JP2007201249A - Temporarily transcribing substrate, manufacturing method of thin-film device using same substrate, and electronic appliance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique which shortens a processing time required for a transcription, when forming a device by using a transcription technique. <P>SOLUTION: A temporarily transcribing substrate (22) is used for holding a transcribed object temporarily when peeling the transcribed object created on a first substrate so as to be moved to a second substrate. A plurality of through-holes (22a) for piercing them from one surface of the substrate (22) to its opposite surface are formed, and a peeled layer (24) is included which is disposed on its one surface so as to cover the respective through-holes and to be broken by the energy given from the external. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improvement in inter-substrate transfer technology for thin film devices.

As a method for forming a laminated body such as a semiconductor element, a technique using a transfer technique is known. For example, in Japanese Patent Application Laid-Open No. 10-125929 (Patent Document 1) or Japanese Patent Application Laid-Open No. 10-125930 (Patent Document 2), a transfer body such as a thin film transistor is previously formed on a manufacturer substrate via a release layer. Then, a method is disclosed in which the transfer target layer is transferred to the temporary transfer substrate by joining the transfer target layer to the temporary transfer substrate and irradiating the release layer with light to cause peeling. According to this method, a desired electronic device can be manufactured by forming a plurality of types of thin film elements or thin film circuits having different manufacturing conditions on the temporary transfer substrate under optimum conditions and then moving the thin film elements to the temporary transfer substrate. .
Japanese Patent Laid-Open No. 10-125929 JP-A-10-125930

  In the process using the transfer technique described above, an adhesive having a liquid solubility such as a water-soluble adhesive is used so that the transferred object is once held on the temporary transfer substrate so that it can be easily removed in a later step. It was. At the time of the second transfer, after joining the transfer destination substrate and the transfer object with a water-insoluble adhesive, the water-soluble adhesive interposed between the transfer object and the temporary transfer substrate is washed with water. It was dissolved. However, in the process of dissolving the water-soluble adhesive, water penetrates from the outer periphery of the joined body of the transferred body and the temporary transfer substrate to the inside through the gap between the both, so that water can enter. Since the opening area is small, it took a long time to dissolve the water-soluble adhesive.

  Accordingly, an object of the present invention is to provide a technique capable of shortening a processing time required for transfer when a device is formed using a transfer technique.

  In order to achieve the above object, the temporary transfer substrate of the present invention temporarily holds the transferred object when the transferred object manufactured on the first substrate is peeled off and moved onto the second substrate. A temporary transfer substrate that is used to have a substrate having a plurality of through holes penetrating one surface and the other surface facing the one surface, and disposed on one surface of the substrate to cover each through hole, And a release layer that is destroyed by external energy application.

  By adopting such a configuration, it is possible to shorten the time for separating the temporary transfer substrate by dissolving the adhesive through the plurality of through holes of the temporary transfer substrate in the release transfer step, and the temporary transfer by the release layer. By blocking a plurality of through holes in the substrate in advance, it is possible to prevent the transferred body from being bent (or distorted) at the through hole when the transferred body is attached to the temporary transfer substrate. Become. The transferred object includes a thin film transistor, a thin film resistor, a capacitor, an inductor, a circuit wiring, a thin film circuit (layer) including these, an integrated circuit, a micro device, etc. (a thin film device that performs a certain function).

  Further, for example, there is no need to consider the positions of the through holes at positions corresponding to the cutting regions of the substrate, avoiding the thin film device on the first substrate side, and the positions of the plurality of through holes of the temporary transfer substrate It is possible to select more freely without considering the number, distribution, hole size, and the like.

  Preferably, the substrate is a translucent substrate and the external energy is light. Energy can be applied to the internal release layer by laser irradiation or the like from the outside of the substrate, and the release layer can be destroyed.

  Preferably, the transfer object is a thin film device such as a thin film element or a thin film circuit. Thin film resistors, capacitors, inductors, circuit wiring, thin film circuits (layers) including these, integrated circuits, micro devices, and the like can be formed on a flexible plastic substrate or the like by a peeling transfer technique.

