KR20210072109A - Micro device transfer device and manufacturing method thereof - Google Patents

Abstract

The present invention discloses a micro device transfer apparatus and a method for manufacturing the same, wherein the transfer apparatus includes a substrate, a metal wiring, and a plurality of silicon electrodes. The metal wiring is formed on the flat surface of the substrate and includes a plurality of electrode driving units. The silicon electrode is formed on one side facing away from the substrate of the metal wiring, and each silicon electrode is installed to correspond to one electrode driving unit, and is driven by the electrode driving unit to pick up or release the micro device. The transfer device provided in the present invention can realize mass transfer of micro devices through electrostatic adsorption, and greatly improves the transfer efficiency.

Description

Micro device transfer device and manufacturing method thereof

The present invention relates to a micro device-related technical field, and more particularly, to a micro device transfer apparatus and a manufacturing method thereof.

One of the development trends of devices used by people in their daily life is miniaturization of devices. For example, in display devices, micro-LEDs are applied, that is, a plurality of micro-sized light-emitting diodes (LEDs) are integrated in the display panel, and it has become one of the current development directions of display technology. . Specifically, since micro light emitting diodes have extremely high luminous efficiency and lifetime, more and more companies have started researching and developing micro light emitting diode display panels, and micro light emitting diodes are expected as the next generation display technology.

In the manufacture of the current micro light emitting diode display panel, due to the limitation of the manufacturing process, high efficiency mass transfer of the micro light emitting diode cannot be realized.

The present invention provides a micro device transfer device and a method for manufacturing the same, which can solve the problem that high-efficiency mass transfer of micro light emitting diodes cannot be realized in the prior art.

In order to solve the above technical problem, the present invention provides a micro device transfer device. The transfer apparatus includes a substrate, metal wiring, and a plurality of silicon electrodes. The substrate includes a flat surface, and the metal wiring is formed on the flat surface of the substrate, and includes a plurality of electrode driving units. The silicon electrode is formed on one side facing away from the substrate of the metal wiring, and each silicon electrode is installed to correspond to one electrode driving unit, and is driven by the electrode driving unit to pick up or release the micro device.

The metal wiring includes a single-layer metal layer, and the single-layer metal layer includes at least one of Cr, Cu, Au, Ni, W, Mo, Ti, and TiN, and has a thickness of 0.1 to 1 μm.

Here, the metal wiring includes an adhesive metal layer and a bonding metal layer sequentially stacked on the substrate, and the silicon electrode is formed on one side of the bonding metal layer facing the substrate.

The material of the adhesive metal layer includes metal Ti or TiN, and has a thickness of 0.1 to 1 μm.

The material of the bonding metal layer includes Au, and the thickness is 0.1 to 2 μm.

Here, the electrode driving unit includes an electrode bonding region and a driving wire region, and the silicon electrode is formed on one side of the electrode bonding region facing away from the substrate.

Here, a plurality of electrode driving units are arranged in an array, and a plurality of silicon electrodes are arranged in an array.

Here, the metal wiring further includes a driving connection sheet and is connected to the plurality of electrode driving units, and the driving connection sheet is used to connect between the external circuits so that the external circuit controls the electrode driving unit through the driving connection sheet.

Here, a dielectric layer is laid on the surface of the silicon electrode.

Here, the silicon electrode is a low resistance silicon electrode.

Here, an insulating layer is formed on the substrate, and the metal wiring is formed on the insulating layer.

Here, the thickness of the substrate is 250 to 1000 μm, and the thickness of the insulating layer is 0.1 to 3 μm.

In order to solve the above technical problem, the present invention provides a method for manufacturing a micro device transfer device. The manufacturing method is:

providing a substrate comprising a flat surface;

forming a metal wiring including a plurality of electrode driving units on a flat surface of the substrate;

and forming a plurality of silicon electrodes on the metal wiring, wherein each of the silicon electrodes is installed to correspond to one electrode driving unit.

Here, the step of forming a plurality of silicon on the metal wiring is

depositing and forming a silicon electrode layer on the metal wiring;

and forming the plurality of silicon electrodes by patterning the silicon electrode layer.

