JP5581599B2 - Thin film device, manufacturing method thereof, and electro-optical device - Google Patents

Description

  Some embodiments of the present invention relate to a thin film device, a method for manufacturing a thin film device using an inter-substrate transfer technique of the thin film device, and an electro-optical device.

  In electro-optical devices such as liquid crystal display devices (LCD), semiconductor application devices such as electroluminescence (EL) display devices, etc., due to reasons such as prevention of breakage due to deformation and dropping, flexibility, weight reduction, etc. It may be desirable to use a plastic substrate for the underlying substrate. However, in general, since a plastic substrate has low heat resistance against a high temperature process required for manufacturing a semiconductor device, it is difficult to form the semiconductor device on the plastic substrate by a normal semiconductor manufacturing process.

  Conventionally, as a technique for forming a semiconductor device on a plastic substrate, an element forming layer (transfer target layer) in which a thin film semiconductor device is formed on a heat-resistant transfer source substrate and then the thin film semiconductor device is formed from the substrate. ) Is peeled off, and this is attached to a plastic substrate, which is a second transfer substrate, to produce a semiconductor application device. These transfer techniques are described in detail in Patent Document 1, for example.

JP 2006-135051 A

  However, in the above transfer technique, the charge may remain in the release layer or at the interface in the manufacturing process. In addition, even when the charge can be completely removed in the manufacturing process, when the transferred layer is transferred onto the charged second transfer substrate, or when the thin film device after transfer is placed on the charged object, The thin film element may be charged by induction. When a thin film element including a semiconductor film is charged, the performance of the element is remarkably deteriorated due to a change in threshold voltage or a breakdown of a gate insulating film, and the circuit including the thin film element may not operate.

  The present invention can be realized as the following application examples or forms so as to solve at least one of the above problems.

  In the present invention, the term “thin film element” refers to individual resistance wirings, etc. included in the layer to be transferred, and an electric circuit composed thereof, and the term “thin film device” refers to a thin film element, and An assembly including a substrate onto which a thin film element is transferred. The “circuit formation region” refers to a region where an electric circuit including a thin film element is formed in the transferred layer when viewed from the direction perpendicular to the main surface of the substrate.

Application Example 1 A method of manufacturing a thin film device includes a step of forming a first release layer on a transfer source substrate, and a step of forming a transfer layer including a circuit formation region of a thin film element on the first release layer. A step of bonding the transfer layer to the first transfer substrate via a second release layer, a step of peeling the transfer source substrate from the transfer layer , and an adhesive having a conductive portion or conductivity on the bonding surface A step of bonding a second transfer substrate provided with the transfer target layer, a step of peeling the first transfer substrate from the transfer target layer bonded to the second transfer substrate, and the conductive portion or the conductive property. Connecting an adhesive having a reference potential of the thin film element to an electrode terminal for applying a reference potential, and bonding the second transfer substrate to the transferred layer, wherein the surface of the second transfer substrate is the surface Having the conductive part or the conductivity when viewed from the vertical direction Region that overlaps with an adhesive in a plan view includes a circuit forming region of the thin film element therein.

According to the above configuration, the semiconductor device can be formed on a lightweight and flexible substrate such as plastic. Further, in the step of peeling the transfer source substrate and the step of bonding the second transfer substrate, charging of the thin film element or thin film device due to physical peeling or contact can be quickly removed. Further, for example, even when the thin film device is placed in a strong electric field, the electric field can be blocked by the conductive portion or the conductive adhesive, so that the circuit of the thin film device can be stably operated.

[Application Example 2 ] More preferably, the conductive part or the conductive adhesive has a resistivity of 10 ¹⁰ Ωcm or less.

  According to the above configuration, for example, when the thin film device is charged, it can be discharged quickly. Further, even when placed in a strong electric field, the electric field can be cut off, so that the circuit of the thin film device can be operated stably.

Application Example 3 The thin film element described in the application example includes a semiconductor film.

  According to the above configuration, the circuit of the thin film element using a semiconductor can be stably operated.

Application Example 4 A thin film device includes a substrate, a conductive portion or a conductive adhesive formed on the substrate, and a thin film element formed on the conductive portion or the conductive adhesive. A region overlapping with the conductive portion or the conductive adhesive in a plan view when the surface of the substrate is viewed from a direction perpendicular to the surface includes a circuit formation region of the thin film element inside. The conductive portion or the conductive adhesive is connected to an electrode terminal that provides a reference potential of the thin film element .

