JPH10125931A - Transfer of thin film element, thin film element, thin film integrated circuit device, active materix substrate and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to select a substrate, which is used at the time of the manufacture of a thin film element, and a substrate (a substrate having a desirable nature as seen from the use of a product), which is used at the time of the actual use of a product, for example, independently and freely. SOLUTION: An isolation layer 120 is kept provided on a substrate 100, which is high in reliability and can transmit a laser beam, and a thin film element 140, such as a TFT, is formed on the substrate 1. A laser beam is irradiated from the side of the substrate 100 to the layer 120, whereby a separation is generated in the layer 120. The element 140 is bonded to a transfer material 180 via an adhesiveness layer 160 and the substrate 100 is made to separate from the layer 120. Thereby, a desirable thin film device can be transferred even to any substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for transferring a thin film element, a thin film element, a thin film integrated circuit device, an active matrix substrate, and a liquid crystal display device.

[0002]

2. Description of the Related Art For example, when manufacturing a liquid crystal display using a thin film transistor (TFT), a process of forming a thin film transistor on a substrate by CVD or the like is performed. Since the process of forming a thin film transistor on a substrate involves high-temperature treatment, the substrate needs to be made of a material having excellent heat resistance, that is, a material having a high softening point and a high melting point. Therefore, at present, quartz glass is used as a substrate that can withstand a temperature of about 1000 ° C., and heat-resistant glass is used as a substrate that can withstand a temperature of about 500 ° C.

[0003]

As described above, the substrate on which the thin-film devices are mounted must satisfy the conditions for manufacturing the thin-film devices. That is, the substrate to be used is determined so as to always satisfy the manufacturing conditions of the mounted device.

However, focusing only on the stage after a substrate on which a thin film element such as a TFT is mounted, the above-mentioned “substrate” may not always be preferable.

For example, as described above, when a manufacturing process involving a high-temperature treatment is performed, a quartz substrate, a heat-resistant glass substrate, or the like is used. However, these are very expensive, and therefore increase the product price.

[0006] Further, the glass substrate is heavy and easily broken. Liquid crystal displays used in portable electronic devices such as palmtop computers and mobile phones are as inexpensive, light and resistant to slight deformation as possible.
It is desirable that it is hard to break when dropped, but in reality,
Glass substrates are usually heavy, vulnerable to deformation, and can be broken by falling.

[0007] That is, there is a groove between the constraint caused by the manufacturing conditions and the preferable characteristics required for the product, and it has been extremely difficult to satisfy both conditions and characteristics.

The present invention has been made in view of such problems, and one of its objects is to provide a substrate used in manufacturing a thin film element and a substrate used in actual use of a product (for example, a product used in a product). It is an object of the present invention to provide a novel technique that allows independent selection of a substrate having a preferable property from the viewpoint of use.

[0009]

The present invention for solving the above-mentioned problems has the following configuration.

(1) The present invention according to claim 1 is a method for transferring a thin film element on a substrate to a transfer member, wherein a step of forming a separation layer on the substrate, and a step of forming a thin film on the separation layer Forming a transfer layer including the element, bonding the transfer layer including the thin film element to the transfer body via an adhesive layer, irradiating the separation layer with light, and forming a layer in the separation layer. And / or a step of causing separation at the interface, and a step of separating the substrate from the separation layer.

That is, for example, a separation layer having a characteristic of absorbing light is provided on a substrate having high reliability in device manufacture, and a thin film element such as a TFT is formed on the substrate. Next, although not particularly limited, for example, a thin film element is bonded to a desired transfer body via an adhesive layer, and then the separation layer is irradiated with light, thereby causing a separation phenomenon in the separation layer. The adhesion between the separation layer and the substrate is reduced. Then, a force is applied to the substrate to separate the substrate from the thin film element. As a result, a desired and highly reliable device can be transferred (formed) to any transfer body.
You can do it.

In the present invention, the step of bonding the thin film element (the layer to be transferred including the thin film element) to the transfer body via the adhesive layer and the step of separating the substrate from the thin film element are not limited in the order. , Whichever comes first. However, the thin film element after the substrate is separated (transferred layer including the thin film element)
In the case where there is a problem in the handling of the substrate, it is desirable to first join the thin film element to the transfer body, and then to separate the substrate.

Further, if a material having a flattening action (for example, a thermosetting resin) is used as the adhesive layer used for bonding the thin film element to the transfer member, the surface of the transferred layer including the thin film element can be formed. Even if a slight level difference occurs, the level difference is flattened and can be neglected, so that good joining to the transfer body can be always achieved, which is convenient.

(2) In the present invention described in claim 2, according to claim 1, the substrate is a light-transmitting substrate, and the irradiation of the light on the separation layer is performed on the light-transmitting substrate. Characterized in that it is performed via

For example, when a transparent substrate such as a quartz substrate is used, a highly reliable thin film device can be manufactured, and light can be collectively irradiated from the back surface of the substrate to the entire surface of the separation layer. Efficiency is improved.

(3) The third aspect of the present invention is characterized in that, in the first or second aspect, the method further comprises a step of removing the separation layer adhered to the transfer body.

The unnecessary separation layer is completely removed.

(4) According to a fourth aspect of the present invention, in any one of the first to third aspects, the transfer body is a transparent substrate.

For example, an inexpensive substrate such as a soda glass substrate or a transparent plastic film having flexibility can be used as the transfer member.

(5) The present invention as set forth in claim 5, wherein the transfer member according to any one of claims 1 to 4, wherein the maximum temperature at the time of forming the layer to be transferred is _Tmax . The glass transition point (Tg) or the softening point is made of a material having the above _Tmax or less.

Cannot withstand the maximum temperature during device manufacture,
Inexpensive glass substrates and the like that could not be used conventionally can be used freely.

(6) The present invention according to claim 6, wherein in the transfer member according to any one of claims 1 to 4, the glass transition point (Tg) or the softening point of the transfer member is determined by the process of forming the thin film element. Or less than the maximum temperature.

The upper limit of the glass transition point (Tg) or the softening point is defined.

(7) According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the transfer body is made of a synthetic resin or a glass material.

For example, if a thin film element is transferred to a synthetic resin plate having flexibility (flexibility) such as a plastic film, excellent characteristics that cannot be obtained with a glass substrate having high rigidity can be realized. When the present invention is applied to a liquid crystal display device, a display device that is flexible, light, and resistant to falling is realized.

Further, an inexpensive substrate such as a soda glass substrate can be used as the transfer member. Soda glass substrates are low cost and economically advantageous substrates. The soda glass substrate has a problem that an alkali component is eluted by a heat treatment at the time of manufacturing a TFT, and conventionally, it has been difficult to apply it to an active matrix type liquid crystal display device. However, according to the present invention, since the already completed thin film device is transferred, the problems associated with the heat treatment described above are eliminated. Therefore, in the field of an active matrix type liquid crystal display device, a substrate having a conventional problem such as a soda glass substrate can be used.