Here, the step of forming a plurality of silicon electrodes on the metal wiring is

providing a silicon sheet comprising a substrate layer and an upper layer silicon;

forming the plurality of silicon electrodes by patterning the upper layer silicon;

A silicon sheet on which a plurality of the silicon electrodes are formed is bonded to a substrate on which a metal wiring is formed to form the silicon electrode on the metal wiring.

The manufacturing method further includes the step of laying a dielectric layer on the surface of the silicon electrode, and exposing at least some metal wires to the transfer device to form a driving connection sheet connected to an external circuit.

The micro device transfer apparatus of the present invention includes a substrate, a metal wiring, and a plurality of silicon electrodes. The metal wiring is formed on the surface of the substrate and includes a plurality of electrode driving units. The silicon electrode is formed on one side facing away from the substrate of the metal wiring, and each silicon electrode is installed to correspond to one electrode driving unit, and is driven by the electrode driving unit to pick up or release the micro device. The transfer apparatus of the present invention uses static electricity to adsorb microelements to implement mass transfer of microelements, and greatly improves transfer efficiency.

In order to more clearly explain the technical solutions in the embodiments of the present invention, the following briefly introduces the attached drawings used in the description of the embodiments, and the attached drawings described below are only some embodiments of the present invention. It will be apparent to those skilled in the art that other drawings may be obtained according to these drawings without creative efforts of those skilled in the art.
1 is a structural diagram of an embodiment of a micro device transfer apparatus of the present invention;
2 is a structural diagram of another embodiment of the micro device transfer apparatus of the present invention;
Fig. 3 is an exemplary structural diagram of an electrode driving unit in the embodiment of the micro device transfer device shown in Fig. 2;
Fig. 4 is another structural example diagram of an electrode driving unit in the embodiment of the micro-element transfer device shown in Fig. 2;
5 is a flowchart illustrating an embodiment of a method for manufacturing a micro device transfer device of the present invention;
6 is a flowchart illustrating an embodiment of forming a plurality of silicon electrodes on a metal wiring in the manufacturing method shown in FIG. 5;
7 is a process flow diagram illustrating an embodiment of the manufacturing method illustrated in FIG. 6 ;
8 is a flowchart illustrating another embodiment of forming a plurality of silicon electrodes on a metal wiring in the manufacturing method shown in FIG. 5;
9 is a view illustrating a process process of an embodiment of the manufacturing method shown in FIG. 8 .

In order for those skilled in the art to better understand the technical solution of the present invention, below, in combination with the accompanying drawings and specific embodiments, the micro device transfer device provided by the present invention and its manufacturing method will be described in more detail. . The micro device includes a micro light emitting diode (Micro-LED), a micro-OLED or other micro-sized electronic device.

The transfer device of the present invention is used to implement the transfer of microelements, taking a micro light emitting diode display panel as an example, and the transfer device of the present invention can implement selective transfer of micro light emitting diodes in large quantities. All micro devices having the same micro characteristics as other micro light emitting diodes can implement mass-selective transfer using the transfer device of the present invention. The micro light emitting diode, that is, the micro device in the present invention is used to realize the self-luminescence of the pixel in the display panel, and one micro device is one pixel point, and in the current display panel, the number of pixel points is usually thousands Since there are tens of thousands of micro devices, there are also tens of thousands of micro devices installed to correspond to the display panel. In general, a micro device is first grown on a growth substrate, and then the growth substrate is transferred to a driving substrate to constitute a display panel. In the above transfer process, the transfer device presented in the present invention uses an electrostatic adsorption micro device, , by applying a voltage to the electrode, the electrode is controlled to selectively pick up or release the micro device, realizing the mass transfer of the micro device, and improving the production efficiency of the display panel.

Specifically, the transfer apparatus of the present invention refers to Fig. 1, which is a structural diagram of an embodiment of the micro device transfer apparatus of the present invention. The micro device transfer apparatus 100 of this embodiment includes a substrate 11 , a metal wiring 12 , and a plurality of silicon electrodes 13 .