According to the above configuration, for example, even when a thin film device including a semiconductor film is placed in a strong electric field, the electric field can be blocked by the conductive portion or the conductive adhesive, so that the circuit of the thin film device is stable. Can be operated.

[Application Example 5 ] More preferably, a resistivity of the conductive portion or the conductive adhesive is 10 ¹⁰ Ωcm or less.

According to the above configuration, for example, when the thin film device is charged, it can be discharged quickly. Further, even when placed in a strong electric field, the electric field can be cut off, so that the circuit of the thin film device can be operated stably.

Application Example 6 The thin film element described in the application example includes a semiconductor film.

According to the above configuration, the circuit of the thin film element using a semiconductor can be stably operated.

Application Example 7 The electro-optical device includes the thin film device according to any one of the application examples described above.

  According to the above configuration, it is possible to obtain an electro-optical device that operates stably even when the thin film device is charged or when the thin film device is placed in an environment with a strong external electric field.

  Here, the “electro-optical device” refers to a general device including an electro-optical device that emits light by an electrical action or outputs an external light by changing an input state. In addition to the (electroluminescence) device, a device including a liquid crystal display device, an electrophoresis device, and an electron emission device that emits light by applying electrons generated by application of an electric field to a light emitting plate is also included.

(a)-(d) is manufacturing process sectional drawing of the thin film apparatus in Embodiment 1. FIG. (E)-(f) Manufacturing process sectional drawing of the thin film apparatus in Embodiment 1. FIG. 1 is a schematic cross-sectional view of a thin film device according to Embodiment 1. FIG. (A)-(d) is manufacturing process sectional drawing of the thin film apparatus in Embodiment 2. FIG. (E)-(f) is manufacturing process sectional drawing of the thin film apparatus in Embodiment 2. FIG. FIG. 4 is a schematic cross-sectional view of a thin film device according to Embodiment 2. FIG. 6 is a circuit diagram of an electro-optical device according to a third embodiment. Schematic which shows the electronic device of Embodiment 4. FIG. FIG. 2 is a plan view schematically showing the thin film device according to the first embodiment. FIG. 6 is a plan view illustrating an outline of a thin film device according to a second embodiment.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings. The following embodiments are merely examples of the present invention, and do not limit the scope of the present invention. Each of the embodiments relates to a case where a thin film transistor is manufactured as a thin film element.

(Embodiment 1)
Embodiment 1 relates to a method of manufacturing a thin film device capable of preventing and removing charging of a thin film element. Hereinafter, with reference to FIGS. 1A to 1D, FIGS. 2E to 2F, and FIG. 3, a method of manufacturing the thin film device according to Embodiment 1 will be described. These drawings are schematic views of manufacturing process sectional views. The manufacturing process of Embodiment 1 includes the following processes.
1) A step of forming a first release layer 102 that is peeled off by applying predetermined energy on the transfer source substrate 100 (FIG. 1A).
2) Step of forming the transfer layer 110 including the thin film element T on the first release layer 102 (FIG. 1B)
3) Step of bonding the transfer target layer 110 to the first transfer substrate 116 via the second release layer 114 (FIG. 1C).
4) By irradiating the first peeling layer 102 with laser light to cause peeling at the interface between the first peeling layer 102 and the transferred layer 110, or to cause in-layer peeling of the first peeling layer 102 Step of peeling the transfer source substrate 100 from the transferred layer 110 (FIG. 1D)
5) Step of bonding the second transfer substrate 120 having the conductive portion 121 in place of the peeled transfer source substrate 100 to the transferred layer 110 (FIG. 2E)
6) Step of separating the first transfer substrate 116 (FIG. 2F)

<1: First release layer forming step>
As shown in FIG. 1A, a base layer 104 that is the lowermost layer of the transfer target layer 110 is formed on the transfer source substrate 100 via the first release layer 102.