(8) The present invention described in claim 8 is characterized in that, in any one of claims 1 to 7, the substrate has heat resistance.

A desired high-temperature treatment can be performed at the time of manufacturing a thin film device, and a highly reliable and high performance thin film device can be manufactured.

(9) In the ninth aspect of the present invention, the substrate according to any one of the first to eighth aspects, wherein the substrate is 310
The substrate is characterized by being a substrate that transmits 10% or more of light of nm.

A light-transmitting substrate capable of supplying light energy that causes ablation in the separation layer is used.

(10) In the present invention according to claim 10, according to any one of claims 1 to 9, when the maximum temperature at the time of forming the layer to be transferred is T _max , T
It is characterized by being composed of a material not less than _max .

A desired high-temperature treatment can be performed at the time of manufacturing a thin film device, and a highly reliable and high performance thin film device can be manufactured.

(11) The present invention described in claim 11 is characterized in that, in any one of claims 1 to 10, the separation layer is made of amorphous silicon.

Amorphous silicon absorbs light, is easily manufactured, and has high practicality.

(12) According to a twelfth aspect of the present invention, in the eleventh aspect, the amorphous silicon contains hydrogen (H) at 2 atomic% or more.

In the case where amorphous silicon containing hydrogen is used, hydrogen is released with light irradiation, thereby generating an internal pressure in the separation layer and having an effect of promoting separation in the separation layer.

(13) According to a thirteenth aspect of the present invention, in the twelfth aspect, the amorphous silicon contains hydrogen (H) in an amount of 10 atomic% or more.

As the hydrogen content increases, the effect of promoting separation in the separation layer becomes more remarkable.

(14) According to a fourteenth aspect of the present invention, in any one of the first to tenth aspects, the isolation layer is made of silicon nitride.

When silicon nitride is used as the separation layer, nitrogen is released with the irradiation of light, thereby promoting separation in the separation layer.

(15) The present invention described in claim 15 is characterized in that, in any one of claims 1 to 10, the separation layer is made of a hydrogen-containing alloy.

When a hydrogen-containing alloy is used as the separation layer, hydrogen is released with the irradiation of light, thereby promoting separation in the separation layer.

(16) The present invention described in claim 16 is characterized in that, in any one of claims 1 to 10, the separation layer is made of a nitrogen-containing metal alloy.

When a nitrogen-containing alloy is used as the separation layer, nitrogen is released with the irradiation of light, thereby promoting separation in the separation layer.

(17) The present invention according to claim 17 provides the following:
11. The method according to claim 1, wherein the separation layer is formed of a multilayer film.

It is apparent that the present invention is not limited to a single-layer film.

(18) The invention according to claim 18 is characterized in that, in claim 17, the multilayer film comprises an amorphous silicon film and a metal film formed thereon.

(19) In the present invention described in claim 19, in any one of claims 1 to 10, the separation layer is made of at least one of ceramics, metal, and organic polymer material. It is characterized by.

[0049] Examples of those that can actually be used as the separation layer are shown together. As the metal, for example, a hydrogen-containing alloy or a nitrogen-containing alloy can be used. In this case, as in the case of amorphous silicon, separation of the separation layer is promoted by release of hydrogen gas or nitrogen gas accompanying light irradiation.

(20) The present invention described in claim 20 is characterized in that, in any one of claims 1 to 19, the light is laser light.

The laser light is coherent light and is suitable for causing separation in the separation layer.

(21) The present invention according to claim 21, wherein the laser beam has a wavelength of 100 n.
m to 350 nm.

By using a laser beam having a short wavelength and light energy, the separation layer can be effectively separated.

As a laser satisfying the above conditions, for example, there is an excimer laser. Excimer laser
A gas laser capable of outputting high-energy laser light in the short-wavelength ultraviolet region, and a rare gas (A
r, Kr, Xe) and a halogen gas (F ₂ , HCl) can be used to output laser beams of four typical wavelengths (XeF =
351 nm, XeCl = 308 nm, KrF = 248 n
m, ArF = 193 nm).

By the irradiation of the excimer laser beam, in the separation layer provided on the substrate, effects such as direct breaking of molecular bonds without heat influence and evaporation of gas can be caused.

(22) In the twentieth aspect, in the twentieth aspect, the wavelength of the laser beam is 350 nm.
〜1200 nm.

In the separation layer, for example, outgassing, vaporization,
When a separation characteristic is given by causing a phase change such as sublimation, a laser beam having a wavelength of about 350 nm to 1200 nm can be used.

(23) The present invention described in claim 23 is characterized in that in any one of claims 1 to 22, the thin film element is a thin film transistor (TFT).

A high-performance TFT can be freely transferred (formed) on a desired transfer member. Therefore, various electronic circuits can be mounted on the transfer body.

(24) According to a twenty-fourth aspect of the present invention, the transfer method according to any one of the first to twenty-third aspects, wherein the transfer method according to the first aspect is performed a plurality of times to make the transfer larger than the substrate. The method is characterized by transferring a plurality of layers to be transferred onto a body.

By repeatedly using a highly reliable substrate, or by transferring a thin film pattern a plurality of times using a plurality of substrates, a large-scale substrate on which a highly reliable thin film element is mounted can be produced.

(25) In the present invention according to claim 25, the transfer method according to any one of claims 1 to 24 is performed a plurality of times to form a thin film on the transfer body. A plurality of layers to be transferred having different levels of element design rules are transferred.

When a plurality of different types of circuits (including functional blocks and the like) are mounted on one substrate, for example, the elements and wiring used for each circuit are determined according to the characteristics required for each circuit. (Design rules, that is, what are called design rules) may be different. Even in such a case, if the transfer is performed for each circuit using the transfer method of the present invention, a plurality of circuits having different design rule levels can be realized on one substrate.

(26) The present invention according to claim 26 is a thin film element which is transferred to the transfer body by using the transfer method according to any one of claims 1 to 22.

A thin-film element formed on an arbitrary substrate by using the thin-film element transfer technique of the present invention (thin-film structure transfer technique).

(27) The invention according to claim 27 is characterized in that in claim 26, the thin film element is a thin film transistor (TFT).

(28) The present invention as set forth in claim 28, wherein a thin film comprising a thin film element transferred to the transfer member by using the transfer method according to any one of claims 1 to 25. An integrated circuit device.

For example, it is also possible to mount a single-chip microcomputer or the like using a thin film transistor (TFT) on a synthetic resin substrate.

(29) The invention according to claim 29, wherein the thin film transistors (TFTs) are arranged in a matrix.
And an active matrix substrate having a pixel portion including a pixel electrode connected to one end of the thin film transistor, wherein the pixel portion is formed using the method according to any one of claims 1 to 24. This is an active matrix substrate manufactured by transferring a thin film transistor.

