JP2010215931A - Film deposition method and film deposition tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film deposition method for preventing generation of any warp of a thin substrate attributable to the internal stress of a thin film formed on the thin substrate such as a glass substrate. <P>SOLUTION: The film deposition method in which the film deposition is executed on a large plate 1, and the large plate 1 after the film deposition is cut and divided into a plurality of strip substrates includes: a joining step of joining the large plate 1 with a holding member 2 for holding the large plate 1 by a joining unit 3 arranged at least inside an outer peripheral edge of the large plate 1; a fitting step of fitting the joined large plate 1 and the holding member 2 to a window part 61 of a fitted member 6 arranged in a film deposition apparatus; a film deposition step of executing the film deposition on the large plate 1 suitable for the window part 61; and a cutting and dividing step of cutting the large plate 1 subjected to the film deposition, dividing it into the strip substrates, and separating the strip substrates from the holding member 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a film forming method for forming a film on a thin plate and a film forming jig used for film forming.

Conventionally, when an optical thin film or the like is formed on a substrate such as a glass substrate by a vacuum deposition method or the like, a phenomenon that the substrate warps due to an internal stress of the optical thin film has occurred. When the substrate is warped, there is a problem that the optical characteristic distribution in the surface of the substrate varies. And, for the purpose of reducing the weight of the optical element, etc., the thickness of this substrate is reduced. On the other hand, for the purpose of improving productivity, a large plate is formed, and this is cut and divided to form a plurality of strip substrates. As a result, the substrate is more likely to be warped.
In order to prevent the occurrence of warping of the substrate due to the internal stress of the thin film formed on such a thin substrate, a method using a frame jig has been proposed (see, for example, Patent Document 1).
The frame jig described in Patent Document 1 is made of a rod-shaped material having a U-shaped cross section, has a shape that is convex or concave in the vertical direction of the U-shaped cross section, and has a U-shaped groove portion of the substrate. The outer periphery is held.

JP 2007-94040 A

FIG. 12 is a schematic view showing a state where the substrate 201 is held by the frame jig 202 described in Patent Document 1. As shown in FIG. Further, the position of the film forming product 204 (a plurality of strip substrates) taken out by cutting and dividing the substrate 201 is indicated by a one-dot chain line.
When the substrate 201 is mounted on the frame jig 202, the holding portion 203 is formed on the outer periphery of the substrate 201. The inside of the holding unit 203 is an effective area from which the film forming product 204 (a plurality of strip substrates) can be taken out.
When the film is formed while being held by the holding unit 203, the occurrence of warpage is suppressed as compared with the conventional case. However, in the film-formed product 204 (a plurality of strip substrates) taken out from the effective area, there is no warpage. Some were not suppressed.

  An object of the present invention is to provide a film forming method and a film forming jig for preventing the thin substrate from warping due to internal stress of a thin film formed on a thin substrate such as a glass substrate.

[Application Example 1]
A film forming method according to this application example is a film forming method of forming a film on a large plate and cutting and dividing the formed large plate into a plurality of strip substrates, the large plate and the large plate A bonding step of bonding a holding member for holding the holding plate at a bonding portion arranged at least inside the outer peripheral edge of the large plate, and a substrate to be disposed in the film forming apparatus together with the holding member. An attachment step of attaching to the window portion of the mounting member, a film formation step of forming a film on the large plate attached to the window portion, cutting the large plate formed into a film and dividing it into the strip substrate; A cutting and dividing step of separating the strip substrate and the holding member.
According to this application example, at least the inner side of the outer periphery of the large plate can be bonded and held by the holding member. Therefore, compared to a method in which the holding portion is concentrated on the outer peripheral side of the large plate as in the case where the outer peripheral edge of the large plate is held by the frame jig, the portion holding the large plate can be effectively arranged. Therefore, the occurrence of warpage of the large plate can be further reduced, and the level of warpage of the strip substrate after cutting and division can be improved.

[Application Example 2]
The film forming method according to this application example is characterized in that, in the joining step, the holding member is joined at a joining portion disposed at least in the center of the large plate.
According to this application example, the center of the large plate can also be bonded and held by the holding member. Therefore, compared with the application example 1, the site | part by which a big board is hold | maintained can be arrange | positioned effectively, and the effect of reducing generation | occurrence | production of the curvature of a big board can be enlarged further.

[Application Example 3]
The film forming method according to this application example is characterized in that the holding member is not cut in the cutting and dividing step.
According to this application example, the holding member after the cutting and dividing step of taking out the strip substrate is not cut, and the holding member is held by unbonding the small piece that has not been taken out from the holding member and the holding member. The member can be reused.

[Application Example 4]
In the film forming method according to this application example, in the cutting and dividing step, the large plate is divided into the strip substrates by being cut so as to avoid the joint portion, and the pass / fail judgment is performed on the plurality of the divided strip substrates. It is characterized by performing.
According to this application example, the small piece portion including the joint portion is not taken out as a film forming product, the film forming product is taken out from the substrate portion excluding the joint portion, and the quality determination of the taken out film forming product is performed. It is possible to provide a high-quality film-forming product free from dirt, adhesion residue, and the like from the adhesive used for bonding.

[Application Example 5]
The film forming method according to this application example is characterized in that the holding member has a convex portion, and the convex portion and the large plate are joined in the joining step.
According to this application example, since the holding member has the convex portion, even when the bonding layer is formed on the entire bonding surface side of the holding member, the bonding formed on the upper surface of the convex portion is in contact with the large plate. Become a layer. Therefore, the position and size of the joint can be easily adjusted by the position and size of the convex portion.
Further, it is not necessary to selectively form a bonding layer for bonding the large plate and the holding member. That is, the trouble of performing masking or the like can be saved.
Furthermore, when bonding with an adhesive, the adhesive that protrudes from the convex portion flows out to the periphery of the convex portion, thereby preventing the formation of unnecessary joint portions and reducing variations in the position and size of the joint portions. can do. And it can prevent that an adhesive agent adheres to the strip board | substrate taken out from a large board.