  As the transfer source substrate 100, a substrate that can sufficiently withstand a high-temperature process for manufacturing a thin film transistor, for example, a translucent heat-resistant substrate such as quartz glass that can withstand about 1000 ° C. can be used. For the transfer source substrate 100, heat resistant glass such as soda glass, Corning 7059, and Nippon Electric Glass OA-10G can be used in addition to quartz glass. The thickness of the transfer source substrate 100 is not used for the final product, and thus there is no large limiting factor, but it is preferably about 0.1 mm to 1.5 mm, more preferably 0.5 mm to 1.5 mm. preferable. If the thickness of the transfer source substrate is too thin, the strength is reduced. Conversely, if the transfer source substrate is too thick, the irradiation light is attenuated when the transmittance of the transfer source substrate is low. However, when the transmittance of the irradiation light of the transfer source substrate is high, the thickness can be increased beyond the upper limit.

  The 1st peeling layer 102 has the characteristic to peel by predetermined energy provision. The property of peeling is a property that causes peeling (also referred to as “in-layer peeling” or “interfacial peeling”) in the layer or interface by irradiation light such as laser light. That is, by irradiating with a certain intensity of light, the interatomic or intermolecular bonding force in the atoms or molecules of the material constituting the first release layer 102 disappears or decreases, and ablation occurs. It causes peeling. In some cases, light irradiation releases gas from the first release layer 102, leading to separation. The case where the component contained in the first release layer 102 is released as a gas and results in separation, and the case where the first release layer 102 absorbs light and becomes a gas, and the vapor is emitted and results in separation. There is.

  As a composition suitable for the first release layer 102 having such characteristics, for example, amorphous (amorphous) silicon (a-Si) can be used. This amorphous silicon may contain hydrogen (H). The hydrogen content is preferably about 2 at% or more, and more preferably 2 to 20 at%. When hydrogen is contained, hydrogen is released by light irradiation, thereby generating an internal pressure in the first peeling layer 102, which promotes peeling. The hydrogen content should be set appropriately for film formation conditions, such as the gas composition, gas pressure, gas atmosphere, gas flow rate, gas temperature, substrate temperature, and power to be applied when using the CVD method. Adjust by.

  In addition, as the material of the first release layer 102, various oxide ceramics such as silicon oxide or silicate compound, titanium oxide or titanate compound, or nitride such as dielectric or semiconductor, silicon nitride, aluminum nitride, titanium nitride, etc. Ceramics, various organic polymer materials, and various metals can be used.

  The thickness of the first release layer 102 is preferably about 1 nm to 20 μm, more preferably about 10 nm to 2 μm, and further preferably about 40 nm to 1 μm. This is because if the thickness of the first release layer 102 is too thin, the uniformity of the formed film thickness is lost and unevenness occurs in the release. If the thickness of the first release layer 102 is too thick, it is necessary to increase the power (light quantity) of irradiation light required for peeling, and it takes time to pattern the first peeling layer 102 after peeling. It is necessary.

  The formation method of the 1st peeling layer 102 should just be a method which can form a peeling layer with uniform thickness, and can be suitably selected according to various conditions, such as a composition and thickness, of the 1st peeling layer 102. . For example, various vapor deposition methods such as CVD (including MOCCVD, low pressure CVD, ECR-CVD), vapor deposition, molecular beam vapor deposition (MB), sputtering, ion plating, PVD, electroplating, immersion plating ( Dipping), various plating methods such as electroless plating method, Langmuir-Blodget (LB) method, coating method such as spin coating, spray coating method, roll coating method, various printing methods, transfer method, inkjet method, powder jet method Applicable to etc. Of these, two or more methods may be combined. In addition, when the first release layer 102 is formed using ceramic by a sol-gel method or an organic polymer material, the first release layer 102 is preferably formed by a coating method, particularly spin coating.

  The underlayer 104 constitutes a base layer that serves as a foundation of the thin film element. For example, the protective layer, the insulating layer, and the transferred layer that physically or chemically protect the transferred layer at the time of manufacture or use. It exhibits at least one of the functions as a barrier layer and a reflection layer for preventing migration of components.

The composition of the underlayer 104 is appropriately selected according to the purpose, but it is more preferable to form a plurality of layers. In the case of being formed between the first peeling layer 102 made of amorphous silicon and the transferred layer 110 as in this embodiment, silicon oxide such as SiO ₂ can be used. In addition, various metals are mentioned. The thickness of the foundation layer 104 is appropriately determined according to the purpose of formation. Usually, the thickness is preferably about 10 nm to 5 μm, and more preferably about 40 nm to 1 μm. This is because if the underlayer 104 is too thin, the functions of the protective layer and the like cannot be achieved, and if the underlayer 104 is too thick, the entire film becomes thick. As a method for forming the base layer 104, various methods described for the first peeling layer 102 can be applied. Here, a silicon oxide film is deposited by a CVD method. Note that the underlayer can be formed as a single layer, or two or more layers using a plurality of materials having the same or different compositions.

