JP2006313827A - Method of manufacturing thin film device and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the transfer failure in forming of devices using the transfer technology. <P>SOLUTION: The thin film device manufacturing method comprises a first step of forming a transferring object (14) on one surface of a first substrate (10) having a peel layer (12) on the one surface, a second step of bonding a second substrate (16) to the first substrate (10) by inserting an adhesive material (18) between the one surface of the first substrate and one surface of the second substrate, a third step of giving an energy to the peel layer of the first substrate to peel the interface of the peel layer and the first substrate or in the peel layer, and a fourth step of transferring the transferring object (14) to the second substrate from the first substrate after separating the first substrate and the second substrate. The first substrate uses a more flexible substrate than the second substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improvement in a technique for manufacturing a thin film device such as a thin film element or a thin film circuit using a transfer technique.

  A technique using a transfer technique is known as a method for manufacturing a thin film device. For example, in Japanese Patent Application Laid-Open No. 10-125929 (Patent Document 1) and 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 transfer source substrate via a release layer. A method is disclosed in which the transfer target is transferred to the transfer destination substrate by bonding the transfer target to the transfer destination substrate and then irradiating the release layer with light or the like to cause peeling. In addition, in the process of moving the transfer object from the transfer source substrate to the transfer destination substrate, the transfer object is once transferred from the transfer source substrate to the temporary transfer substrate, and then transferred from the temporary transfer substrate to the transfer destination substrate. Two-time transfer processes that transfer the body are also known. According to these methods, a desired electronic device can be manufactured by forming multiple types of thin film elements and thin film circuits with different manufacturing conditions on the transfer source substrate under optimum conditions and then moving them to the transfer destination substrate. can do. In particular, when a two-time transfer process is employed, the up-down direction does not have to be reversed between the transfer target formed on the transfer source substrate and the transfer target finally transferred to the transfer destination substrate. There are advantages.

Japanese Patent Laid-Open No. 10-125929 JP-A-10-125930

  In the process using the transfer technology described above, when transferring the transfer object, damage such as cracks or cracks occurs on both or either of the substrates, and the transfer object is not transferred to the desired state, that is, transfer failure occurs. There was a case. Further, the same transfer failure may occur even when each substrate is not damaged. For this reason, an improvement in technology for reducing transfer defects has been desired.

  Therefore, an object of the present invention is to provide a technique capable of reducing transfer defects when a device is formed using a transfer technique.

  According to the first aspect of the present invention, there is provided a first step of forming a transfer target on the one side of the first substrate having a release layer on one side, one side of the second substrate, and one of the first substrates. A second step of bonding the first substrate and the second substrate by interposing an adhesive between them and the release layer; and applying the energy to the release layer of the first substrate; Separating the first substrate and the second substrate from the third step for causing separation at the interface with the first substrate or in the release layer, and separating the transferred object from the first substrate to the second substrate. And a fourth step of transferring to the substrate, wherein the first substrate is more flexible than the second substrate.

  Here, the “transfer object” in the present invention includes various thin film devices such as a thin film element, a thin film circuit, a fine structure, and a functional thin film. More specifically, the transferred object includes a thin film transistor, a thin film diode, other thin film semiconductor elements, a thin film circuit including the semiconductor element, a photoelectric conversion element used for a solar cell, an image sensor, and a switching element. , Actuators such as memory, piezoelectric elements, micromirrors (piezo thin film ceramics), magnetic recording media, magneto-optical recording media, recording media such as optical recording media, magnetic recording heads, coils, inductors, thin-film highly permeable materials and the like Combined micro magnetic devices, filters, reflective films, dichroic mirrors, polarizing elements, etc. optical thin films, semiconductor thin films, superconducting thin films (eg YBCO thin films), magnetic thin films, metal multilayer thin films, metal ceramic multilayer thin films, metal semiconductor multilayer thin films Ceramic semiconductor multilayer thin film, organic thin film and multilayer thin film of other materials, etc. It is below.

