripheral portion of the rotating cooling plate of the vacuum vapor deposition apparatus of FIG. .

Embodiments of a vacuum film forming apparatus as an example of the vacuum process apparatus of the present invention and a method for cooling an object to be processed using the apparatus will be described below with reference to the drawings.

(First embodiment)
[Configuration of Vacuum Film Forming Apparatus]
FIG. 1 is a configuration diagram schematically showing an ion beam assisted vacuum deposition apparatus, which is a vacuum film forming apparatus employing the vacuum process apparatus according to the first embodiment of the present invention.

In the vacuum deposition apparatus 1 of the first embodiment, for example, an exhaust pipe and a vacuum pump (not shown) are connected to a vacuum chamber 10, which is a film forming chamber, so that the inside can be reduced to a predetermined pressure. there is The back pressure in the vacuum chamber 10 during film formation by vacuum deposition is, for example, about 10 ^-2 to 10 ^-5 Pa.

Inside the vacuum chamber 10, from the bottom to the top, a heating source 20 that heats and supplies the process material of the process material supply section, and a process object 30 as a film formation target substrate formed of an optical glass substrate or the like. , and a cooling plate 40 for cooling the process object 30 are arranged at predetermined intervals.
A heat radiation sheet 50 is arranged on the first surface 401 of the cooling plate 40 to absorb at least radiant heat from the process object 30 and radiate the heat toward the cooling plate 40 . The heat radiation sheet 50 is adhered to the first surface 401 of the cooling plate 40 with an adhesive 60, for example.
A heat exchanger 70 is arranged outside the vacuum chamber 10 and is connected to a refrigerant circuit formed in the cooling plate 40 to exchange heat.

The heating source 20 has a process material supply unit 200 such as a first vacuum evaporation source 210 and a second vacuum evaporation source 220 . A first vapor deposition material 211 is accommodated inside the first vacuum evaporation source 210 , and a second vapor deposition material 221 is accommodated inside the second vacuum evaporation source 220 .
The first vapor deposition material 211 is eg SiO ₂ and the second vapor deposition material 221 is eg TiO ₂ or Ta ₂ O ₅ .
Each of the vacuum evaporation sources 210 and 220 is provided with heating means such as resistance heating, electron beam heating, laser beam heating, and electron gun (not shown). Vapor of material shoots out.

For example, in the vacuum chamber 10, a process object as a film-forming target substrate, which is an optical substrate such as quartz glass, is arranged in the direction in which the vapor of the vapor deposition material of the first vacuum evaporation source 210 and the second vacuum evaporation source 220 is ejected. A substrate holder 31 is provided so that a process target surface 301 having a film formation surface 30 faces the process material supply unit 200 side.
The substrate holder 31 is formed, for example, on the first surface 401 side of the cooling plate 40 and configured to hold and support the outer edge of the process object 30 from above the vacuum chamber 10 .

Although FIG. 1 shows an example in which two vacuum deposition sources are provided to form a multilayer film of two types of thin films, a multilayer film of three types of thin films may be formed by providing three vacuum deposition sources. , various embodiments are possible.
When using three vacuum deposition sources, for example, the first deposition material is SiO ₂ , the second deposition material is Si ₃ N ₄ and the third deposition material is a-SiN:H.

Further, for example, an ion source 230 for irradiating the process object 30 with ions such as oxygen ions is provided in the vacuum chamber 10, and ion beam assisted vacuum deposition can be performed.
A process of irradiating the film formation surface of the process object 30 as a film formation target substrate with ions from the ion source 230, thereby forming a film with the vapor deposition material supplied from the process material supply unit 200 and increasing the film thickness; The film can be formed while simultaneously progressing a process in which a partial region near the surface of the already formed film is sputtered by ions irradiated from the ion source 230 to thin the film.

[Cooling system for process object 30]
FIG. 2 is a diagram schematically showing one configuration example of a cooling system for the process object 30 in the vacuum deposition apparatus 1 according to the first embodiment.

The cooling plate 40 has a first surface 401 and a second surface 402 , and the first surface 401 faces a non-process surface 302 of the process object 30 opposite to the process surface 301 in the vacuum chamber 10 . are arranged to

The cooling plate 40 is formed with a coolant circulation path 410 through which coolant circulates.
The refrigerant circulation path 410 is connected to the cold refrigerant supply path 710 of the heat exchanger 70 on the first side (the right side in the example of FIG. 2) 403 side, and the first refrigerant arranged along the first side 401 A path 411, a return path 412 for folding back on the second side (the left side in the example of FIG. 2) 404 side, and a heat exchange that is connected to the return path 412 and returns the warmed hot refrigerant to the heat exchanger 70 side. It is formed by a hot refrigerant discharge path 720 of the vessel 70 and a second refrigerant path 413 connected on the first side (the right side in the example of FIG. 2) 403 side.

