JPH10125930A - Separation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separation method, wherein a material to be separated can be easily separated regardless of the characteristics, condition and the like of the material to be separated and specially, transfer of the material to be speared to various transfer materials is possible. SOLUTION: This separation method (transfer method) is a method, wherein an isolation layer 2, which is constituted of an amorphous silicon layer, for example, is formed on a light-transmitting substrate 1, a layer 4 to be transferred is directly formed on the layer 2 or is formed on the layer 2 via a prescribed intermediate layer 3 and moreover, a transfer material 6 is bonded to the side, which is opposite to the substrate 1, of the layer 4 via an adhesiveness layer 5, such irradiation light 7 as a laser beam is projected onto the layer 2 from the rear side of the substrate 1, separation is generated within the layer of the layer 2 and/or in the interface between the layer 2 and the substrate 1 by an ablation and the layer 4 is made to separate from the substrate 1 to transfer the layer 4 to the transfer material 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of peeling an object to be peeled, and more particularly to a method of peeling a layer to be transferred made of a thin film such as a functional thin film and transferring the transferred layer to a transfer body such as a transparent substrate. It is.

[0002]

2. Description of the Related Art For example, when manufacturing a liquid crystal display (LCD) using a thin film transistor (TFT), a process of forming the thin film transistor on a transparent substrate by CVD or the like is performed.

The thin film transistors include those using amorphous silicon (a-Si) and those using polysilicon (p-S
i), and those formed of polysilicon are classified into those formed through a high-temperature process and those formed through a low-temperature process.

Since such a thin film transistor is formed on a transparent substrate at a high temperature, it is necessary to use a transparent substrate made of a material having excellent heat resistance. Therefore, at present, a transparent substrate made of quartz glass is used because it has a high softening point and a high melting point and can sufficiently withstand a temperature of about 1000 ° C. in a high-temperature process. In the low-temperature process,
Since a temperature around 500 ° C. becomes the highest process temperature, heat-resistant glass is used.

However, quartz glass having such excellent heat resistance is a rare and extremely expensive material as compared with ordinary glass, and it is difficult to produce a large transparent substrate. In addition, heat-resistant glass can be made larger than quartz glass, but it is significantly more expensive than ordinary glass. In addition, both quartz glass and heat-resistant glass are brittle and easily broken, and the weight is large. This is a serious drawback in configuring an LCD. Therefore, it has been an obstacle in producing a large and inexpensive liquid crystal display.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a peeling method which can be easily peeled irrespective of the properties and conditions of an object to be peeled, and in particular, can be transferred to various transfer members. To provide.

[0007]

This and other objects are achieved by the present invention which is defined below as (1) to (25).

(1) A peeling method for peeling an object to be peeled present on a substrate via a separation layer from the substrate, wherein the separation layer is irradiated with irradiation light, and the inside of the separation layer and / or Alternatively, peeling is caused at an interface, and the object to be peeled is separated from the substrate.

(2) A separation method for separating an object to be separated, which is present on a light-transmitting substrate via a separation layer, from the substrate, and irradiating the separation layer with irradiation light from the substrate side.
A separation method, wherein separation is caused in the separation layer and / or at the interface, and the object to be separated is separated from the substrate.

(3) A method of peeling a transferred layer formed on a substrate via a separation layer from the substrate and transferring the transferred layer to another transfer member, wherein the transferred layer is opposite to the substrate. After bonding the transfer body, the separation layer is irradiated with irradiation light to cause peeling in the layer and / or interface of the separation layer, and the transfer target layer is separated from the substrate to form the transfer body. A peeling method characterized by transferring.

(4) A method for separating a transfer layer formed on a light-transmitting substrate via a separation layer from the substrate and transferring the transfer layer to another transfer body, wherein the transfer layer is formed on the substrate. After the transfer body is bonded to the opposite side, the separation layer is irradiated with irradiation light from the substrate side to cause separation in the separation layer and / or at the interface. And transferring to the transfer member after detaching from the transfer member.

(5) a step of forming a separation layer on a light-transmitting substrate; a step of forming a layer to be transferred directly or via a predetermined intermediate layer on the separation layer; Bonding the transfer body to the opposite side of the substrate, and irradiating the separation layer with irradiation light from the substrate side to cause peeling in the layer of the separation layer and / or at the interface; Separating from the substrate and transferring to the transfer body.

(6) The peeling method according to the above (5), further comprising a step of removing the separation layer adhering to the substrate side and / or the transfer body side after the transfer of the transfer-receiving layer to the transfer body. Method.

(7) The peeling method according to any one of the above (3) to (6), wherein the transferred layer is a functional thin film or a thin film device.

(8) The peeling method according to any one of the above (3) to (6), wherein the transferred layer is a thin film transistor.

(9) The peeling method according to any one of the above (3) to (8), wherein the transfer body is a transparent substrate.

(10) The transfer body has a glass transition point (T
g) or the peeling method according to any one of the above (3) to (9), which is made of a material having a softening point of Tmax or less.

(11) The transfer body has a glass transition point (T
g) or the peeling method according to any one of the above (3) to (10), which is made of a material having a softening point of 800 ° C. or lower.

(12) The peeling method according to any one of the above (3) to (11), wherein the transfer body is made of a synthetic resin or a glass material.

(13) The peeling method according to any one of the above (1) to (12), wherein the substrate has heat resistance.

(14) The substrate according to any one of (3) to (12) above, wherein the strain point is made of a material having a maximum temperature of Tmax or more when the maximum temperature at the time of forming the layer to be transferred is Tmax. The stripping method as described.

(15) The method according to any one of the above (1) to (14), wherein the peeling of the separation layer is caused by a loss or a decrease in a bonding force between atoms or molecules of a substance constituting the separation layer. Peeling method.

(16) The peeling method according to any one of the above (1) to (15), wherein the irradiation light is a laser light.

(17) The wavelength of the laser beam is 100 to
The stripping method according to the above (16), wherein the thickness is 350 nm.