  Moreover, the manufacturing method of the thin film device using the temporary transfer substrate includes a first step of forming a transfer target on the one surface side of the first substrate having a first release layer on one surface side, and a second step. By interposing a liquid-soluble adhesive between one surface of the temporary transfer substrate having a plurality of through-holes covered with a release layer and one surface of the first substrate, the temporary transfer substrate and the above-mentioned A second step of bonding the first substrate, and peeling is caused by applying energy to the first peeling layer of the first substrate, and the transfer target is transferred from the first substrate to the temporary transfer. Bonding the temporary transfer substrate and the second substrate by interposing an adhesive between the third step of transferring to the substrate and the one surface of the temporary transfer substrate and the one surface of the second substrate Energy for the fourth release step and the second release layer of the temporary transfer substrate. And removing the adhesive material by supplying a dissolving liquid to the adhesive material through a plurality of through holes of the temporary transfer substrate. And a sixth step of transferring from the temporary transfer substrate to the second substrate.

  By using the temporary transfer substrate with the through-holes closed with a release layer, peeling transfer between thin film device substrates can be avoided during the transfer, and the yield of thin film device manufacturing can be improved. To do. In addition, it is possible to shorten the time for removing the adhesive by exposing the temporary adhesive to the inside of the through-hole by destroying the release layer of the temporary transfer substrate during the transfer.

  Preferably, the sixth step is performed in the dissolving liquid (immersion). Thereby, the dissolution of the adhesive proceeds not only from the plurality of through holes of the temporary transfer substrate but also from the outer peripheral side of the substrate, and the process time can be further shortened. To do.

  In addition, an electronic apparatus according to the present invention includes a thin film device manufactured by the thin film device manufacturing method using the temporary transfer substrate described above. An electronic device using a thin film device manufactured by a more reliable peeling transfer technology can be expected to improve reliability.

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

  FIG. 1 is an explanatory view for explaining a temporary transfer substrate of the present invention. FIG. 4A is a plan view, and FIG. 4B is a cross-sectional view in the A-A ′ direction of FIG.

  As shown in FIG. 1, the temporary transfer substrate 22 is provided with a plurality of holes 22 a penetrating the temporary transfer substrate 22, and a release layer 24 covering each through hole 22 a is provided on one surface side of the temporary transfer substrate 22. It is formed throughout.

  Since the temporary transfer substrate 22 does not need to have special heat resistance, various substrates such as a glass substrate and a plastic substrate can be used. In a later step, in order to impart (light) energy to the release layer 24 via the temporary transfer substrate 22, the temporary transfer substrate 22 is made of a transparent material.

  Further, the through holes 20 of the temporary transfer substrate 16 are evenly arranged on the entire temporary transfer substrate 22 as shown in FIG. The diameter and number of each through hole 20 may be determined as appropriate. For example, the diameter of the hole is set to about 1 μm.

  The peeling layer 24 is a film that breaks when energy is applied, and can be formed of, for example, a semiconductor film such as an amorphous silicon film, a metal film, an organic polymer film, or ceramics.

  In the temporary transfer substrate as shown in FIG. 1, amorphous silicon is deposited on a substrate 22 such as glass by CVD or the like to form a release layer 24, and the substrate 22 is attached using a mask corresponding to a through hole group (not shown). The release layer 24 is manufactured by methods such as anisotropic etching or cutting, machining such as ultrasonic waves, and laser processing.

  Next, an example of manufacturing a thin film device using the temporary transfer substrate described above will be described with reference to FIGS. In this embodiment, a two-time transfer process is described in which a transfer target formed in advance on a transfer source substrate (first substrate) is temporarily held by a temporary transfer substrate and then moved to a transfer destination substrate (first substrate). To do.

  First, as shown in FIG. 2A, a release layer 14 is formed on one side of the transfer source substrate 12. As the transfer source substrate 12, a heat-resistant material such as quartz glass or soda glass, for example, a substrate that can withstand a process temperature of a semiconductor device of about 350 ° C. to 1000 ° C. is used. The transfer source substrate 12 is desirably transparent to the wavelength of the light so that energy can be applied to the release layer 14 by light irradiation in a later step. Moreover, as the peeling layer 14, what has the characteristic which produces peeling by receiving energy provision, such as light irradiation, is used. Such a release layer 14 can be formed of, for example, a semiconductor film such as an amorphous silicon film, a metal film, an organic polymer, ceramics, or the like.

  As shown in FIG. 2B, a plurality of transfer objects 14 are formed above the release layer 14. Each transferred object 14 includes, for example, a plurality of thin film elements (for example, thin film transistors) and wiring.