<2: Transferred layer forming step>
As shown in FIG. 1B, a thin film element is formed on the base layer 104 to complete the transferred layer 110. The transferred layer 110 is an element forming layer itself including a thin film element.
In this embodiment, the case where an electric circuit including a thin film transistor (TFT) is formed as a thin film element is illustrated.

  FIG. 1B shows an enlarged cross-sectional view of the transferred layer 110 including a thin film transistor (thin film element) T. In the figure, only the thin film transistor is shown, but other thin film elements may include passive components such as wiring, pixel electrodes, connection pads, resistors, and capacitors.

  The thin film transistor T includes a semiconductor film 103 including a source 103s, a drain 103d, and a channel 103c, a gate insulating film 106, a gate electrode 105, an interlayer insulating film 108, and a wiring layer 107. The thin film transistor is manufactured by applying a normal thin film semiconductor manufacturing technique. The outline is illustrated below.

  The semiconductor film 103 is formed using a known semiconductor thin film formation technique. For example, a silicon film is formed on the base layer 104 by depositing silicon by a CVD method. Next, the semiconductor film 103 is formed by patterning the silicon film into the shape of a transistor region for the thin film transistor T.

  When the semiconductor film 103 is formed, a thin film transistor using the semiconductor film 103 as a transistor region is formed. First, the gate insulating film 106 is formed by directly depositing silicon oxide or the like by a CVD method. Next, ion implantation for the channel 103 c is performed on the semiconductor film 103. Next, a gate electrode 105 is formed by depositing a metal film such as tantalum, or depositing polysilicon in which impurities are diffused at a high concentration by a CVD method, and performing patterning. Next, high concentration impurity implantation is performed on the source 103s and drain 103d regions of the semiconductor film 103 using the gate electrode 105 as a mask, thereby forming the source 103s and drain 103d in a self-aligning manner. Next, a heat treatment for impurity activation is performed, and a silicon oxide film is deposited by a CVD method or the like, thereby forming an interlayer insulating film 108. Contact holes reaching the source 103 s and the drain 103 d are provided in the interlayer insulating film 108. Then, by depositing polysilicon doped with impurities at a high concentration by CVD or by depositing a metal film by sputtering, these are patterned to form the wiring layer 107.

  In this manner, a transfer layer (element forming layer) 110 including the thin film transistor T as a thin film element is formed. The method for forming the thin film transistor is not limited to the above, and a known thin film semiconductor manufacturing technique can be applied.

<3: First transfer substrate bonding step>
First, a second release layer 114 that is peeled off by applying predetermined energy is formed on the first transfer substrate 116. In the present embodiment, the first transfer substrate 116 can use the same material as the transfer source substrate 100. The composition, formation method, and thickness of the second release layer 114 are the same as those of the first release layer 102.

  Next, as shown in FIG. 1C, the second release layer 114 formed on the first transfer substrate 116 and the transfer target layer 110 are bonded via the adhesive layer 112. The adhesive layer 112 is formed by applying an adhesive on the transfer layer 110 or the second release layer 114 by spin coating or the like. As the adhesive used for the adhesive layer 112, for example, various curable adhesives such as a reactive curable adhesive, a thermosetting adhesive, a photocurable adhesive, and an anaerobic curable adhesive can be used. The composition is appropriately selected from epoxy, acrylate, silicone and the like. It is preferable to suppress the amount of adhesive used as much as possible so that the thickness of the adhesive layer 112 is as thin as possible when it is removed later.

<4: Transfer substrate peeling process>
As shown in FIG. 1D, energy L is applied to the first peeling layer 102 to cause interfacial peeling and / or intra-layer peeling in the first peeling layer 102, thereby transferring the transfer source substrate 100 from the transferred layer 110. It is peeled off.

The application of energy L is preferably by laser light irradiation. Any laser beam may be used as long as it causes in-layer peeling and / or interfacial peeling in the first peeling layer 102. In particular, an excimer laser outputs high energy in a short wavelength region and is extremely short in time. This is preferable because ablation can be generated in the first release layer 102. The energy density of the laser beam in the case of excimer lasers, it is preferable to be 10~5000mJ / cm ² or so, and more preferably, especially 100~5000mJ / cm ² approximately.