(18) The wavelength of the laser beam is 350 to
The stripping method according to the above (16), which is 1200 nm.

(19) The stripping method according to any one of (1) to (18), wherein the separation layer is made of amorphous silicon.

(20) The stripping method according to the above (19), wherein the amorphous silicon contains H (hydrogen) in an amount of 2 at% or more.

(21) The peeling method according to any one of the above (1) to (18), wherein the separation layer is made of a ceramic.

(22) The peeling method according to any one of the above (1) to (18), wherein the separation layer is made of a metal.

(23) The peeling method according to any one of the above (1) to (18), wherein the separation layer is made of an organic polymer material.

(24) The organic polymer material is -CH2
-, -CO-, -CONH-, -NH-, -COO-,
The peeling method according to the above (23), wherein the method has at least one kind of bond of -N = N- and -CH = N-.

(25) The stripping method according to the above (23) or (24), wherein the organic polymer material has an aromatic hydrocarbon in a constitutional formula.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a peeling method according to the present invention will be described in detail with reference to preferred embodiments shown in the accompanying drawings.

FIGS. 1 to 8 are sectional views showing the steps of an embodiment of the peeling method of the present invention. Hereinafter, the steps of the peeling method (transfer method) of the present invention will be sequentially described based on these drawings.

[1] As shown in FIG. 1, a separation layer (light absorbing layer) 2 is formed on one surface (separation layer forming surface 11) of a substrate 1.

When the substrate 1 is irradiated with the irradiation light 7 from the substrate 1 side, it is preferable that the substrate 1 has a light-transmitting property through which the irradiation light 7 can be transmitted.

In this case, the transmittance of the irradiation light 7 is preferably at least 10%, more preferably at least 50%. If the transmittance is too low, the attenuation (loss) of the irradiation light 7 increases, and a larger amount of light is required to peel off the separation layer 2.

The substrate 1 is preferably made of a highly reliable material, particularly preferably a material having excellent heat resistance. The reason for this is that, for example, when forming the transferred layer 4 and the intermediate layer 3 described later, the process temperature increases depending on the type and the forming method (for example, 3
(About 50 to 1000 ° C).
This is because if the substrate 1 is excellent in heat resistance, the range of setting of film forming conditions such as temperature conditions in forming the transferred layer 4 and the like on the substrate 1 is widened.

Accordingly, the substrate 1 is preferably made of a material having a strain point equal to or higher than Tmax, where Tmax is the maximum temperature at the time of forming the layer 4 to be transferred. Specifically, the constituent material of the substrate 1 preferably has a strain point of 350 ° C. or higher, more preferably 500 ° C. or higher. Examples of such a material include heat-resistant glass such as quartz glass, soda glass, Corning 7059, and NEC Glass OA-2.

If the process temperature for forming the later-described separation layer 2, intermediate layer 3, and transfer layer 4 is to be lowered, the substrate 1 is also made of an inexpensive glass material or synthetic resin having a low melting point. be able to.

The thickness of the substrate 1 is not particularly limited, but is usually preferably about 0.1 to 5.0 mm, and more preferably about 0.5 to 1.5 mm. If the thickness of the substrate 1 is too thin, the strength is reduced. If the thickness of the substrate 1 is too low, the irradiation light 7 tends to be attenuated when the transmittance of the substrate 1 is low. When the transmittance of the irradiation light 7 of the substrate 1 is high, the thickness may exceed the upper limit.

The thickness of the separation layer forming portion of the substrate 1 is preferably uniform so that the irradiation light 7 can be uniformly irradiated.

Further, the separation layer forming surface 11 and the irradiation light incident surface 12 of the substrate 1 are not limited to the flat surface as shown, but may be a curved surface.

In the present invention, the substrate 1 is separated by separating the separation layer 2 between the substrate 1 and the transferred layer 4 instead of removing the substrate 1 by etching or the like. At the same time, there is a wide range of options for the substrate 1 such as using a relatively thick substrate.

Next, the separation layer 2 will be described.

The separation layer 2 absorbs irradiation light 7 described later,
It has a property of causing peeling (hereinafter referred to as “intralayer peeling” or “interfacial peeling”) in the layer and / or at the interface 2 a or 2 b, and is preferably separated by irradiation with the irradiation light 7. The loss or reduction of the bonding force between the atoms or molecules of the substance constituting the layer 2, or in reality, abrasion or the like, may result in delamination and / or interfacial delamination.

Further, the separation layer 2 is irradiated by the irradiation light 7.
In some cases, gas is released from the gas and the separation effect is exhibited. That is, there is a case where the component contained in the separation layer 2 is released as a gas, and a case where the separation layer 2 absorbs light and becomes a gas for a moment, and the vapor is released to contribute to separation. .

The composition of the separation layer 2 is, for example, as follows.

Amorphous Silicon (a-Si) This amorphous silicon may contain H (hydrogen). In this case, the content of H is preferably about 2 at% or more, and more preferably about 2 to 20 at%. As described above, when H is contained in a predetermined amount, irradiation of the irradiation light 7 releases hydrogen, and an internal pressure is generated in the separation layer 2, which serves as a force for peeling the upper and lower thin films.

The content of H in the amorphous silicon can be determined by appropriately setting film forming conditions such as gas composition, gas pressure, gas atmosphere, gas flow rate, temperature, substrate temperature, and input power in CVD. Can be adjusted.

Various oxide ceramics such as silicon oxide or silicate compound, titanium oxide or titanate compound, zirconium oxide or zirconate compound, lanthanum oxide or lanthanic acid compound, dielectric (ferroelectric) or semiconductor , SiO, SiO2, and Si3 O2. Examples of the silicate compound include K2 SiO3.
, Li2 SiO3, CaSiO3, ZrSiO4, N
a2 SiO3.

As the titanium oxide, TiO, Ti2 O3
And TiO2. Examples of the titanate compound include BaTiO4, BaTiO3, Ba2Ti9O2.
0, BaTi5 O11, CaTiO3, SrTiO3, P
bTiO3, MgTiO3, ZrTiO2, SnTiO
4, Al2 TiO5 and FeTiO3.

