TWI521690B - Transfer-bonding method for light-emitting devices and light-emitting device array - Google Patents

Description

Light-emitting element transfer method and light-emitting element array

The present application relates to a method of fabricating an array of light-emitting elements, and more particularly to a method of transferring a light-emitting element.

The inorganic light-emitting diode display has the characteristics of active light emission and high brightness, and thus has been widely used in the technical fields of illumination, display, and the like. However, monolithic micro-displays have always faced the technical bottleneck of colorization. At present, it has been proposed in the prior art to use a epitaxial technique to fabricate a plurality of light-emitting layers capable of emitting different colors of light in a single light-emitting diode wafer, so that a single light-emitting diode wafer can provide different color lights. However, since the lattice constants of the light-emitting layers capable of emitting different color lights are different, it is not easy to grow on the same substrate. In addition, other conventional techniques have proposed a colorization technique using a light-emitting diode chip with different color conversion materials, but this technology still faces problems such as low conversion efficiency and uniformity of color conversion materials.

In addition to the above two colorization techniques, there are also known techniques for the transfer of light-emitting diodes. Since the light-emitting diodes capable of emitting different color lights can be respectively grown on appropriate substrates, the light-emitting diodes can be compared. Good epitaxial quality and luminous efficiency. Therefore, the transposition technology of the light-emitting diode is more organic, which increases the brightness and display quality of the single-chip microdisplay. However, how to quickly and efficiently transfer the light-emitting diodes to the circuit substrate of the single-chip microdisplay is one of the current topics of concern in the industry.

An embodiment of the present application provides a method for transferring a light-emitting element and an array of light-emitting elements.

An embodiment of the present application provides a method for transferring a light-emitting element, which comprises the following steps (a) to (d). Step (a): forming a plurality of array-arranged light-emitting elements on a first substrate, each of the light-emitting elements including an element layer and a sacrificial pattern, and the sacrificial pattern is between the element layer and the first substrate. Step (b): forming a protective layer on the first substrate to selectively cover a portion of the light-emitting elements, wherein a portion of the light-emitting elements are not covered by the protective layer. Step (c): bonding the component layer not covered by the protective layer to a second substrate. Step (d): removing the sacrificial pattern covered by the unprotected layer to separate part of the element layer from the first substrate and transferring it onto the second substrate.

An embodiment of the present application provides an array of light-emitting elements, including a circuit substrate and a plurality of component layers capable of emitting different colors of light, wherein the circuit substrate has a plurality of pads and a plurality of conductive bumps on the pads, and more An element layer capable of emitting different color lights is electrically connected to the circuit substrate through the conductive bumps and the pads. The element layers capable of emitting different color lights have different thicknesses, and the conductive bumps joined to the element layers capable of emitting different color lights have different heights such that the top surfaces of the element layers capable of emitting different color lights are at the same level.

Another embodiment of the present application provides an array of light emitting elements including a circuit substrate and a plurality of component layers capable of emitting different color lights, wherein the circuit substrate has a plurality of pads and a plurality of conductive bumps on the pads, and A plurality of component layers capable of emitting different color lights are electrically connected to the circuit substrate through the conductive bumps and the pads. Component layer capable of emitting different colored lights There are different thicknesses, and the conductive bumps that are bonded to the component layers capable of emitting different colored lights have different heights so that the top surfaces of the component layers capable of emitting different colored lights are at different levels.

One embodiment of the present application can quickly and efficiently transfer a light-emitting element from one substrate to another, contributing to the application of the light-emitting element in the field of microdisplays.

In order to make the above-described features of the present application more apparent, the following detailed description of the embodiments and the accompanying drawings are set forth below.

[First Embodiment]

1A to 1K are schematic flow charts showing a method of transferring a light-emitting element according to an embodiment of the present application. Referring to FIG. 1A, first, a plurality of arrayed light-emitting elements 100 are formed on a first substrate SUB1. Each of the light-emitting elements 100 includes an element layer 110 and a sacrificial pattern 120, and the sacrificial pattern 120 is located on the element layer 110 and the first substrate SUB1. between. In the present embodiment, the element layer 110 on the same first substrate SUB1 is adapted to emit light of the same color. For example, the element layer 110 on the first substrate SUB1 is, for example, a red light emitting diode, a green light emitting diode or a blue light emitting diode. In addition, each of the component layers 110 already includes an electrode (not shown).