[Application Example 6]
The film forming method according to this application example is characterized in that, in the joining step, the large plate and the holding member are molecularly joined.
According to this application example, since the large plate and the holding member are bonded by molecular bonding, the large plate can be firmly bonded. Furthermore, even if the large plate and the holding member have different linear expansion coefficients, the stress due to thermal expansion is relieved, and positional deviation between the large plate and the holding member can be prevented. Therefore, the effect of preventing the warpage of the large plate can be enhanced.
Further, even in a film forming process exposed to a high temperature atmosphere, there is no degassing such as an adhesive, so there is no concern of contamination of the film forming product due to such degassing.

[Application Example 7]
The film forming method according to this application example is characterized in that the large plate and the holding member are quartz, and the large plate and the holding member are joined together with a crystal optical axis aligned.
According to this application example, the large plate and the holding member are made of crystal, and the large plate and the holding member are joined with the crystal optical axis of the crystal aligned, so that the anisotropy of the linear expansion coefficient It is possible to reduce the residual stress caused by the above. The above can reduce the residual stress compared with combining a quartz crystal plate having anisotropy of linear expansion coefficient with a holding member having an isotropic coefficient of linear expansion coefficient. Therefore, by matching the orientations of the crystal optical axes of the large plate and the holding member, the effect of further preventing the warpage of the large plate can be increased.

[Application Example 8]
The film forming method according to this application example is characterized in that, in the attaching step, the large plate is attached via a film forming jig.
According to this application example, it is possible to improve the work efficiency of attaching the large plate to the window portion.

[Application Example 9]
The film forming jig according to this application example is a main body capable of accommodating a large plate to be deposited and a holding member joined by a joining portion disposed on the large plate at least inside the outer peripheral edge of the large plate. And an outer flange portion that is formed to protrude sideways from the main body portion and is attached to a mounted member that is disposed in the film forming apparatus, and is formed to protrude inward of the main body portion and the holding member And an opening that is formed at the bottom of the main body and exposes the film forming surface of the large plate.
According to this application example, since the holding member joined to the large plate is accommodated in the main body portion and held by the inner flange portion, the large plate and the holding member can be stably held. Further, since the film formation surface of the large plate is exposed from the opening, even if the large plate is bonded to the holding member, the film can be reliably formed on the film formation surface.

The top view which shows the joining state in the joining process which concerns on 1st Embodiment of this invention. Sectional drawing which shows the said joining state which concerns on the said embodiment. Sectional drawing which shows the attachment state in the attachment process which concerns on the said embodiment. The perspective view of the to-be-mounted member which concerns on the said embodiment. Schematic of a plasma polymerization apparatus. Schematic explaining the joining process in which a joining layer is formed from a plasma polymerization film. Schematic explaining the joining process in which a joining layer is formed from a plasma polymerization film. The top view (A) which shows the masking state which concerns on 2nd Embodiment of this invention, and sectional drawing (B) along the BB line. Schematic of the plasma polymerization apparatus according to the second embodiment. Schematic explaining the formation process of the plasma polymerization film | membrane which concerns on the said 2nd Embodiment. Sectional drawing which shows the attachment state in the attachment process which concerns on the said 2nd Embodiment. The top view which shows the state holding the board | substrate by the conventional method.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a plan view showing a state in which the large plate 1 and the holding member 2 are joined.
FIG. 2 is a cross-sectional view illustrating a state in which the large plate 1 and the holding member 2 are joined.
A large plate 1 used as a substrate for forming an optical thin film and the like, and a holding member 2 for holding the large plate 1 are joined via a joining layer 31 at a joining portion 3 to constitute a laminate. is doing. The joined large plate 1 and holding member 2 are attached to a film forming jig 5 described later, and the film forming surface of the large plate 1 is exposed from the opening 54 of the film forming jig 5 (see FIG. 3). The film forming jig 5 is mounted on a window portion 61 of a mounted member 6 described later (see FIG. 3), and the mounted member 6 is carried into a film forming apparatus (not shown). When a film forming process is performed in the film forming apparatus, an optical thin film or the like is formed on the film forming surface of the large plate 1. The strip substrate 4 is taken out from the large plate 1 after the film formation process.

The large plate 1 is made of glass, silicon, quartz or the like, and is used as a substrate on which an optical thin film or the like is formed.
In this embodiment, the large plate 1 is formed in a plate shape having a square shape of about 80 mm × 80 mm in plan view and a thickness of about 1 mm to 0.5 mm. Then, a strip substrate 4 of about 10 mm × 10 mm is taken out from the large plate 1. Note that the position of the alternate long and short dash line shown in FIG. 1 is shown for the convenience of the description of the present embodiment, and is changed as appropriate according to the shape, dimensions, the number of extractions, etc. of the strip substrate 4.
The large plate 1 is joined to the holding member 2 at the joining surface. The surface opposite to the bonding surface is a film formation surface on which a film is formed.
The film formation surface and the bonding surface are preferably smooth. If the film formation surface is smooth, the formed film can be easily smoothed, and the quality of the strip substrate 4 can be improved. Further, if the joining surface is smooth, it becomes easy to form the surface of the joining layer 31 formed on the joining surface smoothly, or the contact area with the joining surface of the holding member 2 to be joined becomes large. Can be strengthened. Furthermore, it is more preferable that the joining surface is mirror-finished because the joining force can be further increased.