The substrate 11 is used to load the metal wiring 12 and the silicon electrode 13 for implementing electrostatic transfer, and an optional material thereof may be a transparent or opaque material, for example, silicon or Pyrex glass. . The substrate 11 has a flat structure, and the surface on which the metal wiring is installed is a flat surface 111. The metal wiring 12 includes a plurality of electrode driving units, and the flat surface 111 of the substrate 11 is provided. is formed in That is, the metal wiring 12 work is performed on the flat surface 111 of the substrate 11 to form a plurality of electrode driving units. Since the metal wiring 12 is formed on the flat surface 111, the metal wiring 12 itself is also flat. It is formed in layers, and therefore, compared to that formed on the uneven surface, the metal wiring 12 formed on the plane in this embodiment can be made more precise. The metal wiring 12 constitutes an electrical transmission circuit to implement independent driving for each electrode.

The silicon electrode 13 is formed on one side facing the substrate 11 of the metal wiring 12, and each silicon 13 is installed to correspond to one electrode driving unit, and is driven by the electrode driving unit to form a micro device. Pick up or release In this embodiment, the silicon electrode 13 formed on the metal wiring 12 can be used as an electrostatic electrode that simultaneously implements a bump structure and electrostatic absorption corresponding to a micro device. Here, the silicon electrode 13 is manufactured using a silicon material, and can be directly formed on the flat metal wiring 12 through the method of wafer bonding. If a bump structure or an electrostatic electrode is manufactured using other materials, concavities and convexities After installing the structure, it is necessary to form an electrostatic electrode by forming a metal wiring on the ferrous structure, and also to install a bump structure on the electrostatic electrode to cope with the absorption of microelements.

In addition, the silicon electrode 13 is formed directly on the flat metal wiring 12, and a relatively high electrostatic electrode can be installed, thereby generating a certain strength of adsorption force for the micro device, and the electrostatic electrode of a certain height can be connected with it. The effect of electrostatic adsorption on adjacent microdevices is relatively small. In the method of forming the electrostatic electrode by forming the metal wiring in the concave-convex structure, the concave-convex structure must not be too high, otherwise it is disadvantageous to the metal wiring. Therefore, the silicon electrode used in this embodiment has a simple structure as well as a simple process, and is more efficient and stable in adsorption to micro devices. In addition, the transfer device of this embodiment configures an electrode driving unit through a metal wiring to control each silicon electrode, and when a voltage is applied to the metal wiring, that is, the electrode driving unit, the silicon electrode forms an electrostatic adsorption force to form a micro device. pick up Each of the electrode driving units of the transfer device of this embodiment can be controlled separately, that is, each of the silicon electrodes can be driven independently, and thus it is possible to implement selective pickup or release of microelements.

Based on the embodiment of the transfer apparatus shown in Fig. 1, the present invention further presents another embodiment, with reference to Fig. 2. Fig. 2 is a structural diagram of another embodiment of the micro-element transfer apparatus of the present invention. . The transfer apparatus 200 includes a substrate 21 , a metal wiring 22 , a plurality of silicon electrodes 23 , an insulating layer 24 , and a dielectric layer 25 . All descriptions of the embodiment illustrated in FIG. 1 can be applied to the embodiment illustrated in FIG. 2 , and repeated descriptions are not provided herein.

It should be explained that in this embodiment, the thickness of the substrate 21 is 250 to 1000 μm, and a flat insulating layer 24 is further formed on its surface, and the metal wiring 22 is formed on the insulating layer 24 surface. , the insulating layer 24 is formed by depositing a material such as silicon dioxide, silicon nitride or alumina, which is convenient for the deposition of the metal wiring 22, and prevents the substrate 21 of the silicon material from affecting the metal wiring 22 prevent. The thickness of the insulating layer 24 may be 0.1 to 3 μm.