  Further, as shown in the figure, the water-soluble adhesive 18 is provided between the surface on the release layer 24 side of the temporary transfer substrate 22 having a plurality of through-holes 22a and the surface on the transfer target 16 side of the transfer source substrate 12. By interposing, the temporary transfer substrate 22 and the transfer source substrate 12 are joined.

  Since the temporary transfer substrate 22 does not need to have special heat resistance, various substrates such as a glass substrate and a plastic substrate can be used. Further, the number of through holes 22a of the temporary transfer substrate 22 and the diameter of each through hole 22a can be determined as appropriate. For example, it is set to about 1 μm. As described above, since each through hole 22a is covered (closed) by the release layer 24, the thin film of the transfer target 14 is prevented from being bent by the opening portion of the through hole 22a.

  As shown in FIG. 2 (C), the release layer 14 is destroyed by applying energy to the release layer 14 of the transfer source substrate 12, and the interface between the release layer 14 and the transfer source substrate 12 or in the release layer layer. Causes peeling.

  Specifically, as shown in the figure, the release layer 14 is irradiated with laser light through the transfer source substrate 12 to cause laser ablation in the release layer 14. Ablation is a state in which a solid material that absorbs irradiated light (a constituent material of the release layer 12) is photochemically or thermally excited, and its surface and internal atomic or molecular bonds are cut and released. In general, all or part of the constituent material of the release layer 12 appears as a phenomenon that causes a phase change such as melting and transpiration (vaporization). In addition, a phase change may result in a fine foamed state, which may reduce the bonding force.

As a result, as shown in FIG. 2D, the transfer source substrate 12 is separated, and the transfer body 16 is transferred from the transfer source substrate 12 to the temporary transfer substrate 22 side.
Next, as shown in FIG. 3 (A), an adhesive 34 is interposed between one surface of the temporary transfer substrate 22 where the transfer target 16 is present and one surface of the transfer destination substrate 32, thereby temporarily The transfer substrate 22 and the transfer destination substrate 32 are joined. Examples of the adhesive 34 used in this step include various curable adhesives such as a reactive curable adhesive, a thermosetting adhesive, a photocurable adhesive such as an ultraviolet curable adhesive, and an anaerobic curable adhesive. And epoxy, acrylate, silicone resin adhesive, and the like.

  As shown in FIG. 3B, energy is applied to the release layer 24 from the side of the temporary transfer substrate 22 where the transfer target 16 does not exist, thereby causing the release layer 24 in the through-hole 22a portion to break. Specifically, the release layer 24 is irradiated with laser light through the transfer source substrate 22 to cause the laser ablation described above on the release layer 24. Thereby, the peeling layer 24 which covers each through-hole 22a part is removed.

  Next, the water-soluble adhesive 18 is melted by supplying water as a dissolving liquid to the water-soluble adhesive 18 through each of the through holes 22 a provided in the temporary transfer substrate 22. In addition, in this example, the water-soluble adhesive 18 can also be dissolved by supplying water to the water-soluble adhesive 18 from the outer periphery of the joined body of the temporary transfer substrate 16 and the transfer destination substrate 24 through the gap between them. Is progressing.

  As shown in FIG. 3C, this step is desirably performed by immersing the entire joined body of the temporary transfer substrate 22 and the transfer destination substrate 32 in water 44 in the water tank 42. Note that only the other surface side of the temporary transfer substrate 16 may be immersed in water. Alternatively, water may be introduced into each through hole 22a from the other surface side of the temporary transfer substrate 22 while being pressurized.

  When the water-soluble adhesive 18 is dissolved and removed by supplying water through these paths (through holes), the temporary transfer substrate 22 is separated from the transfer destination substrate 32.

  As shown in FIG. 3D, the transfer target 14 is transferred from the temporary transfer substrate 16 to the transfer destination substrate 32, and the transfer target is formed on the transfer destination substrate (for example, a flexible resin substrate) 24. The

  In the above-described peeling transfer method, the temporary transfer substrate 22 having a plurality of through holes 22a is used, and water as a dissolving liquid is supplied to the water-soluble adhesive 18 through each of the through holes 22a. In addition, it is possible to efficiently supply water while ensuring a large opening area into which water can enter. Therefore, the time required for dissolving the water-soluble adhesive 18 can be greatly shortened, and the processing time required for transferring the transfer target 14 can be shortened.

  In addition, according to the present embodiment, the temporary transfer substrate 22 in which the through hole 22a is closed by the release layer 24 is used. Thereby, when the temporary transfer substrate 22 in which the through hole 22a is not closed is used, the adhesion between the transfer target (thin film device, thin film circuit, thin film circuit layer, etc.) and the temporary transfer substrate is reduced. It is possible to avoid the occurrence of bending and distortion of the transferred object.

  Next, an example of an electronic apparatus including a thin film device manufactured by the manufacturing method described above will be described. The thin film device according to the present embodiment can be applied to the manufacture of a liquid crystal display panel, an electroluminescence display panel, and the like that constitute a display unit, a circuit unit, and the like in various electronic devices.

  FIG. 4 is a schematic perspective view illustrating an example of an electronic device. FIG. 4A shows an application example to a mobile phone, and the mobile phone 530 includes an antenna portion 531, an audio output portion 532, an audio input portion 533, an operation portion 534, and a display portion 535.

  FIG. 4B shows an application example to a video camera. The video camera 540 includes an image receiving unit 541, an operation unit 542, an audio input unit 543, and a display unit 544.

  FIG. 4C illustrates an example of application to a television device. The television device 550 includes a display portion 551.

  FIG. 4D illustrates an application example to a roll-up television device, and the roll-up television device 560 includes a display portion 561. Further, the thin film device according to the present invention is not limited to the above-described example, and can be applied to various electronic devices. For example, in addition to these, it can also be used for a fax machine with a display function, a finder for a digital camera, a portable TV, an electronic notebook, an electric bulletin board, a display for advertisements, and the like.

  The present invention is not limited to the contents of the above-described embodiments, and various modifications can be made within the scope of the gist of the present invention.

For example, the number, size, and distribution of the through holes 22a in the temporary transfer substrate can be made to correspond to the arrangement pattern of the transfer object on the transfer source substrate.
In the above-described embodiment, the case where a water-soluble adhesive is used as an example of a liquid-soluble adhesive and water is used as a dissolving liquid has been described. However, the scope of application of the present invention is limited to this. Instead, any adhesive that can be dissolved and removed using some liquid later can be used as the liquid-soluble adhesive.

FIG. 1 is an explanatory view illustrating a temporary transfer substrate according to an embodiment of the present invention. FIG. 2 is a process diagram for explaining a method of manufacturing a thin film device using the temporary transfer substrate according to the embodiment of the present invention. FIG. 3 is a process diagram for explaining a method of manufacturing a thin film device using the temporary transfer substrate according to the embodiment of the present invention. It is explanatory drawing explaining the example of the electronic device using a thin film device.

Explanation of symbols

12 Transfer source substrate, 16 Transfer object, 22 Temporary transfer substrate, 22a Through hole, 24 Release layer, 32 Transfer destination substrate

Claims (6)

A temporary transfer substrate used for temporarily holding the transferred object when the transferred object manufactured on the first substrate is peeled off and moved onto the second substrate,
A substrate having a plurality of through holes penetrating one side and the other side opposite to the one side;
A release layer disposed on one side of the substrate to cover each through-hole and to be destroyed by external energy application;
A temporary transfer substrate comprising:   The temporary transfer substrate according to claim 1, wherein the substrate is a light-transmitting substrate and the external energy is light.   The temporary transfer substrate according to claim 1, wherein the transfer target is a thin film element or a thin film circuit. A first step of forming a transfer object on the one surface side of the first substrate having a first release layer on one surface side;
The temporary transfer is performed by interposing a liquid-soluble adhesive between one surface of the temporary transfer substrate having a plurality of through-holes covered with the second release layer and one surface of the first substrate. A second step of bonding the substrate and the first substrate;
A third step of causing peeling by applying energy to the first peeling layer of the first substrate, and transferring the transferred object from the first substrate to the temporary transfer substrate;
A fourth step of bonding the temporary transfer substrate and the second substrate by interposing an adhesive between the one surface of the temporary transfer substrate and the one surface of the second substrate;
A fifth step of destroying the release layer by applying energy to the second release layer of the temporary transfer substrate;
The adhesive is removed by supplying a dissolving liquid to the adhesive through a plurality of through-holes in the temporary transfer substrate, and the transferred body is transferred from the temporary transfer substrate to the second substrate. 6 steps,
A method for manufacturing a thin film device using a temporary transfer substrate.   The method of manufacturing a thin film device using the temporary transfer substrate according to claim 4, wherein the sixth step is performed in the dissolving liquid. An electronic apparatus comprising a thin film device manufactured by a method for manufacturing a thin film device using the temporary transfer substrate according to claim 4.

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