JP2002184959A - Transfer method of functional device and functional panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer method of a functional device which can select a substrate for forming the functional device and a substrate used when the functional device is applied to an actual product individually and to provide a functional panel. SOLUTION: A barrier layer 2 made of tantalum oxide and a functional device layer 3 made of TFT are formed on a glass substrate 1 to form a functional device substrate. The surface of the functional device layer 3 is coated with a resin by spin-coating, and then the resin is cured to form a protective layer 4. The glass substrate 1 is etched from its rear surface with an etchant comprising a solution of fluoric acid to remove the glass substrate 1 and a thin layer functional device substrate comprising the barrier layer 2 and the functional device layer 3 is obtained. A transfer element 6 made of organic polymer is bonded to the barrier layer 2 of the thin layer functional device substrate with an adhesive layer 5 and the functional device layer 3 is transferred from the glass substrate 1 to the transfer element 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for transferring a functional element such as a thin film transistor (TFT) to a substrate such as an organic polymer and a functional panel manufactured using the method.

[0002]

2. Description of the Related Art When manufacturing a liquid crystal display or the like using a TFT as a functional element, a CVD (Chemical Vapor
A TFT is formed on a transparent substrate such as glass by a Deposition method or the like. Since a process of forming a TFT on a substrate involves high-temperature treatment, a material having a high softening point and a high melting point and having excellent heat resistance needs to be used for the substrate. Therefore, a heat-resistant glass having a heat resistance of about 500 ° C. is currently used as the substrate.

[0003]

As described above, the substrate on which the functional element is formed is one that satisfies the conditions for manufacturing the functional element substrate. However, a substrate suitable for forming a functional element may not necessarily have effective characteristics after commercialization.

[0004] For example, a glass substrate is a functional element T
Although it is a substrate suitable for manufacturing a liquid crystal display using FT, a glass substrate is heavy, is easily broken, and is susceptible to deformation. Liquid crystal displays used in portable electronic devices such as mobile phones and portable terminals, for which demand is rapidly increasing, require substrates that are inexpensive, light, resistant to deformation, and not damaged by falling. However, such a substrate has problems that it does not have the heat resistance required in the manufacturing process and that the substrate is greatly warped during transportation. That is, there is a gap between the characteristics required for the substrate from the manufacturing conditions and the characteristics required for the substrate after commercialization, and it is extremely difficult to select a substrate that satisfies both conditions and characteristics simultaneously.

In order to solve this problem, Japanese Patent Laid-Open Publication No. 10-1
In the method of transferring a thin film element described in Japanese Patent No. 25931, a separation layer is formed between a thin film element that is a functional element and a substrate used during manufacturing, and a laser beam is irradiated from the substrate side to cause separation in the separation layer. By peeling off from a substrate used in manufacturing a thin film element and transferring it to a substrate used in a product, it is possible to select a substrate used in manufacturing and in a product. However, when the thin film element and the substrate are separated from each other by absorbing the laser beam into the separation layer as described above, there is a problem that the thin film element is heated by the heat generated in the separation layer, and the performance of the element is reduced. Occurs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for transferring a functional element, which makes it possible to individually select a substrate on which the functional element is formed and a substrate to be used as a product without deteriorating the performance of the functional element. And to provide a functional panel.

[0007]

According to the present invention, there is provided a substrate forming step of forming a functional element substrate by forming a functional element on a surface of a substrate, and reducing or removing a thickness of the substrate from a back surface of the substrate. A method of transferring a functional element, comprising: a thinning step of thinning a functional element substrate; and a transfer step of transferring the thinned functional element substrate to a transfer body.

According to the present invention, the functional element substrate is thinned by reducing or removing the thickness of the substrate from the back surface of the substrate, and the thinned functional element substrate is transferred to a transfer body.
It is possible to individually select a substrate on which a functional element is formed and a substrate used when used as a product without deteriorating the performance of the functional element. As a result, a functional element can be formed on a substrate requiring a temperature limit by a high-temperature process with good characteristics, and a free functional element substrate can be formed.

Further, the present invention is characterized in that a protective layer for protecting the functional element is formed on the surface of the functional element.

According to the present invention, since the protective layer for protecting the functional element is formed on the surface of the functional element in the thinning step, it is possible to prevent the functional element from being damaged when the substrate is thinned. it can.