Examples of zirconium oxide include ZrO 2, and examples of zirconate compounds include BaZrO 2
3, ZrSiO4, PbZrO3, MgZrO3, K2
ZrO3.

PZT, PLZT, PLLZT, PB
Ceramics such as ZT or dielectrics (ferroelectrics) Nitride ceramics such as silicon nitride, aluminum nitride, titanium nitride, etc. Organic polymer materials As organic polymer materials, -CH2-, -CO- (ketone), -CONH- (Amide), -NH- (imide),
-COO- (ester), -N = N- (azo), -CH
= N- (Schiff) or the like (these bonds are broken by irradiation with the irradiation light 7), particularly any material having many of these bonds. The organic polymer material has an aromatic hydrocarbon (1
Or two or more benzene rings or condensed rings thereof).

Specific examples of such organic polymer materials include polyolefins such as polyethylene and polypropylene, polyimides, polyamides, polyesters, polymethyl methacrylate (PMMA), polyphenylene sulfide (PPS), and polyether sulfone (PE).
S), epoxy resin and the like.

Metal As the metal, for example, Al, Li, Ti, Mn, I
n, Sn, Y, La, Ce, Nd, Pr, Gd, Sm,
Alternatively, an alloy containing at least one of these may be used.

The thickness of the separation layer 2 varies depending on conditions such as the purpose of peeling and the composition, layer structure, and forming method of the separation layer 2. However, it is usually preferably about 1 nm to 20 μm.
It is more preferably about 10 nm to 2 μm,
More preferably, it is about 1 μm.

If the thickness of the separation layer 2 is too small, the uniformity of the film may be impaired and the separation may be uneven. If the thickness is too large, good separation of the separation layer 2 may be obtained. In order to secure the power, it is necessary to increase the power (light amount) of the irradiation light 7, and it takes time to remove the separation layer 2 later. The thickness of the separation layer 2 is preferably as uniform as possible.

The method for forming the separation layer 2 is not particularly limited.
It is appropriately selected according to various conditions such as a film composition and a film thickness. For example, CVD (MOCVD, low pressure CVD, ECR-CVD
), Vapor deposition, molecular beam deposition (MB), sputtering, ion plating, various vapor deposition methods such as PVD, various plating methods such as electroplating, immersion plating (dipping), and electroless plating, Langmuir Bloe Examples include a coating method such as a jet (LB) method, spin coating, spray coating, and roll coating, various printing methods, a transfer method, an inkjet method, a powder jet method, and the like. it can.

For example, when the composition of the separation layer 2 is amorphous silicon (a-Si), it is preferable to form the film by CVD, especially low pressure CVD or plasma CVD.

When the separation layer 2 is made of ceramics by a sol-gel method or when it is made of an organic polymer material, it is preferable to form a film by a coating method, particularly spin coating.

The formation of the separation layer 2 may be performed in two or more steps (for example, a layer forming step and a heat treatment step).

[2] As shown in FIG. 2, an intermediate layer (underlayer) 3 is formed on the separation layer 2.

The intermediate layer 3 is formed for various formation purposes. For example, a protective layer, an insulating layer, a conductive layer, an irradiation layer, which physically or chemically protects a transferred layer 4 described later during manufacturing or use. Examples of the light-shielding layer include a layer that functions as a light-shielding layer, a barrier layer that prevents migration of components to or from the transferred layer 4, and a reflective layer.

The composition of the intermediate layer 3 is appropriately set according to the purpose of its formation. For example, the composition of the intermediate layer 3 formed between the separation layer 2 made of amorphous silicon and the transfer layer 4 made of a thin film transistor is formed. In this case, silicon oxide such as SiO2 is used. In the case of the intermediate layer 3 formed between the separation layer 2 and the layer 4 to be transferred by PZT, for example, Pt,
Metals such as Au, W, Ta, Mo, Al, Cr, Ti, or alloys containing these as the main components may be used.

The thickness of the intermediate layer 3 is appropriately determined depending on the purpose of forming the intermediate layer 3 and the degree of the function that can be exhibited.
Usually, it is preferably about 10 nm to 5 μm,
More preferably, it is about nm to about 1 μm.

The method for forming the intermediate layer 3 is the same as the method for forming the intermediate layer 3. Also,
The formation of the intermediate layer 3 may be performed in two or more steps.

The intermediate layer 3 may be formed of two or more layers having the same or different composition. In the present invention, the transfer layer 4 may be formed directly on the separation layer 2 without forming the intermediate layer 3.

[3] As shown in FIG. 3, a transferred layer (substrate) 4 is formed on the intermediate layer 3.

The transfer layer 4 is a layer to be transferred to a transfer body 6 described later, and can be formed by the same method as the formation method described above for the separation layer 2.

The purpose, type, form, structure, composition, physical or chemical properties, etc. of the layer 4 to be transferred are not particularly limited, but in consideration of the purpose and usefulness of the transfer, a thin film, especially a functional thin film Alternatively, it is preferably a thin film device.

As the functional thin film and the thin film device,
For example, thin film transistors, thin film diodes, other thin film semiconductor devices, electrodes (eg, transparent electrodes such as ITO and mesa films), photoelectric conversion elements used for solar cells and image sensors, switching elements, memories, piezoelectric elements, etc. Actuators, micromirrors (piezoelectric thin film ceramics), magnetic recording media, magneto-optical recording media, recording media such as optical recording media, magnetic recording thin-film heads, coils, inductors, thin-film high-permeability materials and micro-magnetic devices combining them, Optical thin films such as filters, reflective films, dichroic mirrors, and polarizing elements, semiconductor thin films, superconducting thin films (eg, YBCO thin films), magnetic thin films, metal multilayer thin films, metal ceramic multilayer thin films, metal semiconductor multilayer thin films,
Examples include a ceramic semiconductor multilayer thin film, an organic thin film and a multilayer thin film of another substance.