  The irradiation time is preferably about 1 to 1000 nsec, and more preferably about 10 to 100 nsec. If the energy density is low or the irradiation time is short, sufficient ablation does not occur, and if the energy density is high or the irradiation time is long, the semiconductor film 103 is adversely affected by the irradiation light transmitted through the first peeling layer 102 and the base layer 104. It is because it may affect.

  It is preferable to irradiate the laser beam so that its intensity is uniform throughout the release layer. The light irradiation direction is not limited to the direction perpendicular to the release layer, and may be a direction inclined by a predetermined angle with respect to the release layer. In addition, when the area of the release layer is larger than the irradiation area of one irradiation light, the entire region of the release layer may be irradiated with light in a plurality of times. Moreover, you may irradiate the same location several times. Moreover, you may irradiate the same area | region or a different area | region several times with the light of a different kind and a different wavelength (wavelength range).

<5: Adhesion process to second transfer substrate>
As shown in FIG. 2E, a second transfer substrate 120 having a conductive portion 121 is bonded in place of the peeled transfer source substrate 100.

The second transfer substrate 120 is used as a permanent substrate mounted on the final product, and can be used even if it has relatively poor heat resistance and corrosion resistance compared to the transfer source substrate 100. Further, depending on the application, it may be low in rigidity, flexible and elastic. Examples of such materials include various synthetic resins. The synthetic resin may be either a thermoplastic resin or a thermal effect resin. For example, other resins such as polyethylene, polypropylene, and ethylene-propylene copolymer are applicable. As the glass material, for example, quartz glass, alkali silicate glass, soda lime glass, and others can be used. Examples of the material for the conductive part include various metals and organic conductive materials. As the metal, for example, a wide variety of other metals and alloys such as aluminum, stainless steel, and copper are applicable. As the organic conductive material, for example, various other materials such as polythiophene, polypyrrole, polyaniline, polyphenylene vinylene, and polyacene can be used. Further, the second transfer substrate 120 itself may be made of the conductive material as described above. The resistivity of the conductive portion of the second transfer substrate 120 is desirably 10 ¹⁰ Ωcm or less. At this time, as shown in FIG. 9, the area of the conductive portion 121 of the second transfer substrate 120 is larger than the area of the circuit formation region 111 of the transferred layer 110, and is larger than the main surface of the second transfer substrate 120. As viewed from the vertical direction and from the second transfer substrate 120 side, it is desirable that the circuit formation region 111 of the transferred layer is completely covered by the conductive portion 121 of the second transfer substrate 120. FIG. 9 shows a plan view when viewed from the direction perpendicular to the main surface of the second transfer substrate 120 and from the transfer layer 110 side. The conductive portion 121 is also present under the circuit formation region 111.

  The second transfer substrate 120 may be a substrate made of a plurality of materials such as an insulating substrate covered with a conductive material, in addition to a substrate made of a single material. For example, a conductive material may be formed on an insulating substrate such as a glass substrate with ITO, a glass substrate with a metal film, or a PET film with ITO. The second transfer substrate 120 may be in a state where an oxide film is attached to the surface of the conductive portion 121.

  The second transfer substrate 120 is bonded via an adhesive layer 122. The adhesive layer 122 is preferably a permanent adhesive. This is because a permanent adhesive can be semi-permanently bonded to the second transfer substrate 120. As an adhesive that can be semi-permanently bonded, for example, epoxy-based, acrylate-based, and the like can be used.

<6: First transfer substrate separation step>
When the transfer layer 110 is adhered to the second transfer substrate 120, the first transfer substrate 116 is separated from the transfer layer 110 as necessary. Specifically, the first transfer substrate 116 is peeled from the transferred layer 110 by irradiating the second peeling layer 114 with laser light to cause interfacial peeling and / or intralayer peeling in the second peeling layer 114. . The irradiation mode of the laser light is the same as that in the first release layer 102. In the case of removing the adhesive layer 112, the adhesive layer 112 is removed using a solvent or the like according to the property of the adhesive to obtain a thin film device (FIG. 2F).