The holding member 2 is made of glass, silicon, crystal, ceramic, metal, or the like, and is used for holding the large plate 1. The large plate 1 and the holding member 2 are preferably made of the same material or a material having a similar linear expansion coefficient. This is because the residual stress caused by the difference in linear expansion coefficient can be reduced. It is even more preferable that the ones having a linear expansion coefficient have the directivity and are joined together.
The holding member 2 includes a flat plate portion 21 and a convex portion 22 in the present embodiment.
In the present embodiment, the flat plate portion 21 is formed in a plate shape that has a larger area than the large plate 1 and has a substantially square shape in plan view. The thickness is preferably formed in a plate shape of about 0.3 mm to 5 mm.
The holding member 2 is joined to the large plate 1 at the joining surface.
The convex portion 22 is formed on the joint surface side of the holding member 2. The convex portion 22 is formed corresponding to the position where the joint portion 3 is formed. Specifically, when the large plate 1 and the holding member 2 are bonded, the bonding portion 3 is formed at a position where the bonding portion 3 is formed at least inside the outer peripheral edge of the large plate 1. In the present embodiment, one convex portion 22 is formed near each of the four corners of the flat plate portion 21, and one convex portion 22 is formed near the central portion. The upper surface of the convex portion 22 is preferably smooth. If the upper surface of the convex portion 22 is smooth, it becomes easy to form the surface of the bonding layer 31 formed on the bonding surface smoothly, and the contact area with the surface of the large plate 1 to be bonded increases. Can be strengthened. Furthermore, it is more preferable that the joining surface is mirror-finished because the joining force can be further increased.

The bonding portion 3 is formed by bonding a bonding layer 31 to at least one of the large plate 1 and the holding member 2 and bonding the large plate 1 and the holding member 2 together. The joint portions 3 are provided at a total of five locations inside at least the outer peripheral edge of the large plate 1.
In the present embodiment, the case where the bonding layer 31 is a plasma polymerized film 131 capable of molecular bonding will be described (see FIGS. 6 and 7). The thickness of the bonding layer 31 and the plasma polymerized film 131 is shown thicker than the thickness of the large plate 1 and the holding member 2 in order to facilitate understanding of the contents in the drawing.
If the plasma polymerized film 131 is formed on each surface where the large plate 1 and the holding member 2 are bonded to each other, the large plate 1 and the holding member 2 can be joined.
Further, when the plasma polymerized film 131 is formed on one surface where the large plate 1 and the holding member 2 are bonded, the other member on which the plasma polymerized film 131 is not formed is silicon-containing such as quartz or glass. If it is a substrate or a silicon dioxide film is formed on the bonding surface side of the other member, the large plate 1 and the holding member 2 can be bonded.
In the present embodiment, a case where a plasma polymerization film 131 is formed on the bonding surface side of the holding member 2 and a silicon-containing substrate is used as the large plate 1 will be described.
The detailed molecular bonding process will be described later.

FIG. 3 is an enlarged cross-sectional view showing a state in which the large plate 1 and the holding member 2 joined to each other are attached to the window portion 61 of the mounted member 6 via the film forming jig 5.
FIG. 4 is a perspective view of the mounted member 6.
The large plate 1 is attached to the mounted member 6 together with the holding member 2. The mounted member 6 to which the large plate 1 and the holding member 2 are attached is disposed in the film forming apparatus and a film forming process is performed.
The mounted member 6 is formed in a conical dome shape. In the mounted member 6, windows 61 are arranged radially from the top to the bottom. The window 61 is formed open so that the film-forming surface of the large plate 1 is exposed to the inner surface side of the mounted member 6 when the large plate 1 is attached. Therefore, the holding member 2 is mounted toward the outer surface side of the mounted member 6. Further, a film forming jig 5 for attaching the large plate 1 and the holding member 2 is attached to the window portion 61. The inner surface side of the mounted member 6 is closer to the center of gravity of the conical dome and means the side farther from the center of gravity than the outer surface side.

The film forming jig 5 includes a main body 51, an outer flange 52 formed to protrude to the side of the main body 51, an inner flange 53 formed to protrude inward of the main body 51, and a main body And an opening 54 formed at the bottom of the.
The main body 51 is formed so as to accommodate the large plate 1 and the holding member 2.
The outer flange portion 52 is formed so as to be detachably mounted on the window portion 61 of the mounted member 6. The main body portion 51 and the outer flange portion 52 have an inverted L-shaped cross section, and the outer flange portion 52 is hooked and attached to the window portion 61. Further, a hole (not shown) may be provided in a portion that contacts the outer flange portion 52 of the mounted member 6, and a pin (not illustrated) may be provided in a portion that contacts the mounted member 6 of the outer flange portion 52. If the pin is inserted into the hole, the film forming jig 5 is more stably attached to the window portion 61.
The inner flange portion 53 is formed so as to be able to hold the holding member 2. Since the main body 51 and the inner flange 53 have an L-shaped cross section, the holding member 2 is hooked and held on the inner flange 53. Further, a pin (not shown) may be provided in a portion of the inner flange portion 53 that contacts the holding member 2, and a hole (not shown) may be provided in a portion of the holding member 2 that contacts the inner flange portion 53. If the pin is inserted into the hole, the holding member 2 is more stably held with respect to the inner flange portion 53.
The opening 54 is formed so that the film forming surface of the large plate 1 is exposed when the holding member 2 is held.
In the present embodiment, since the holding member 2 is larger than the large plate 1, the side end of the holding member 2 protrudes outward from the side end of the large plate 1 and has a step shape (FIG. 2). reference).
Therefore, the holding member 2 is held against the inner flange portion 53 of the film forming jig 5 using this step. At this time, the large plate 1 is disposed in the opening 54, and the film formation surface of the large plate 1 is exposed.