The metal wiring 22 may be manufactured and formed using a single-layer metal, specifically, a microelectronic metal material, for example, at least one of Cr, Cu, Au, Ni, W, Mo, Ti, and TiN is used. and its thickness may be 0.1 to 1 μm. The metal wiring 22 may be manufactured using a multi-layered metal. For example, in this embodiment, the metal wiring 22 includes an adhesive metal layer and a bonding metal layer sequentially stacked on a substrate, wherein the adhesive metal layer is made of metal Ti, TiN, etc. that are easily adhered to the insulating layer 24 . The thickness may be 0.1 to 1 μm, and the bonding metal layer uses a silicon electrode and a material that easily implements bonding, such as Au, and the thickness may be 0.1 to 2 μm. The silicon electrode 23 is also formed on one side facing away from the substrate 21 of the bonding metal layer.

The silicon electrode 23 is formed on one side facing away from the substrate of the bonding metal layer. The silicon electrode 23 may be a single electrode or a double electrode, and for different types of electrodes, the metal wiring 22 uses a different design, that is, the formed electrode driving unit 221 has a different structure accordingly. use the

Referring specifically to 3 and 4, FIG. 3 is an exemplary view of the structure of the electrode driving unit in the embodiment of the micro device transfer device shown in FIG. 2, and FIG. 4 is the implementation of the micro device transfer device shown in FIG. It is another structural example diagram of the electrode driving unit in the example.

The structure of the electrode driving unit in FIGS. 3 and 4 corresponds to a single electrode and a double electrode, respectively, and in FIG. 3 , the electrode driving unit 221 includes one driving wire region 2211 and one electrode bonding region 2212 . The electrode driving unit 221 in FIG. 4 includes two electrode driving wire regions 2211 and two electrode bonding regions 2212 .

Here, the driving wire region 2211 is used to be connected to the driving line, and the electrode bonding region 2212 is used to be connected to the silicon electrode 23, so in this embodiment, the adhesive metal layer is mainly used for the driving wire region 2211. and the bonding metal layer mainly constitutes the electrode bonding region 2212 . That is, the silicon electrode 23 is formed on one side of the electrode bonding region 2212 facing away from the substrate 21 .

Similar to the micro light emitting diodes arranged in an array in a micro light emitting diode display panel, the present invention uses the design of the array arrangement accordingly for the transfer of the arrayed micro elements. That is, a plurality of electrode driving units in the metal wiring 22 . 221 uses an array arrangement, and the silicon electrode 23 formed on the metal wiring 22 uses an array arrangement.

In order to implement electrical driving for the electrode driving unit 221, the formed metal wiring 22 further includes a driving connection sheet 222, and the driving connection sheet 222 includes a plurality of electrode driving units 221 and an external circuit. By connecting them, an external circuit controls the electrode driving unit 221 through the driving connection sheet 222 .

In this embodiment, the dielectric layer 25 is further laid on the surface of the silicon electrode 23, so that the exposure of electric charges can be effectively prevented. The materials of the insulating layer 24 and the dielectric layer 25 may be the same, simplifying the manufacturing process. Their material can use insulating media such as silicon dioxide, silicon nitride and alumina, and the thickness is 0.1~2μm installed. In addition, the silicon electrode 23 can be an electrode by selecting low-resistance silicon, and has better conductivity.

In this embodiment, the metal wiring of the moving device is further improved, and all the metal wiring is installed on a flat insulating layer surface, that is, each silicon can be controlled separately, and also the manufacturing process is convenient.

Since the volume of the micro device is very small, the silicon electrode of the transfer device must also be designed to be very small. The micro device transfer device of the present invention is mainly manufactured using a Micro-Electro-Mechanical System (MEMS) process. will be. MEMS refers to high-tech devices that are a few millimeters or smaller in size, internal structures are typically microns or even nanoscale, and are self-contained intelligent systems.

For a detailed manufacturing process, refer to FIG. 5, and FIG. 5 is a flowchart illustrating an embodiment of a method for manufacturing a micro device transfer device of the present invention.

S11: Provide a diary.

In this embodiment, a single crystal silicon sheet can be selected as a substrate, and the thickness thereof is 250 to 1000 μm.

S12: An insulating layer is formed on the flat surface of the substrate.