The cooling plate 40 is maintained at, for example, about 0.degree. C. to 60.degree.

The heat radiation sheet 50 is attached to the first surface 401 of the cooling plate 40 with an adhesive 60, absorbs at least the radiant heat of the process object 30, and transfers the heat to the cooling sheet 40 side, specifically the first surface 401 side. radiate.

The thermal radiation sheet 50 absorbs the radiation heat from the process object 30 whose temperature Tg is raised to about 200° C. by receiving a predetermined amount of heat from the heating source 20, and converts the heat into electromagnetic waves (for example, far infrared rays). and radiates heat to the outside, that is, to the first surface 401 side of the cooling plate 40 cooled by the heat exchange system.

Here, the temperature of the cooling plate 40 is Tc, the temperature of the heat radiation sheet 50 is Ts, the emissivity of the heat radiation sheet 50 is εs, the temperature of the process object is Tg, the emissivity of the process object 30 is εg, and the heat source Denoting the amount of superheat from 20 to process object 30 as Qh and the Stefan-Boltzmann constant as σ, the temperature of process object 30 is given by:

FIG. 3 is a diagram showing the result of theoretical calculation of the cooling effect with and without the heat radiation sheet in the cooling system of the process object 30. As shown in FIG.
In FIG. 13 , the horizontal axis represents the temperature Tc of the cooling plate 40 and the vertical axis represents the temperature Tg of the process object 30 .
Further, the curve indicated by A indicates the temperature Tg of the process object 30 when the emissivity εs of the thermal radiation sheet 50 is 0.2, and the curve indicated by B indicates the temperature Tg when the emissivity εs of the thermal radiation sheet 50 is 0.50. A curve indicated by C indicates the temperature Tg of the process object 30 when the emissivity εs of the thermal radiation sheet 50 is 0.9.
Note that when the emissivity εs of the thermal radiation sheet 50 is 0.2, it corresponds to the case where there is no thermal radiation sheet.
Also, the temperature Tc of the cooling plate 40 varies depending on the performance of the heat exchanger 70 .

The calculation conditions are as follows.
・Tc = Ts
・εs: 0.2/0.5/0.9
・εg = 0.9
・Qh=0.044 W・cm ⁻²
・σ=5.67×10 ⁻⁸ W・m ⁻²・K ⁻⁴

As a result, as shown in FIG. 3, when there is no thermal radiation sheet 50 and the emissivity εs is 0.2, the temperature Tc of the process object 30 is 193 degrees.
When the emissivity εs of the heat radiation sheet 50 is 0.5, the temperature Tc of the process object 30 drops to 119.8 degrees.
When the emissivity εs of the heat radiation sheet 50 is 0.9, the temperature Tc of the process object 30 drops to 82.7 degrees.

As described above, in the vacuum process apparatus of the first embodiment, the cooling plate 40 has the first surface 401 and the second surface 402 , and the first surface 401 is located inside the vacuum chamber 10 . The heat radiation sheet 50 is attached to the first surface 401 of the cooling plate 40 with an adhesive 60 to dissipate heat. Since the radiation sheet 50 absorbs at least the radiant heat of the process object 30 and radiates the heat to the cooling sheet 40 side, the cooling effect for the process object 30 in vacuum is improved compared to the case where there is no heat radiation sheet. It is possible to realize an efficient cooling system.

As described above, according to the first embodiment, the vacuum process apparatus includes the vacuum chamber 10 and the heat source that heats and supplies the process material of the process material supply unit 200 arranged in the vacuum chamber 10. 20, a process object 30 arranged in the vacuum chamber 10 such that a process object surface 301 faces the process material supply unit 200 side, and a process material is supplied to form a predetermined object; a first surface; 401 and a second surface 402, and arranged in the vacuum chamber 10 such that the first surface 401 faces the non-process surface 302 opposite the process surface 301 of the process object 30. 40 and a heat radiation sheet 50 disposed on the first surface 401 of the cooling plate 40 .

Therefore, according to the first embodiment, the following effects can be obtained.
It is easy to maintain the seal and the degree of process vacuum, and it can be efficiently applied even when the process object rotates or moves at high speed in the vacuum chamber, and moreover, efficient cooling can be realized.
More specifically, the heat radiation sheet 50 is attached to the first surface 401 of the cooling plate 40 with an adhesive 60 , and the heat radiation sheet 50 absorbs at least the radiant heat of the process object 30 and cools the cooling sheet 40 . Since the heat is radiated to the side, the cooling effect for the process object 30 in vacuum can be improved compared to the case where there is no heat radiation sheet, and an efficient cooling system can be realized.