An active matrix substrate in which a pixel portion is formed on a desired substrate by using the thin film element transfer technology (thin film structure transfer technology) of the present invention. Since a substrate can be freely selected without restrictions imposed by manufacturing conditions, it is also possible to realize a novel active matrix substrate that has not existed conventionally.

(30) According to the present invention, a thin film transistor (TFT) connected to a scanning line and a signal line arranged in a matrix and a pixel electrode connected to one end of the thin film transistor are formed. An active matrix substrate including a pixel portion and including a driver circuit for supplying a signal to the scanning line and the signal line, formed using the method according to claim 25, An active matrix substrate including a thin film transistor of the pixel portion at a first design rule level and a thin film transistor forming the driver circuit at a second design rule level.

This is an active matrix substrate in which not only a pixel portion but also a driver circuit are mounted on the active matrix substrate, and the design rule level of the driver circuit and the design rule level of the pixel portion are different. For example, if the thin film pattern of the driver circuit is formed by using a silicon TFT manufacturing apparatus, the degree of integration can be improved.

(31) The invention according to claim 31 is a liquid crystal display device manufactured using the active matrix substrate according to any one of claims 29 to 30.

For example, a liquid crystal display device using a plastic substrate and having a flexible bending property can be realized.

[0075]

Next, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIGS. 1 to 6 are views for explaining a first embodiment (transfer method of a thin film element) of the present invention.

[Step 1] As shown in FIG. 1, a separation layer (light absorbing layer) 120 is formed on a substrate 100.

Hereinafter, the substrate 100 and the separation layer 120 will be described.

Description of the Substrate 100 It is preferable that the substrate 100 has a light-transmitting property through which light can pass.

In this case, the light transmittance is preferably 10% or more, more preferably 50% or more. If the transmittance is too low, the attenuation (loss) of light increases, and a larger amount of light is required to separate the separation layer 120.

The substrate 100 is preferably made of a highly reliable material, and particularly preferably made of a material having excellent heat resistance. The reason for this is that, for example, when forming a layer to be transferred 140 or an intermediate layer 142 to be described later, the process temperature may be high (for example, about 350 to 1000 ° C.) depending on the type and formation method.
Even in such a case, if the substrate 100 is excellent in heat resistance, the range of setting of film forming conditions such as temperature conditions in forming the transferred layer 140 and the like on the substrate 100 is widened.

Therefore, it is preferable that the substrate 100 be made of a material whose strain point is equal to or higher than Tmax when the maximum temperature at the time of forming the transfer layer 140 is Tmax. Specifically, the constituent material of the substrate 100 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, Corning 7059, and NEC Glass OA-2.

The thickness of the substrate 100 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 100 is too small, the strength is reduced. If the thickness is too large, light is easily attenuated when the transmittance of the substrate 100 is low. When the light transmittance of the substrate 100 is high, the thickness may exceed the upper limit. In order to uniformly irradiate light, the substrate 10
Preferably, the thickness of 0 is uniform.

Description of the Separation Layer 120 The separation layer 120 absorbs the irradiated light and peels off in its layer and / or at the interface (hereinafter, “in-layer peeling”,
"Interfacial separation"), and preferably, the irradiation of light reduces or reduces the bonding force between atoms or molecules of the substance forming the separation layer 120, that is, It is preferable that abrasion occurs to result in delamination and / or interfacial delamination.

Further, in some cases, gas is released from the separation layer 120 by light irradiation, and a separation effect may be exhibited.
That is, there is a case where the component contained in the separation layer 120 is released as a gas, and a case where the separation layer 120 absorbs light and becomes a gas for a moment and the vapor is released to contribute to separation. . Examples of the composition of the separation layer 120 include those described in the following AE.

A. Amorphous silicon (a-Si) This amorphous silicon may contain hydrogen (H). In this case, the content of H is preferably about 2 atomic% or more, and more preferably about 2 to 20 atomic%. As described above, when a predetermined amount of hydrogen (H) is contained, hydrogen is released by light irradiation, and an internal pressure is generated in the separation layer 120, which serves as a force for separating upper and lower thin films. The content of hydrogen (H) in the amorphous silicon is adjusted by appropriately setting film forming conditions, for example, conditions such as gas composition, gas pressure, gas atmosphere, gas flow rate, temperature, substrate temperature, and input power in CVD. be able to.

B. Various oxide ceramics, such as silicon oxide or silicate compound, titanium oxide or titanate compound, zirconium oxide or zirconate compound, lanthanum oxide or lanthanum oxide compound, conductive material (ferroelectric material) or semiconductor. , SiO ₂ , and Si ₃ O _2. Examples of the silicate compound include K ₂ SiO ₃ and L
i ₂ SiO ₃ , CaSiO ₃ , ZrSiO ₄ , Na ₂ SiO ₃
Is mentioned.

As the titanium oxide, TiO, Ti ₂ O ₃ ,
Ti0 _2, and examples of titanate compounds, for _{example, BaTi0 4, BaTiO 3, Ba} 2 Ti 9 O 20, Ba
_{Ti 5 O 11, CaTiO 3,} SrTiO 3, PbTiO 3,
MgTiO ₃ , ZrTiO ₂ , SnTiO ₄ , Al ₂ TiO
₅ , FeTiO ₃ .

Examples of zirconium oxide include ZrO ₂ , and examples of zirconate compounds include BaZrO 2
₃ , ZrSiO ₄ , PbZrO ₃ , MgZrO ₃ , K ₂ Zr
O ₃ is mentioned.

C. PZT, PLZT, PLLZT, PB
C. Ceramics such as ZT or dielectric (ferroelectric) B. Nitride ceramics such as silicon nitride, aluminum nitride, titanium nitride, etc. Organic polymer material As the organic polymer material, -CH-, -CO- (ketone), -CONH- (amide), -NH- (imide),
-COO- (ester), -N = N- (azo), -CH
= N- (shif) or the like (these bonds are broken by irradiation of light), in particular, any material having many of these bonds may be used. Further, the organic polymer material may have an aromatic hydrocarbon (one or more benzene rings or a condensed ring thereof) in the structural formula.

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.

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

The thickness of the separation layer 120 varies depending on the purpose of peeling and various conditions such as the composition of the separation layer 120, the layer structure, the formation method, and the like, but is usually preferably about 1 nm to 20 μm, and preferably about 10 nm to 20 nm. It is more preferably about 2 μm, and further preferably about 40 nm to 1 μm.
If the thickness of the separation layer 120 is too small, the uniformity of the film is impaired, and the separation may be uneven. If the thickness is too large, good separation properties of the separation layer 120 are ensured. In addition, it is necessary to increase the light power (light amount), and it takes time to remove the separation layer 120 later. Note that the thickness of the separation layer 120 is preferably as uniform as possible.

The method for forming the separation layer 120 is not particularly limited, and is appropriately selected according to various conditions such as a film composition and a film thickness.
For example, CVD (MOCVD, low pressure CVD, ECR-
Various vapor deposition methods such as vapor deposition, molecular beam deposition (MB), sputtering, ion plating, PVD, various plating methods such as electroplating, immersion plating (dipping), and electroless plating, and Langmuir. Coating methods such as a projet (LB) method, spin coating, spray coating, and roll coating, various printing methods, a transfer method, an ink jet method, a powder jet method, and the like.
It can also be formed by combining the above.

For example, when the composition of the separation layer 120 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 120 is made of a ceramic 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.

[Step 2] Next, as shown in FIG. 2, a transfer target layer (thin film device layer) 140 is formed on the separation layer 120.

The K portion of this thin film device layer 140 (FIG. 2)
2 is shown on the right side of FIG. 2). As illustrated, the thin-film device layer 140 includes, for example, a SiO ₂ film (intermediate layer) 142.
The TFT includes a TFT (thin film transistor) formed thereon. The TFT includes a source / drain layer 146 formed by introducing an n-type impurity into a polysilicon layer, a channel layer 144, a gate insulating film 148, , Gate electrode 1
50, an interlayer insulating film 154, and an electrode 152 made of, for example, aluminum.

In this embodiment, the SiO ₂ film is used as the intermediate layer provided in contact with the separation layer 120.
Other insulating films such as Si ₃ N ₄ can also be used. The thickness of the SiO ₂ film (intermediate layer) is appropriately determined depending on the purpose of its formation and the degree of the function that can be exhibited, but is usually preferably about 10 nm to 5 μm, more preferably 40 nm to 5 μm.
More preferably, it is about 1 μm. The intermediate layer is formed for various purposes, for example, a protective layer for physically or chemically protecting the transferred layer 140, an insulating layer, a conductive layer, a laser light shielding layer, a barrier layer for preventing migration, and a reflective layer. That exhibit at least one of the functions described above.

In some cases, the transfer layer (thin film device layer) 140 may be formed directly on the separation layer 120 without forming an intermediate layer such as a SiO ₂ film.

The transfer layer 140 (thin film device layer) is a layer including a thin film element such as a TFT as shown on the right side of FIG.

As the thin film element, in addition to the TFT, for example, a thin film diode, a photoelectric conversion element (photo sensor, solar cell) formed of a PIN junction of silicon, a silicon resistance element, other thin film semiconductor devices, and electrodes (for example: ITO,
Actuators such as transparent electrodes such as mesa films), switching elements, memories, piezoelectric elements, etc., micro mirrors (piezo thin film ceramics), magnetic recording thin film heads, coils, inductors, thin magnetic highly permeable materials, and micro magnetic devices combining them , Filters, reflective films,
There are dichroic mirrors and the like.

Such a thin film element (thin film device)
In relation to the forming method, it is usually formed through a relatively high process temperature. Therefore, in this case, as described above, the substrate 100 needs to have a high reliability that can withstand the process temperature.

[Step 3] Next, as shown in FIG. 3, the thin film device layer 140 is transferred to the transfer member 180 via the adhesive layer 160.
Is bonded (adhered) to

Preferable examples of the adhesive forming the adhesive layer 160 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. The adhesive may be of any composition, for example, epoxy, acrylate, or silicone. Such an adhesive layer 160
Is formed by, for example, a coating method.

In the case of using the curable adhesive, for example, a curable adhesive is applied on the layer to be transferred (thin film device layer) 140 and a transfer member 180 is bonded thereon. The curable adhesive is cured by a suitable curing method, and the transfer target layer (thin film device layer) 140 and the transfer body 180 are bonded and fixed.

When the adhesive is of a photo-curing type, light is irradiated from one outside of the light-transmitting substrate 100 or the light-transmitting transfer body 180 (or from both outsides of the light-transmitting substrate and the transfer body). . As the adhesive, a photocurable adhesive, such as an ultraviolet curable adhesive, which hardly affects the thin film device layer is preferable.

It is to be noted that, unlike the drawing, an adhesive layer 160 may be formed on the transfer body 180 side, and a transfer target layer (thin film device layer) 140 may be bonded thereon. For example, the transfer member 18
For example, in the case where 0 itself has an adhesive function, the formation of the adhesive layer 160 may be omitted.

The transfer member 180 is not particularly limited, but includes a substrate (plate material), particularly a transparent substrate. In addition,
Such a substrate may be a flat plate or a curved plate. Further, the transfer member 180 may have inferior properties such as heat resistance and corrosion resistance as compared with the substrate 100. The reason is that in the present invention, the transfer layer (thin film device layer) 140 is formed on the substrate 100 side, and then the transfer layer (thin film device layer) 140 is transferred to the transfer body 180. This is because the properties to be obtained, especially the heat resistance, do not depend on the temperature conditions and the like when the transfer target layer (thin film device layer) 140 is formed.

Accordingly, assuming that the maximum temperature at the time of forming the transfer layer 140 is Tmax, a material having a glass transition point (Tg) or a softening point of Tmax or less can be used as the material of the transfer body 0. For example, the transfer member 180 is
Glass transition point (Tg) or softening point is preferably 800
It can be composed of a material having a temperature of not more than 500C, more preferably not more than 500C, and still more preferably not more than 320C.

The mechanical properties of the transfer member 180 are preferably those having a certain degree of rigidity (strength), but may be those having flexibility and elasticity.

As a constituent material of such a transfer member 180, various synthetic resins or various glass materials can be mentioned, and particularly, various synthetic resins and ordinary (low melting point) inexpensive glass materials are preferable.

The synthetic resin may be either a thermoplastic resin or a thermosetting resin. Examples of the synthetic resin include polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA), and the like.
Cyclic polyolefin, modified polyolefin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polyamideimide, polycarbonate, poly- (4-methylbenten-1), ionomer, acrylic resin, polymethyl methacrylate, acrylic-styrene Polyester, polyether, polyether such as polymer (AS resin), butadiene-styrene copolymer, polio copolymer (EVOH), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and precyclohexane terephthalate (PCT) Ketone (PEK), polyetheretherketone (PEEK), polyetherimide, polyacetal (POM), polyphenylene oxide, modified polyphenylene oxide, polyarylene DOO, aromatic polyester (liquid crystal polymer), polytetrafluoroethylene, polyvinylidene fluoride, other fluorine-based resins, styrene-based,
Various thermoplastic elastomers such as polyolefin, polyvinyl chloride, polyurethane, fluoro rubber, chlorinated polyethylene, etc., ethoxy resin, phenol resin, urea resin, melamine resin, unsaturated polyester, silicone resin, polyurethane, etc., or these And copolymers, blends, polymer alloys and the like, and one or more of these can be used (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 a transfer member 180 made of a synthetic resin is used, a large transfer member 180 can be integrally formed and has a complicated shape such as a member 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, the use of a synthetic resin is advantageous in manufacturing a large and inexpensive device (for example, a liquid crystal display).

The transfer member 180 is, for example, a device constituting 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 member 180 may be a material such as metal, ceramics, stone, wood paper or the like, or may be on any surface constituting a product (on a clock, on an air conditioner, or on a printed circuit board). On the surface of a structure such as a wall, a pillar, a ceiling, or a window glass.

[Step 4] Next, as shown in FIG.
The light is irradiated from the back side of 00.

This light is applied to the separation layer 120 after passing through the substrate 100. As a result, intra-layer peeling and / or interfacial peeling occurs in the separation layer 120, and the bonding force decreases or disappears.

The principle that separation within the separation layer 120 and / or interfacial separation occurs is that ablation occurs in the constituent material of the separation layer 120, that the gas contained in the separation layer 120 is released, and that immediately after the irradiation. It is presumed that this is due to a phase change such as melting and transpiration that occurs during the heating.

Here, ablation means that the fixed material (the constituent material of the separation layer 120) that has absorbed the irradiation light is photochemically or thermally excited, and the surface or internal bonds of atoms or molecules are cut off and released. This phenomenon mainly occurs as a phenomenon in which all or a part of the constituent material of the separation layer 120 undergoes a phase change such as melting and evaporation (vaporization). In addition, the phase change may cause a very small firing state, and the bonding force may be reduced.

Whether the separation layer 120 causes in-layer peeling, interfacial peeling, or both is determined by the separation layer 1
20 and other various factors, and one of the factors is a condition such as a type, a wavelength, an intensity, and a reaching depth of irradiated light.

The light to be irradiated may be any light as long as it causes separation within the separation layer 120 and / or interfacial separation, such as X-ray, ultraviolet light, visible light, infrared light (heat ray), and laser light. , Millimeter wave, microwave,
Electron beam, radiation (α ray, β ray, γ ray) and the like.
Above all, separation (ablation) of the separation layer 120
Laser light is preferable in that the laser light is easily generated.

Examples of a laser device for generating this laser light include various gas lasers and solid-state lasers (semiconductor lasers). Excimer lasers, Nd-YAG lasers, Ar lasers, CO ₂ 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 range, ablation can occur in the separation layer 2 in a very short time, and therefore, almost no temperature rise occurs in the adjacent transfer member 180, substrate 100, or the like. Without causing deterioration, damage,
The separation layer 120 can be peeled.

In the case where the ablation is caused in the separation layer 120, if the wavelength of the light is dependent, it is preferable that the wavelength of the laser light to be applied is about 100 nm to 350 nm.

FIG. 7 shows an example of the transmittance of the substrate 100 with respect to the wavelength of light. As shown in the figure, the transmittance has a characteristic of sharply increasing at a wavelength of 300 nm. In such a case, light having a wavelength of 300 nm or more (for example,
Xe-Cl excimer laser light having a wavelength of 308 nm) is irradiated.

Further, for example, gas release,
When a phase change such as vaporization and sublimation is caused to give separation characteristics, the wavelength of the laser light to be irradiated is from 350 to 1200.
It is preferably about nm.

The energy density of the irradiated laser beam, particularly the energy density of an excimer laser, is as follows:
It is preferably about 10 to 5000 mJ / cm ² ,
More preferably, it is about 100 to 500 mJ / cm ² . The irradiation time is preferably about 1 to 1000 nsec, more preferably 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, irradiation light transmitted through the separation layer 120 adversely affects the transferred layer 140. May cause.

As a countermeasure against the case where the irradiation light transmitted through the separation layer 120 reaches the transfer receiving layer 140 and exerts an adverse effect, for example, as shown in FIG. Metal film 12 such as tantalum (Ta)
4 is formed. As a result, the laser beam transmitted through the separation layer 120 is completely reflected at the interface of the metal film 124, and does not adversely affect the thin film element above it.

It is preferable that the irradiation light typified by the laser light is irradiated so that its intensity becomes uniform. The irradiation direction of the irradiation light is not limited to the direction perpendicular to the separation layer 120,
The direction may be inclined at a predetermined angle with respect to the separation layer 120.

When the area of the separation layer 120 is larger than the irradiation area of one irradiation light, the whole area of the separation layer 120 can be irradiated with the irradiation light in plural times. The same location may be irradiated more than once. Also,
Irradiation light (laser light) of different types and different wavelengths (wavelength ranges) may be irradiated to the same region or different regions twice or more.

Next, as shown in FIG. 5, a force is applied to the substrate 100 to separate the substrate 100 from the separation layer 120. Although not shown in FIG. 5, after the separation, the substrate 100
Separation layers may also adhere on top.

Next, as shown in FIG. 6, the remaining separation layer 120 is subjected to, for example, cleaning, etching, ashing,
It is removed by a method such as polishing or a combination thereof. Thereby, the transferred layer (thin film device layer) 14
0 has been transferred to the transfer member 180.

If a part of the separation layer adheres to the separated substrate 100, it is removed in the same manner. When the substrate 100 is made of an expensive material such as quartz glass or a rare material, the substrate 100 is preferably provided for reuse. That is, the present invention can be applied to the substrate 100 to be reused,
High usefulness.

Through the steps described above, the transfer of the transfer target layer (thin film device layer) 140 to the transfer member 180 is completed. Thereafter, removal of the SiO ₂ film adjacent to the transfer target layer (thin film device layer) 140, formation of a conductive layer such as wiring on the transfer target layer 140, or formation of a desired protective film can also be performed.

In the present invention, the transferred layer (thin film device layer) 140 itself, which is the object to be peeled, is not directly peeled but is separated at the separation layer bonded to the transferred layer (thin film device layer) 140. The object to be peeled (the layer to be transferred 14
0) Irrespective of the characteristics, conditions, etc., the separation (transfer) can be easily and reliably and uniformly performed, and the object to be peeled (the layer to be transferred 140) is not damaged by the peeling operation. The high reliability of 140 can be maintained.

(Second Embodiment) A specific example of a manufacturing process for forming a TFT having a CMOS structure on a substrate and transferring the TFT to a transfer member will be described with reference to FIGS.

(Step 1) As shown in FIG. 8, a separation layer (eg, LPCVD) is formed on a substrate (eg, a quartz substrate) 100.
Amorphous silicon layer formed by the method)) 120
And an intermediate layer (for example, an SiO ₂ film) 142 and an amorphous silicon layer (for example, formed by an LPCVD method) 143 are sequentially laminated, and then a laser beam is applied from above to the entire surface of the amorphous silicon layer 143. Irradiate and anneal. Thereby, the amorphous silicon layer 143 is recrystallized to become a polysilicon layer.

(Step 2) Subsequently, as shown in FIG. 9, the polysilicon layer obtained by the laser annealing is patterned to form islands 144a and 144b.

(Step 3) As shown in FIG. 10, the gate insulating film 148 covering the islands 144a and 144b
a, 148b are formed by, for example, a CVD method.

(Step 4) As shown in FIG. 11, a gate electrode 150 made of polysilicon or metal is used.
a, 150b are formed.

(Step 5) As shown in FIG. 12, a mask layer 170 made of polyimide or the like is formed, and a gate electrode 15 is formed.
Using 0b and the mask layer 170 as a mask, ion implantation of, for example, boron (B) is performed in a self-aligned manner.
Thus, p ⁺ layers 172a and 172b are formed.

(Step 6) As shown in FIG. 13, a mask layer 174 made of polyimide or the like is formed, and a gate electrode 1 is formed.
Using the mask 50a and the mask layer 174 as a mask, ion implantation of, for example, phosphorus (P) is performed in a self-aligned manner.
Thus, n ⁺ layers 146a and 146b are formed.

(Step 7) As shown in FIG. 14, an interlayer insulating film 154 is formed, and after selectively forming a contact hole, electrodes 152a to 152d are formed.

The TFT having the CMOS structure formed as described above corresponds to the layer to be transferred (thin film device layer) 140 in FIGS. Note that a protective film may be formed over the interlayer insulating film 154.

(Step 8) As shown in FIG.
Epoxy resin layer 160 as an adhesive layer on the TFT having the structure
Is formed, and then through the epoxy resin layer 160,
The TFT is attached to a transfer body (for example, a soda glass substrate) 180. Subsequently, heat is applied to cure the epoxy resin, and the transfer body 180 and the TFT are bonded (joined).

Note that the adhesive layer 160 may be a photopolymer resin which is an ultraviolet-curable adhesive. In this case, the polymer is cured by irradiating ultraviolet rays from the transfer body 180 side instead of heat.

(Step 9) As shown in FIG.
For example, Xe-Cl excimer laser light is radiated from the back surface of 0. Thereby, the inside of the separation layer 120 and / or
Alternatively, separation occurs at the interface.

(Step 10) As shown in FIG.
Peel off 00.

(Step 11) Finally, the separation layer 120 is removed by etching. As a result, as shown in FIG. 18, the TFT having the CMOS structure is transferred to the transfer body 180.

(Third Embodiment) When the techniques described in the first and second embodiments are used, for example, a thin film element as shown in FIG. Can be formed on a desired substrate.

In FIG. 19A, a CPU 300, a RAM 320, and an input / output circuit 360, each of which is composed of a thin film element, are provided on a flexible substrate 182 made of plastic or the like, and power supply voltages for these circuits are supplied. A solar cell 340 having an amorphous silicon PIN junction is mounted.

Since the microcomputer shown in FIG. 19A is formed on a flexible substrate, the microcomputer shown in FIG.
As shown in (1), it is resistant to bending, and because it is lightweight, it is resistant to falling.

(Fourth Embodiment) In the present embodiment,
20 and 2 using the above-described thin film device transfer technology.
An example of a manufacturing process for producing an active matrix type liquid crystal display device using an active matrix substrate as shown in FIG.

(Structure of Liquid Crystal Display Device) As shown in FIG. 20, the active matrix type liquid crystal display device has an illumination light source 400 such as a backlight, a polarizing plate 420, an active matrix substrate 440, a liquid crystal 460, a counter substrate 480,
A polarizing plate 500 is provided.

When a flexible substrate such as a plastic film is used for the active matrix substrate 440 and the counter substrate 480 of the present invention, a flexible liquid crystal panel using a reflector instead of the illumination light source 400 can be used. It is possible to realize an active matrix type liquid crystal panel which is strong, shock-resistant and lightweight. When the pixel electrode is formed of metal, the reflector and the polarizing plate 420 are not required.

The active matrix substrate 440 used in the present embodiment is a driver built-in type active matrix substrate in which TFTs are arranged in a pixel portion 442 and a driver circuit (scanning line driver and data line driver) 444 is mounted. is there.

FIG. 21 is a cross-sectional view of a main part of this active matrix type liquid crystal display device, and FIG. 22 is a circuit configuration of a main part of the liquid crystal display device.

As shown in FIG. 22, the pixel portion 442
The liquid crystal 460 includes a TFT (M1) having a gate connected to the gate line G1, one of the source and drain connected to the data line D1, and the other of the source and drain connected to the liquid crystal 460.

The driver section 444 is provided with the T of the pixel section.
TFT formed by the same process as FT (M1)
(M2).

As shown on the left side of FIG.
The TFT (M1) at 42 has a source / drain layer 1
100a, 1100b, a channel 1100e, a gate insulating film 1200a, a gate electrode 1300a, an insulating film 1500, and source / drain electrodes 1400a, 1400.
400b.

Reference numeral 1700 denotes a pixel electrode, and reference numeral 1702 denotes a pixel electrode 1700 corresponding to a liquid crystal 460.
Shows a region where a voltage is applied (region where a voltage is applied to the liquid crystal). In the figure, the alignment film is omitted. The pixel electrode 1700 is made of ITO (in the case of a light transmission type liquid crystal panel) or metal such as aluminum (in the case of a reflection type liquid crystal panel). In FIG. 21, the base insulating film (intermediate layer) 1000 under the pixel electrode 1700 is completely removed in the voltage application region 1702 to the liquid crystal. However, the present invention is not limited to this. If the film (intermediate layer) 1000 is thin and does not hinder voltage application to the liquid crystal, it may be left.

As shown on the right side of FIG. 21, the TFT (M2) constituting the driver section 444 includes a source / drain layer 1100c, 1100d, a channel 1100f, a gate insulating film 1200b, and a gate electrode 1300b. , An insulating film 1500, and source / drain electrodes 1400c and 1400d.

Note that, in FIG.
Is, for example, a counter substrate (for example, a soda glass substrate), and reference numeral 482 is a common electrode. Reference numeral 1000 denotes an SiO ₂ film, reference numeral 1600 denotes an interlayer insulating film (for example, an SiO ₂ film), and reference numeral 18 denotes
00 is an adhesive layer. Reference numeral 1900 denotes a substrate (transfer body) made of, for example, a soda glass substrate.

(Manufacturing Process of Liquid Crystal Display) Hereinafter, the manufacturing process of the liquid crystal display of FIG. 21 will be described with reference to FIGS.
This will be described with reference to FIG.

First, through the same manufacturing process as in FIGS. 8 to 18, TFTs (M1, M2) as shown in FIG. 23 are mounted on a substrate (for example, a quartz substrate) 3000 having high reliability and transmitting a laser beam. To form a protective film 1600. In FIG. 23, reference numeral 3100 denotes a separation layer (laser absorption layer). Also, in FIG.
Both (M1, M2) are n-type MOSFETs.
However, the present invention is not limited to this.
An ET or CMOS structure may be used.

Next, as shown in FIG.
0 and the base insulating film 1000 are selectively etched,
Openings 4000 and 4200 are selectively formed. These two openings are formed simultaneously using a common etching process. In FIG. 24, at the opening 4200,
Although the base insulating film (intermediate layer) 1000 is completely removed, the present invention is not limited to this. If the base insulating film (intermediate layer) 1000 is thin and does not hinder voltage application to the liquid crystal, May be left.

Next, as shown in FIG. 25, a pixel electrode 1700 made of a metal such as an ITO film or aluminum is used.
To form When an ITO film is used, a transmissive liquid crystal panel is used. When a metal such as aluminum is used, a reflective liquid crystal panel is used. Next, as shown in FIG. 26, the substrate 1900 is bonded (bonded) via the bonding layer 1800.

Next, as shown in FIG.
Then, an excimer laser beam is irradiated from the back surface of the substrate, and thereafter, the substrate 3000 is peeled off.

Next, a separation layer (laser absorption layer) 3100
Is removed. Thus, an active matrix substrate 440 as shown in FIG. 27 is completed. Pixel electrode 1700
Is exposed (area indicated by reference numeral 1702), and can be electrically connected to the liquid crystal. Thereafter, an alignment film is formed on the surface of the insulating film (intermediate layer such as SiO ₂ ) 1000 of the active matrix substrate 440 and the surface of the pixel electrode 1702, and the alignment processing is performed. In FIG. 27, the alignment film is omitted.

The pixel electrode 170 is further provided on the surface.
A common electrode opposed to the substrate 9 is formed, and the opposing substrate 480 whose surface is subjected to an alignment treatment and the active matrix substrate 440 of FIG. 21 are sealed with a sealing material (sealant), and liquid crystal is sealed between the two substrates. Thus, a liquid crystal display device as shown in FIG. 21 is completed.

(Fifth Embodiment) FIG. 28 shows a fifth embodiment of the present invention.

In the present embodiment, the above-described method of transferring a thin film device is executed a plurality of times to transfer a plurality of patterns including thin film elements onto a substrate (transfer body) larger than the transfer source substrate. First, a large-scale active matrix substrate is formed.

That is, the transfer is performed a plurality of times on the large substrate 7000 to form the pixel portions 7100a to 7100P. As shown by the dashed line on the upper side of FIG. 28, a TFT and a wiring are formed in the pixel portion. FIG.
8, reference numeral 7210 is a scanning line, reference numeral 7200 is a signal line, reference numeral 7220 is a gate electrode, and reference numeral 7230 is a pixel electrode.

By repeatedly using a highly reliable substrate or performing the transfer of a thin film pattern a plurality of times using a plurality of first substrates, a large-scale active matrix mounting a highly reliable thin film element can be obtained. A substrate can be created.

(Sixth Embodiment) FIG. 29 shows a sixth embodiment of the present invention.

The feature of this embodiment is that the above-described method of transferring a thin film device is executed a plurality of times, and a design rule (that is, a design rule for pattern design) is formed on a substrate larger than the transfer source substrate. Is to transfer a plurality of patterns including different thin film elements (that is, thin film elements having different minimum line widths).

In FIG. 29, in the active matrix substrate on which the driver is mounted, the pixel portions (7100a to 710)
A driver circuit (8000 to 8032) formed by a finer manufacturing process than that of the substrate circuit 6000 is formed around the substrate 6000 by multiple transfers.

Since the shift register constituting the driver circuit operates at a logic level under a low voltage, the withstand voltage may be lower than that of the pixel TFT.
Higher integration can be achieved by making the TFT smaller than T.

According to the present embodiment, a plurality of circuits having different design rule levels (ie, different manufacturing processes) can be realized on one substrate. The sampling means (the thin-film transistor M2 in FIG. 22) for sampling the data signal under the control of the shift register is provided by the pixel TF
Since a high breakdown voltage is required as in the case of T, the pixel TFT is preferably formed by the same process / design rule as the pixel TFT.

[0182]

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

(Example 1) A quartz substrate having a length of 50 mm, a width of 50 mm and 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 (Si ₂ H ₆ gas, 425 ° C.). The thickness of the separation layer was 100 nm.

Next, on the separation layer, SiO ₂ was used as an intermediate layer.
The film is formed by ECR-CVD (SiH ₄ + O ₂ 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 (Si ₂ H ₆ gas, 425 ° C.), and the amorphous silicon film is crystallized by irradiating the amorphous silicon film with laser light (wavelength 308 nm). And 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 SiO ₂ , and then a gate electrode (a high melting point metal such as Mo is laminated on polysilicon to form a gate electrode) on the gate insulating film. Then, ion implantation was performed 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 / c
m ² , and 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 member)
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 prepared 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 amount of H in the amorphous silicon film was adjusted by appropriately setting the conditions at the time of film formation by the low-pressure CVD method.

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

(Example 4) A ceramic thin film (composition: BaTiO ₃ ,
Except that the film thickness was 400 nm).
The transfer of the thin film transistor was performed.

Example 5 A ceramic thin film having a separation layer formed by a laser-ablation method (composition: Pb
The transfer of the thin film transistor was performed in the same manner as in Example 1 except that (Zr, Ti) O ₃ (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 (thickness: 20) formed by spin coating a 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 performed 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 / c
m ² , and 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 / c
m ² , and the irradiation time was 20 nsec.

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

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 all of the transferred thin film transistors were uniformly transferred without any defect or unevenness.

As described above, by using the transfer technique of the present invention, it is possible to transfer a thin film element (transferred layer) to various transfer members. 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 glass materials having a low melting point, which are inferior in properties such as heat resistance and corrosion resistance 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.

[0212] 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.

[0214]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first step in a first embodiment of a method for transferring a thin film element of the present invention.

FIG. 2 is a cross-sectional view showing a second step in the first embodiment of the method for transferring a thin film element of the present invention.

FIG. 3 is a cross-sectional view showing a third step in the first embodiment of the method for transferring a thin film element of the present invention.

FIG. 4 is a cross-sectional view showing a fourth step in the first embodiment of the method for transferring a thin film element of the present invention.

FIG. 5 is a cross-sectional view showing a fifth step in the first embodiment of the method for transferring a thin film element of the present invention.

FIG. 6 is a cross-sectional view showing a sixth step in the first embodiment of the method for transferring a thin film element of the present invention.

FIG. 7 is a diagram showing a change in transmittance of a first substrate (the substrate 100 in FIG. 1) with respect to a wavelength of laser light.

FIG. 8 is a sectional view showing a first step in a second embodiment of the method for transferring a thin film element of the present invention.

FIG. 9 is a cross-sectional view showing a second step in the second embodiment of the method for transferring a thin film element of the present invention.