An insulating layer is prepared on a flat surface of the substrate, and an insulating material such as silicon dioxide or silicon nitride can be selected and deposited, and the insulating layer thickness can be selected from 0.1 to 3 μm.

S13: A metal wiring is formed on the surface of the insulating layer, and the metal wiring includes a plurality of electrode driving units.

In this embodiment, the fabrication of the metal wiring can be completed through the sputtering process, and corresponding to the above embodiment, the metal wiring may be a single-layer metal or a multi-layer metal. Taking the two-layer metal as an example, first, an adhesive metal layer can be sputtered on the surface of the insulating layer, and as the wiring metal, the material can be selected from Ti and TiN, and the thickness is 0.1 to 2 microns. Then, a bonding metal layer is formed through a sputtering process, the material may be Au, and the thickness is 0.1 to 2 microns. Finally, the metal wiring is patterned through photolithography etching to form an electrode driving unit and a driving connecting sheet.

S14: A plurality of silicon electrodes are formed on the metal wiring, and each silicon electrode is provided corresponding to one electrode driving unit.

Forming the silicon electrode in this step (S14) can be completed by various processes. First, referring to FIGS. 6 and 7, FIG. 6 is a flowchart illustrating an embodiment of forming a plurality of silicon electrodes on a metal wiring in the manufacturing method shown in FIG. 5, and FIG. 7 is a manufacturing method shown in FIG. It is an illustration of the process process of an embodiment.

S141: A silicon electrode layer is deposited on the metal wiring.

A silicon electrode layer can be deposited on a metal wiring and a substrate through Chemical Vapor Deposition (CVD) or ion implantation. Specifically, low-resistance silicon is used.

S143: The silicon electrode layer is patterned to form a plurality of silicon electrodes.

The silicon electrode layer 20 is etched using photolithography, and a patterned bump silicon electrode can be formed corresponding to the electrode driving unit.

This method mainly uses deposition and etching processes to complete the silicon electrode structure, and the process is simple.

Next, referring to FIGS. 8 and 9 , FIG. 8 is a flowchart illustrating another embodiment of forming a plurality of silicon electrodes on a metal wiring in the manufacturing method illustrated in FIG. 5 . 9 is a view illustrating a process process of an embodiment of the manufacturing method shown in FIG. 8 .

S142: A silicon sheet is provided, wherein the silicon sheet includes a substrate layer and an upper layer silicon.

The silicon sheet 30 can select a silicon-on-insulator (SOI) material, and specifically includes an upper silicon layer and a substrate layer, and an acid-repellent layer between them. The silicon sheet of the above structure reduces parasitic capacitance and has lower power consumption. The top silicon thickness is chosen between 1 and 100 microns, and the resistivity is less than 1 ohm per centimeter.

S144: The upper layer silicon is patterned to form a plurality of silicon electrodes.

The upper layer silicon is etched to form a plurality of silicon electrodes, and the etching depth is 1 to 100 microns, and the etching depth is the finally obtained height as a silicon electrode.

S146: A silicon sheet on which a plurality of silicon electrodes are formed is bonded to a substrate on which a metal wiring is formed to form a silicon electrode on the metal wiring.

The silicon sheet 30 is wafer bonded to the substrate. For example, the bonding metal of the metal wiring on the substrate uses Au, and this process can be completed through a bonding method such as Au-Si co-crystal bonding through Au. . Next, the substrate layer and the acid sleeve layer of the silicon sheet 30 are removed through an etching process to finally form a bump silicon electrode on the substrate.

In this embodiment, the fabrication of the silicon electrode is mainly completed through wafer bonding and etching processes, and the process is simple.

After completing the step S14, further, in the present embodiment, the step S15 is further performed.

S15: A dielectric layer is laid on the surface of the silicon electrode, and a driving connection sheet is formed on the transfer device.

A dielectric layer is laid on the surface of the silicon electrode, and in this embodiment, compact alumina can be grown through atomic layer deposition, and the thickness can be 0.1 to 2 microns. Alumina is a high-hardness compound, has no conductivity, and is an insulating medium that has both a protective action. Finally, some dielectric layers are etched through photolithography, exposing some metal wires to make a driving connection sheet that can be connected to external circuits.

In this embodiment, a method for manufacturing a micro device transfer device is disclosed, and the method is simple in operation and simple in process, easy to mass-produce in actual production, and has relatively high practicality and usability.

The above is merely an embodiment of the present invention, and thus does not limit the scope of the patent of the present invention, and an equivalent structure or equivalent process transformation according to the contents of the specification and attached drawings of the present invention, or directly or indirectly applied to other related technical fields. All of these will be included within the scope of the patent protection of the present invention.

Claims (16)

A transfer device used to transfer microdevices, comprising:
a substrate comprising a flat surface;
a metal wiring formed on the flat surface of the substrate and including a plurality of electrode driving units;
and a plurality of silicon electrodes formed on one side of the metal wiring facing away from the substrate,
Each of the silicon electrodes is installed in correspondence with the electrode driving unit, and is driven by the electrode driving unit to pick up or release the micro device. According to claim 1,
The metal wiring includes a single-layer metal layer, and the single-layer metal layer includes at least one of Cr, Cu, Au, Ni, W, Mo, Ti, and TiN, and has a thickness of 0.1 to 1 μm. According to claim 1,
The metal wiring includes an adhesive metal layer and a bonding metal layer sequentially stacked on the substrate, and the silicon electrode is formed on one side of the bonding metal layer away from the substrate. 4. The method of claim 3,
The material of the adhesive metal layer includes a metal Ti or TiN, the thickness of the transfer device is 0.1 ~ 1㎛. 4. The method of claim 3,
The material of the bonding metal layer includes Au, and the thickness of the transfer device is 0.1 to 2 μm. 3. The method of claim 2,
The electrode driving unit includes an electrode bonding region and a driving wire region, and the silicon electrode is formed on one side of the electrode bonding region facing away from the substrate. According to claim 1,
The plurality of electrode driving units are arranged in an array, and the plurality of silicon electrodes are arranged in an array. According to claim 1,
The metal wiring further includes a driving connection sheet and is connected to the plurality of electrode driving units, and the driving connection sheet is used to connect between external circuits to control the electrode driving unit through the external circuit virtual driving connection sheet A transfer device to make it happen. According to claim 1,
A transfer device in which a dielectric layer is laid on the surface of the silicon electrode. According to claim 1,
The silicon electrode is a low-resistance silicon electrode transfer device. According to claim 1,
An insulating layer is formed on the substrate, and the metal wiring is formed on the insulating layer. According to claim 1,
The thickness of the substrate is 250 to 1000 μm, and the thickness of the insulating layer is 0.1 to 3 μm. A method of manufacturing a transfer device, wherein the transfer device is used to transfer a microdevice, the manufacturing method comprising:
providing a substrate comprising a flat surface;
forming a metal wiring including a plurality of electrode driving units on a flat surface of the substrate;
and forming a plurality of silicon electrodes on the metal wiring,
Each of the silicon electrodes is a method of manufacturing a transfer device that is installed to correspond to one electrode driving unit. 14. The method of claim 13,
The step of forming a plurality of silicon on the metal wiring is
depositing and forming a silicon electrode layer on the metal wiring;
and forming the plurality of silicon electrodes by patterning the silicon electrode layer. 14. The method of claim 13,
The step of forming a plurality of silicon electrodes on the metal wiring is
providing a silicon sheet comprising a substrate layer and an upper layer silicon;
forming the plurality of silicon electrodes by patterning the upper layer silicon;
A method of manufacturing a transfer device for forming the silicon electrode on the metal wiring by bonding a silicon sheet on which the plurality of silicon electrodes are formed to a substrate on which a metal wiring is formed. 14. The method of claim 13,
Further comprising the step of laying a dielectric layer on the surface of the silicon electrode,
A method of manufacturing a transfer apparatus, wherein at least some metal wires are exposed to the transfer apparatus to form a driving connection sheet connected to an external circuit.

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