<7: Step of connecting the substrate to an electrode for applying a reference potential of the thin film element>
In FIG. 3, the conductive part 121 continues from the front surface to the back surface of the substrate. The conductive portion 121 of the second transfer substrate 120 is connected to an electrode terminal 130 that provides a reference potential of the thin film element. Any connection method may be used as long as electrical conductivity is ensured. For example, as the method, the electrode terminal 130 for applying the reference potential of the thin film element is connected to a conductive casing 200 such as metal, and the conductive section 121 is connected to the conductive casing 200 via the connection portion 210. Electrically connect to For the connection portion 210, a conductive adhesive, a conductive double-sided tape, solder, a metal screw, or the like can be used.

  Note that the method of connecting the conductive portion 121 of the second transfer substrate 120 to the electrode for applying the reference potential of the thin film element is not limited to the above method. You may connect directly, without going through a housing | casing.

  As described above, according to the manufacturing method of the first embodiment, it is possible to discharge the charge accompanying peeling and joining repeatedly performed in the process through the second transfer substrate to be finally joined, so that the thin film element circuit is stabilized. Can be operated.

  Further, according to the manufacturing method of the first embodiment, the potential of the second transfer substrate is equal to the reference potential of the thin film element, so that the thin film element circuit can be stably operated.

  In addition, according to the manufacturing method of the first embodiment, since the electric field can be shielded even when the thin film device is placed in a strong electric field after the manufacturing, it is possible to prevent the influence on the characteristics of the thin film element, and the thin film The element circuit can be stably operated.

(Embodiment 2)
Embodiment 2 relates to a method of manufacturing a thin film device that can prevent / remove charging of a thin film element. Hereinafter, with reference to FIGS. 4A to 4D, FIGS. 5E to 5F, and FIG. 6, a method of manufacturing the thin film device according to the second embodiment will be described. These drawings are schematic views of manufacturing process sectional views. The manufacturing process of the second embodiment includes the following processes.
1) A step of forming a first release layer 102 to be peeled off by applying predetermined energy on the transfer source substrate 100 (FIG. 4A).
2) Step of forming the transfer layer 110 including the thin film element T on the first release layer 102 (FIG. 4B)
3) Step of bonding the transfer target layer 110 to the first transfer substrate 116 via the second release layer 114 (FIG. 4C).
4) A step of peeling the transfer source substrate 100 by applying energy L to the first peeling layer 102 to cause interface peeling and / or peeling within the layer (FIG. 4D).
5) A step of joining the second transfer substrate 125 using the conductive adhesive 127 instead of the peeled transfer source substrate 100 (FIG. 5E).
6) Step of separating the first transfer substrate 116 (FIG. 5F)
7) A step of connecting the second transfer substrate 125 to the electrode 130 for applying the reference potential of the thin film element T (FIG. 6).

  Of the above steps, 5) except for the step of bonding the second transfer substrate using a conductive adhesive, is substantially the same as in the first embodiment, so the description is largely omitted, and the description focuses on the differences. To do. The processes up to the step of peeling the transfer source substrate shown in FIG.

  As shown in FIG. 5E, the transfer source substrate is peeled after peeling the transfer source substrate by applying energy L to the first release layer 102 to cause interface peeling and / or intra-layer peeling. Instead of this, the second transfer substrate 125 is bonded via a conductive adhesive 127. At this time, as shown in FIG. 10, it is desirable that the area to which the conductive adhesive 127 is applied is larger than the area of the circuit formation region 111 of the transferred layer 110. Furthermore, as shown in FIG. 10, the circuit formation region 111 of the transferred layer 110 is electrically conductive when viewed from the direction perpendicular to the main surface of the second transfer substrate 125 and from the second transfer substrate 125 side. It is desirable that the adhesive 127 having the above is completely covered by the region to which the adhesive 127 is applied. FIG. 10 is a plan view when viewed from the direction perpendicular to the main surface of the second transfer substrate 125 and from the transfer layer 110 side. In FIG. 10, a conductive adhesive is shown. 127 is also applied under the circuit forming region 111.