FIG. 10 is a sectional view showing a third step in the second embodiment of the method for transferring a thin film element of the present invention.

FIG. 11 is a cross-sectional view showing a fourth step in the second embodiment of the method for transferring a thin film element of the present invention.

FIG. 12 is a cross-sectional view showing a fifth step in the second embodiment of the method for transferring a thin film element of the present invention.

FIG. 13 is a sectional view showing a sixth step in the second embodiment of the method for transferring a thin film element of the present invention.

FIG. 14 is a cross-sectional view showing a seventh step in the second embodiment of the method for transferring a thin film element of the present invention.

FIG. 15 is a sectional view showing an eighth step in the second embodiment of the method for transferring a thin film element of the present invention.

FIG. 16 is a sectional view showing a ninth step in the second embodiment of the method for transferring a thin film element of the present invention.

FIG. 17 is a sectional view showing a tenth step in the second embodiment of the method for transferring a thin film element of the present invention.

FIG. 18 is a sectional view showing an eleventh step in the second embodiment of the method for transferring a thin film element of the present invention.

19A and 19B are perspective views of a microcomputer manufactured by using the present invention.

FIG. 20 is a diagram illustrating a configuration of a liquid crystal display device.

FIG. 21 is a diagram showing a cross-sectional structure of a main part of a liquid crystal display device.

FIG. 22 is a diagram illustrating a configuration of a main part of the liquid crystal display device.

FIG. 23 is a cross-sectional view of a device showing a first step in a method for manufacturing an active matrix substrate using the present invention.

FIG. 24 is a cross-sectional view of a device showing a second step in the method of manufacturing an active matrix substrate using the present invention.

FIG. 25 is a cross-sectional view of a device showing a third step in the method for manufacturing an active matrix substrate using the present invention.

FIG. 26 is a cross-sectional view of a device showing a fourth step in the method for manufacturing an active matrix substrate using the present invention.

FIG. 27 is a cross-sectional view of a device showing a fifth step of the method for manufacturing an active matrix substrate using the present invention.

FIG. 28 is a view for explaining another example of the method for transferring a thin film element of the present invention.

FIG. 29 is a view for explaining still another example of the method for transferring a thin film element according to the present invention.

FIG. 30 is a view for explaining a modification of the method for transferring a thin film element of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 substrate 120 amorphous silicon layer (laser absorption layer) 140 thin film device layer 160 adhesive layer 180 transfer body

Claims (31)

[Claims] 1. A method of transferring a thin film element on a substrate to a transfer body, comprising: forming a separation layer on the substrate; and forming a transfer layer including the thin film element on the separation layer. Bonding a transfer-receiving layer including the thin-film element to the transfer body via an adhesive layer; and irradiating the separation layer with light to cause peeling in the separation layer and / or at the interface. Separating the substrate from the separation layer. 2. The thin film element according to claim 1, wherein the substrate is a light-transmitting substrate, and the irradiation of the light to the separation layer is performed through the light-transmitting substrate. Transfer method. 3. The method according to claim 1, further comprising a step of removing the separation layer attached to the transfer body. 4. The method for transferring a thin film element according to claim 1, wherein the transfer body is a transparent substrate. 5. The transfer body according to claim 1, wherein a maximum temperature at the time of forming the layer to be transferred is T _max.
Wherein the glass transition point (Tg) or softening point of the material is equal to or less than the _Tmax . 6. The transfer body according to claim 1, wherein the transfer body has a glass transition point (Tg) or a softening point.
A method for transferring a thin film element, wherein the temperature is lower than or equal to the maximum temperature of the process for forming the thin film element. 7. The method according to claim 1, wherein the transfer member is made of a synthetic resin or a glass material. 8. The method according to claim 1, wherein the substrate has heat resistance. 9. The method for transferring a thin film element according to claim 1, wherein the substrate transmits at least 10% of 310 nm light. 10. The substrate according to claim 1, wherein the substrate is formed of a material whose strain point is _{equal to} or higher than _Tmax when a maximum temperature at the time of forming the transfer-receiving layer is _Tmax . A method for transferring a thin film element, characterized by comprising: 11. The method according to claim 1, wherein the separation layer is made of amorphous silicon. 12. The method according to claim 11, wherein the amorphous silicon contains hydrogen (H) at 2 atomic% or more. 13. The amorphous silicon according to claim 12, wherein the amorphous silicon contains 10 atomic% of hydrogen (H).
A method for transferring a thin-film element, comprising: 14. The method according to claim 1, wherein the separation layer is made of silicon nitride. 15. The method according to claim 1, wherein the separation layer is made of a hydrogen-containing alloy. 16. The method according to claim 1, wherein the separation layer is made of a nitrogen-containing metal alloy. 17. The method according to claim 1, wherein the separation layer is formed of a multilayer film. 18. The method according to claim 17, wherein the multilayer film includes an amorphous silicon film and a metal film formed thereon. 19. The method according to claim 1, wherein the separation layer is made of at least one of a ceramic, a metal, and an organic polymer material. 20. The method according to claim 1, wherein the light is a laser beam. 21. The method according to claim 20, wherein a wavelength of the laser light is 100 nm to 350 nm. 22. The method according to claim 20, wherein the wavelength of the laser beam is 350 nm to 1200 nm. 23. The method according to claim 1, wherein the thin film element is a thin film transistor (TFT). 24. The transfer method according to claim 1, wherein the transfer method according to claim 1 is performed a plurality of times to transfer a plurality of layers to be transferred onto the transfer body that is larger than the substrate. A method of transferring a thin film element. 25. The transfer method according to claim 1, wherein the transfer method according to claim 1 is executed a plurality of times, and a plurality of substrates having different levels of thin film element design rules are formed on the transfer body. A method for transferring a thin film element, comprising transferring a transfer layer. 26. A thin-film element transferred onto the transfer member by using the transfer method according to claim 1. Description: 27. The thin film element according to claim 26, wherein the thin film element is a thin film transistor (TFT). 28. A thin-film integrated circuit device including a thin-film element transferred to the transfer body by using the transfer method according to claim 1. Description: 29. An active matrix substrate comprising a pixel portion including thin-film transistors (TFTs) arranged in a matrix and a pixel electrode connected to one end of the thin-film transistor. 24. An active matrix substrate manufactured by transferring the thin film transistor of the pixel portion using the method according to any one of 24. 30. A pixel portion comprising: a thin film transistor (TFT) connected to a scanning line and a signal line arranged in a matrix; and a pixel electrode connected to one end of the thin film transistor. An active matrix substrate including a driver circuit for supplying a signal to a scanning line and the signal line, the driver circuit including: a pixel circuit of a first design rule level formed by using the method according to claim 25. An active matrix substrate comprising a thin film transistor and a thin film transistor constituting the driver circuit at a second design rule level. 31. A liquid crystal display device manufactured using the active matrix substrate according to claim 29.