Next, referring to FIG. 1B, a protective layer PV is formed on the first substrate SUB1 to selectively cover a portion of the light emitting element 100, wherein a portion of the light emitting element 100 is not covered by the protective layer PV. In this embodiment, the protective layer PV is, for example, a photoresist material or other dielectric material to ensure the illumination covered by the protective layer PV during the subsequent removal of the sacrificial pattern 120. The element 100 is not separated from the first substrate SUB1. For example, the material of the protective layer PV may be polyimide or other polymer materials, and the material of the protective layer PV may also be yttrium oxide (SiOx), tantalum nitride (SiNx) or other inorganic dielectric materials. .

Referring to FIG. 1C and FIG. 1D, the device layer 110 not covered by the protective layer PV is bonded to a second substrate SUB2, and the sacrificial pattern 120 not covered by the protective layer PV is removed (as shown in FIG. 1C). The part of the element layer 110 is separated from the first substrate SUB1 and transferred to the second substrate SUB2 (as shown in FIG. 1D). In this embodiment, the second substrate SUB2 is, for example, a circuit substrate in monolithic micro-displays (such as a complementary gold-oxygen semiconductor wafer having a plurality of pads PAD), and is not covered by the protective layer PV. The element layer 110 is bonded to the pad PAD on the second substrate SUB2 through the conductive bumps B, for example. For example, the conductive bumps B are, for example, gold bumps or other alloy bumps, and the bonding (electrical connection) of the conductive bumps B to the pads PAD on the second substrate SUB2 is, for example, transmitted back. Reflow or other welding process is achieved.

As shown in FIG. 1C, during the bonding of the conductive bump B and the pad PAD, the protective layer PV can effectively and directly control the distance between the first substrate SUB1 and the second substrate SUB2 to avoid excessive pressing. . In other words, the protective layer PV provides a bonding stop function, making process control easier.

In the present embodiment, the method of removing the sacrificial pattern is, for example, a wet etch. It is worth noting that the selected etchant is related to the material of the protective layer PV. Specifically, the etching rate of the selected etchant to the sacrificial pattern 120 needs to be much higher than the etching rate of the protective layer PV. It is ensured that the element layer 110 and the sacrificial pattern 120 covered by the protective layer PV are not damaged by the etchant.

1A to 1D have schematically described a method of transferring the light-emitting element 100 from the first substrate SUB1 to the second substrate SUB2, in order to transfer the element layers suitable for emitting different color lights onto the same second substrate SUB2, this embodiment The process steps illustrated in Figures 1E-1K can be selectively performed.

1E, a plurality of arrayed light-emitting elements 100' are formed on another first substrate SUB1'. Each of the light-emitting elements 100' includes an element layer 110' and a sacrificial pattern 120', and the sacrificial pattern 120' is located at the element layer. 110' is between the first substrate SUB1'. In the present embodiment, the element layer 110' on the same first substrate SUB1' is adapted to emit light of the same color. For example, the element layer 110' on the first substrate SUB1' is, for example, a red light emitting diode, a green light emitting diode or a blue light emitting diode. It is to be noted that the element layer 110' and the element layer 110 are adapted to emit light of different colors, respectively.

As shown in Fig. 1E, a protective layer PV' is formed on the first substrate SUB1' to selectively cover a portion of the light-emitting element 100', wherein a portion of the light-emitting element 100' is not covered by the protective layer PV'. The protective layer PV' in Fig. 1E has the same function as the protective layer PV in Fig. 1B, and therefore will not be described again.

1F and FIG. 1G, the device layer 110' not covered by the protective layer PV' is bonded to a second substrate SUB2, and the sacrificial pattern 120' not covered by the protective layer PV' is removed (as shown in FIG. 1F), so that part of the element layer 110' is separated from the first substrate SUB1' and transferred to the second substrate SUB2 (as shown in FIG. 1G). In this embodiment, the unprotected layer The element layer 110' covered by the PV' is bonded to the pad PAD on the second substrate SUB2 through the conductive bump B', for example. For example, the conductive bump B' is, for example, a gold bump or other alloy bump, and the bonding (electrical connection) of the conductive bump B' to the pad PAD on the second substrate SUB2 is, for example, Reached by reflow or other welding processes.

Referring to FIG. 1H, a plurality of arrayed light-emitting elements 100" are formed on another first substrate SUB1". Each of the light-emitting elements 100" includes an element layer 110" and a sacrificial pattern 120", and the sacrificial pattern 120" is located at the element layer 110. Between "with the first substrate SUB1". In the present embodiment, the element layer 110" located on the same first substrate SUB1" is adapted to emit light of the same color. For example, the element layer 110 ′ on the first substrate SUB 1 ′′ is, for example, a red light emitting diode, a green light emitting diode or a blue light emitting diode. It is to be noted that the element layer 110", the element layer 110' and the element layer 110 are adapted to emit light of different colors, respectively.