Further, the present invention provides a substrate forming step of forming a functional element on at least one surface of two substrates to form a first substrate and a second substrate; A panel forming step of bonding a substrate and a second substrate to form a panel, and reducing or removing a thickness of the substrate from both sides of the panel to form a first substrate and a second substrate.
A method for transferring a functional element, comprising: a thinning step of thinning a substrate; and a transferring step of transferring the thinned first substrate and second substrate to a transfer body.

According to the present invention, a panel is formed by bonding a first substrate and a second substrate such that a functional element is on the inside, and the thickness of the substrate is reduced or removed from both sides of the panel to form a thin layer. Since the first substrate and the second substrate are transferred to the transfer member, the substrate can be thinned without protecting the surface of the functional element, and the process can be simplified.

Further, the present invention is characterized in that, in the transfer step, a transfer body is transferred to one substrate, and the other substrate is coated.

According to the present invention, in the transfer step, the transfer body is transferred to one substrate and the other substrate is coated, so that the panel can be thinned.

Further, the present invention is characterized in that a barrier layer for protecting the functional element is formed between the functional element and the substrate.

According to the present invention, since the barrier layer for protecting the functional element is formed between the functional element and the substrate in the thinning step, the substrate can be removed without damaging the functional element. The functional element substrate after transfer can be reduced in weight.

Further, the present invention is characterized in that the barrier layer is made of a metal oxide. According to the present invention, since the barrier layer is made of a metal oxide, the barrier layer has high resistance when the substrate is thinned, and can prevent the functional element from being damaged.

Further, the present invention is characterized in that the substrate is made of glass. According to the present invention, since the substrate is made of glass, a part of the glass substrate can be left by controlling the conditions for thinning, and the substrate can be thinned without forming a barrier layer. .

Further, the present invention is characterized in that the transfer member is made of an organic polymer. According to the present invention, since the transfer body is made of an organic polymer, the functional element substrate becomes flexible, and various applications are possible.

The present invention also provides a functional panel manufactured by using the method for transferring a functional element according to any one of claims 1 to 8.

According to the present invention, since the functional panel is manufactured by using the above-described method for transferring a functional element, functional panels having various functions can be easily obtained.

[0022]

Embodiments of a functional panel according to the present invention will be described below with reference to the drawings.

FIG. 1 is a process chart of a method for transferring a functional element according to a first embodiment of the present invention. First, a tantalum thin film (thickness: 2000 Å) is formed on a glass substrate 1 by a sputtering method. This tantalum is anodized in an aqueous solution of ammonium tartrate to form tantalum oxide, thereby forming a barrier layer (thickness: 300 °). A gate electrode wiring (thickness 1800 Å) and a gate insulating layer (thickness 300 形成) are formed thereon, and an amorphous silicon semiconductor layer (thickness 500 Å).
Formation, aluminum source electrode wiring (thickness 300)
0Å) The formation is sequentially performed to form a functional element layer 3 composed of a TFT to form a functional element substrate (a). In addition, as the barrier layer 2, other than tantalum, for example, an oxide of a metal such as titanium and tungsten may be used, a plurality of layers may be used, or a combination of a plurality of metal oxides may be used.

In order to protect the functional element layer 3 from etching in the thinning step, a resin is spin-coated on the surface of the functional element layer 3 and then cured to form a protective layer 4 (b). Thereafter, etching is performed from the back surface of the glass substrate 1 using an etching solution composed of an aqueous solution of hydrofluoric acid in order to reduce the thickness of the glass substrate 1. Since the barrier layer 2 made of tantalum oxide does not dissolve in the above-described etching solution, the glass substrate 1 is removed, and a thin functional element substrate including the barrier layer 2 and the functional element layer 3 is obtained (c). .

As a method of reducing the thickness of the glass substrate 1, in addition to the above method, a method of mechanically polishing and shaving the substrate, and a method of chemically and mechanically polishing the substrate by using both mechanical polishing and etching. A method of polishing (CMP method), a method of scraping a substrate by blasting, and the like can be applied. Next, after rinsing with pure water and drying, the thinned barrier layer 2 of the functional element substrate and the transfer body 6 made of an organic polymer are adhered via the adhesive layer 5 made of an adhesive resin (d). ). Since the functional element substrate after etching the glass substrate 1 is thin, the functional element substrate is mounted on another glass substrate by electrostatic attraction to form a support, and then transferred to the transfer body 6. Here, polyether sulfone is used as the organic polymer. Finally, the protective layer 4 is removed using a release agent (e). As described above, the functional element layer 3 can be transferred from the glass substrate 1 to the transfer body 6. In this manner, the transfer substrate 7 that is light, resists deformation, and is not easily damaged when dropped can be obtained.