Next, a film forming method will be described.
The film forming method of the present embodiment includes a joining step for joining the large plate 1 and the holding member 2, an attaching step for attaching the joined large plate 1 and the holding member 2 to the window portion 61 of the mounted member 6, a window A film forming process for forming a film on the large plate 1 attached to the unit 61 and a cutting and dividing process for cutting the formed large plate 1 and dividing it into a plurality of strip substrates 4 are configured.

[Jointing process]
In the present embodiment, the large plate 1 and the holding member 2 are bonded by molecular bonding via the bonding layer 31. The process will be described with reference to FIGS.
FIG. 5 is a schematic view of a plasma polymerization apparatus used in the present embodiment.
In FIG. 5, the plasma polymerization apparatus 100 includes a chamber 101, a first electrode 111 and a second electrode 112 provided in the chamber 101, and a high frequency between the first electrode 111 and the second electrode 112. The power supply circuit 120 applies a voltage, the gas supply unit 140 supplies gas into the chamber 101, and the exhaust pump 150 discharges the gas inside the chamber 101.
The first electrode 111 supports a base material on which the plasma polymerized film 131 is to be formed. In the present embodiment, since the holding member 2 is used as the base material, the surface of the holding member 2 on which the convex portion 22 is not formed is supported by the first electrode 111.
The first electrode 111 and the second electrode 112 are arranged to face each other with the holding member 2 interposed therebetween. That is, the joint surface on which the convex portion 22 is formed is disposed to face the first electrode 111.

The power supply circuit 120 includes a matching box 121 and a high frequency power supply 122.
The gas supply unit 140 includes a liquid storage unit 141 that stores a liquid film material (raw material liquid), a vaporizer 142 that vaporizes the liquid film material and changes it into a raw material gas, and a gas cylinder 143 that stores a carrier gas. I have. The carrier gas stored in the gas cylinder 143 is a gas that is discharged by the action of an electric field and is introduced into the chamber 101 in order to maintain this discharge, and corresponds to, for example, argon gas or helium gas.
The liquid storage unit 141, the vaporizer 142, the gas cylinder 143, and the chamber 101 are connected by a pipe 102, and the mixed gas of the gaseous film material and the carrier gas is supplied into the chamber 101. ing.
The film material stored in the liquid storage unit 141 is a raw material for forming the plasma polymerization film 131 on the holding member 2 by the plasma polymerization apparatus 100 and is vaporized by the vaporization apparatus 142 to become a raw material gas.

Examples of the source gas include methylsiloxane, hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, decamethylcyclopentasiloxane, octamethylcyclotetrasiloxane, and methylphenylsiloxane. Examples include gallium, trimethylaluminum, triethylaluminum, triisobutylaluminum, trimethylindium, triethylindium, trimethylzinc, triethylzinc, organometallic compounds, various hydrocarbon compounds, various fluorine compounds, and the like.
The plasma polymerized film 131 obtained by using such a raw material gas is obtained by polymerizing these raw materials (polymer), that is, polyorganosiloxane, organometallic polymer, hydrocarbon polymer, fluorine polymer, and the like. Will be composed.

Polyorganosiloxane usually exhibits water repellency, but can be easily desorbed by applying various activation treatments, and can be changed to hydrophilic. That is, polyorganosiloxane is a material that can easily control water repellency and hydrophilicity.
Even if the plasma polymerized films 131 made of polyorganosiloxane exhibiting water repellency are brought into contact with each other, the adhesion is inhibited by the organic group, and it is extremely difficult to adhere. On the other hand, plasma polymerized films 131 made of polyorganosiloxane exhibiting hydrophilicity can be bonded particularly easily when they are brought into contact with each other. That is, the advantage that the water repellency and the hydrophilicity can be easily controlled leads to the advantage that the adhesiveness can be easily controlled. Therefore, the plasma polymerized film 131 made of polyorganosiloxane is preferably used in this embodiment. Will be used. And since polyorganosiloxane is comparatively rich in flexibility, even if the constituent materials of the large plate 1 and the holding member 2 are different and the linear expansion coefficients are different, the large plate 1 and the holding member 2 are between. The stress accompanying the thermal expansion which arises can be relieved. Furthermore, since polyorganosiloxane has excellent chemical resistance, it can be effectively used for joining members that are exposed to chemicals for a long time.

  Among the polyorganosiloxanes, those mainly composed of a polymer of octamethyltrisiloxane are preferred. The plasma polymerized film 131 mainly composed of a polymer of octamethyltrisiloxane is preferably used in the bonding method of the present embodiment because of its excellent adhesiveness. The polymer of octamethyltrisiloxane is liquid at room temperature and has an appropriate viscosity, so it is easy to handle.

Next, the process of forming the plasma polymerized film 131 will be described with reference to FIGS.
First, as shown in FIGS. 6A to 6C, a plasma polymerized film 131 is formed on the joint surface of the holding member 2 (polymerized film forming step).
In this polymerization film forming step, the holding member 2 is held as a base material on the first electrode 111 of the chamber 101 of the plasma polymerization apparatus 100. Then, a predetermined amount of oxygen is introduced into the chamber 101 and a high frequency voltage is applied from the power supply circuit 120 between the first electrode 111 and the second electrode 112 to activate the holding member 2 itself (substrate activation). To implement.
Thereafter, when the gas supply unit 140 is operated, a mixed gas of the source gas and the carrier gas is supplied into the chamber 101. The supplied mixed gas is filled into the chamber 101, and as shown in FIG. 6A, the mixed gas is exposed to the holding member 2 as a base material.