Among them, the application to a thin film device, a micro magnetic device, a structure of a micro three-dimensional structure, an actuator, a micro mirror, and the like is particularly high and is preferable.

Such a functional thin film or thin film device is usually formed at a relatively high process temperature in relation to the method of forming the functional thin film or the thin film device. Therefore, in this case, as described above, the substrate 1 needs to have a high reliability that can withstand the process temperature.

The transferred layer 4 may be a single layer or a laminate of a plurality of layers. Further, a predetermined patterning such as the thin film transistor may be applied. The formation (lamination) and patterning of the transfer-receiving layer 4 are performed by a predetermined method according to the method. Such a transferred layer 4 is usually formed through a plurality of steps.

The formation of the transfer-receiving layer 4 by the thin film transistor is described in, for example, Japanese Patent Publication No. 2-50630 or H.
Ohshima et al: International Symposium Digest of
Technical Papers SID 1983 ”B / W and Color LC Video
Display Addressed by PolySi TFTs ”.

The thickness of the layer 4 to be transferred is not particularly limited, either, and is appropriately set according to various conditions such as the purpose of formation, function, composition, and characteristics. When the layer 4 to be transferred is a thin film transistor, the total thickness is preferably about 0.5 to 200 μm, more preferably about 1.0 to 10 μm. In the case of other thin films, a suitable total thickness may be in a wider range, for example, about 50 nm to 1000 μm.

The layer 4 to be transferred is not limited to a thin film as described above, but may be a thick film such as a coating film or a sheet. )
May be an object to be transferred or an object to be peeled.

[4] As shown in FIG. 4, an adhesive layer 5 is formed on a layer to be transferred (object to be peeled) 4, and a transfer body 6 is bonded (joined) through the adhesive layer 5.

Preferable examples of the adhesive forming the adhesive layer 5 include a light-curable adhesive such as a reaction-curable adhesive, a thermosetting adhesive, and an ultraviolet-curable adhesive, and an anaerobic-curable adhesive. Various curable adhesives can be used. As the composition of the adhesive,
For example, any type such as an epoxy type, an acrylate type, and a silicone type may be used. The formation of the adhesive layer 5 is performed by, for example, a coating method.

In the case of using the curable adhesive, for example, a curable adhesive is applied on the layer 4 to be transferred, and a transfer member 6 described later is bonded thereon, and then cured according to the characteristics of the curable adhesive. The transferable layer 4 and the transfer body 6 are adhered and fixed by curing the curable adhesive by a method.

When a photo-curable adhesive is used, the light-transmissive transfer member 6 is placed on the uncured adhesive layer 5 and then transferred to the transfer member 6.
It is preferable to irradiate curing light from above to cure the adhesive. If the substrate 1 has a light-transmitting property, it is preferable to cure the adhesive by irradiating curing light from both sides of the substrate 1 and the transfer body 6, which is preferable because curing is ensured.

It is to be noted that, different from the illustration, the adhesive layer 5 may be formed on the transfer body 6 side, and the transferred layer 4 may be bonded thereon. Further, an intermediate layer as described above may be provided between the transfer layer 4 and the adhesive layer 5. Further, for example, when the transfer body 6 itself has an adhesive function, the formation of the adhesive layer 5 may be omitted.

The transfer body 6 is not particularly limited.
Substrates (plate materials), particularly transparent substrates, may be mentioned. Note that such a substrate may be a flat plate or a curved plate.

The transfer member 6 may be inferior to the substrate 1 in properties such as heat resistance and corrosion resistance. The reason is that, in the present invention, the transferred layer 4 is formed on the substrate 1 side,
After that, since the transferred layer 4 is transferred onto the transfer member 6, the characteristics required for the transfer member 6, especially the heat resistance, do not depend on the temperature conditions at the time of forming the transferred layer 4.

Accordingly, assuming that the maximum temperature at the time of forming the transfer layer 4 is Tmax, a material having a glass transition point (Tg) or softening point of Tmax or less can be used as the material of the transfer body 6. For example, the transfer body 6 can be made of a material having a glass transition point (Tg) or a softening point of preferably 800 ° C. or lower, more preferably 500 ° C. or lower, and further preferably 320 ° C. or lower.

As the mechanical properties of the transfer member 6, those having a certain degree of rigidity (strength) are preferable, but those having flexibility and elasticity may be used.

As a constituent material of such a transfer body 6,
Various synthetic resins and various glass materials are mentioned, and particularly, various synthetic resins and ordinary (low melting point) inexpensive glass materials are preferable.

As the synthetic resin, any of a thermoplastic resin and a thermosetting resin may be used. For example, polyolefin such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA),
Cyclic polyolefin, modified polyolefin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polyamideimide, polycarbonate, poly- (4-methylpentene-1), ionomer, acrylic resin, polymethyl methacrylate (PM
MA), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene copolymer (AS resin), butadiene-styrene copolymer, polyoxymethylene, polyvinyl alcohol (PVA),
Polyester such as ethylene-vinyl alcohol copolymer (EVOH), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexane terephthalate (PCT), polyether, polyether ketone (PEK), polyether ether ketone (PEEK) ), Polyetherimide, polyacetal (POM), polyphenylene oxide, modified polyphenylene oxide, polysulfone, polyphenylene sulfide (PPS), polyether sulfone (PE)
S), polyarylate, aromatic polyester (liquid crystal polymer), polytetrafluoroethylene, polyvinylidene fluoride, other fluororesins, styrene, polyolefin, polyvinyl chloride, polyurethane, polyester, polyamide, polybutadiene , Trans-polyisoprene-based, fluororubber-based, chlorinated polyethylene-based thermoplastic elastomers, epoxy resins, phenolic resins, urea resins, melamine resins, unsaturated polyesters, silicone resins, polyurethanes, etc. Examples thereof include polymers, blends, and polymer alloys, and one or more of these can be used in combination (for example, as a laminate of two or more layers).

Examples of the glass material include silicate glass (quartz glass), alkali silicate glass, soda lime glass, potassium lime glass, lead (alkali) glass, barium glass, borosilicate glass and the like. Of these, those other than silicate glass have a lower melting point than silicate glass, are relatively easy to mold and process, and are inexpensive, and are therefore preferable.