  The second transfer substrate 125 is used as a permanent substrate mounted on the final product, and can be used even if it has relatively poor heat resistance and corrosion resistance compared to the transfer source substrate 100. Further, depending on the application, it may be low in rigidity, flexible and elastic. Examples of such materials include various synthetic resins. The synthetic resin may be either a thermoplastic resin or a thermal effect resin. For example, other resins such as polyethylene, polypropylene, and ethylene-propylene copolymer are applicable. As the glass material, for example, quartz glass, alkali silicate glass, soda lime glass, and others can be used. Various metals and organic conductive materials can also be used. As the metal, for example, a wide variety of other metals and alloys such as aluminum, stainless steel, and copper are applicable. As the organic conductive material, for example, various other materials such as polythiophene, polypyrrole, polyaniline, polyphenylene vinylene, and polyacene can be used.

  As the second transfer substrate 125, in addition to a substrate made of a single material, a device constituting an independent device itself, for example, a color filter, an electrode layer, a dielectric layer, an insulating layer, a semiconductor element, etc. In addition, a member constituting a part of the device may be used.

The second transfer substrate 125 is bonded via a conductive adhesive 127. The conductive adhesive 127 preferably has a resistivity of 10 ¹⁰ Ωcm or less. As a conductive adhesive, for example, a conductive adhesive made of resin made of a material such as conductive paste such as silver paste, copper paste, solder paste, polyolefin, fluorine polymer, thermoplastic elastomer or silicone rubber Etc. are available.

The conductive adhesive 127 is preferably applied on the second transfer substrate 125 over an area larger than the size of the transferred layer 110. This is to facilitate electrical connection in a later process.
The subsequent steps (FIG. 5 (f)) are exactly the same as those in FIG. 2 (f) in the first embodiment.

  Next, as shown in FIG. 6, a conductive adhesive 127 is connected to an electrode for applying a reference potential of the thin film element T. Any connection method may be used as long as electrical conductivity is ensured. For example, as the method, an electrode for applying a reference potential of the thin film element T and a conductive casing 200 such as metal are connected, and a conductive adhesive 127 is electrically connected to the conductive casing 200. To do. For the connection portion 220, a conductive adhesive, a conductive double-sided tape, solder, a metal screw, or the like can be used.

  Note that the method for connecting the conductive adhesive 127 to the electrode for applying the reference potential of the thin film element T is not limited to the above method. You may connect directly, without going through the housing | casing 200. FIG. In FIG. 6, the conductive adhesive 127 is applied only to the upper surface of the second transfer substrate 125, but it may be applied to the entire surface including the upper and lower surfaces and the side surfaces.

  As described above, according to the manufacturing method of the second embodiment, it is possible to discharge the charge accompanying peeling and bonding repeatedly performed in the process through the second transfer substrate 125 to be finally bonded, and thus the thin film element circuit is stabilized. Can be operated.

  Further, according to the manufacturing method of the second embodiment, the potential of the second transfer substrate 125 and the reference potential of the thin film element T become equal, so that the thin film element circuit can be stably operated.

  Further, according to the manufacturing method of the second embodiment, since the electric field can be shielded even when the thin film device is placed in a strong electric field after manufacturing, it is possible to prevent the characteristics of the thin film element T from being affected, The thin film element circuit can be stably operated.

(Embodiment 3)
<Electro-optical device>
The third embodiment relates to an example of an electro-optical device including the above-described thin film device. FIG. 7 shows a circuit diagram of the electro-optical device 1 using the thin film device.

  As shown in FIG. 7, the electro-optical device 1 is configured such that each pixel G includes the thin film transistor T, a liquid crystal LC electrically connected to the thin film transistor T, and a capacitor C, which are wired in the row direction. The scanning lines Vscan and the data lines Vdata wired in the column direction are connected in a matrix. A row selection signal is supplied from the scanning driver 2 to the scanning line Vscan. A data signal is supplied from the data driver 3 to the data line Vdata. The electro-optical device 1 is configured such that a signal from the data line Vdata is written to the pixel G when the scanning line Vscan is selected.

  The electro-optical device 1 is formed by the above manufacturing method.

  That is, as the transferred layer 110, the scanning driver 2 and the data driver 3, and the scanning lines Vscan and the data lines Vdata are formed in a matrix from these drivers, and each pixel G surrounded by these wirings has a thin film transistor. T and capacitor C are formed.

  On the other hand, a stainless steel substrate is used as the second transfer substrate 120.

  A thin film and a terminal provided on the second transfer substrate 120 for controlling the potential of the entire second transfer substrate 120 by transferring the transfer target layer 110 to the second transfer substrate 120 and, if necessary, through a liquid crystal sealing step. The electro-optical device 1 can be completed by electrically connecting a terminal for supplying a reference potential of the element circuit.

  According to the third embodiment, since the electric field can be shielded by the second transfer substrate 120 or the conductive adhesive 127 even when the thin film device is placed in a strong electric field, the thin film element circuit operates stably. Thus, an electro-optical device including a thin film transistor with stable circuit operation can be provided.

(Embodiment 4)
<Electronic device equipped with electro-optical device>
The fourth embodiment relates to an example of an electronic apparatus including the above-described electro-optical device.

  FIG. 8 shows an example of an electronic apparatus provided with the electro-optical device 1 as shown in FIG. FIG. 8 shows an example applied to the television apparatus 300, and the electronic apparatus includes the electro-optical device 1 according to the present embodiment.

  The structures of the electro-optical device and the electronic apparatus are merely examples, and can be widely applied to devices using thin film elements that are transferred and manufactured by the method for manufacturing a thin film device of the present invention.

  The method for manufacturing a thin film device of the present invention is not limited to the above-described embodiment, and can be used with various modifications.

  Further, the electro-optical device is not limited to the form of an element related to display, such as an EL display device, an electrophoretic device, and an electron emission device, as well as a liquid crystal display device, and can be applied in various ways.

  Further, the electronic device is not limited to the above-described configuration. For example, a personal computer, a mobile phone, a video camera, a head-mounted display, a rear-type or front-type projector, a fax machine with a display function, a digital camera finder, a mobile phone The present invention can be applied to a type TV, a DSP device, a PDA, an electronic notebook, an electric bulletin board, an IC card, a display for public announcements, and the like.

  C condenser, G pixel, L energy (laser light), LC liquid crystal, T thin film transistor as thin film element, 1 electro-optical device, 2 scanning driver, 3 data driver, 100 transfer source substrate, 102 first release layer, 103 semiconductor Film, 103c channel, 103s source, 103d drain, 104 underlayer, 105 gate electrode, 106 gate insulating film, 107 wiring layer, 108 interlayer insulating film, 110 transferred layer (element forming layer), 111 transferred layer circuit forming region , 112 Adhesive layer, 114 Second release layer, 116 First transfer substrate, 120, 125 Second transfer substrate, 121 Conductive part, 122 Adhesive layer, 127 Conductive adhesive layer, 130 Provides reference potential for thin film element circuit Terminal, 200 housing, 210 conductive contact portion, 220 conductive Ntakuto part, 300 television device.

Claims (7)

Forming a first release layer on the transfer source substrate;
Forming a transfer layer including a circuit formation region of a thin film element on the first release layer;
Bonding the transferred layer to a first transfer substrate via a second release layer;
Peeling the transfer source substrate from the transferred layer;
Bonding a second transfer substrate having a conductive portion or a conductive adhesive on the bonding surface to the transferred layer ;
Peeling the first transfer substrate from the transferred layer bonded to the second transfer substrate;
Connecting the conductive part or the conductive adhesive with an electrode terminal for providing a reference potential of the thin film element,
In the step of bonding the second transfer substrate to the transfer target layer, the surface of the second transfer substrate overlaps the conductive portion or the conductive adhesive in a plan view when viewed from a direction perpendicular to the surface. The region includes a circuit forming region of the thin film element inside, and a method of manufacturing a thin film device. The method for manufacturing a thin film device according to claim 1 , wherein a resistivity of the conductive part or the conductive adhesive is 10 ¹⁰ Ωcm or less. The thin film element includes a semiconductor film, method of manufacturing a thin film device according to claim 1 or 2. A substrate,
A conductive part or a conductive adhesive formed on the substrate;
A thin film element formed on the conductive part or the conductive adhesive ,
The region overlapping the conductive portion or the conductive adhesive in a plan view when the surface of the substrate is viewed from a direction perpendicular to the surface includes a circuit formation region of the thin film element inside,
The thin film device, wherein the conductive part or the conductive adhesive is connected to an electrode terminal that provides a reference potential of the thin film element . The resistivity of the conductive part or the conductive adhesive is 10 ¹⁰ The thin film device according to claim 4, which is Ωcm or less. The thin film device according to claim 4, wherein the thin film element includes a semiconductor film. Electro-optical device which comprises a thin film device according to any one of claims 4 to 6.

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