The ratio (mixing ratio) of the raw material gas in the mixed gas is slightly different depending on the kind of the raw material gas and the carrier gas, the target film forming speed, and the like. It is preferable to set, and it is more preferable to set to about 30 to 60%.
The frequency applied between the first electrode 111 and the second electrode 112 is not particularly limited, but is preferably about 1 kHz to 100 MHz, and more preferably about 10 to 60 MHz. But not limited high frequency power density, in particular, is preferably about 0.01 to 10 / cm ^2, more preferably about 0.1 to 1 W / cm ^2.

The pressure in the chamber 101 during film formation is preferably about 133.3 × 10 ^{−5 to} 1333 Pa (1 × 10 ^{−5 to} 10 Torr), and is preferably 133.3 × 10 ^{−4 to} 133.3 Pa (1 × 10 ^{-4 to 1} Torr) is more preferable.
The raw material gas flow rate is preferably about 0.5 to 200 sccm, more preferably about 1 to 100 sccm.
The carrier gas flow rate is preferably about 5 to 750 sccm, more preferably about 10 to 500 sccm.
The treatment time is preferably about 1 to 10 minutes, more preferably about 4 to 7 minutes.
The temperature of the holding member 2 as a base material is preferably 25 ° C. or higher, and more preferably 25 to 100 ° C.

By applying a high-frequency voltage between the first electrode 111 and the second electrode 112, gas molecules existing between the electrodes 111 and 112 are ionized, and plasma is generated. The molecules of the raw material gas are polymerized by the energy of the plasma, and the polymer adheres to and accumulates on the surface (the flat plate portion 21 and the convex portion 22) of the holding member 2 as shown in FIG. As a result, as shown in FIG. 6C, a plasma polymerization film 131 is formed on the joint surface of the holding member 2.
The average thickness of the plasma polymerized film 131 is 10 to 1000 nm, and preferably 50 to 500 nm. When the average thickness of the plasma polymerized film 131 is less than 10 nm, sufficient bonding strength cannot be obtained, and when it exceeds 1000 nm, the dimensional accuracy of the bonded body is significantly reduced.

Thereafter, as shown in FIG. 6D, the plasma polymerization film 131 is activated to activate the surface (surface activation step).
For the surface activation step, for example, a method of irradiating plasma, a method of contacting with ozone gas, a method of treating with ozone water, a method of treating with alkali, or the like can be used.
Here, the activation means that the surface of the plasma polymerized film 131 and the internal molecular bond are cut and an unterminated bond is generated, or an OH group is bonded to the cut bond. A state or a state in which these states are mixed.
In this surface activation step, a method of irradiating plasma is preferable in order to efficiently activate the surface of the plasma polymerization film 131. The reason for irradiating the surface of the plasma polymerized film 131 is that the molecular structure of the plasma polymerized film 131 is not cut more than necessary, for example, until it reaches the boundary between the plasma polymerized film 131 and the holding member 2. This is to avoid deterioration of characteristics.

As the plasma used in this embodiment, for example, oxygen, argon, nitrogen, air, water, or the like can be used singly or in combination. Among these, it is preferable to use oxygen.
By using such plasma, it is possible to prevent the characteristic of the plasma polymerized film 131 from being remarkably deteriorated, eliminate a wide range of unevenness, and perform processing in a shorter time. And since plasma can be generated with the same equipment as the apparatus for forming the plasma polymerized film, there is also an advantage that the manufacturing cost can be reduced.
The time for irradiating the plasma is not particularly limited as long as the molecular bond in the vicinity of the surface of the plasma polymerized film 131 can be broken, but is preferably about 5 to 30 minutes, and preferably 10 to 60 seconds. More preferred.
OH groups are introduced into the surface of the plasma polymerization film 131 activated in this way.
In the present embodiment, a step of cleaning the holding member 2 may be provided between the plasma polymerization film forming step and the surface activation step. This cleaning step is performed using chemicals, water, or other appropriate means.

Next, the holding member 2 whose surface of the plasma polymerized film 131 is activated and the large plate 1 made of a silicon-containing substrate are bonded and integrated (bonding step).
That is, as shown in FIGS. 7A and 7B, the large plate 1 is pressed against the joint surface of the holding member 2 on which the plasma polymerized film 131 is formed. At this time, the convex portion 22 of the holding member 2 is brought into contact with and pressed against a position that becomes the joint portion 3 inside the outer peripheral edge of the large plate 1. Note that a bonding jig may be used so that the position of the joint portion 3 is not shifted.
By pressing, a bond is formed between the surface of the plasma polymerized film 131 formed on the convex portion 22 and the surface of the large plate 1 which is a silicon-containing substrate, and the large plate 1 and the holding member 2 are joined ( Molecular bonding).
Since the activated state of the plasma polymerized film 131 whose surface has been activated relaxes over time, the plasma polymerized film 131 shifts to the bonding step immediately after the surface activation step. Specifically, after the surface activation step, it is preferable to shift to the pasting step within 60 minutes, and it is more preferable to shift within 5 minutes. Within this time, the surface of the plasma polymerized film 131 is maintained in a sufficiently active state, so that sufficient bonding strength can be obtained at the time of bonding. In this embodiment, the plasma polymerization film 131 is formed only on the bonding surface of the holding member 2 and then activated and bonded. However, the plasma polymerization film 131 is similarly applied to the bonding surface of the large plate 1. After forming, this may be activated and bonded.

  In the case where both the large plate 1 and the holding member 2 are made of quartz, it is preferable that the crystal optical axes of the large plates 1 are bonded together and integrated. This is because by integrating in this way, the residual stress caused by the anisotropy of the linear expansion coefficient of quartz can be reduced. Therefore, the effect of preventing the warp of the large plate 1 can be increased.