(Second embodiment)
FIG. 4 is a diagram schematically showing a configuration example of a cooling system for a process object in a vacuum vapor deposition apparatus employing the vacuum process apparatus according to the second embodiment.
5A and 5B show a plurality of process objects and a plurality of heat sources 20-1 and 20 circularly held on the outer periphery of the rotating cooling plate 40A of the vacuum deposition apparatus of FIG. -2, 20-3 is a diagram schematically showing an arrangement example.

The difference of the vacuum deposition apparatus 1A according to the second embodiment from the vacuum deposition apparatus 1 according to the first embodiment is as follows.
In the vacuum vapor deposition apparatus 1A according to the second embodiment, a plurality of cooling plates 40A are arranged in the vacuum chamber 10A in a direction in which the vapor of the process material of the vacuum evaporation sources including the vapor deposition source of the process material supply unit is ejected. is held so that the process target surface 301 faces the process material supply portion side of the heat source 20, and has a planar disc shape (or dome shape), and the center of the planar disc is the center of rotation. The shaft is sealed in the vacuum chamber 10A so as to be rotatable by being driven by a motor (not shown).
Refrigerant circulation path 710A in cooling plate 40A is configured to be able to circulate within the cooling plate to which two refrigerant circulation paths 710 shown in FIG. 2 are connected.

In addition, the cooling plate 40A is provided on the first surface 401, and cools the process object 30 so that a gap is formed between the non-process object surface 302 of the process object 30 and the radiation surface 501 of the heat radiation sheet 50A. It has a holding portion 420 that holds the outer edge of the .

According to the second embodiment, the plurality of process objects 30 are each fixed to the rotatable cooling plate 40A by the holding part 420, and in the fixed state, the non-process object surface 302 of the process object 30 and the Since a gap is formed between the heat radiation sheet 50A and the radiation surface 501, as the cooling plate 40A rotates, an annular air cooling path is formed as indicated by arrow Y in FIG. 5(A). As a result, problems such as heat buildup in a certain area can be prevented, and a more efficient cooling system can be realized.

Furthermore, according to the second embodiment, the following effects can be obtained.
That is, according to the second embodiment, since the plurality of process objects 30 are each fixed to the rotatable cooling plate 40A by the holding portion 420, in the vacuum process, the yield can be improved while coping with mass production. can be improved.

The invention is not limited to the above description.
For example, it is applicable not only to the ion beam assisted vacuum deposition apparatus and method, but also to other vacuum deposition apparatuses and methods. In addition to vacuum film formation, the present invention can also be applied to other thin film formation apparatuses and methods such as film formation by sputtering or film formation by CVD (chemical vapor deposition).
In addition, various modifications are possible without departing from the gist of the present invention.

10, 10A... vacuum chamber, 20, 20A, 20-1, 20-2, 20-3... heating source, 200... process material supply unit, 210... first vacuum deposition source, 211 ... first vapor deposition material, 220 ... second vacuum vapor deposition source, 221 ... second vapor deposition material, 230 ... ion source, 30 ... process object, 301 ... process object surface, 302 Non-process target surfaces 40, 40A Cooling plate 401 First surface 402 Second surface 410 First coolant path 420 Return path 430... Second refrigerant path, 50, 50A... Thermal radiation sheet, 60... Adhesive, 70... Heat exchanger, 710, 710A... Refrigerant circulation path.

Claims (4)

A vacuum process apparatus for supplying process material to a plurality of process objects each having a process surface and an opposite non-process surface, comprising:
a vacuum chamber containing the plurality of process objects ;
a heating source that heats and supplies the process material of the process material supply unit arranged in the vacuum chamber;
a holding unit that holds the plurality of process objects such that the process object surfaces face the process material supply unit side; and a first surface that faces the non-process object surfaces of the plurality of process objects. and a cooling plate located within the vacuum chamber and
a thermal radiation sheet having an emissivity of 0.5 or higher, disposed on the first surface;
has
The cooling plate is axially sealed to the vacuum chamber so as to be rotatable around a rotation center on the central side of the cooling plate in plan view of the first surface,
The holding part holds outer edges of the plurality of process objects such that a gap is formed between the non-process object surface and the heat radiation sheet surface.
Vacuum process equipment. 2. The vacuum process apparatus according to claim 1, wherein said thermal emission sheet is attached to said first surface with an adhesive. 3. The vacuum process apparatus according to claim 1, wherein the cooling plate is formed with a coolant circulation path through which a coolant circulates. A method for cooling a process object in a vacuum process apparatus according to any one of claims 1 to 3 ,
A method for cooling a process object in a vacuum process apparatus, wherein at least radiant heat of the plurality of process objects is absorbed by the heat radiation sheet and radiated toward the cooling plate to cool the plurality of process objects.

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