FIG. 2 is a process chart of a method for transferring a functional element according to a second embodiment of the present invention. In the present embodiment, unlike the first embodiment, a functional element layer 3 made of a TFT is formed on a glass substrate 1 without providing a barrier layer 2 (a). Forming a protective layer 4 on the surface of the functional element layer 3 (b), and controlling the etching rate by strictly controlling the temperature, concentration, stirring method and the like of the etching solution;
The glass substrate 1 is uniformly thinned to form a glass thin plate 8 (c). The transfer body 6 made of an organic polymer and the glass thin plate 8 are adhered via the adhesive layer 5, and the protective layer 4 is removed (d). In this manner, the transfer substrate 9 that is light, resists deformation, and is not easily damaged when dropped is obtained.

FIG. 3 is a process chart of a method for transferring a functional element according to a third embodiment of the present invention. First, a tantalum thin film is formed on a glass substrate 1 by a sputtering method.
This tantalum is anodically oxidized to form tantalum oxide and the barrier layer 2 is formed. A gate electrode wiring, a gate insulating layer, an amorphous silicon semiconductor layer, a source electrode wiring, and the like are sequentially formed thereon to form a functional element layer 3 composed of a TFT. Thus, the TFT substrate 1 as the first substrate
0 is obtained. Similarly, a barrier layer 12 is formed, and a color filter layer 13 is formed thereon, thereby obtaining a color filter substrate 20 as a second substrate (a).
The distance between the TFT substrate 10 and the color filter substrate 20 is 5
Plastic beads are sprinkled between the substrates so as to have a thickness of μm, and they are bonded so that the functional element layer 3 and the color filter layer 13 are on the inside. Thereafter, a liquid crystal is injected and sealed to form a liquid crystal layer 25, thereby forming a panel 30 (b). The resin is applied around the panel 30 and then cured to prevent the intrusion of the etchant from around the panel 30. The glass substrates 1 and 11 are etched from both sides of the panel 30 prepared as described above using an etching solution composed of an aqueous solution of hydrofluoric acid. Since tantalum oxide does not dissolve in the etching solution, the glass substrates 1 and 11 are removed to obtain a panel 31 including the barrier layers 2 and 12, the functional element layer 3, the color filter layer 13 and the liquid crystal layer 25 (c).

As a method of reducing the thickness of the glass substrate, in addition to the above-described methods, a method of mechanically polishing and shaving the substrate, and a method of chemically and mechanically polishing the substrate by using both mechanical polishing and etching. A polishing method, a method of scraping a substrate by blasting, and the like can be applied. After rinsing with pure water and drying, the resin applied and cured around the panel is removed using a release agent. Transfer members 6 and 16 made of an organic polymer are attached to the thinned TFT substrate 10 and color filter substrate 20 on both sides of the panel via adhesive layers 5 and 15 made of an adhesive resin. Here, polyether sulfone is used as the organic polymer. As described above, it is possible to obtain the functional panel 32 which is light, resists deformation, and is not easily damaged when dropped.

FIG. 4 is a process chart of a method for transferring a functional element according to a fourth embodiment of the present invention. In the present embodiment, unlike the third embodiment, the barrier layers 2 and 12 are not provided,
The functional element layer 3 made of TFT and the color filter layer 13 are formed on the glass substrates 1 and 11. by this,
The TFT substrate 40 and the color filter substrate 50 as the first and second substrates are obtained (a). TFT substrate 40
Plastic beads are sprayed between the color filter substrate 50 and the functional element layer 3 and the color filter layer 13.
Glue so that is inside. Thereafter, liquid crystal is injected and sealed to form a liquid crystal layer 25, and the panel 6
0 is created (b). The etching rate is controlled by strictly controlling the temperature, concentration, stirring method, and the like of the etching solution, and the thickness of the glass substrates 1 and 11 is reduced uniformly to obtain the thinned panel 61 (c). Panel 61
Transfer members 6 and 16 made of an organic polymer are bonded to both surfaces of the substrate via adhesive layers 5 and 15 made of an adhesive resin (d). As described above, it is possible to obtain the functional panel 62 which is light, resists deformation, and is not easily damaged when dropped.