In this embodiment, as shown in FIG. 7C, the large plate 1 and the holding member 2 are pressurized as necessary after the bonding step (pressurizing step).
In this pressurizing step, it is preferable to pressurize the large plate 1 and the holding member 2 with a large force in order to increase the bonding strength. Specifically, the pressure for pressurization is preferably about 1 to 10 MPa, and more preferably 1 to 5 MPa, although it varies depending on conditions such as the thickness of the large plate 1 and the holding member 2 and the apparatus. The pressurization time is not particularly limited, but is preferably about 10 sec to 30 min.

After pressurizing the large plate 1 and the holding member 2, they are heated (heating step). By heating, the bonding strength can be increased.
This heating step is provided as necessary, and the heating temperature is 25 to 100 ° C, and preferably 50 to 100 ° C. If it exceeds 100 ° C., the large plate 1 and the holding member 2 may be deteriorated and deteriorated. The heating time is preferably about 1 to 30 minutes.
In addition, although this heating process may be performed independently after a pressurization process, performing simultaneously with a pressurization process is preferable when strengthening joint strength.

[Mounting process]
Next, the large plate 1 and the holding member 2 bonded together in the bonding step are attached to the window portion 61 of the mounted member 6 through the film forming jig 5.
The outer flange portion 52 of the film forming jig 5 is mounted in advance on the window portion 61 of the mounted member 6. Then, as shown in FIG. 3, the holding member 2 is attached to the inner flange portion 53 of the film forming jig 5 by using a shape in which the side end of the holding member 2 and the side end of the large plate 1 are stepped. Hold on. At this time, the large plate 1 is disposed in the opening 54, and the film formation surface of the large plate 1 is exposed to the inner surface side of the mounted member 6.

[Film formation process]
In the next film formation process, an optical thin film is formed on the film formation surface of the large plate 1.
Formation of the optical thin film is carried out using a predetermined film forming method by carrying the member 6 to which the large plate 1 and the holding member 2 are attached through the film forming jig 5 into the film forming apparatus.
In the present embodiment, a dielectric multilayer film in which two kinds of films of a high refractive index material and a low refractive index material having different refractive indexes are alternately laminated will be described as an example of an optical thin film.
The dielectric multilayer film is formed by alternately forming a high refractive index material layer of TiO _{2 and} a low refractive index material layer of SiO ₂ in multiple layers using a vacuum deposition method. The dielectric multilayer film formed on the film-forming surface of the large plate 1 is formed by the strong compressive stress of the SiO ₂ film of the low refractive index material and the weak tensile stress of the TiO ₂ film of the high refractive index material. An internal stress is generated in which the film formation surface is warped convexly.
After the dielectric multilayer film is formed, the mounted member 6 is unloaded from the film forming apparatus.

(Cutting division process)
Next, in the cutting and dividing step, the strip substrate 4 is taken out from the large plate 1 on which the optical thin film is formed.
A strip substrate 4 can be obtained by cutting and dividing along a dicing line formed in a lattice shape by using a dicing machine to avoid a joint. The strip substrate 4 is inspected for warpage by visual inspection or the like, and a pass / fail judgment is made.
Each lattice formed by intersecting dicing lines is formed larger than the upper surface of the convex portion 22 of the holding member 2. Therefore, contact between the cutting edge of the dicing machine and the convex portion 22 can be prevented.
Further, when the large plate 1 is cut and divided, the holding member 2 is not cut. Therefore, after the strip-shaped substrate 4 is taken out, a small piece of the large plate 1 remains on the convex portion 22 of the holding member 2. The small piece of the large plate 1 is not an object of the strip substrate 4.

After this cutting and dividing step, a holding member regeneration step may be performed.
As described above, since the holding member 2 is not cut by the dicing machine in the cutting and dividing step, the flat plate portion 21 and the convex portion 22 are not cut and divided.
Therefore, if the small piece of the large plate 1 remaining on the convex portion 22 is removed, it can be reused as the holding member 2 again. For example, if the large plate 1 is a silicon oxide-containing substrate, the small piece of the large plate 1 can be peeled off from the convex portion 22 by immersing it in a hydrofluoric acid aqueous solution having a concentration of several vol% together with the holding member 2 for several hours. .
After peeling, the holding member 2 can be reused as the holding member 2 by washing and drying.

[Effects of First Embodiment]
Therefore, in the present embodiment, the following operational effects can be achieved.
(1) In the film forming method according to the present embodiment, the large plate 1 is bonded and held by the convex portion 22 of the holding member 2 via the bonding layer 31, and the bonded portion 3 is formed at least inside the outer peripheral edge of the large plate 1. can do. Therefore, the site | part which hold | maintains the big board 1 can be arrange | positioned effectively. Therefore, the warpage of the large plate 1 can be further reduced, and the level of warpage of the strip substrate after cutting and division can be improved.

(2) In particular, since the joint portion 3 is also formed in the vicinity of the center of the large plate 1, the portion that holds the large plate 1 can be effectively arranged. Therefore, the occurrence of warping of the large plate 1 can be further reduced, and the effect of preventing warpage of the strip substrate after cutting and division can be increased.

(3) In the joining step, since the holding member 2 has the convex portion 22, it is the convex portion 22 that contacts the large plate 1 even when the joining layer 31 is formed on the entire joining surface side of the holding member 2. The bonding layer 31 is formed on the upper surface. Therefore, the position and size of the joint portion 3 can be easily adjusted by the position and size of the convex portion 22.
Furthermore, it is not necessary to selectively form the bonding layer 31 on the bonding surface side of the holding member 2, and the step of masking the holding member 2 can be omitted.