  According to such a manufacturing method, it is possible to avoid occurrence of damage and the like and to reduce the occurrence of transfer failure by setting the first substrate, which is the substrate to be removed, to be more easily bent. Become.

  Specific modes for realizing a state in which the first substrate described above is more easily bent than the second substrate include the following. For example, when the first substrate and the second substrate are made of the same constituent material, the thickness of the first substrate may be made thinner than the thickness of the second substrate. Moreover, you may employ | adopt as a constituent material of a 1st board | substrate a smaller elastic modulus than the constituent material of a 2nd board | substrate.

  According to these, it is possible to easily realize a state in which the first substrate is more easily bent than the second substrate.

  In the fourth step described above, it is preferable that the two substrates are separated by applying an external force to the first substrate while fixing the second substrate by a method such as vacuum suction.

  Thereby, it is possible to more reliably avoid the occurrence of damage to each substrate.

  The second aspect of the present invention is an electronic apparatus including the thin film device manufactured by the manufacturing method described above. Here, the “electronic device” means a general device having a circuit board and other elements and having a certain function, and there is no particular limitation on its configuration. Such electronic devices include, for example, IC cards, mobile phones, video cameras, personal computers, head mounted displays, rear or front projectors, televisions, roll-up televisions, fax machines with display functions, and digital cameras. Finder, portable TV, DSP device, PDA, electronic notebook, electric bulletin board, display for advertisement announcement, and the like.

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

  1 and 2 are diagrams illustrating a method for manufacturing a thin film device according to an embodiment. FIG. 3 is a cross-sectional view showing a specific example of a transfer target (details will be described later). FIG. 4 is a diagram for explaining in detail a process of separating each substrate (details will be described later). In the present embodiment, a two-time transfer process in which a transfer target formed in advance on a transfer source substrate is temporarily held by a temporary transfer substrate and then moved to a transfer destination substrate will be described. In this embodiment, the transfer source substrate corresponds to a “first substrate”, and the temporary transfer substrate corresponds to a “second substrate”.

  First, as shown in FIG. 1A, a release layer 12 is formed on one side of the transfer source substrate 10, and a transfer body 14 is formed on the release layer 12. For example, as illustrated in FIG. 3, the transfer target 14 includes a plurality of thin film elements (for example, thin film transistors T), wirings, and the like. Here, the transfer source substrate 10 in this step has an appropriate thickness and can withstand a heat-resistant material such as quartz glass or soda glass, for example, about 350 ° C. to 1000 ° C. which is a process temperature of a semiconductor device. Is used. The transfer source substrate 10 is desirably transparent to the wavelength of the light so that energy can be applied to the release layer 12 by light irradiation in a later step. Moreover, as the peeling layer 12, what has the characteristic which produces peeling by receiving energy provision, such as light irradiation, is used. Such a release layer 12 can be formed of, for example, a semiconductor film such as an amorphous silicon film, a metal film, a conductive oxide film, a conductive polymer film, or a conductive ceramic.

  Next, as shown in FIG. 1B, the temporary transfer substrate 16 and the transfer surface are transferred by interposing a water-soluble adhesive 18 between the one surface of the temporary transfer substrate 16 and the one surface of the transfer source substrate 10. The original substrate 10 is bonded. In the present embodiment, a glass substrate such as quartz glass or soda glass is used as the temporary transfer substrate 16.

  Next, as shown in FIG. 1C, energy is applied to the release layer 12 of the transfer source substrate 10 to cause peeling at the interface between the release layer 12 and the transfer source substrate 10 or in the release layer layer. . Specifically, as shown in the figure, the release layer 12 is irradiated with laser light through the transfer source substrate 10 to cause laser ablation in the release layer 12. 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.

  Next, as shown in FIG. 1D, the transfer source substrate 10 and the temporary transfer substrate 14 are separated. As a result, the transfer target 14 is transferred from the transfer source substrate 10 to the temporary transfer substrate 16.

  FIG. 4 is a partially enlarged view for explaining in detail a process of separating each substrate (transfer source substrate 10 and temporary transfer substrate 14). As described above, in this embodiment, both the transfer source substrate 10 and the temporary transfer substrate 16 are made of glass. Then, as shown in FIG. 4, by making the plate thickness L1 of the transfer source substrate 10 thinner than the plate thickness L2 of the temporary transfer substrate 16, a state in which the transfer source substrate 10 is more easily bent than the temporary transfer substrate 16 is realized. ing. Further, in this step, the two substrates are separated by applying an external force F to the transfer source substrate 10 while fixing the temporary transfer substrate 16 by a method such as vacuum suction.

  In addition, by adopting a material having a lower elastic modulus than that of the temporary transfer substrate 16 as a constituent material of the transfer source substrate 10, a state in which the transfer source substrate 10 is more easily bent than the temporary transfer substrate 16 can be easily realized. can do. Further, the degree of bending of the transfer source substrate 10 may be adjusted by combining the increase / decrease of the plate thickness and the selection of the constituent materials.

  Next, as shown in FIG. 2A, the temporary transfer substrate 16 and the transfer destination substrate are interposed by interposing an adhesive 22 between one surface of the temporary transfer substrate 16 and one surface of the transfer destination substrate 20. 20 is joined. Examples of the adhesive 22 used in this step include acrylate resin-based and epoxy resin-based adhesives.

  Next, as shown in FIG. 2B, the water-soluble adhesive 18 is dissolved and removed by supplying water as a dissolving liquid to the water-soluble adhesive 18. As a result, the transfer target 14 is transferred from the temporary transfer substrate 16 to the transfer destination substrate 20.

  As described above, according to the present embodiment, the transfer source substrate 10 which is the substrate to be removed is more easily bent than the temporary transfer substrate 16, thereby avoiding the damage of each substrate and the like. The occurrence of defects can be reduced.

  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. 5 is a schematic perspective view illustrating an example of an electronic apparatus. FIG. 5A 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. 5B 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. 5C illustrates an example of application to a television device, and the television device 550 includes a display portion 551. FIG. 5D 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, in the above-described embodiment, the embodiment of the present invention will be described by exemplifying a case where the present invention is applied to a process of transferring a transfer object from a transfer source substrate to a temporary transfer substrate in a so-called twice transfer process. However, the application range of the present invention is not limited to this, and the present invention can also be applied to the case where the transfer of the transfer target is completed by a single transfer process.

It is a figure explaining the manufacturing method of the thin film device of one Embodiment. It is a figure explaining the manufacturing method of the thin film device of one Embodiment. It is sectional drawing which shows the specific example of a to-be-transferred body. It is the elements on larger scale explaining in detail the process of separating each substrate. It is a schematic perspective view which shows the example of an electronic device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Transfer source substrate (first substrate), 12 ... Release layer, 14 ... Transfer object, 16 ... Temporary transfer substrate (second substrate), 18 ... Water-soluble adhesive, 20 ... Transfer destination substrate, 22 ... Adhesive

Claims (5)

A first step of forming a transfer body on the one surface side of the first substrate having a release layer on one surface side;
A second step of bonding the first substrate and the second substrate by interposing an adhesive between the one surface of the second substrate and the one surface of the first substrate;
A third step of causing peeling in an interface between the peeling layer and the first substrate or in the peeling layer layer by applying energy to the peeling layer of the first substrate;
A fourth step of separating the first substrate and the second substrate and transferring the transferred object from the first substrate to the second substrate;
A method for manufacturing a thin film device, wherein the first substrate is more flexible than the second substrate.   2. The method of manufacturing a thin film device according to claim 1, wherein the first substrate is made of the same constituent material as the second substrate and is thinner than the second substrate.   The thin film device manufacturing method according to claim 1, wherein the first substrate is made of a constituent material having a smaller elastic modulus than that of the constituent material of the second substrate.   The thin film device manufacturing method according to claim 1, wherein the fourth step is performed by fixing the second substrate and applying an external force to the first substrate. The electronic device comprised including the thin film device manufactured by the manufacturing method in any one of Claims 1 thru | or 4.

Images