As shown in FIG. 1H, a protective layer PV" is formed on the first substrate SUB1" to selectively cover a portion of the light-emitting element 100", wherein a portion of the light-emitting element 100" is not covered by the protective layer PV". The protective layer PV" has the same function as the protective layer PV in FIG. 1B, and thus will not be described again.

Referring to FIG. 1I, the device layer 110" covered by the unprotected layer PV" is bonded to a second substrate SUB2, and the sacrificial pattern 120" covered by the unprotected layer PV" is removed to make part of the components. The layer 110" is separated from the first substrate SUB1" and transferred onto the second substrate SUB2 (as shown in FIG. 1G). In this embodiment, the device layer 110" not covered by the protective layer PV" is bonded to the pad PAD on the second substrate SUB2, for example, through the conductive bump B". For example, the conductive bump B" is, for example, Gold bump Or other alloy bumps, and the bonding (electrical connection) of the conductive bumps B" to the pads PAD on the second substrate SUB2 is achieved, for example, by reflow or other soldering processes.

As shown in FIG. 1A to FIG. 1I, in this embodiment, the element layer 110, the element layer 110', and the element layer 110" are sequentially transferred onto the second substrate SUB2. In detail, the device layer 110 and the conductive bump are in this embodiment. The total thickness of the block B is smaller than the total thickness of the element layer 110' and the conductive bump B', and the total thickness of the element layer 110' and the conductive bump B' is smaller than the total thickness of the element layer 110" and the conductive bump B". When the total thickness of the element layer 110 and the conductive bump B is smaller than the total thickness of the element layer 110' and the conductive bump B', the element layer 110" is not subjected to the element layer 110 during the transfer to the second substrate SU2B. put one's oar in. Similarly, when the total thickness of the element layer 110' and the conductive bump B' is smaller than the total thickness of the element layer 110" and the conductive bump B", the element layer 110"" is transferred to the second substrate SU2B. It is not interfered by the element layer 110'.

Referring to FIG. 1J, in order to ensure an abnormal short circuit between the element layers 110, 110', 100", the present embodiment may form an insulating layer IN on the second substrate SUB2 to fill the element layers 110, 110. Between ', 100', a common electrode COM is formed on the element layers 110, 110', 100" and the insulating layer IN.

Referring to FIG. 1K, since the element layers 110, 110', 100" capable of emitting different color lights are different in thickness, and the conductive bumps B, B', B" have different heights, different color lights can be emitted. The top surface of the element layers 110, 110', 100" is located at different levels. In the above embodiment, a flat layer PLN may be formed on the common electrode COM, and after the fabrication of the flat layer PLN is completed, the embodiment Optionally A black matrix BM and/or a microlens array MLA is formed on the flat layer PLN. For example, the black matrix BM has a plurality of openings AP, and each of the openings AP is located at least one of the element layers 110, 110', 100". Further, the microlens array MLA includes a plurality of arrays of microlenses ML, and Each of the microlenses ML is located above at least one of the element layers 110, 110', 100". More specifically, each of the microlenses ML is located in each of its openings AP, and corresponds to at least one of the element layers 110, 110', 100".

Since the embodiment adopts the matching of the sacrificial patterns 120, 120', 120", the protective layer PV, the PV', the PV" and the conductive bumps B, B', B", the embodiment can be very efficiently different. The component layers 110, 110', 100" are transferred to the second substrate SUB2.

In order to more efficiently transfer the light-emitting elements capable of emitting different color lights onto the same second substrate SUB2, the present embodiment proposes the bonding sequence in FIGS. 2, 3 and 4 through FIG. 2, FIG. 3 and FIG. The bonding order in the middle allows all of the light-emitting elements to be smoothly transferred onto the second substrate SUB2 without the problem that some of the light-emitting elements remain on the first substrate SUB1 (or the first substrate SUB1', SUB1").

As shown in FIG. 2 to FIG. 4, first, three first substrates SUB1 (as shown in FIG. 3) or four first substrates SUB1 (shown in FIG. 2 or FIG. 4) are provided, one of which is on the first substrate SUB. There is a red light-emitting element 110R, and the other first substrate SUB1 has a blue light-emitting element 110B, and the remaining first substrate SUB1 has a green light-emitting element 110G. Next, the red light-emitting element 110R, the green light-emitting element 110G, and the blue light-emitting element 110B on the first substrate SUB1 are transferred to predetermined positions of the second substrate SUB2 (as indicated by the dashed arrows). So you can be fast and efficient The red light emitting element 110R, the green light emitting element 110G, and the blue light emitting element 110B are transferred to the second substrate SUB2 and transferred from the first substrate SUB1 to the second substrate SUB2, and some of the light emitting elements are still left on the first substrate SUB1. The problem.

Sacrificial pattern manufacturing method

5A to 5C are views showing a method of manufacturing a sacrificial pattern. First, referring to FIG. 5A, a sacrificial layer 120a and a semiconductor epitaxial layer 110a are sequentially formed on the first substrate SUB1, wherein the first substrate SUB1 is, for example, a sapphire substrate, and the sacrificial layer 120a is formed by, for example, epitaxy. A zinc oxide (ZnO) epitaxial layer, an AlGaN epitaxial layer, an AlInN epitaxial layer, or the like.

Next, referring to FIG. 5B, the semiconductor epitaxial layer 110a and the sacrificial layer 120a are patterned to form a plurality of element layers 110 and a plurality of sacrificial patterns 120 between the element layer 110 and the first substrate SUB1 on the first substrate SUB1. In this embodiment. The method of patterning the semiconductor epitaxial layer 110a and the sacrificial layer 120a is, for example, a photolithography etching process.

Finally, referring to FIG. 5C, when a part of the element layer 110 is covered by the protective layer PV, the sacrificial pattern 120 not covered by the protective layer PV may be removed by an etchant, so that the element layer not covered by the protective layer PV The 110 is separated from the first substrate SUB1. When the material of the sacrificial pattern 120 is zinc oxide, the etchant used includes phosphoric acid (H ₃ PO ₄ ), hydrochloric acid (HCl) or other acidic solution. When the material of the sacrificial pattern 120b is AlGaN or AlInN, the etchant used includes potassium hydroxide (KOH), nitric acid (HNO ₃ ) or other solutions.

6A to 6C illustrate another method of fabricating a sacrificial pattern. Please refer to 6A, a gate sacrificial layer 120b is formed on the first substrate SUB1, and a semiconductor epitaxial layer 110a is formed on the gate sacrificial layer 120b and the first substrate SUB1, wherein the first substrate SUB1 is, for example, a sapphire substrate, and The gate sacrificial layer 120b is, for example, a zinc oxide (ZnO) epitaxial layer, an AlGaN epitaxial layer, an AlInN epitaxial layer, or the like formed by epitaxy.

Next, referring to FIG. 6B, the semiconductor epitaxial layer 110a is patterned to form a plurality of element layers 110 and a plurality of gate-shaped sacrificial patterns 120b embedded between the element layer 110 and the first substrate SUB1 on the first substrate SUB1. In this embodiment. The method of patterning the semiconductor epitaxial layer 110a is, for example, a photolithography etching process.

Finally, referring to FIG. 6C, when a part of the element layer 110 is covered by the protective layer PV, the sacrificial pattern 120b not covered by the protective layer PV may be removed by an etchant, so that the element layer not covered by the protective layer PV The 110 can be easily separated from the first substrate SUB1. When the material of the sacrificial pattern 120b is zinc oxide, the etchant used includes phosphoric acid (H ₃ PO ₄ ), hydrochloric acid (HCl) or other acidic solution. When the material of the sacrificial pattern 120b is AlGaN or AlInN, the etchant used includes potassium hydroxide (KOH), nitric acid (HNO ₃ ) or other solutions.

[Second embodiment]

7A to 7K are schematic flow charts showing a method of transferring a light-emitting element according to a second embodiment of the present application. Referring to FIG. 7A, first, a first type doped semiconductor layer 210a, a light emitting layer 210b, and a second type doped semiconductor layer 210c are sequentially formed on the growth substrate SUB. In the present embodiment, the first type doped semiconductor layer 210a is, for example, an N-type doping formed by epitaxial means. The GaN epitaxial layer, the light-emitting layer 210b is, for example, a single or multiple quantum well light-emitting layer formed by epitaxial means, and the second-type doped semiconductor layer 210c is, for example, a P-type doped GaN formed by epitaxial means. Epitaxial layer. The general knowledge in this field can be used to fabricate components such as photonic crystals, resonant cavities, and ohmic contact layers at this stage according to actual design requirements, and this embodiment will not be described in detail.

Referring to FIG. 7B, a sacrificial layer 120a is formed on the first substrate SUB1, and the second type doped semiconductor layer 210c is temporarily bonded to the sacrificial layer 120a.

Referring to FIG. 7C, the first type doped semiconductor layer 210a is separated from the growth substrate SUB. In the present embodiment, the method of separating the first type doped semiconductor layer 210a from the growth substrate SUB includes a laser lift-off technique. In addition, a person skilled in the art can selectively perform a thinning process (eg, grinding or etch back) of the first type doped semiconductor layer 210a after the first type doped semiconductor layer 210a is separated from the growth substrate SUB, or Fabrication of the photonic crystal is performed on the first type doped semiconductor layer 210a.

Referring to FIG. 7D, after the first type doped semiconductor layer 210a is separated from the growth substrate SUB, the first type semiconductor layer 210a, the light emitting layer 210b, the second type semiconductor layer 210c, and the sacrificial layer 120a are patterned to form a plurality of first The semiconductor pattern 210a', the plurality of light emitting patterns 210b', the plurality of second type semiconductor patterns 210c', and the sacrificial pattern 120.

Referring to FIG. 7E, a plurality of electrodes 210d are formed on the first type semiconductor pattern 210a', wherein the first type semiconductor pattern 210a', the light emitting pattern 210b', and the second type semiconductor pattern 210c' are located on the same sacrificial pattern 120. And the electrode 210d constitutes an element layer 210.

Referring to FIG. 7F, a protective layer PV is formed on the first substrate SUB1 to selectively cover a portion of the element layer 210 and the sacrificial pattern 120, wherein a portion of the element layer 210 and the sacrificial pattern 120 are not covered by the protective layer PV. In this embodiment, the protective layer PV is, for example, a photoresist material or other dielectric material to ensure that the component layer 210 covered by the protective layer PV does not overlap with the first during the subsequent removal of the sacrificial pattern 120. The substrate SUB1 is separated. For example, the material of the protective layer PV may be polyimide or other polymer materials, and the material of the protective layer PV may also be yttrium oxide (SiOx), tantalum nitride (SiNx) or other inorganic dielectric materials. .

Next, referring to FIG. 7G, a second substrate SUB2 is provided. The second substrate SUB2 is, for example, a circuit substrate in monolithic micro-displays (such as a complementary gold-oxygen semiconductor wafer having a plurality of pads PAD). Next, the element layer 210 not covered by the protective layer PV is bonded to a second substrate SUB2, and the sacrificial pattern 120 not covered by the protective layer PV is removed to separate part of the element layer 110 from the first substrate SUB1. And transferred to the second substrate SUB2. The component layer 210 not covered by the protective layer PV is bonded to the pad PAD on the second substrate SUB2 through the conductive bump B, for example. For example, the conductive bumps B are, for example, gold bumps or other alloy bumps, and the bonding (electrical connection) of the conductive bumps B to the pads PAD on the second substrate SUB2 is, for example, transmitted back. Reflow or other welding process is achieved.

As shown in FIG. 7G, during the bonding of the conductive bumps B and the pads PAD, the protective layer PV can effectively and directly control the distance between the first substrate SUB1 and the second substrate SUB2 to avoid excessive pressing. . In other words, The protective layer PV provides the function of a bonding stop, making process control easier.

Referring to FIG. 7H, after transferring the element layer 210 to the second substrate SUB2, those skilled in the art can selectively repeat the steps in the foregoing FIGS. 7A to 7G at least once to bring the element layer 210' and the element. The layer 210" is transferred onto the second substrate SUB2. Since the element layers 210, 210', 210" are capable of emitting different colors of light (for example, a combination of red, blue, and green light), the element layer 210 on the second substrate SUB2, 210', 210" can provide full color display.

As shown in FIG. 7H, since the element layers 210, 210', 210" capable of emitting different color lights have different thicknesses, and the conductive bumps B, B', B bonded to the element layers 210, 210', 210" "There are also different heights, so the top surfaces of the component layers 210, 210', 210" can be located at the same level. However, the embodiment does not limit that the top surfaces of the component layers 210, 210', 210" must be at the same level. After the height adjustment of the conductive bumps B, B', B", the component layer 210 can also be used. The top surfaces of 210', 210" are located at different levels.

Referring to FIG. 7I and FIG. 7J, after the element layers 210, 210', 210" are bonded to the second substrate SUB2, an insulating flat layer is formed between the element layers 210, 210', 210" on the second substrate SUB2. PLN' (shown in FIG. 7I), a common electrode COM is formed on the element layers 210, 210', 210" and the insulating flat layer PLN'. Thereafter, a black matrix BM is formed on the common electrode COM, which is black. The matrix BM has a plurality of openings AP, and each of the openings AP is located above one of the element layers 210, 210' or 210". In this embodiment, the black matrix BM can be selected with good electrical conductivity. Since the black matrix BM is directly disposed on the common electrode COM, the black matrix BM can further reduce the resistance value of the common electrode COM to further improve the luminous efficiency of the element layers 210, 210', 210".

Finally, referring to FIG. 7K, in order to further optimize the optical performance of the element layers 210, 210', 210", the embodiment may selectively form a microlens array MLA above the element layers 210, 210', 210". The array MLA includes a plurality of array-arranged microlenses ML, and each microlens ML is located above at least one of the element layers 210, 210' or 210", respectively.

[Third embodiment]

8A to 8K are schematic flow charts showing a method of transferring a light-emitting element according to a third embodiment of the present application. The transfer method of the light-emitting element of the present embodiment is similar to the transfer method of the light-emitting element of the second embodiment, but the main difference between the two is the steps illustrated in FIGS. 8B to 8H. Therefore, a detailed description will be made below with reference to FIGS. 8A to 8K.

Referring to FIG. 8A, first, a first type doped semiconductor layer 310a, a light emitting layer 310b, and a second type doped semiconductor layer 310c are sequentially formed on the growth substrate SUB. In this embodiment, the first type doped semiconductor layer 310a is, for example, an N-type doped GaN epitaxial layer formed by epitaxial method, and the luminescent layer 310b is, for example, a single or multiple quantum formed by epitaxial means. The well-emitting layer, and the second-type doped semiconductor layer 310c is, for example, a P-type doped GaN epitaxial layer formed by epitaxy. Photonic crystals can be produced at this stage according to actual design requirements by those skilled in the art, and will not be described in detail in this embodiment.

Referring to FIG. 8B, a plurality of layers are formed on the second type doped semiconductor layer 310c. The electrodes 310d' have good ohmic contact between the electrodes 310d and the second type doped semiconductor layer 310c.

Referring to FIG. 8C, a sacrificial layer 120a is formed on the first substrate SUB1, and the second type doped semiconductor layer 310c is temporarily bonded to the sacrificial layer 120a.

Referring to FIG. 8D, the first type doped semiconductor layer 310a is separated from the growth substrate SUB. In the present embodiment, the method of separating the first type doped semiconductor layer 310a from the growth substrate SUB includes a laser lift-off technique. In addition, a person skilled in the art can selectively perform a thinning process (eg, grinding or etch back) of the first type doped semiconductor layer 310a after the first type doped semiconductor layer 310a is separated from the growth substrate SUB, or Fabrication of the photonic crystal is performed on the first type doped semiconductor layer 310a.

Referring to FIG. 8E, after the first type doped semiconductor layer 310a is separated from the growth substrate SUB, the first type semiconductor layer 310a, the light emitting layer 310b, the second type semiconductor layer 310c, and the sacrificial layer 120a are patterned to form a plurality of first The semiconductor pattern 310a', the plurality of light emitting patterns 310b', the plurality of second type semiconductor patterns 310c', and the sacrificial pattern 120. Here, the first type semiconductor pattern 310a', the light emitting pattern 310b', the second type semiconductor pattern 310c', and the electrode 310d' on the same sacrificial pattern 120 constitute an element layer 310.

Referring to FIG. 8F, a protective layer PV is formed on the first substrate SUB1 to selectively cover a portion of the element layer 310 and the sacrificial pattern 120, wherein a portion of the element layer 310 and the sacrificial pattern 120 are not covered by the protective layer PV. In this embodiment, the protective layer PV is, for example, a photoresist material or other The dielectric material is such that during the removal of the subsequent sacrificial pattern 120, it is ensured that the element layer 310 covered by the protective layer PV is not separated from the first substrate SUB1. For example, the material of the protective layer PV may be polyimide or other polymer materials, and the material of the protective layer PV may also be yttrium oxide (SiOx), tantalum nitride (SiNx) or other inorganic dielectric materials. .

Next, referring to FIG. 8G, a second substrate SUB2 is provided. The second substrate SUB2 is, for example, a stamp mold, and the template has a plurality of protrusions P. Next, the protrusion P on the second substrate SUB2 is bonded to the element layer 310 not covered by the protective layer PV. Thereafter, the sacrificial pattern 120 not covered by the protective layer PV is removed, so that part of the element layer 310 is transferred onto the stencil (SUB2).

Next, referring to FIG. 8H, the component layer 310 transferred to the stencil (SUB2) is then bonded to a circuit substrate SUB3 to further transfer the component layer 310 onto the circuit substrate SUB3, wherein the circuit substrate SUB3 is, for example, a monolithic microdisplay ( A circuit substrate in a monolithic micro-displays (such as a complementary MOS wafer having a plurality of pads PAD). In the present embodiment, the element layer 310 is bonded to the pad PAD on the second substrate SUB2 through the conductive bump B, for example. For example, the conductive bumps B are, for example, gold bumps or other alloy bumps, and the bonding (electrical connection) of the conductive bumps B to the pads PAD on the second substrate SUB2 is, for example, transmitted back. Reflow or other welding process is achieved.

Referring to FIG. 8I, after the component layer 310 is first transferred to the second substrate SUB2 and then transferred to the circuit substrate SUB3, those skilled in the art can selectively repeat the steps in the foregoing FIGS. 8A to 8H at least once. The element layer 310' and the element layer 310" are transferred onto the wiring substrate SUB3.

As shown in FIG. 8H, since the element layers 310, 310', 310" capable of emitting different color lights have different thicknesses, and the conductive bumps B, B', B bonded to the element layers 310, 310', 310" "There are also different heights, so the top surfaces of the component layers 310, 310', 310" can be located at the same level. However, this embodiment does not limit that the top surfaces of the element layers 310, 310', 310" must be at the same level. After the height adjustment of the conductive bumps B, B', B", the component layer 310 can also be used. The top surfaces of 310', 310" are located at different levels.

Since the process described in FIG. 8I to FIG. 8K is the same as the process shown in FIG. 7I to FIG. 7K, the present embodiment will not be repeated here.

It can be seen from the above various embodiments that the present application can quickly and efficiently transfer a light-emitting element from one substrate to another, which contributes to the application of the light-emitting element in the field of microdisplays.

Although the present application has been disclosed in the above embodiments, it is not intended to limit the application, and any person having ordinary skill in the art can make some changes without departing from the spirit and scope of the present application. Retouching, the scope of protection of this application is subject to the definition of the scope of the patent application attached.

100, 100', 100" ‧ ‧ luminescent components

100R‧‧‧Red light-emitting elements

100G‧‧‧Green light-emitting elements

100B‧‧‧Blue light-emitting element

110, 110', 110" ‧ ‧ component layers

110a‧‧‧Semiconductor epitaxial layer

120, 120', 120", 120b‧‧‧ sacrificial patterns

120a‧‧‧sacrificial layer

210a, 310a‧‧‧ first type doped semiconductor layer

210b, 310b‧‧‧ luminescent layer

210c, 310c‧‧‧Second type doped semiconductor layer

210, 210', 210", 310, 310', 310" ‧ ‧ component layers

210a', 310a'‧‧‧ first type semiconductor pattern

210b’, 310b’‧‧‧ illuminating patterns

210c', 310c'‧‧‧ second type semiconductor pattern

210d, 310d‧‧‧ electrodes

PV, PV'‧‧‧ protective layer

B, B’‧‧‧ conductive bumps

IN‧‧‧Insulation

COM‧‧‧ common electrode

PLN‧‧‧flat layer

PLN’‧‧‧Insulated flat layer

BM‧‧‧Black Matrix

AP‧‧‧ openings

MLA‧‧‧Microlens Array

ML‧‧‧microlens

SUB‧‧‧ growth substrate

SUB1, SUB1', SUB1"‧‧‧ first substrate

SUB2‧‧‧second substrate

SUB3‧‧‧ circuit substrate

PAD‧‧‧ pads

1A to 1K are schematic flow charts showing a method of transferring a light-emitting element according to a first embodiment of the present application.

2, 3, and 4 show the bonding order of the light-emitting element and the second substrate.

5A to 5C are views showing a method of manufacturing a sacrificial pattern.

6A to 6C illustrate another method of fabricating a sacrificial pattern.

7A to 7K are schematic flow charts showing a method of transferring a light-emitting element according to a second embodiment of the present application.

8A to 8K are schematic flow charts showing a method of transferring a light-emitting element according to a third embodiment of the present application.

100‧‧‧Lighting elements

110‧‧‧Component layer

120‧‧‧sacrificial pattern

PV‧‧‧ protective layer

B‧‧‧conductive bumps

SUB1‧‧‧ first substrate

SUB2‧‧‧second substrate

PAD‧‧‧ pads

Claims (19)

A method for transferring a light-emitting element, comprising: (a) forming a plurality of array-arranged light-emitting elements on a first substrate, each light-emitting element comprising an element layer and a sacrificial pattern, wherein the sacrificial pattern is located at the element layer and the (b) forming a protective layer on the first substrate to selectively cover a portion of the light-emitting elements, wherein a portion of the light-emitting elements are not covered by the protective layer; (c) is not protected by the protective layer The covered component layer is bonded to a second substrate; and (d) removing the sacrificial pattern not covered by the protective layer from the first substrate and the component layer such that a portion of the component layer and the first The substrate is separated and transferred onto the second substrate. The method for transferring a light-emitting element according to claim 1, wherein the method of forming the light-emitting elements on the first substrate comprises: sequentially forming a first-type doped semiconductor layer on a growth substrate, a light-emitting layer and a second-type doped semiconductor layer; forming a sacrificial layer on the first substrate; bonding the second-type doped semiconductor layer to the sacrificial layer; and the first-type doped semiconductor layer and the growth Separating the substrate; patterning the first type semiconductor layer, the light emitting layer, the second type semiconductor layer, and the sacrificial layer to form a plurality of first type semiconductor patterns, a plurality of light emitting patterns, a plurality of second type semiconductor patterns, and The sacrificial pattern; and forming a plurality of electrodes on the first type semiconductor patterns. The method of transferring a light-emitting element according to claim 2, wherein the sacrificial layer comprises a gate-like sacrificial layer. The method for transferring a light-emitting element according to claim 1, wherein the second substrate comprises a circuit substrate, the circuit substrate has a plurality of pads and a plurality of conductive bumps on the pads, and is not The component layer covered by the protective layer is bonded to the pad through a portion of the conductive bump, and when the sacrificial pattern not covered by the protective layer is removed, part of the component layer is transferred onto the circuit substrate. The method for transferring a light-emitting element according to claim 4, further comprising repeating steps (a) to (d) at least once to transfer an element layer capable of emitting light of different colors onto the circuit substrate. The method for transferring a light-emitting element according to claim 5, wherein the element layers capable of emitting different color lights have different thicknesses, and the conductive bumps joined to the element layers capable of emitting different color lights have different heights, so that The top surfaces of the component layers capable of emitting different colored lights are at the same level. The method for transferring a light-emitting element according to claim 1, further comprising: forming a common electrode on the element layers on the second substrate. The method for transferring a light-emitting element according to claim 7, further comprising: forming a black matrix on the common electrode, the black matrix having a plurality of openings, and each of the openings is located above at least one of the element layers. The method for transferring a light-emitting element according to claim 1, further comprising: forming a microlens array comprising a plurality of array-arranged microlenses, each of the microlenses being respectively located in at least one of the element layers on square. The method for transferring a light-emitting element according to claim 1, wherein the method of forming the light-emitting elements on the first substrate comprises: sequentially forming a first-type doped semiconductor layer on a growth substrate, a light emitting layer and a second type doped semiconductor layer; forming a plurality of electrodes on the second type doped semiconductor layer; forming a sacrificial layer on the first substrate; and the sacrificial layer and the second type doped semiconductor a layer and the electrodes are bonded; separating the first type doped semiconductor layer from the growth substrate; patterning the first type semiconductor layer, the light emitting layer, the second type semiconductor layer, and the sacrificial layer to form a plurality of a first type semiconductor pattern, a plurality of light emitting patterns, a plurality of second type semiconductor patterns, and the sacrificial patterns. The method of transferring a light-emitting element according to claim 10, wherein the sacrificial layer comprises a gate-like sacrificial layer. The method for transferring a light-emitting element according to claim 10, wherein the second substrate comprises a stamp mold having a plurality of protrusions, and the light-emitting element not covered by the protective layer And engaging the protrusions, and when the sacrificial pattern not covered by the protective layer is removed, part of the element layer is transferred onto the stencil. The method for transferring a light-emitting element according to claim 12, further comprising: (e) bonding the component layer transferred to the portion of the stencil to a circuit substrate to further transfer the component layer to a circuit substrate. The circuit substrate has a plurality of pads and a plurality of conductive bumps on the pads, and the electrodes are coupled to the pads through the conductive bumps of the portions. The method for transferring a light-emitting element according to claim 10, further comprising repeating steps (a) to (e) at least once to transfer an element layer capable of emitting light of different colors onto the circuit substrate. The method for transferring a light-emitting element according to claim 14, wherein the element layers capable of emitting different color lights have different thicknesses, and the conductive bumps joined to the element layers capable of emitting different color lights have different heights, so that The top surfaces of the component layers capable of emitting different colored lights are at different levels. An array of light-emitting elements includes: a circuit substrate having a plurality of pads and a plurality of conductive bumps on the pads; and a plurality of component layers capable of emitting different colors of light, through the conductive bumps and the connections The pad is electrically connected to the circuit substrate, wherein the component layers capable of emitting different color lights have different thicknesses, and the conductive bumps bonded to the component layers capable of emitting different color lights have different heights to enable components capable of emitting different color lights The top surfaces of the layers are at the same level. The light-emitting device array of claim 16, further comprising: a common electrode disposed on the component layers. The light-emitting device array of claim 17, further comprising: a black matrix on the common electrode, wherein the black matrix has a plurality of openings, and each of the openings is located above one of the component layers. The light-emitting element array of claim 16, further comprising: a microlens array comprising a plurality of array-arranged microlenses, and each of the The microlenses are respectively located above one of the component layers.