KR101372395B1 - Method for separating nanogenerator and method for manufacturing nanogenerator using the same - Google Patents

Abstract

The present invention relates to a method for separating a nanogenerator characterized in including the step of manufacturing the nanogenerator on a sacrificial substrate; the step of laminating a metal layer on the nanogenerator; and the step of separating a part of the sacrificial substrate by mounting mechanical or thermal energy to the metal layer. According to one embodiment, the nanogenerator is separated by using the difference of stress between the sacrificial substrate and the metal layer, not by separating the nanogenerator from the sacrificial substrate through an existing wet etching. As such, the method is safer and more economically feasible than a chemical separation method using an etching solution since the nanogenerator can be separated from the sacrificial substrate in a mechanical way. Moreover, the method can prevent the damage to the nanogenerator due to the etching solution in advance.

Description

Separation method of nanogenerator and manufacturing method of flexible nanogenerator using same {METHOD FOR SEPARATING NANOGENERATOR AND METHOD FOR MANUFACTURING NANOGENERATOR USING THE SAME}

The present invention relates to a method for separating a nanogenerator and a method for manufacturing a flexible nanogenerator using the same, and more specifically, to separate a nanogenerator using a stress difference between a sacrificial substrate and the metal layer, and thus, a solid state thin film in a mechanical manner. Since the nanogenerator can be separated from the sacrificial substrate, the present invention relates to a method of device separation and a method of manufacturing a flexible nanogenerator using the same, which is safer and more economical than a chemical separation method using an etchant.

Nowadays, the development of information and communication technologies is leading to the need for new types of high performance flexible devices. In order to operate such electronic devices, a flexible energy device technology capable of supplying and storing an energy source together with a high performance semiconductor device is required.A high performance energy production or storage technology cannot be realized due to the limitation of the plastic substrate, which cannot be processed at a high temperature. It was. Conventional piezoelectric devices such as piezoelectric devices are manufactured on rigid silicon substrates and are being applied in the same form, because the manufacturing process of these devices is manufactured through high temperature semiconductor processes. However, the limitation of such an element substrate has a problem of limiting the application range of a piezoelectric element, a secondary battery, and the like.

In particular, one of the elements whose effect is limited by the substrate limitation is a piezoelectric element. The piezoelectric element means an element exhibiting a piezoelectric phenomenon. The piezoelectric element is also referred to as a piezoelectric element, and quartz, tourmaline, Rochelle salt, etc. have been used as piezoelectric elements since early, and lead zirconate, barium titanate (BaTiO3, BTO), ammonium dihydrogen phosphate, and tartaric acid have been recently developed. Artificial crystals such as ethylenediamine also have excellent piezoelectric properties, and doping can lead to better piezoelectric properties.

Such a piezoelectric element generates electricity according to a pressure applied from the outside, or when the piezoelectric element is applied to a flexible substrate which can be naturally bent, it is possible to immediately convert the bending property of the naturally occurring flexible substrate into electrical energy. There is an advantage, but piezoelectric elements, particularly large area piezoelectric elements, implemented in the flexible substrate have not been disclosed. Furthermore, in order to charge the generated electrical energy, the conventional technique usually uses a separate charging means outside the BTO element, but this has a problem of excessively occupying the size of the device using the piezoelectric element.

In addition, the microgenerators, ie, nanogenerators, which are completed through high temperature processes are very important to be separated from the sacrificial substrate. Currently, general device separation is performed by etching with a chemical solution. However, in this case, problems such as element damage by the etchant, exposure of the worker to a dangerous working environment, element deformation by the etchant, and the like occur.

Accordingly, an object of the present invention is to provide a novel method for separating nanogenerators and a method for producing nanogenerators based thereon.

In order to solve the above problems, the present invention comprises the steps of manufacturing a nanogenerator on a sacrificial substrate; Depositing a metal layer on the nanogenerator; And separating part of the sacrificial substrate by applying mechanical or thermal energy to the metal layer.

According to an embodiment of the present invention, the sacrificial substrate is provided with an etch mask layer including silicon oxide or silicon nitride.

According to one embodiment of the present invention, in accordance with the separating step, some layers of the sacrificial substrate; An etch mask layer disposed on a portion of the sacrificial substrate; And a nanogenerator provided on the etching mask layer.

According to an embodiment of the present invention, the separation is performed by incompatibility of the residual compressive stress of the sacrificial substrate and the residual tensile stress of the metal layer, and the separation proceeds in the horizontal direction of the sacrificial substrate.

According to an embodiment of the present invention, the device isolation method further includes removing a part of the sacrificial substrate and then removing a part of the sacrificial substrate according to a chemical etching process.

According to an embodiment of the present invention, the sacrificial substrate is a silicon substrate, and the metal layer is a nickel layer.

The present invention also provides a flexible nanogenerator, wherein the nanogenerator is manufactured on a sacrificial substrate and then separated from the sacrificial substrate according to a horizontal crack of the sacrificial substrate.

According to an embodiment of the present invention, an etching mask layer, which is a silicon oxide or silicon nitride layer, is provided below the nanogenerator.

The present invention also provides a method for manufacturing a flexible nanogenerator, the method comprising the steps of: laminating an etching mask layer including silicon oxide or silicon nitride on a silicon substrate (100); Manufacturing a nanogenerator (300) on the etching mask layer (200); Stacking a nickel layer (400) on the nanogenerator (300); Applying mechanical or thermal energy to the nickel layer (400) to generate a crack in the silicon substrate in a horizontal direction; Separating the nanogenerator (300) and the nickel layer (400) from the silicon substrate (100) by the crack in the horizontal direction; And removing some silicon substrates 110 remaining under the nanogenerators 300. It provides a method of manufacturing a flexible nanogenerator comprising the step of transferring the nanogenerator to the flexible substrate (500).

According to one embodiment of the present invention, the crack in the horizontal direction is carried out at a thickness of 10 ~ 15μm from the top of the silicon substrate.

According to an embodiment of the present invention, the method of manufacturing the flexible nanogenerator may further include removing the nickel layer after removing some of the silicon substrates 110 remaining under the nanogenerator 300. It provides a method for producing a flexible nano-generator characterized in that.

According to an embodiment of the present invention, the method of manufacturing the flexible nanogenerator may include transferring the nanogenerator to the flexible substrate after removing the partial silicon substrate 110 and before removing the nickel layer. It includes more.

The present invention also provides a flexible nanogenerator produced by the method described above.

The present invention separates the nanogenerators by using the stress difference between the sacrificial substrate and the metal layer, rather than separating the nanogenerators from the sacrificial substrate through a conventional wet etching process. Therefore, since the nanogenerator can be separated from the sacrificial substrate in a mechanical manner, it is safer and more economical than the chemical separation method using an etchant. Furthermore, there is an advantage that damage to the nanogenerator due to the etchant can be avoided in advance.

1 to 13 are a plan view and a cross-sectional view of the nano-generator manufacturing method according to an embodiment of the present invention.

Hereinafter, an element isolation method according to each embodiment of the present invention will be described with reference to the accompanying drawings.

The following examples are intended to illustrate the present invention and should not be construed as limiting the scope of the present invention. Accordingly, equivalent inventions performing the same functions as the present invention are also within the scope of the present invention.

In addition, in adding reference numerals to the constituent elements of the drawings, it is to be noted that the same constituent elements are denoted by the same reference numerals even though they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; may be "connected," "coupled," or "connected. &Quot;

A nanogenerator based on a piezoelectric material was prepared on a sacrificial substrate of the present invention on a silicon substrate on which an etch mask layer was stacked, and then a metal layer was laminated on the device, and then mechanical or thermal energy was applied to the metal layer. A device isolation method for separating a portion of the sacrificial substrate is provided. In the present specification, the nanogenerator refers to a micro power generator capable of self-producing a current by an external physical force such as bending of a substrate.

A technical feature of the present invention is to use a stress difference between a metal layer and a sacrificial substrate to generate a horizontal crack in the sacrificial substrate and to separate the device manufactured by a conventional method on the sacrificial substrate, Is followed by a conventional technique. Here, the difference in stress is a difference between the tensile stress of the metal layer and the compressive stress of the sacrificial substrate, and the difference between the stress that the metal layer stretches due to the external energy and the stress of the sacrificial substrate, Cracks occur. According to the present invention, since the device can be separated from the sacrificial substrate in a mechanical manner, there is an advantage that it is safer and more economical than the chemical separation method using an etchant. Hereinafter, an embodiment using a nanogenerator as a device The present invention will be described in more detail.

1 to 10 are a plan view and a cross-sectional view of the nano-generator manufacturing method according to an embodiment of the present invention.

Referring to FIG. 1, a silicon substrate 100 as a sacrificial substrate is disclosed. In the present invention, the sacrificial substrate 100 provides a stress deviation with a metal layer to be laminated later, so that a part of the substrate is separated. In an embodiment of the present invention, the compressive stress of the silicon substrate 100 is inconsistent with the tensile stress of the metal layer, and then the silicon substrate 100 is cracked in the horizontal direction by external energy applied thereto. Cracks are described in more detail below. In the present invention, since the thickness of the cracked substrate is controlled and controlled according to the stress difference between the metal layer and the sacrificial substrate, flexible characteristics can be given to the substrate itself separated as necessary.