FIG. 5 is a process chart of a method for transferring a functional element according to a fifth embodiment of the present invention. A tantalum thin film is formed on a substrate 1 made of glass by a sputtering method. This tantalum is anodically oxidized to tantalum oxide to form the barrier layer 2. A gate electrode wiring, a gate insulating layer, a semiconductive layer of amorphous silicon, a source electrode wiring, and the like are sequentially formed thereon to form a functional element layer 3 composed of a TFT. Thus, the TFT substrate 10 is obtained. Similarly, the barrier layer 12 is formed, and the color filter layer 13 is formed thereon. Thus, the color filter substrate 20 is obtained (a). Plastic beads are sprayed between the functional element substrate 10 and the color filter substrate 20 so that the distance between the functional element substrate 10 and the color filter substrate 20 is 5 μm, and the functional element layer 3 and the color filter layer 13 are bonded to each other. Thereafter, a liquid crystal is injected and sealed to form the panel 30 (b). The resin is applied around the panel 30 and then cured to prevent the intrusion of the etchant from around the panel 30. The panel 30 prepared in this way was prepared by etching the glass substrates 1 and 1 using an etching solution comprising an aqueous solution of hydrofluoric acid.
1 is etched. Since tantalum oxide does not dissolve in the etching solution, the glass substrates 1 and 11 are removed to obtain a panel 31 including the barrier layers 2 and 12, the functional element layer 3, the color filter layer 13 and the liquid crystal layer 25 (c).

As a method of reducing the thickness of the glass substrate, in addition to the above method, a method of mechanically polishing and shaving the substrate, and a method of chemically and mechanically polishing the substrate by using both mechanical polishing and etching. A polishing method, a method of scraping a substrate by blasting, and the like can be applied. After rinsing with pure water and drying, the resin applied and cured around the panel 30 is removed using a release agent. Thinned TFT
A transfer body 6 made of an organic polymer is bonded to a substrate 10 via an adhesive layer 5 made of an adhesive resin. Here, polyether sulfone is used as the organic polymer. afterwards,
A resin is coated on the thinned color filter substrate 20 using a spin coater or a slot coater and cured to form a coating layer 35 (d). In this way, a functional panel 33 that is light, resists deformation, and is not easily damaged when dropped can be obtained.

FIG. 6 is a process chart of a method for transferring a functional element according to a sixth embodiment of the present invention. In the present embodiment, the fifth
Unlike the first embodiment, the barrier layers 2 and 12 are not provided, and the functional element layer 3 made of TFT and the color filter layer 13 are formed on the glass substrates 1 and 11. Thereby, the first
Then, a TFT substrate 40 and a color filter substrate 50 as the second substrate are obtained (a). Plastic beads are sprinkled between the TFT substrate 40 and the color filter substrate 50, and bonded so that the functional element layer 3 and the color filter layer 13 are inside. Thereafter, a liquid crystal is injected and sealed to form a liquid crystal layer 25, thereby forming a panel 60 (b). The etching rate depends on the temperature of the etching solution,
Control by strictly controlling the concentration, stirring method, etc.,
By uniformly reducing the thickness of the glass substrates 1 and 11, the panel 61 thinned can be obtained (c). The TFT substrate 10 on which the glass substrate remains and the transfer body 6 are bonded via the adhesive layer 5. Thereafter, the color filter substrate 20 on which the glass substrate remains is coated with a resin using a slot coater, and cured to form a coating layer 35. As described above, it is possible to obtain the functional panel 63 which is light, resists deformation, and is not easily damaged even when dropped.

As described above, according to the method for transferring a functional element of the present invention, it is possible to transfer a functional element to various substrates regardless of a substrate. For example, by transferring a functional element to a substrate on which a functional element cannot be directly formed or is difficult to form, a functional panel having a characteristic which has not been obtained conventionally can be manufactured.