When the transfer member 6 is made of synthetic resin, the large transfer member 6 can be integrally formed and has a complicated shape such as one having a curved surface or irregularities. However, various advantages such as easy production and low material cost and low production cost can be enjoyed. Therefore, a large and inexpensive device (for example, a liquid crystal display) can be easily manufactured.

The transfer member 6 may be one that constitutes an independent device such as a liquid crystal cell, or a device such as a color filter, an electrode layer, a dielectric layer, an insulating layer, or a semiconductor element. May be a part of the above.

Further, the transfer body 6 may be a substance such as metal, ceramics, stone, wood, paper, or the like, or on any surface constituting a certain product (on a clock, on an air conditioner, or on a print surface). On a substrate, etc.), or on the surface of a structure such as a wall, a column, a beam, a ceiling, or a window glass.

[5] As shown in FIG. 5, the irradiation light 7 is irradiated from the back side of the substrate 1 (the irradiation light incident surface 12 side). After passing through the substrate 1, the irradiation light 7 is applied to the separation layer 2 from the interface 2 a side. As a result, as shown in FIG. 6 or FIG. 7, in-layer peeling and / or interfacial peeling occurs in the separation layer 2 and the bonding force decreases or disappears. The transfer layer 4 separates from the substrate 1 and is transferred to the transfer body 6.

FIG. 6 shows a case in which separation in the separation layer 2 has occurred, and FIG. 7 shows a case in which separation in the separation layer 2 at the interface 2a has occurred. The principle that the separation within the separation layer 2 and / or the interfacial separation occurs is that ablation occurs in the constituent material of the separation layer 2, the gas contained in the separation layer 2 is released, and the separation occurs immediately after the irradiation. It is presumed that this is due to a phase change such as melting and transpiration.

Here, ablation means that the solid material (constituting material of the separation layer 2) which has absorbed the irradiation light is photochemically or thermally excited, and the surface or the inside of the material is cut off the bonds of atoms or molecules to be released. Mainly, the separation layer 2
All or a part of the constituent material of (1) appears as a phenomenon that causes a phase change such as melting and evaporation (vaporization). In addition, a minute foaming state may be caused by the phase change, and the bonding force may be reduced.

Whether the separation layer 2 causes intra-layer separation, interfacial separation, or both of them depends on the composition of the separation layer 2 and other various factors, and one of the factors is as follows. Conditions such as the type, wavelength, intensity, and reaching depth of the irradiation light 7 are given.

The irradiation light 7 may be any as long as it causes separation within the separation layer 2 and / or interface separation, such as X-rays, ultraviolet light, visible light, infrared light (heat rays), and laser light. , Millimeter wave, microwave, electron beam,
Radiation (α-rays, β-rays, γ-rays) and the like can be mentioned, and among them, laser light is preferable because it easily causes separation (ablation) of the separation layer 2.

Examples of a laser device for generating this laser beam include various gas lasers and solid-state lasers (semiconductor lasers). Excimer lasers, Nd-YAG lasers, Ar lasers, CO2 lasers, CO lasers, He-N
An e-laser or the like is suitably used, and among them, an excimer laser is particularly preferable.

Since the excimer laser outputs high energy in a short wavelength region, ablation can be caused in the separation layer 2 in a very short time, so that the adjacent or nearby intermediate layer 3, transferred layer 4, The separation layer 2 can be peeled off without substantially increasing the temperature of the substrate 1 or the like, that is, without causing deterioration or damage.

When the irradiation light for causing ablation in the separation layer 2 has wavelength dependence, the wavelength of the laser light to be irradiated is preferably about 100 to 350 nm.

When the separation characteristics are given to the separation layer 2 by causing a phase change such as gas release, vaporization, and sublimation, the wavelength of the laser light to be irradiated is 350 to 1200 nm.
It is preferred to be on the order of magnitude.

The energy density of the irradiated laser beam, particularly the energy density of an excimer laser, is
It is preferably about 10 to 5000 mJ / cm2, and 100
More preferably, it is about 500 mJ / cm2. Further, the irradiation time is preferably about 1 to 1000 nsec,
More preferably, it is about 10 to 100 nsec. If the energy density is low or the irradiation time is short, sufficient ablation or the like does not occur, and if the energy density is high or the irradiation time is long, the transfer light is transmitted through the separation layer 2 and the intermediate layer 3. 4 may be adversely affected.

Irradiation light 7 represented by such a laser light
Is preferably applied so that its intensity becomes uniform.

The irradiation direction of the irradiation light 7 is not limited to the direction perpendicular to the separation layer 2 but may be a direction inclined at a predetermined angle with respect to the separation layer 2.

When the area of the separation layer 2 is larger than the irradiation area of one irradiation light, the whole area of the separation layer 2 is
Irradiation light can be irradiated in a plurality of times. Also,
The same location may be irradiated more than once.

In addition, different types and different wavelengths (wavelength ranges)
Irradiation light (laser light) in the same area or a different area
Irradiation may be performed more than once.

[6] As shown in FIG. 8, the separation layer 2 adhering to the intermediate layer 3 is removed by a method such as cleaning, etching, ashing, polishing or a combination thereof.

In the case of separation within the separation layer 2 as shown in FIG. 6, the separation layer 2 adhering to the substrate 1 is also removed.

If the substrate 1 is made of an expensive or rare material such as quartz glass, the substrate 1
Is preferably subjected to reuse. In other words, the present invention can be applied to the substrate 1 to be reused, and is highly useful.

Through the above steps, the transfer of the transferred layer 4 to the transfer member 6 is completed. Thereafter, removal of the intermediate layer 3 adjacent to the layer to be transferred 4 or formation of another arbitrary layer can also be performed.

In the present invention, the transfer target layer 4 itself, which is the transfer target layer 4, is not directly peeled but is separated at the separation layer 2 joined to the transfer target layer 4, so that the transfer target layer (transfer target layer 4) Irrespective of the characteristics, conditions, etc., the transfer (transfer) can be easily and surely and uniformly performed, and there is no damage to the transfer target layer (transfer target layer 4) due to the peeling operation. High reliability can be maintained.

In the illustrated embodiment, the method of transferring the transfer-receiving layer 4 to the transfer body 6 has been described. However, the transfer method of the present invention may not perform such transfer. In this case, an object to be peeled is used instead of the above-mentioned layer to be transferred 4. The object to be peeled may be either a layered material or a material that does not constitute a layer.

The object to be peeled is, for example, removal (trimming) of an unnecessary portion of the thin film (particularly a functional thin film) as described above, dust, oxide, heavy metal, carbon, and other impurities. Any method may be used, such as removal of extraneous matter and recycling of substrates and the like using the same.

The transfer member 6 is not limited to the above-described material, and may be a material having completely different properties from the substrate 1 (with or without translucency), such as various metallic materials, ceramics, carbon, paper, rubber, and the like. ) May be used. In particular, when the transfer body 6 is a material that cannot directly form the transfer-receiving layer 4 or is not suitable for forming the transfer-receiving layer 4, the application of the present invention is highly valuable.

In the illustrated embodiment, the irradiation light 7 is irradiated from the substrate 1 side. However, for example, when the adhered matter (object to be peeled) is removed, or when the transfer layer 4 is irradiated with the irradiation light 7, the irradiation light 7 is adversely affected. In the case of not receiving the light, the irradiation direction of the irradiation light 7 is not limited to the above, and the irradiation light may be irradiated from the side opposite to the substrate 1.

Although the peeling method of the present invention has been described with reference to the illustrated embodiment, the present invention is not limited to this.

For example, the transfer layer 4 may be peeled or transferred in the aforementioned pattern by irradiating the irradiation light partially in the plane direction of the separation layer 2, that is, in a predetermined pattern. First method). In this case, in the step [5], the irradiation light incident surface 12 of the substrate 1 is subjected to masking corresponding to the pattern and irradiated with the irradiation light 7, or the irradiation position of the irradiation light 7 is changed. It can be performed by a method such as precise control.

The separation layer 2 is formed on the separation layer forming surface 1 of the substrate 1.
Instead of forming on the entire surface, the separation layer 2 can be formed in a predetermined pattern (second method). in this case,
A method in which the separation layer 2 is formed in a predetermined pattern by masking or the like in advance, or a method in which the separation layer 2 is formed on the entire surface of the separation layer formation surface 11 and then patterned or trimmed by etching or the like is possible.

According to the first and second methods as described above, the transfer of the transferred layer 4 can be performed together with the patterning and trimming.

Further, by the same method as described above,
The transfer may be repeated two or more times. In this case, if the number of transfers is an even number, the positional relationship between the front and back of the transfer layer formed on the last transfer body should be the same as the state where the transfer layer was first formed on the substrate 1. it can.

A large transparent substrate (for example, an effective area of 900 mm × 1600 mm) is used as the transfer body 6, and a small unit transfer layer 4 (for example, an effective area of 45 mm × 40 mm) is formed on a small substrate 1 (for example, 45 mm × 40 mm). Thin film transistor) a plurality of times (for example, about 800 times), preferably successively to adjacent positions,
Forming the transferred layer 4 over the entire effective area of the large transparent substrate,
Finally, a liquid crystal display having the same size as the large transparent substrate can be manufactured.

[0123]

Next, specific examples of the present invention will be described.

(Example 1) A quartz substrate having a length of 50 mm x a width of 50 mm x a thickness of 1.1 mm (softening point: 1630 ° C, strain point: 10
70 ° C., transmittance of excimer laser: almost 100%), and an amorphous silicon (a-Si) film as a separation layer (laser light absorption layer) is formed on one side of this quartz substrate by low pressure CVD.
It was formed by a method (Si2 H6 gas, 425 DEG C.). The thickness of the separation layer was 100 nm.

Next, on the separation layer, SiO2 was used as an intermediate layer.
The film is formed by ECR-CVD (SiH4 + O2 gas, 100
C). The thickness of the intermediate layer was 200 nm.

Next, on the intermediate layer, a layer having a thickness of 5
A 0 nm amorphous silicon film is formed by a low pressure CVD method (Si2 H6 gas, 425 DEG C.), and the amorphous silicon film is irradiated with a laser beam (wavelength: 308 nm) to be crystallized to form a polysilicon film. . Thereafter, the polysilicon film was subjected to predetermined patterning to form a region serving as a source, a drain, and a channel of the thin film transistor. Thereafter, the surface of the polysilicon film is thermally oxidized at a high temperature of 1000 ° C. or more to form a gate insulating film SiO2, and then a gate electrode (a high melting point metal such as Mo is laminated on the polysilicon is formed on the gate insulating film). Structure), and ion implantation using the gate electrode as a mask to form source / drain regions in a self-aligned manner (self-alignment), thereby forming a thin film transistor. Thereafter, if necessary, electrodes and wirings connected to the source / drain regions,
A wiring connected to the gate electrode is formed. Although Al is used for these electrodes and wirings, the present invention is not limited to this. Further, when there is a concern about melting of Al due to laser irradiation in a later step, a metal having a higher melting point than Al (a metal not melted by laser irradiation in a later step) may be used.

Next, an ultraviolet curable adhesive was applied on the thin film transistor (film thickness: 100 μm), and a large-sized 200 mm × 300 mm × 1.1 mm thick transfer member was applied to the coating film. Transparent glass substrate (soda glass,
(Softening point: 740 ° C., strain point: 511 ° C.), and then the adhesive was cured by irradiating ultraviolet rays from the glass substrate side, and these were bonded and fixed.

Next, a Xe-Cl excimer laser (wavelength:
308 nm) from the quartz substrate side to cause peeling (intralayer peeling and interfacial peeling) of the separation layer. Irradiated Xe-
The energy density of Cl excimer laser is 250mJ / cm
2. The irradiation time was 20 nsec. Excimer laser irradiation includes spot beam irradiation and line beam irradiation. In the case of spot beam irradiation, spot irradiation is performed on a predetermined unit area (for example, 8 mm × 8 mm), and this spot irradiation is performed 1/1 of the unit area. Irradiation is performed while shifting by about 10 steps. In the case of line beam irradiation, a predetermined unit area (for example, 378 mm × 0.1 mm or 378 mm × 0.3
mm (these are regions where 90% or more of energy can be obtained) are similarly shifted by about 1/10. Thereby, each point of the separation layer receives at least 10 irradiations. This laser irradiation is performed while shifting the irradiation area over the entire surface of the quartz substrate.

Thereafter, a quartz substrate and a glass substrate (transfer body)
Were peeled off at the separation layer, and the thin film transistor and the intermediate layer formed on the quartz substrate were transferred to the glass substrate side.

Thereafter, the separation layer adhered to the surface of the intermediate layer on the glass substrate side was removed by etching, washing or a combination thereof. The same processing was performed on the quartz substrate, and the quartz substrate was reused.

If the glass substrate serving as the transfer body is a substrate larger than the quartz substrate, the transfer from the quartz substrate to the glass substrate as in this embodiment is repeatedly performed on different areas in a plane, and Further, more thin film transistors than the number of thin film transistors that can be formed over the quartz substrate can be formed. Further, the thin film transistor can be repeatedly stacked over a glass substrate to form more thin film transistors.

(Example 2) The separation layer was formed by adding H (hydrogen) to 20
A thin film transistor was transferred in the same manner as in Example 1 except that the amorphous silicon film contained at%.

The adjustment of the amount of H in the amorphous silicon film was carried out by appropriately setting the conditions at the time of film formation by the low-pressure CVD method.

Example 3 A ceramic thin film (composition: P) in which a separation layer was formed by a sol-gel method by spin coating.
A thin film transistor was transferred in the same manner as in Example 1 except that bTiO3 (thickness: 200 nm) was used.

(Example 4) A ceramic thin film (composition: BaTiO3,
Except that the film thickness was 400 nm).
The transfer of the thin film transistor was performed.

Example 5 A ceramic thin film (composition: Pb) in which a separation layer was formed by a laser ablation method
The transfer of the thin film transistor was performed in the same manner as in Example 1 except that (Zr, Ti) O3 (PZT), film thickness: 50 nm).

Example 6 A thin film transistor was transferred in the same manner as in Example 1 except that the separation layer was a polyimide film (thickness: 200 nm) formed by spin coating.

(Example 7) A polyphenylene sulfide film (film thickness: 20) formed by spin coating the separation layer was used.
The transfer of the thin film transistor was performed in the same manner as in Example 1 except that the thickness was set to 0 nm).

Example 8 A thin film transistor was transferred in the same manner as in Example 1 except that the separation layer was an Al layer (thickness: 300 nm) formed by sputtering.

Example 9 Example 2 was repeated except that a Kr-F excimer laser (wavelength: 248 nm) was used as the irradiation light.
The transfer of the thin film transistor was performed in the same manner as described above. The energy density of the irradiated laser was 250 mJ / cm
2. The irradiation time was 20 nsec.

Example 10 Nd-YA was used as the irradiation light.
The transfer of the thin film transistor was performed in the same manner as in Example 2 except that an IG laser (wavelength: 1068 nm) was used. The energy density of the irradiated laser was 400 mJ / cm
2. The irradiation time was 20 nsec.

Embodiment 11 As a layer to be transferred, a polysilicon film (thickness: 80 nm) formed by a high-temperature process at 1000 ° C.
The transfer of the thin film transistor was performed in the same manner as in Example 1 except that the thin film transistor was used.

Example 12 A thin film transistor was transferred in the same manner as in Example 1 except that a transparent substrate made of polycarbonate (glass transition point: 130 ° C.) was used as a transfer body.

Example 13 A thin film transistor was transferred in the same manner as in Example 2 except that a transparent substrate made of an AS resin (glass transition point: 70 to 90 ° C.) was used as a transfer body.

Example 14 A thin film transistor was transferred in the same manner as in Example 3 except that a transparent substrate made of polymethyl methacrylate (glass transition point: 70 to 90 ° C.) was used as a transfer body.

Example 15 A thin film transistor was transferred in the same manner as in Example 5, except that a transparent substrate made of polyethylene terephthalate (glass transition point: 67 ° C.) was used as a transfer body.

Example 16 A thin film transistor was transferred in the same manner as in Example 6, except that a transparent substrate made of high-density polyethylene (glass transition point: 77 to 90 ° C.) was used as a transfer body.

Example 17 A thin film transistor was transferred in the same manner as in Example 9 except that a transparent substrate made of polyamide (glass transition point: 145 ° C.) was used as a transfer body.

Example 18 A thin film transistor was transferred in the same manner as in Example 10, except that a transparent substrate made of an epoxy resin (glass transition point: 120 ° C.) was used as a transfer body.

Example 19 A thin film transistor was transferred in the same manner as in Example 11 except that a transparent substrate made of polymethyl methacrylate (glass transition point: 70 to 90 ° C.) was used as a transfer body.

In each of Examples 1 to 19, when the state of the transferred thin film transistor was visually observed with the naked eye and a microscope, it was found that there was no defect or unevenness and the transfer was uniform.

[0152]

As described above, according to the peeling method of the present invention, the peeling can be easily and reliably performed regardless of the properties and conditions of the object (layer to be transferred). It is possible to transfer to various transfer bodies regardless of the body. For example, even when a thin film cannot be directly formed or is not suitable for forming, a material that is easily formed, a material formed of an inexpensive material, or a large object that is difficult to move, it is transferred. To form it.