(4) In the joining step, the large plate 1 and the holding member 2 are joined by molecular joining, so that they can be joined firmly. Furthermore, even if the large plate 1 and the holding member 2 have different linear expansion coefficients, the stress due to thermal expansion is relieved, and positional deviation between the large plate 1 and the holding member 2 during film formation is prevented. be able to. Therefore, the effect of preventing the warp of the large plate 1 can be enhanced.
Further, even in a film forming process exposed to a high temperature atmosphere, there is no degassing such as an adhesive, so there is no concern of contamination of the film forming product due to such degassing.

(5) The film forming jig 5 according to the present embodiment accommodates the holding member 2 joined to the large plate 1 in the main body 51, and the side end of the holding member 2 and the side end of the large plate 1 are stepped. The holding member 2 can be held by the inner flange portion 53 of the film forming jig 5 by using the formed shape. Therefore, it is possible to stably hold the large plate 1 and the holding member 2. Further, since the film formation surface of the large plate 1 is exposed from the opening 54, even when the large plate 1 is bonded to the holding member 2, it is possible to reliably form a film on the film formation surface.

(6) In the attaching step, the large plate 1 and the holding member 2 joined to each other can be attached to the mounted member 6 via the film-forming jig 5, so that the work efficiency of attaching the large plate 1 to the window portion 61 is achieved. Can be improved.

(7) Since the holding member 2 is not cut in the cutting and dividing step, the holding member 2 can be recycled if the small piece of the large plate 1 remaining on the convex portion 22 is peeled off.

[Second Embodiment]
This embodiment is different from the above-described first embodiment in that no protrusion is formed on the holding member. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

FIG. 8 is a plan view and a cross-sectional view of the holding member 2 ′ supported together with the masking 7 on the first electrode 111 of the plasma polymerization apparatus 100. In this embodiment, since the convex portion is not formed on the holding member 2 ′, the masking 7 is attached to the holding member 2 ′, and the bonding layer 31 is selectively formed.
The holding member 2 ′ is made of glass, silicon, crystal, ceramic, metal or the like.
In the present embodiment, the holding member 2 ′ is formed in a plate shape having a substantially square shape in plan view. As in the case of the first embodiment, the joining surface is preferably smooth and more preferably mirror-finished.

The masking 7 is provided with an opening 71 corresponding to the position and size of the plasma polymerization film 131 formed as the bonding layer 31 on the bonding surface of the holding member 2 ′. Here, the opening 71 is provided to have the same position and size as the bonding layer 31 formed by the convex portion 22 of the holding member 2 of the first embodiment.
When the masking 7 is attached to the holding member 2 ′, the joint surface of the holding member 2 ′ is exposed from the opening 71. At this time, if there is a gap between the masking 7 and the holding member 2 ′, the polymer enters, adheres to, and accumulates in the gap from the opening 71, and a plasma polymerized film is also formed on the portion other than the joint 3. Since it may be formed, it is preferable to closely contact the masking 7 and the holding member 2 ′ so that no gap is generated. For example, the inner surface of the masking 7 and the holding member 2 ′ may be formed smoothly so that the gap does not occur, or the gap is sealed with a sealing member or the like.

FIG. 9 is a schematic view showing a state in which the holding member 2 ′ to which the masking 7 is attached is disposed in the plasma polymerization apparatus 100.
FIG. 10 is a schematic view showing a process of forming the plasma polymerized film 131.
In the plasma polymerization apparatus 100, the first electrode 111 and the second electrode 112 are disposed to face each other with the holding member 2 ′ and the masking 7 interposed therebetween. That is, the joint surface of the holding member 2 ′ exposed from the opening 71 is disposed to face the second electrode 112.
When the formation process of the plasma polymerized film 131 is performed in the same manner as in the first embodiment with the masking 7 attached, first, as shown in FIG. 10A, the holding member 2 ′ as the base material and the masking 7 The mixed gas is exposed.
Thereafter, molecules in the source gas are polymerized by the energy of the generated plasma, and as shown in FIG. 10B, the polymer is attached to the bonding surface of the holding member 2 ′ exposed from the opening 71 and the masking 7. ,accumulate. As a result, as shown in FIG. 10C, a plasma polymerization film 131 is formed on the joint surface of the holding member 2 ′. Thereafter, when the masking 7 is removed, the polymer is selectively attached and deposited on the joint surface of the holding member 2 ′ exposed from the opening 71.
Thereafter, as shown in FIG. 10D, the plasma polymerization film 131 is activated to activate the surface (surface activation step).
And if the large board 1 and holding member 2 'are joined like 1st Embodiment, the junction part 3 will be formed.

FIG. 11 is a cross-sectional view showing a state in which the large plate 1 joined to the holding member 2 ′ is attached to the mounted member 6 in the present embodiment. Similar to the first embodiment, it is attached to the window portion 61 of the mounted member 6 via the film forming jig 5.
Thereafter, similarly to the first embodiment, a strip substrate 4 can be obtained through a film forming process and a cutting and dividing process.

[Effects of Second Embodiment]
Therefore, in this embodiment, in addition to the operational effects (2), (4), (5), (6), (7) of the first embodiment described above, the following operational effects can be achieved.
(8) In the film forming method according to the present embodiment, the large plate 1 is bonded and held via the bonding layer 31 without providing the convex portion on the holding member 2 ′, and the bonded portion 3 is at least the outer peripheral edge of the large plate 1. It can be formed more inside. Therefore, the site | part which hold | maintains the big board 1 can be arrange | positioned effectively. Therefore, the occurrence of warping of the large plate 1 can be further reduced, and the effect of preventing warpage of the strip substrate after cutting and division can be increased.
(9) Since the masking 7 is attached to the holding member 2 ′ to form the plasma polymerized film 131, the bonding layer 31 can be formed at an accurate position and size on the film forming surface of the holding member 2 ′. I can do it.