Referring to FIG. 2, an etch mask layer 200, such as silicon oxide, is deposited on the silicon substrate 100. In the present invention, when the silicon substrate 100 is later removed, the etching mask layer 200 becomes a kind of support substrate for supporting the device, and when the sacrificial substrate separated by the crack is removed by the etching process, the etching is performed. It can serve as a stop layer for the process. In one embodiment of the present invention, the etch mask layer is silicon oxide, but alternatively silicon nitride may be used.

3 and 4, the nanoelectrode 300 is manufactured by sequentially stacking the lower electrode layer 301, the piezoelectric material layer 302, and the upper electrode layer 303 on the etching mask layer 200. The piezoelectric material layer 302 is a power generation layer that produces a current according to the bending of the flexible substrate to be transferred later. In the embodiment of the present invention, the piezoelectric material layer 302 was BTO, but the scope of the present invention is not limited thereto. Do not.

The lower electrode layer, the piezoelectric material layer, and the upper electrode layer may be stacked according to a metal lamination process according to the prior art. After lamination, a heat treatment process may be performed to fabricate a nanogenerator using a piezoelectric material such as BTO. Through such heat treatment, the piezoelectric material is crystallized, and an electric field is applied by giving a voltage difference to the upper electrode and the lower electrode again. At this time, the larger the electric field applied to the leakage current (leakage current) is a problem that the electric field is not properly generated. To solve this problem, the leakage current may be minimized by increasing the thickness of the BTO or by forming an insulating material (not shown) under and below the piezoelectric material layer such as BTO. In particular, since the present invention proceeds a high temperature heat treatment process and a voltage application process in a sacrificial substrate such as silicon, it is possible to eliminate the process limitations due to the use of a flexible substrate.

Referring to FIG. 5, the nickel layer 400, which is a metal layer, is stacked on the nanogenerator 300 manufactured on the etch mask layer 200 of FIG. 4. According to the exemplary embodiment of the present invention, the nickel layer 400 may be stacked through a conventional semiconductor process such as sputtering or PVD, and may be stacked according to a conventional metal coating method. According to the lamination, the nickel 400 bonded to the nanogenerator 300 is formed.

Since the nickel layer 400, which is the stacked metal layer, has its own residual tensile stress, stress mismatch between the substrate and the nickel layer occurs accordingly (see FIG. 6).

Referring to FIG. 7, cracks, which are a phenomenon of cracking in a predetermined direction due to external physical shock or application of thermal energy, are generated. That is, a mismatch or asymmetry of the residual tensile stress of nickel and the residual compressive stress of the silicon substrate by applying mechanical energy (for example, physical impact) or thermal energy to the nickel layer 400 which is a metal layer having residual tensile stress. Due to its properties, cracks occur in the horizontal direction of the substrate at a depth of 10 to 15 μm above the silicon substrate, and the present invention is a metal layer having a tensile stress different from the residual compressive stress of the silicon substrate. The device is separated by generating energy by applying energy from the outside. Particularly, since the cracks of the silicon substrate itself are used for the separation of these devices, there is an advantage that the devices manufactured on the silicon substrate can be separated and transferred in a circular shape. In addition, since the crack formation height in the horizontal direction may be controlled according to the stress difference between the metal layer and the sacrificial substrate, if necessary, the lower substrate may be made to provide flexible characteristics to the sacrificial substrate such as silicon.

According to the process of FIG. 7 described above, a part of the silicon substrate 101 is cracked and separated from the silicon substrate 100 according to the residual tensile stress incongruity of the metal layer in contact with the silicon substrate. The thickness of 101 is about 10-15 micrometers.

8 and 9, the remaining silicon substrate 101 is then removed by chemical or physical etching processes. For example, the silicon substrate may be removed by immersing the portion of the silicon substrate 101 in a specific etching solution for removing the silicon substrate. Accordingly, the nanogenerator 300-nickel 400 manufactured on the etch mask layer 200 at the lower portion is manufactured.

Referring to FIG. 10, the nanogenerator 300-nickel 400 manufactured on the etch mask layer 200 is physically moved to the flexible substrate 500 to be bonded. As a result, the flexible nanogenerator 300 transferred to the flexible plastic substrate 500 is completed.

Referring to FIG. 11, the nickel layer 400 is removed through a conventional chemical etching process. For example, the nickel layer 400 may be removed by immersing an upper portion of the device bonded to the support layer 500 in a specific etching solution for etching the nickel layer 400. However, in addition to this, the nickel layer 400 may be selectively removed according to various conventional metal layer removal methods, which is also within the scope of the present invention.

Referring to FIG. 12, another electrode layer 600 may be stacked on the flexible nanogenerator 300, and the electrode layer 600 constitutes an upper electrode of the nanogenerator. That is, according to another embodiment of the present invention, the nanogenerator may be formed after the upper electrode is transferred to the flexible substrate, and FIG. 11 illustrates this. Gold, platinum, copper, and the like may be used as the electrode material, although nickel is a metal layer of several μm for peeling a silicon substrate, although it is a metal material, it is preferable to remove it with a specific etchant to maintain the flexibility of the device.

Referring to FIG. 13, nanogenerators may be provided on both sides of the flexible substrate in the same manner, thereby allowing the flexible nanogenerator to generate a positive voltage on one side and a negative voltage on the other side according to one direction bending of the flexible substrate. Is completed.

According to the present invention, the device is separated using a stress difference between a sacrificial substrate such as a silicon substrate and a metal layer such as nickel, rather than a method of separating the nanogenerator from the sacrificial substrate through a conventional wet etching process. do. Therefore, since the device can be separated from the sacrificial substrate in a mechanical manner, it is safer and more economical than a chemical separation method using an etchant. Furthermore, there is an advantage that the damage of the device due to the etchant can be avoided in advance.

It is to be understood that the terms "comprises", "comprising", or "having" as used in the foregoing description mean that the constituent element can be implanted unless specifically stated to the contrary, But should be construed as further including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (14)

Preparing a nanogenerator on the sacrificial substrate;
Depositing a metal layer on the nanogenerator;
Separating a portion of the sacrificial substrate by applying mechanical or thermal energy to the metal layer; And
After removing a portion of the sacrificial substrate, removing the portion of the sacrificial substrate by a chemical etching process;
Including;
And the separation is performed by incompatibility of the residual compressive stress of the sacrificial substrate and the residual tensile stress of the metal layer. The method of claim 1,
The method of claim 1, wherein the sacrificial substrate is provided with an etching mask layer including silicon oxide or silicon nitride. 3. The method of claim 2,
According to the separating step,
A partial layer of the sacrificial substrate;
An etching mask layer provided on a portion of the sacrificial substrate; And
Nanogenerator separation method characterized in that the nanogenerator provided on the etching mask layer is obtained. delete The method of claim 1,
The separation method of the nano-generator characterized in that the progress in the horizontal direction of the sacrificial substrate. delete The method of claim 1,
And wherein the sacrificial substrate is a silicon substrate and the metal layer is a nickel layer. A flexible nanogenerator prepared by the method according to any one of claims 1 to 3, 5 and 7. The method of claim 8,
A flexible nanogenerator, characterized in that an etching mask layer, which is a silicon oxide or silicon nitride layer, is provided below the nanogenerator. Flexible nanogenerator manufacturing method
Laminating an etch mask layer (200) comprising silicon oxide or silicon nitride on a silicon substrate (100);
Manufacturing a nanogenerator (300) on the etching mask layer (200);
Stacking a nickel layer (400) on the nanogenerator (300);
Applying mechanical or thermal energy to the nickel layer (400) to generate a crack in the silicon substrate in a horizontal direction;
Separating the nanogenerator (300) and the nickel layer (400) from the silicon substrate (100) by the crack in the horizontal direction; And
Separating some silicon substrates 101 remaining under the nanogenerators 300 and then removing the silicon substrates 101 by a chemical etching process;
Transferring the nanogenerator to the flexible substrate (500);
Including;
The separation is performed by the incompatibility of the residual compressive stress of the silicon substrate (100) and the residual tensile stress of the nickel layer (400). The method of claim 10,
The crack in the horizontal direction is a flexible nano-generator manufacturing method characterized in that proceeding from the top of the silicon substrate 10 ~ 15μm thick. The method of claim 11, wherein the flexible nanogenerator manufacturing method comprises
After removing the part of the silicon substrate (110) remaining in the lower portion of the nano-generator (300), the method further comprising the step of removing the nickel layer. The method of claim 12, wherein the flexible nanogenerator manufacturing method
The method of claim 1, further comprising the step of transferring the nanogenerator to a flexible substrate after removing the silicon substrate 110 and before removing the nickel layer. A flexible nanogenerator prepared by the method according to any one of claims 10 to 13.

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