In particular, as the transfer body, materials such as various synthetic resins and a glass material having a low melting point, which are inferior in heat resistance, corrosion resistance and the like as compared with the substrate material, can be used. Therefore, for example, when manufacturing a liquid crystal display in which a thin film transistor (especially a polysilicon TFT) is formed on a transparent substrate, a quartz glass substrate having excellent heat resistance is used as a substrate, and various synthetic resins and low melting points are used as a transfer body. By using a transparent substrate made of an inexpensive and easy-to-process material such as a glass material, a large and inexpensive liquid crystal display can be easily manufactured. Such advantages are not limited to the liquid crystal display, but are the same in the manufacture of other devices.

While enjoying the above advantages,
A transferable layer such as a functional thin film can be formed and patterned on a highly reliable substrate, especially a substrate with high heat resistance such as a quartz glass substrate, regardless of the material characteristics of the transfer body. Thus, a highly reliable functional thin film can be formed on the transfer member.

Although such a highly reliable substrate is expensive, it can be reused, thereby reducing the manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the steps of an embodiment of the peeling method of the present invention.

FIG. 2 is a cross-sectional view showing the steps of an embodiment of the peeling method of the present invention.

FIG. 3 is a cross-sectional view showing the steps of an example of the peeling method of the present invention.

FIG. 4 is a cross-sectional view showing the steps of an embodiment of the peeling method of the present invention.

FIG. 5 is a cross-sectional view showing the steps of an embodiment of the peeling method of the present invention.

FIG. 6 is a cross-sectional view showing a step of an embodiment of the peeling method of the present invention.

FIG. 7 is a cross-sectional view showing a step of an embodiment of the peeling method of the present invention.

FIG. 8 is a cross-sectional view showing the steps of an example of the peeling method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 11 Separation layer formation surface 12 Irradiation light incidence surface 2 Separation layer 2a, 2b interface 3 Intermediate layer 4 Transfer receiving layer 5 Adhesive layer 6 Transfer body 7 Irradiation light

Claims (25)

[Claims] 1. A separation method for separating an object to be separated, which is present on a substrate via a separation layer, from the substrate, wherein the separation layer is irradiated with irradiation light to emit light in the separation layer and / or within the separation layer. A peeling method, wherein peeling occurs at an interface, and the object to be peeled is separated from the substrate. 2. A separation method for separating an object to be separated present on a light-transmitting substrate via a separation layer from the substrate, wherein the separation layer is irradiated with irradiation light from the substrate side. A separation method in which separation is caused in a layer and / or an interface of the separation layer, and the object to be separated is separated from the substrate. 3. A method for peeling a transfer layer formed on a substrate via a separation layer from the substrate and transferring the transfer layer to another transfer body, wherein the transfer layer is provided on a side of the transfer layer opposite to the substrate. After bonding the transfer member, the separation layer is irradiated with irradiation light to cause separation in the layer and / or interface of the separation layer, and the transfer target layer is separated from the substrate and transferred to the transfer member. A peeling method. 4. A method of peeling a transfer layer formed on a light-transmitting substrate via a separation layer from the substrate and transferring the transfer layer to another transfer body, wherein the transfer layer and the substrate of the transfer layer are After joining the transfer body to the opposite side, the separation layer is irradiated with irradiation light from the substrate side to cause peeling in the layer and / or interface of the separation layer, and the transferred layer is removed from the substrate. A peeling method, comprising separating and transferring to the transfer body. 5. A step of forming a separation layer on a light-transmitting substrate; a step of forming a transfer layer on the separation layer directly or via a predetermined intermediate layer; Bonding the transfer body to the opposite side of the substrate, irradiating the separation layer with irradiation light from the substrate side to cause peeling in the separation layer and / or at the interface, and to transfer the transfer target layer to the substrate. Separating from the transfer member and transferring to the transfer member. 6. After transferring the transfer-receiving layer to the transfer body,
The stripping method according to claim 5, further comprising a step of removing the separation layer attached to the substrate side and / or the transfer body side. 7. The peeling method according to claim 3, wherein the transferred layer is a functional thin film or a thin film device. 8. The method according to claim 3, wherein the transferred layer is a thin film transistor. 9. The transfer member according to claim 3, wherein the transfer member is a transparent substrate.
9. The peeling method according to any one of items 1 to 8. 10. The transfer member is made of a material having a glass transition point (Tg) or a softening point equal to or lower than Tmax, where Tmax is a maximum temperature at the time of forming a layer to be transferred. The stripping method according to any one of the above. 11. The transfer body has a glass transition point (Tg).
The peeling method according to any one of claims 3 to 10, wherein the peeling method is made of a material having a softening point of 800 ° C or lower. 12. The method according to claim 3, wherein the transfer body is made of a synthetic resin or a glass material. 13. The peeling method according to claim 1, wherein the substrate has heat resistance. 14. The peeling method according to claim 3, wherein the substrate is made of a material having a strain point equal to or higher than Tmax when a maximum temperature at the time of forming the transferred layer is Tmax. . 15. The peeling method according to claim 1, wherein the peeling of the separation layer is caused by a loss or a decrease in a bonding force between atoms or molecules of a substance constituting the separation layer. 16. The peeling method according to claim 1, wherein the irradiation light is a laser light. 17. The wavelength of the laser light is 100 to 35.
17. The method according to claim 16, wherein the thickness is 0 nm. 18. The wavelength of the laser light is 350 to 12
17. The peeling method according to claim 16, wherein the thickness is 00 nm. 19. The method according to claim 1, wherein the separation layer is made of amorphous silicon. 20. The stripping method according to claim 19, wherein the amorphous silicon contains H (hydrogen) at 2 at% or more. 21. The peeling method according to claim 1, wherein the separation layer is made of a ceramic. 22. The peeling method according to claim 1, wherein the separation layer is made of a metal. 23. The peeling method according to claim 1, wherein the separation layer is made of an organic polymer material. 24. The organic polymer material is —CH 2 —,
-CO-, -CONH-, -NH-, -COO-, -N
24. The peeling method according to claim 23, wherein the peeling method has at least one kind of bond of = N- and -CH = N-. 25. The organic polymer material having an aromatic hydrocarbon in a constitutional formula.
4. The peeling method according to 1.