[Third Embodiment]
This embodiment is different from the first embodiment described above in that an adhesive layer is formed as the bonding layer 31. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

As the adhesive used in the present embodiment, a heat-resistant adhesive is used.
In the joining step, an adhesive is applied to the convex portion 22 of the holding member 2. At this time, the adhesive that has flowed out of the convex portion 22 travels along the side surface of the convex portion 22 and spreads to the flat plate portion 21.
When the large plate 1 and the holding member 2 are joined, the height of the convex portion 22 is formed high so that the adhesive spread to the flat plate portion 21 does not contact the large plate 1 or the convex portion 22 It is preferable to provide a recess around the root so that the adhesive flows into the recess. Further, in order to develop the adhesive strength of the heat resistant adhesive, the thickness of the adhesive layer is set to several tens of μm. Therefore, in order to more effectively prevent the adhesive from contacting the large plate 1, It is also preferable that the height from the surface of the portion 21 to the upper surface of the convex portion 22 is set to 100 μm or more.
Others are performed in the same manner as in the first embodiment.

[Effects of Third Embodiment]
Therefore, in this embodiment, in addition to the operational effects (1), (2), (5), and (6) of the first embodiment described above, the following operational effects can be achieved.
(10) Since the adhesive is applied to the convex portion 22 formed on the holding member 2, the adhesive that has flowed out from the convex portion 22 can be propagated along the side surface of the convex portion 22 and spread to the flat plate portion 21. . Therefore, it is possible to prevent unnecessary formation of the joint portion 3 and to reduce variations in the position and size of the joint portion 3. Further, it is possible to prevent the adhesive from adhering to the strip substrate 4 taken out from the large plate 1.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the said embodiment, although the shape of the large board 1 and the holding member 2 was made into the substantially square shape in planar view, other shapes, such as a rectangle, a polygon, and a circle, may be sufficient. That is, it is possible to use the large plate 1 whose shape and size are appropriately changed according to the shape, size, number of the strips 4 taken out, etc. The member 2 can be used.

  In the above-described embodiment, the holding member 2 is held by the inner flange portion 53 of the film forming jig 5. However, the large plate 1 may be held by the inner flange portion 53.

  Further, the position and size of the joint portion 3 are not limited to the form shown in the embodiment. For example, a frame-like joint 3 along the outer periphery may be formed at least inside the outer periphery of the large plate 1, and a bridge-like joint 3 may be formed on the frame. .

Moreover, in the said embodiment, although the joining layer 31 was formed in the joining surface of the holding member 2, you may form in the joining surface of the large board 1, and you may form in both joining surfaces.
Note that what is described as a large plate does not mean the size of the substrate. In a film formation method for obtaining a strip substrate (film formation product) by cutting and dividing after film formation, the substrate prepared before film formation is described as a large plate.

  The present invention can be used as a film forming method for forming an optical thin film or the like and a film forming jig used for film forming.

  DESCRIPTION OF SYMBOLS 1 ... Large plate, 2 and 2 '... Holding member, 3 ... Joint part, 4 ... Strip board, 5 ... Film-forming jig, 6 ... Mounted member, 22 ... Convex part, 51 ... Main-body part, 52 ... Outside Flange portion, 53 ... inner flange portion, 54 ... opening portion, 61 ... window portion

Claims (9)

A film forming method of forming a film on a large plate and cutting and dividing the large plate after the film formation into a plurality of strip substrates,
A joining step of joining the large plate and a holding member for holding the large plate at a joint portion disposed at least inside the outer peripheral edge of the large plate;
An attaching step for attaching the joined large plate together with the holding member to a window portion of a member to be attached disposed in the film forming apparatus;
A film forming process for forming a film on the large plate attached to the window;
A cutting and dividing step of cutting the formed large plate and dividing it into the strip substrates, and separating the strip substrate and the holding member;
A film forming method comprising: In the film-forming method of Claim 1,
In the bonding step, the film forming method is characterized in that the holding member is bonded at a bonding portion disposed at least in the center of the large plate. In the film-forming method of Claim 1 or Claim 2,
In the cutting and dividing step, the film forming method is characterized in that the holding member is not cut. In the film-forming method in any one of Claim 1- Claim 3,
In the cutting and dividing step, the large plate is cut to avoid the joint portion and divided into the strip substrates,
A film forming method comprising performing a pass / fail judgment on the plurality of the divided strip substrates. In the film-forming method as described in any one of Claim 1- Claim 4,
The holding member has a convex portion,
In the bonding step, the convex portion and the large plate are bonded to each other. In the film-forming method as described in any one of Claim 1- Claim 5,
In the bonding step, the large plate and the holding member are molecularly bonded. In the film-forming method as described in any one of Claim 1- Claim 6,
The large plate and the holding member are made of crystal, and the large plate and the holding member are joined together with a crystal optical axis aligned. In the film-forming method as described in any one of Claim 1- Claim 7,
In the attaching step, the large plate is attached through a film forming jig. A main body capable of accommodating a large plate to be deposited, and a holding member joined by a joint disposed on the large plate at least inside the outer peripheral edge of the large plate;
An outer flange portion that is formed to protrude from the main body side and is attached to a member to be mounted that is disposed in the film forming apparatus,
An inner flange formed to protrude inward of the main body and holding the holding member;
A film forming jig comprising: an opening formed on a bottom of the main body and exposing a film forming surface of the large plate.

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