In particular, when manufacturing a liquid crystal panel in which TFTs are formed on a transparent substrate, a functional thin film is formed and processed in advance using a substrate such as heat resistant glass having excellent heat resistance and corrosion resistance. By transferring the TFT layer to a lightweight substrate having excellent impact resistance, a liquid crystal display having both excellent reliability and portability can be easily manufactured. Such advantages are not limited to liquid crystal displays, but can be similarly enjoyed in the manufacture of other flat panel display devices, thin film integrated circuit devices, and the like.

[0035]

As described above, according to the present invention, a substrate for forming a functional element and a substrate for use as a product can be individually selected without deteriorating the performance of the functional element. Become. As a result, the functional element can be transferred to a flexible substrate, and the functional element can be formed by a high-temperature process with good characteristics on a substrate requiring temperature limitation, and a free functional element substrate can be formed. .

According to the present invention, it is possible to prevent the functional element from being damaged when the substrate is thinned.

Further, according to the present invention, it is possible to transfer to a different substrate without protecting the surface of the functional element, and the process can be simplified.

According to the present invention, the thickness of the panel can be reduced. Further, according to the present invention, the substrate can be removed without damaging the functional element, and the weight of the functional element substrate after transfer can be reduced.

According to the present invention, by controlling the conditions for thinning, a part of the glass substrate can be left, and the thickness of the substrate can be reduced without forming a barrier layer.

Further, according to the present invention, the functional element substrate becomes flexible, and various applications are possible.

According to the present invention, a functional panel having various functions can be easily obtained by transferring a functional element.

[Brief description of the drawings]

FIG. 1 is a process chart of a method for transferring a functional element according to a first embodiment of the present invention.

FIG. 2 is a process chart of a method for transferring a functional element according to a second embodiment of the present invention.

FIG. 3 is a process chart of a method for transferring a functional element according to a third embodiment of the present invention.

FIG. 4 is a process chart of a method for transferring a functional element according to a fourth embodiment of the present invention.

FIG. 5 is a process chart of a method for transferring a functional element according to a fifth embodiment of the present invention.

FIG. 6 is a process chart of a method for transferring a functional element according to a sixth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1,11 Glass substrate 2,12 Barrier layer 3 Functional element layer 4 Protective layer 5,15 Adhesive layer 6,16 Transfer body 7,9 Transfer substrate 8 Glass thin plate 13 Color filter layer 10,40 TFT substrate 20,50 Color filter substrate 25 liquid crystal layer 35 coating layer 30, 60 panel 31, 61 thinned panel 32, 33, 62, 63 functional panel

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/336 (72) Inventor Toshio Takemoto 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka (72) Inventor Yasunori Nishimura 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka F-term in Sharp Corporation (reference) 2H092 HA28 JA24 JA34 JA37 KA05 MA07 MA17 NA25 PA01 PA08 5F110 AA17 CC07 DD02 DD12 DD24 GG02 GG15 GG25 HK03 QQ16 5G435 AA17 BB12 EE12 EE33 GG12 KK05

Claims (9)

[Claims] 1. A substrate forming step of forming a functional element substrate by forming a functional element on a surface of a substrate, and reducing or removing a thickness of the substrate from a back surface of the substrate to reduce the thickness of the functional element substrate. A method for transferring a functional element, comprising: a thinning step; and a transfer step of transferring the thinned functional element substrate to a transfer body. 2. The method according to claim 1, wherein a protective layer for protecting the functional element is formed on a surface of the functional element. 3. A substrate forming step of forming a functional element on at least one surface of two substrates to form a first substrate and a second substrate; and a first substrate and a second substrate having the functional element inside. A panel forming step of bonding the two substrates to form a panel; a thinning step of reducing the thickness of the substrate from both sides of the panel to reduce the thickness of the first substrate and the second substrate; Transferring the thinned first and second substrates to a transfer body. 4. The method according to claim 3, wherein, in the transfer step, a transfer body is transferred to one substrate and the other substrate is coated. 5. The method according to claim 1, wherein a barrier layer for protecting the functional element is formed between the functional element and the substrate. 6. The method according to claim 5, wherein the barrier layer is made of a metal oxide. 7. The method according to claim 1, wherein the substrate is made of glass. 8. The method according to claim 1, wherein the transfer body is made of an organic polymer. 9. A functional panel manufactured by using the method for transferring a functional element according to claim 1. Description: