CN110911537A - Common cathode LED chip and manufacturing method thereof - Google Patents
Common cathode LED chip and manufacturing method thereof Download PDFInfo
- Publication number
- CN110911537A CN110911537A CN201911202411.8A CN201911202411A CN110911537A CN 110911537 A CN110911537 A CN 110911537A CN 201911202411 A CN201911202411 A CN 201911202411A CN 110911537 A CN110911537 A CN 110911537A
- Authority
- CN
- China
- Prior art keywords
- layer
- type semiconductor
- semiconductor layer
- common cathode
- led chip
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/44—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the coatings, e.g. passivation layer or anti-reflective coating
- H01L33/46—Reflective coating, e.g. dielectric Bragg reflector
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/15—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components with at least one potential-jump barrier or surface barrier specially adapted for light emission
- H01L27/153—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components with at least one potential-jump barrier or surface barrier specially adapted for light emission in a repetitive configuration, e.g. LED bars
- H01L27/156—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components with at least one potential-jump barrier or surface barrier specially adapted for light emission in a repetitive configuration, e.g. LED bars two-dimensional arrays
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/005—Processes
- H01L33/0062—Processes for devices with an active region comprising only III-V compounds
- H01L33/0066—Processes for devices with an active region comprising only III-V compounds with a substrate not being a III-V compound
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/005—Processes
- H01L33/0062—Processes for devices with an active region comprising only III-V compounds
- H01L33/0075—Processes for devices with an active region comprising only III-V compounds comprising nitride compounds
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/36—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes
- H01L33/38—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes with a particular shape
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/36—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes
- H01L33/38—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes with a particular shape
- H01L33/385—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes with a particular shape the electrode extending at least partially onto a side surface of the semiconductor body
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2933/00—Details relating to devices covered by the group H01L33/00 but not provided for in its subgroups
- H01L2933/0008—Processes
- H01L2933/0016—Processes relating to electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2933/00—Details relating to devices covered by the group H01L33/00 but not provided for in its subgroups
- H01L2933/0008—Processes
- H01L2933/0025—Processes relating to coatings
Abstract
The invention provides a common cathode LED chip and a manufacturing method thereof, wherein the chip comprises a p-type semiconductor layer, a luminous layer, an n-type semiconductor layer, a groove, a connecting layer, a transparent conducting layer, a quantum dot layer and a protective layer, the groove penetrates through the n-type semiconductor layer, the luminous layer and the p-type semiconductor layer to isolate a plurality of LED units, the connecting layer stretches across the groove, and two ends of the connecting layer are respectively contacted with the n-type semiconductor layers of two adjacent LED units to realize the common connection of cathodes of the two adjacent LED units. The LED chip provided by the invention adopts a common cathode design, a plurality of LED chips can be integrated into a whole, the transfer amount is less than one third of that of the traditional method, the size of the chip is larger than that of a single chip, the transfer difficulty is relatively low, and the problems of high transfer difficulty, high transfer frequency, low transfer yield and color crosstalk between adjacent LEDs of the conventional Micro LED can be solved.
Description
Technical Field
The invention belongs to the technical field of LED manufacturing, and particularly relates to a common-cathode LED chip and a manufacturing method thereof.
Background
With the progress of Display technology, the market is increasingly dissatisfied with the disadvantages of low contrast, low color gamut, low response speed, etc. of Liquid Crystal Displays (LCDs), and the disadvantages of burn-in, heavy granular sensation, color cast, poor light comfort, etc. of Organic Light Emitting Displays (OLEDs). The Micro LED display technology as the next generation display technology has the advantages of high contrast, high color gamut, high response speed, ultrahigh resolution, long service life and the like, has the advantages of an LCD and an OLED, and does not have the defects. The Micro LED also has the advantages of flexible display and low energy consumption, and is known as a final display technology.
Micro LED displays are fabricated by transferring a large number of Micro LEDs onto a driving substrate. A4K television has 2540 million Micro LEDs. And Micro LEDs are extremely small, typically no larger than 80 μm (television) in size, and can be as small as hundreds of nanometers (AR, VR displays). When the transfer rate is 10 pieces/s, 29.4 days are needed for manufacturing one television, and the efficiency is extremely low. In order to increase the transfer rate, the mass transfer techniques invented to solve the problem, such as electrostatic adsorption, vacuum adsorption, intermolecular force adsorption and other transfer head array transfer methods, water flow, magnetic self-assembly methods, laser selective transfer methods and the like, all have various problems, the transfer yield cannot meet the commercialization requirement, and the repair is difficult.
On the other hand, because Micro LEDs are small in size and have a large lateral light proportion, color crosstalk between adjacent LEDs due to lateral light exists. One prior solution is to make the upper part of the substrate in the shape of a reflective cup and to supplement it with a reflective coating. The substrate is difficult to manufacture.
Therefore, how to fabricate the Micro LEDs to reduce the transfer difficulty, reduce the transfer times to improve the transfer yield, and solve the color crosstalk problem between adjacent LEDs is an important technical problem to be solved urgently by those skilled in the art.
Disclosure of Invention
In view of the above disadvantages of the prior art, an object of the present invention is to provide a common cathode LED chip and a method for manufacturing the same, which are used to solve the problems of high transfer difficulty, high transfer times, low transfer yield, and color crosstalk between adjacent LEDs of the conventional Micro LED.
To achieve the above and other related objects, the present invention provides a common cathode LED chip, comprising: a p-type semiconductor layer; a light emitting layer over the p-type semiconductor layer; an n-type semiconductor layer over the light emitting layer; the groove penetrates through the n-type semiconductor layer, the light emitting layer and the p-type semiconductor layer to isolate a plurality of LED units; the connecting layer stretches across the groove, and two ends of the connecting layer are respectively contacted with the n-type semiconductor layers of the two adjacent LED units to realize the common connection of the cathodes of the two adjacent LED units; the transparent conducting layer is positioned on the n-type semiconductor layer and the connecting layer; a quantum dot layer located over the transparent conductive layer of the LED unit; and the protective layer is positioned on the quantum dot layer.
Optionally, the common cathode LED chip further includes a lead-out groove, a bridging layer spans between the lead-out groove and the adjacent groove, an n electrode is disposed in the lead-out groove, and the n electrode contacts the bridging layer through the lead-out groove and extends to the surface of the p-type semiconductor layer.
Further, the surface of the p-type semiconductor layer of the LED unit is provided with a p electrode, and the p electrode is coplanar with the n electrode.
Optionally, the common cathode LED chip further comprises a reflective layer covering at least the sidewall of the groove.
Optionally, the n-type semiconductor layer comprises an n-type gallium nitride layer, the p-type semiconductor layer comprises a p-type gallium nitride layer, or the n-type semiconductor layer comprises an n-type aluminum gallium nitride layer, and the p-type semiconductor layer comprises a p-type aluminum gallium nitride layer.
Optionally, the common cathode LED chip further comprises an electron blocking layer located between the light emitting layer and the p-type semiconductor layer.
Optionally, the light emitting layer comprises a quantum well superlattice layer.
OptionallyThe reflecting layer comprises Bragg reflecting layers, and the Bragg reflecting layers are Ti which are alternately laminated3O5/SiO2。
Optionally, the material of the transparent conductive layer includes ITO, and the material of the protective layer includes silicon dioxide.
The invention also provides a manufacturing method of the common cathode LED chip, which comprises the following steps: 1) providing a substrate, and sequentially forming a buffer layer, a non-doped semiconductor layer, an n-type semiconductor layer, a light emitting layer, an electron blocking layer and a p-type semiconductor layer on the substrate from bottom to top to form a wafer; 2) forming a groove penetrating through the p-type semiconductor layer, the electron blocking layer and the light emitting layer and penetrating into the n-type semiconductor layer to isolate a plurality of LED units; 3) forming a p-electrode on the p-type semiconductor layer of each LED unit and forming an n-electrode on the p-type semiconductor layer of at least one LED unit, wherein the n-electrode extends and covers the side wall of the groove part; 4) forming the reflecting layer on the inner surface of the groove; 5) bonding the wafer on a temporary substrate, and stripping the substrate; 6) removing the buffer layer, the non-doped semiconductor layer and part of the n-type semiconductor layer until the reflecting layer is exposed, or removing the reflecting layer partially; 7) forming a connecting layer on the reflecting layer, wherein two ends of the connecting layer are respectively contacted with the n-type semiconductor layers of two adjacent LED units, so that the common connection of the cathodes of the adjacent LED units is realized; 8) depositing a transparent conductive layer over the connection layer, n-type semiconductor layer; 9) forming a quantum dot layer on the transparent conductive layer; 10) depositing a protective layer over the quantum dot layer.
Optionally, the substrate is sapphire, silicon carbide or a silicon wafer, and the temporary substrate is a silicon wafer or glass.
Optionally, the undoped layer includes an undoped gallium nitride layer or an aluminum gallium nitride layer, the buffer layer includes at least one of an aluminum nitride buffer layer, a gallium nitride buffer layer, an aluminum gallium nitride buffer layer, and an aluminum indium gallium nitride buffer layer, and the adhesive material is polydimethylsiloxane.
Optionally, the n-type semiconductor layer comprises an n-type gallium nitride layer and the p-type semiconductor layer comprises a p-type gallium nitride layer; or the n-type semiconductor layer comprises an n-type aluminum gallium nitride layer, and the p-type semiconductor layer comprises a p-type aluminum gallium nitride layer; the light emitting layer includes a quantum well superlattice layer.
Optionally, the reflective layer includes bragg reflective layers, the bragg reflective layers being Ti alternately stacked3O5/SiO2(ii) a The material of the transparent conductive layer comprises ITO, and the material of the protective layer comprises silicon dioxide.
As described above, the common cathode LED chip and the manufacturing method thereof of the present invention have the following advantages:
according to the Micro LED chip, a common cathode design is adopted, a plurality of Micro LED chips can be integrated into a whole, the transfer amount is less than one third of that of the traditional method, the size of the chip is larger than that of a single chip, the transfer difficulty is relatively low, and the problems that the conventional Micro LED chip is large in transfer difficulty, large in transfer frequency and low in transfer yield can be solved.
According to the invention, the reflecting layer is manufactured on the side wall of each LED unit, so that the problem of color crosstalk between adjacent LEDs can be avoided. .
The p electrode and the n electrode adopt coplanar design, which is beneficial to the design of the substrate and the connection of the chip and the target substrate.
Drawings
Fig. 1 to 15 are schematic diagrams showing steps of a method for manufacturing a common cathode LED chip according to an embodiment of the present invention.
Description of the element reference numerals
101 substrate
102 undoped semiconductor layer
103 n type semiconductor layer
104 light emitting layer
105 p-type semiconductor layer
106 groove
107 lead-out groove
108 p electrode
109 n electrode
110 reflective layer
112 temporary substrate
111 adhesive layer
113 connecting layer
114 cross-over layer
115 transparent conductive layer
116 red quantum dot layer
117 green quantum dot layer
118 blue quantum dot layer
119 protective layer
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.
As in the detailed description of the embodiments of the present invention, the cross-sectional views illustrating the device structures are not partially enlarged in general scale for convenience of illustration, and the schematic views are only examples, which should not limit the scope of the present invention. In addition, the three-dimensional dimensions of length, width and depth should be included in the actual fabrication.
For convenience in description, spatial relational terms such as "below," "beneath," "below," "under," "over," "upper," and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that these terms of spatial relationship are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the figures. Further, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.
In the context of this application, a structure described as having a first feature "on" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed in between the first and second features, such that the first and second features may not be in direct contact.
It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the drawings only show the components related to the present invention rather than being drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of each component in actual implementation may be changed arbitrarily, and the layout of the components may be more complicated.
As shown in fig. 14 and 15, the present embodiment provides a common cathode LED chip, including: a p-type semiconductor layer 105, a light emitting layer 104, an n-type semiconductor layer 103, a groove 106, a reflective layer 110, a connection layer 113, a transparent conductive layer 115, a quantum dot layer, and a protective layer 119.
The LED chips include Micro LED chips (Micro light emitting diodes) with a size of typically less than 80 microns, for which the present invention has a superior effect on their transfer.
The light emitting layer 104 is located above the p-type semiconductor layer 105, for example, the light emitting layer 104 may be a quantum well superlattice layer.
The n-type semiconductor layer 103 is located above the light emitting layer 104, and in one embodiment, the n-type semiconductor layer 103 is an n-type gallium nitride layer and the p-type semiconductor layer 105 is a p-type gallium nitride layer.
In another embodiment, the n-type semiconductor layer 103 may also be an n-type aluminum gallium nitride layer, and the p-type semiconductor layer 105 may also be a p-type aluminum gallium nitride layer.
In this embodiment, the common cathode LED chip further includes an electron blocking layer located between the light emitting layer 104 and the p-type semiconductor layer 105.
The groove 106 penetrates through the n-type semiconductor layer 103, the light emitting layer 104 and the p-type semiconductor layer 105 to isolate a plurality of LED units. For example, the common cathode LED chip may include four LED units separated by a plurality of grooves 106, wherein three LED units are light emitting units, and the other unit is used for manufacturing the n-electrode 109 and is a non-light emitting unit. The common cathode LED chip further comprises a lead-out groove 107, a bridging layer 114 spans between the lead-out groove 107 and the adjacent groove 106, an n electrode 109 is arranged in the lead-out groove 107, and the n electrode 109 is in contact with the bridging layer 114 through the lead-out groove 107 and extends to the surface of the p-type semiconductor layer 105. The invention integrates a plurality of Micro LED chips into a whole, the transfer amount is less than one third of that of the traditional method, the size of the chip is larger than that of a single chip, and the transfer difficulty is relatively low.
The surface of the p-type semiconductor layer 105 of the LED unit is provided with a p electrode 108, and the p electrode 108 and the n electrode 109 are coplanar, so that the design of a substrate and the connection of a chip and a target substrate are facilitated.
The reflective layer 110 covers at least the sidewalls of the recess 106, and in this embodiment, the reflective layer covers the sidewalls and the bottom of the recess 106. The reflective layer 110 includes bragg reflective layers 110, and the bragg reflective layers 110 are Ti layers alternately stacked3O5/SiO2. The reflective layer 110 can effectively reduce the side light emission of the chip, and solve the problem of color crosstalk between adjacent LEDs. In this embodiment, a thin silicon dioxide layer is further disposed on the lower surface of the bragg reflector 110 to provide better insulation performance and improve the adhesion of the bragg reflector 110.
The connecting layer 113 spans the groove 106, and two ends of the connecting layer are respectively contacted with the n-type semiconductor layers 103 of two adjacent LED units, so that the cathodes of the two adjacent LED units are connected in common. The material of the connection layer 113 may be one or more of Cu, Au, Ni, Ti, Al, and Cr.
The transparent conductive layer 115 is located on the n-type semiconductor layer 103 and the connection layer 113, and the transparent conductive layer 115 can facilitate current diffusion in the n-type semiconductor layer 103, in this embodiment, the transparent conductive layer 115 is made of Indium Tin Oxide (ITO), and the thickness of the transparent conductive layer 115 may be in a range from 10 nm to 100 nm, for example, 30 nm.
The quantum dot layer is located over the transparent conductive layer 115 of the LED units so that different LED units emit different colors of light.
In one embodiment, the quantum dot layers may include a red quantum dot layer 116, a green quantum dot layer 117, and a blue quantum dot layer 118, as shown in FIG. 12, which emit red, green, and blue light, respectively. In another embodiment, only a red quantum dot layer 116 and a green quantum dot layer 117 can be formed on the transparent conductive layer 115 to emit red and green light, respectively, and the blue light is directly emitted from the LED. In another embodiment, the red, green, or blue quantum dot layers 116, 117, 118 can cover two LED units, one for the common cathode and not emitting light, as shown in fig. 13, and the blue quantum dot layer 118 covers two LED units, so that the quantum dot layer covers substantially the entire LED surface, as shown in fig. 15, for the structure shown in fig. 13, the structure after the protective layer 119 is formed on the red, green, and blue quantum dot layers 116, 117, 118. Alternatively, the red, green, and blue quantum dot layers 116, 117, and 118 may have different areas, or the LED units thereunder may have different sizes.
The protection layer 119 is located on the quantum dot layer for protecting the quantum dot layer, for example, the material of the protection layer 119 may be silicon dioxide.
Fig. 11 is a simplified schematic diagram of fig. 10, and as shown in fig. 11, the connection layer 113, the bridging layer 114 and the n-electrode 109 can be regarded as a whole, which together form a cathode, and the cathode is shared by a plurality of Micro LED units.
According to the Micro LED chip provided by the embodiment of the invention, a common cathode design is adopted, a plurality of Micro LED chips can be integrated into a whole, the transfer amount is less than one third of that of the traditional method, the size of the chip is larger than that of a single chip, the transfer difficulty is relatively low, and the problems of high transfer difficulty, high transfer frequency, low transfer yield and color crosstalk between adjacent LEDs of the existing Micro LED can be solved.
As shown in fig. 1 to fig. 15, the present embodiment further provides a method for manufacturing a common cathode LED chip, where the method includes the following steps:
as shown in fig. 1, step 1) is first performed to provide a substrate 101, and a buffer layer, an undoped semiconductor layer 102, an n-type semiconductor layer 103, a light emitting layer 104, an electron blocking layer, and a p-type semiconductor layer 105 are sequentially formed on the substrate 101 from bottom to top to form a wafer.
As an example, the substrate 101 is sapphire, silicon carbide or a silicon wafer, and specifically, the sapphire substrate or the silicon carbide substrate may be fed into a magnetron sputtering machine, and an AlN buffer layer may be deposited on the sapphire substrate or the silicon carbide substrate, and the thickness of the AlN buffer layer may be 10 to 20 nanometers, for example, 15 nanometers. The sapphire substrate or the silicon carbide substrate can also be sent into an MOCVD (metal oxide chemical vapor deposition) reaction chamber, and a low-temperature gallium nitride buffer layer is deposited on the sapphire substrate or the silicon carbide substrate, wherein the thickness of the low-temperature gallium nitride buffer layer can be 10-30 nanometers, such as 20 nanometers.
Then, the substrate 101 on which the buffer layer is grown may be fed into an MOCVD reaction chamber, and the undoped semiconductor layer 102, the n-type semiconductor layer 103, the light emitting layer 104, the electron blocking layer, and the p-type semiconductor layer 105 may be sequentially grown thereon to form a wafer.
The non-doped layer comprises a non-doped gallium nitride layer or an aluminum gallium nitride layer, and the buffer layer comprises one of an aluminum nitride buffer layer, a gallium nitride buffer layer, an aluminum gallium nitride buffer layer and an aluminum indium gallium nitride buffer layer.
In an embodiment, the undoped semiconductor layer 102 is an undoped gallium nitride layer, the buffer layer is a gallium nitride buffer layer, the n-type semiconductor layer 103 is an n-type gallium nitride layer, and the p-type semiconductor layer 105 is a p-type gallium nitride layer. In another embodiment, the undoped layer is an undoped AlGaN layer, the buffer layer is an AlGaN buffer layer, the n-type semiconductor layer 103 is an n-type AlGaN layer, and the p-type semiconductor layer 105 is a p-type AlGaN layer. The light emitting layer 104 includes a quantum well superlattice layer.
As shown in fig. 2, step 2) is then performed to form a recess 106 penetrating the p-type semiconductor layer 105, the electron blocking layer and the light emitting layer 104 and reaching deep into the n-type semiconductor layer 103, so as to isolate a plurality of LED units,
specifically, a groove 106 penetrating through the p-type semiconductor layer 105, the electron blocking layer, and the light emitting layer 104 and penetrating into the n-type semiconductor layer 103 may be formed by using a photolithography process and an inductively coupled plasma etching (ICP) process, and one of the grooves 106 may be defined as a lead-out groove 107.
As shown in fig. 3, step 3) is then performed to form a p-electrode 108 on the p-type semiconductor layer 105 of each LED unit and form an n-electrode 109 on the p-type semiconductor layer 105 of at least one LED unit, wherein the n-electrode 109 extends and covers a portion of the sidewall of the extraction groove 107.
Specifically, an electrode layer including a p-electrode 108 and an n-electrode 109 may be deposited on the p-type semiconductor layer 105 by thermal deposition or electron beam deposition, wherein the n-electrode 109 extends to cover a portion of the sidewall of the extraction groove 107, and the electrode layer may be one or more of Cu, Au, Ni, Ti, Al, and Cr.
As shown in fig. 4, step 4) is performed to form the reflective layer 110 on the inner surface of the recess 106.
In the present embodiment, the reflective layer 110 includes a bragg reflective layer 110, and the bragg reflective layer 110 is formed by a plurality of Ti layers3O5/SiO2Stacking the materials, wherein the manufacturing method is an electron beam evaporation method. In addition, a thin silicon dioxide layer may be deposited by PECVD (plasma enhanced chemical vapor deposition) before the bragg reflector layer 110 is formed, so as to provide better insulating property and improve adhesion of the bragg reflector layer 110.
As shown in fig. 5 to 6, step 5) is performed to bond the wafer to the temporary substrate 112 through the bonding layer 111, and the substrate 101 is peeled.
Specifically, the temporary substrate 112 may be a silicon wafer or glass, the material of the adhesive layer 111 may be Polydimethylsiloxane (PDMS), and the wafer may be adhered to the temporary substrate 112 by a hot pressing method.
Then, the substrate 101 is removed by laser lift-off.
As shown in fig. 7 to 8, step 6) is performed to remove the buffer layer, the undoped semiconductor layer 102, and a portion of the n-type semiconductor layer 103 until the reflective layer 110 is exposed, or until the reflective layer 110 is partially removed.
For example, the buffer layer, the undoped semiconductor layer 102, and the n-type semiconductor layer 103 may be etched using a plasma etching process until the bragg reflective layer 110 is exposed, or until the bragg reflective layer 110 is partially etched; the etched wafer is shown in fig. 8.
As shown in fig. 9, step 7) is performed next, a connection layer 113 is formed on the reflection layer 110, and both ends of the connection layer 113 are respectively in contact with the n-type semiconductor layers 103 of two adjacent LED units, so that the cathodes of the adjacent LED units are connected in common. The material of the connection layer 113 may be one or more of Cu, Au, Ni, Ti, Al, and Cr. Here, the connection layer 113 on the top of the extraction groove is also referred to as a crossover layer 114.
As shown in fig. 10 and 11, step 8) is then performed to deposit a transparent conductive layer 115 over the connection layer 113 and the n-type semiconductor layer 103. For example, the transparent conductive layer 115 may be ITO, which may be formed by a sputtering method.
Fig. 11 is a simplified schematic diagram of fig. 10, and as shown in fig. 11, the connection layer 113, the transparent conductive layer 115 and the n-electrode 109 can be regarded as a whole, and they together form a cathode, which is shared by a plurality of Micro LED units.
As shown in fig. 12 and 13, step 9) is then performed to form a quantum dot layer on the transparent conductive layer 115.
In one embodiment, the quantum dot layers may include a red quantum dot layer 116, a green quantum dot layer 117, and a blue quantum dot layer 118, as shown in FIG. 12, which emit red, green, and blue light, respectively. In another embodiment, only a red quantum dot layer 116 and a green quantum dot layer 117 can be formed on the transparent conductive layer 115 to emit red and green light, respectively, and the blue light is directly emitted from the LED. In another embodiment, the red, green, or blue quantum dot layers 116, 117, 118 can cover two LED units, one for the common cathode, without emitting light, as shown in fig. 13, and the blue quantum dot layer 118 covers two LED units, such that the quantum dot layer covers substantially the entire LED surface. Alternatively, the red, green, and blue quantum dot layers 116, 117, and 118 may have different areas, or the LED units thereunder may have different sizes.
As shown in fig. 14 and 15, 10) a protective layer 119 is deposited over the quantum dot layer.
For example, the protective layer 119 may be deposited on the quantum dot layer by PECVD (plasma enhanced chemical vapor deposition), and the material of the protective layer 119 may be silicon dioxide.
Fig. 14 shows a schematic structure of the structure shown in fig. 12, in which a protective layer 119 is formed on the red quantum dot layer 116, the green quantum dot layer 117, and the blue quantum dot layer 118.
Fig. 15 shows a schematic structure of the structure shown in fig. 13, in which a protective layer 119 is formed on the red quantum dot layer 116, the green quantum dot layer 117, and the blue quantum dot layer 118.
Further, the LED chip may be finally transferred onto the target substrate by a secondary bonding or other transfer method.
As described above, the common cathode LED chip and the manufacturing method thereof of the present invention have the following advantages:
according to the Micro LED chip provided by the embodiment of the invention, a common cathode design is adopted, a plurality of Micro LED chips can be integrated into a whole, the transfer amount is less than one third of that of the traditional method, the size of the chip is larger than that of a single chip, the transfer difficulty is relatively low, and the problems of high transfer difficulty, high transfer frequency and low transfer yield of the conventional Micro LED can be solved.
According to the invention, the reflecting layer is manufactured on the side wall of each LED unit, so that the problem of color crosstalk between adjacent LEDs can be avoided.
The p-electrode 108 and the n-electrode 109 adopt a coplanar design, which is beneficial to the design of the substrate and the connection of the chip and the target substrate.
Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.
Claims (14)
1. A common cathode LED chip, comprising:
a p-type semiconductor layer;
a light emitting layer over the p-type semiconductor layer;
an n-type semiconductor layer over the light emitting layer;
the groove penetrates through the n-type semiconductor layer, the light emitting layer and the p-type semiconductor layer to isolate a plurality of LED units;
the connecting layer stretches across the groove, and two ends of the connecting layer are respectively contacted with the n-type semiconductor layers of the two adjacent LED units to realize the common connection of the cathodes of the two adjacent LED units;
the transparent conducting layer is positioned on the n-type semiconductor layer and the connecting layer;
a quantum dot layer located over the transparent conductive layer of the LED unit;
and the protective layer is positioned on the quantum dot layer.
2. A common cathode LED chip according to claim 1, wherein: the common cathode LED chip further comprises a lead-out groove, a bridging layer is arranged between the lead-out groove and the adjacent groove in a crossing mode, an n electrode is arranged in the lead-out groove, and the n electrode is in contact with the bridging layer through the lead-out groove and extends to the surface of the p-type semiconductor layer.
3. A common cathode LED chip according to claim 2, wherein: the surface of the p-type semiconductor layer of the LED unit is provided with a p electrode, and the p electrode is coplanar with the n electrode.
4. A common cathode LED chip according to claim 1, wherein: the common cathode LED chip further comprises a reflecting layer, and the reflecting layer at least covers the side wall of the groove.
5. A common cathode LED chip according to claim 1, wherein: the n-type semiconductor layer comprises an n-type gallium nitride layer, the p-type semiconductor layer comprises a p-type gallium nitride layer, or the n-type semiconductor layer comprises an n-type aluminum gallium nitride layer, and the p-type semiconductor layer comprises a p-type aluminum gallium nitride layer.
6. A common cathode LED chip according to claim 1, wherein: the common cathode LED chip further comprises an electron blocking layer, and the electron blocking layer is located between the light emitting layer and the p-type semiconductor layer.
7. A common cathode LED chip according to claim 1, wherein: the light emitting layer includes a quantum well superlattice layer.
8. A common cathode LED chip according to claim 1, wherein: the reflecting layer comprises Bragg reflecting layers, and the Bragg reflecting layers are alternately laminated Ti3O5/SiO2。
9. A common cathode LED chip according to claim 1, wherein: the material of the transparent conductive layer comprises ITO, and the material of the protective layer comprises silicon dioxide.
10. A method for manufacturing a common cathode LED chip is characterized by comprising the following steps:
1) providing a substrate, and sequentially forming a buffer layer, a non-doped semiconductor layer, an n-type semiconductor layer, a light emitting layer, an electron blocking layer and a p-type semiconductor layer on the substrate from bottom to top to form a wafer;
2) forming a groove penetrating through the p-type semiconductor layer, the electron blocking layer and the light emitting layer and penetrating into the n-type semiconductor layer to isolate a plurality of LED units;
3) forming a p-electrode on the p-type semiconductor layer of each LED unit and forming an n-electrode on the p-type semiconductor layer of at least one LED unit, wherein the n-electrode extends and covers the side wall of the groove part;
4) forming the reflecting layer on the inner surface of the groove;
5) bonding the wafer on a temporary substrate, and stripping the substrate;
6) removing the buffer layer, the non-doped semiconductor layer and part of the n-type semiconductor layer until the reflecting layer is exposed, or removing the reflecting layer partially;
7) forming a connecting layer on the reflecting layer, wherein two ends of the connecting layer are respectively contacted with the n-type semiconductor layers of two adjacent LED units, so that the common connection of the cathodes of the adjacent LED units is realized;
8) depositing a transparent conductive layer over the connection layer, n-type semiconductor layer;
9) forming a quantum dot layer on the transparent conductive layer;
10) depositing a protective layer over the quantum dot layer.
11. A method of fabricating a common cathode LED chip according to claim 10, wherein: the substrate is sapphire, silicon carbide or a silicon wafer, and the temporary substrate is a silicon wafer or glass.
12. A method of fabricating a common cathode LED chip according to claim 10, wherein: the non-doped layer comprises a non-doped gallium nitride layer or an aluminum gallium nitrogen layer, the buffer layer comprises at least one of an aluminum nitride buffer layer, a gallium nitride buffer layer, an aluminum gallium nitrogen buffer layer and an aluminum indium gallium nitrogen buffer layer, and the bonding material is polydimethylsiloxane.
13. A method of fabricating a common cathode LED chip according to claim 10, wherein: the n-type semiconductor layer comprises an n-type gallium nitride layer, and the p-type semiconductor layer comprises a p-type gallium nitride layer; or the n-type semiconductor layer comprises an n-type aluminum gallium nitride layer, and the p-type semiconductor layer comprises a p-type aluminum gallium nitride layer; the light emitting layer includes a quantum well superlattice layer.
14. A method of fabricating a common cathode LED chip according to claim 10, wherein: the reflecting layer comprises Bragg reflecting layers, and the Bragg reflecting layers are alternately laminated Ti3O5/SiO2(ii) a The material of the transparent conductive layer comprises ITO, and the material of the protective layer comprises silicon dioxide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911202411.8A CN110911537B (en) | 2019-11-29 | 2019-11-29 | Common cathode LED chip and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911202411.8A CN110911537B (en) | 2019-11-29 | 2019-11-29 | Common cathode LED chip and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110911537A true CN110911537A (en) | 2020-03-24 |
| CN110911537B CN110911537B (en) | 2021-12-28 |
Family
ID=69820687
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911202411.8A Active CN110911537B (en) | 2019-11-29 | 2019-11-29 | Common cathode LED chip and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110911537B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112289899A (en) * | 2020-09-29 | 2021-01-29 | 东莞市中麒光电技术有限公司 | Micro LED wafer structure and preparation method thereof |
| CN112885936A (en) * | 2020-12-01 | 2021-06-01 | 北京工业大学 | Micro-LED array with transparent electrode structure and preparation method |
| WO2022052058A1 (en) * | 2020-09-11 | 2022-03-17 | 华为技术有限公司 | Light emitting panel and preparation method therefor, and electronic device |
| CN115458640A (en) * | 2022-10-09 | 2022-12-09 | 佛山思坦半导体科技有限公司 | Display device manufacturing method, display device and display equipment |
| WO2024082397A1 (en) * | 2022-10-21 | 2024-04-25 | 福建兆元光电有限公司 | Method for manufacturing anti-crosstalk structure of integrated color micro led |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102270633A (en) * | 2011-07-29 | 2011-12-07 | 贵州大学 | High-power flip-chip array LED chip and manufacturing method thereof |
| CN203521455U (en) * | 2013-10-23 | 2014-04-02 | 扬州中科半导体照明有限公司 | LED chip |
| WO2014061971A1 (en) * | 2012-10-18 | 2014-04-24 | 일진엘이디(주) | High-brightness semiconductor light-emitting element having light-emitting region separation trench and excellent current dispersion effect |
| CN104241487A (en) * | 2013-06-19 | 2014-12-24 | Lg伊诺特有限公司 | Light emitting device and lighting apparatus including the same |
| CN104347776A (en) * | 2014-10-31 | 2015-02-11 | 厦门市三安光电科技有限公司 | LED (light emitting diode) structure and preparing method of LED structure |
| CN105789234A (en) * | 2010-09-24 | 2016-07-20 | 首尔半导体株式会社 | Wafer-level Light Emitting Diode Package And Method Of Fabricating The Same |
| CN107690713A (en) * | 2015-05-26 | 2018-02-13 | Lg 伊诺特有限公司 | Light-emitting component |
| CN110034217A (en) * | 2017-12-27 | 2019-07-19 | Lg伊诺特有限公司 | Semiconductor devices |
| CN110212070A (en) * | 2018-02-28 | 2019-09-06 | 日亚化学工业株式会社 | Light-emitting component and light emitting device |
| US20190348570A1 (en) * | 2013-08-27 | 2019-11-14 | Epistar Corporation | Semiconductor light-emitting device |
| CN110459660A (en) * | 2019-08-06 | 2019-11-15 | 天津三安光电有限公司 | A kind of light emitting diode and manufacture craft, light emitting device |
| KR20190129345A (en) * | 2018-05-10 | 2019-11-20 | 엘지이노텍 주식회사 | Semiconductor device |
-
2019
- 2019-11-29 CN CN201911202411.8A patent/CN110911537B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105789234A (en) * | 2010-09-24 | 2016-07-20 | 首尔半导体株式会社 | Wafer-level Light Emitting Diode Package And Method Of Fabricating The Same |
| CN102270633A (en) * | 2011-07-29 | 2011-12-07 | 贵州大学 | High-power flip-chip array LED chip and manufacturing method thereof |
| WO2014061971A1 (en) * | 2012-10-18 | 2014-04-24 | 일진엘이디(주) | High-brightness semiconductor light-emitting element having light-emitting region separation trench and excellent current dispersion effect |
| CN104241487A (en) * | 2013-06-19 | 2014-12-24 | Lg伊诺特有限公司 | Light emitting device and lighting apparatus including the same |
| US20190348570A1 (en) * | 2013-08-27 | 2019-11-14 | Epistar Corporation | Semiconductor light-emitting device |
| CN203521455U (en) * | 2013-10-23 | 2014-04-02 | 扬州中科半导体照明有限公司 | LED chip |
| CN104347776A (en) * | 2014-10-31 | 2015-02-11 | 厦门市三安光电科技有限公司 | LED (light emitting diode) structure and preparing method of LED structure |
| CN107690713A (en) * | 2015-05-26 | 2018-02-13 | Lg 伊诺特有限公司 | Light-emitting component |
| CN110034217A (en) * | 2017-12-27 | 2019-07-19 | Lg伊诺特有限公司 | Semiconductor devices |
| CN110212070A (en) * | 2018-02-28 | 2019-09-06 | 日亚化学工业株式会社 | Light-emitting component and light emitting device |
| KR20190129345A (en) * | 2018-05-10 | 2019-11-20 | 엘지이노텍 주식회사 | Semiconductor device |
| CN110459660A (en) * | 2019-08-06 | 2019-11-15 | 天津三安光电有限公司 | A kind of light emitting diode and manufacture craft, light emitting device |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022052058A1 (en) * | 2020-09-11 | 2022-03-17 | 华为技术有限公司 | Light emitting panel and preparation method therefor, and electronic device |
| CN112289899A (en) * | 2020-09-29 | 2021-01-29 | 东莞市中麒光电技术有限公司 | Micro LED wafer structure and preparation method thereof |
| CN112289899B (en) * | 2020-09-29 | 2022-04-26 | 东莞市中麒光电技术有限公司 | Micro LED wafer structure and preparation method thereof |
| CN112885936A (en) * | 2020-12-01 | 2021-06-01 | 北京工业大学 | Micro-LED array with transparent electrode structure and preparation method |
| CN115458640A (en) * | 2022-10-09 | 2022-12-09 | 佛山思坦半导体科技有限公司 | Display device manufacturing method, display device and display equipment |
| CN115458640B (en) * | 2022-10-09 | 2023-11-24 | 佛山思坦半导体科技有限公司 | Display device manufacturing method, display device and display equipment |
| WO2024082397A1 (en) * | 2022-10-21 | 2024-04-25 | 福建兆元光电有限公司 | Method for manufacturing anti-crosstalk structure of integrated color micro led |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110911537B (en) | 2021-12-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110911537B (en) | Common cathode LED chip and manufacturing method thereof | |
| US7781778B2 (en) | Semiconductor light emitting device and method of manufacturing the same employing nanowires and a phosphor film | |
| KR101891777B1 (en) | Light emitting device having dielectric reflector and method of manufacturing the same | |
| US20040188791A1 (en) | Light emitting diode and method for producing the same | |
| JP2020504449A (en) | Optoelectronic device with light emitting diode | |
| WO2012130115A1 (en) | Flip-chip light emitting diode and manufacturing method thereof | |
| TWI750650B (en) | Emissive display substrate for surface mount micro-led fluidic assembly and method for making same | |
| WO2021119906A1 (en) | Light-emitting diode | |
| CN110265586A (en) | Display panel and its manufacturing method | |
| US20210057481A1 (en) | Light emitting device for display and display apparatus having the same | |
| CN111129062B (en) | LED display module, LED display screen and manufacturing method | |
| CN110311053A (en) | Display panel and its manufacturing method | |
| CN110265587A (en) | Display panel and its manufacturing method | |
| TW202205467A (en) | Monolithic electronic device | |
| CN215342604U (en) | LED chip structure and display module | |
| CN215815879U (en) | LED chip structure, display module and electronic equipment | |
| TWI740488B (en) | Planar surface mount micro-led for fluidic assembly and method for making same | |
| CN114497325A (en) | Quantum dot embedded full-color Micro-LED display chip and preparation method thereof | |
| KR20230031909A (en) | light emitting array | |
| US20190027652A1 (en) | Light Emitting Diode and Fabrication Method Thereof | |
| CN111863871A (en) | Display panel and preparation method thereof | |
| CN113270441B (en) | LED chip structure, preparation method thereof, display module and electronic equipment | |
| CN114420720B (en) | MicroLED display panel manufacturing method and display panel | |
| CN215988812U (en) | Miniature light-emitting diode and miniature light-emitting diode display | |
| US11411145B2 (en) | Light-emitting element package |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |