KR-102963492-B1 - Micro LED with Horizontal Electrode Structure and Manufacturing Method thereof

KR102963492B1KR 102963492 B1KR102963492 B1KR 102963492B1KR-102963492-B1

Abstract

A micro LED having a horizontal electrode structure and a method for manufacturing the same are disclosed. According to one aspect of the present embodiment, a micro LED is provided comprising a substrate, a buffer layer deposited on the substrate, an n-type semiconductor layer, an active layer, and a p-type semiconductor layer sequentially deposited on the buffer layer, a plurality of ohmic electrode layers each deposited on the n-type semiconductor layer and the p-type semiconductor layer, a passivation layer applied to the upper or side of the substrate, the buffer layer, the n-type semiconductor layer, the active layer, the p-type semiconductor layer, and the ohmic electrode layers to protect and insulate each component from the outside, and a plurality of electrodes disposed on each ohmic electrode layer and supplying power to the n-type semiconductor layer and the p-type semiconductor layer, respectively, wherein a mesa etching is performed in a vertical direction from the p-type semiconductor layer to a position in the vertical direction of the n-type semiconductor layer.

Inventors

민정홍
이상헌
정성훈
정태훈

Assignees

한국광기술원

Dates

Publication Date: 20260513
Application Date: 20231127

Claims (16)

Substrate; A buffer layer deposited on the above substrate; n-type semiconductor layer, active layer, and p-type semiconductor layer deposited sequentially on the above buffer layer; First and second ohmic electrode layers respectively deposited on the n-type semiconductor layer and the p-type semiconductor layer; A passivation layer applied to the upper or side of the substrate, the buffer layer, the n-type semiconductor layer, the active layer, the p-type semiconductor layer, and the ohmic electrode layer to protect and insulate each component from the outside; and It includes first and second electrodes disposed on each ohmic electrode layer and supplying power to the n-type semiconductor layer and the p-type semiconductor layer, respectively. Mesa etching is performed vertically from the p-type semiconductor layer to a position in the vertical direction of the n-type semiconductor layer for a percentage of the total area of the p-type semiconductor layer or the n-type semiconductor layer, wherein the mesa etching is performed only at one corner in the area direction of the p-type semiconductor layer and the n-type semiconductor layer. The second ohmic electrode layer is deposited at a position located at a predetermined radius away from the area where mesa etching was performed on the top of the p-type semiconductor layer, and The second electrode is disposed on the second ohmic electrode and is implemented on the top of the p-type semiconductor layer, and A micro LED characterized in that the first electrode is deposited from the first ohmic electrode layer along a mesa etching plane to the top of the p-type semiconductor layer, and is positioned in an area on the top of the p-type semiconductor layer where the second electrode is not located, thereby being implemented to be positioned at the same height as the second electrode in the vertical direction.
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A first deposition process in which a buffer layer, an n-type semiconductor layer, an active layer, and a p-type semiconductor layer are grown or deposited on a substrate; A first etching process in which a number of percent of the total area of the p-type semiconductor layer or the n-type semiconductor layer is etched in a vertical direction from the p-type semiconductor layer to a position on the n-type semiconductor layer; A second deposition process in which a first and a second ohmic electrode layer are respectively deposited on the upper surface of the n-type semiconductor layer exposed by the above etching process and on the p-type semiconductor layer; A third deposition process in which a passivation layer is deposited on the upper or side surface of each layer; A second etching process in which the passivation layer is etched by an area of each ohmic electrode layer until each ohmic electrode layer is exposed; and A fourth deposition process in which first and second electrodes are deposited from each ohmic electrode layer onto the p-type semiconductor layer, wherein The above mesa etching is performed only at one corner in the area direction of the p-type semiconductor layer and the n-type semiconductor layer, and The second ohmic electrode layer is deposited at a position located at a predetermined radius away from the area where mesa etching was performed on the top of the p-type semiconductor layer, and The second electrode is disposed on the second ohmic electrode and is implemented on the top of the p-type semiconductor layer, and A method for manufacturing a micro LED characterized in that the first electrode is deposited from the first ohmic electrode layer along a mesa etching plane to the top of the p-type semiconductor layer, and is positioned in an area on the top of the p-type semiconductor layer where the second electrode is not located, thereby being implemented to be positioned at the same height as the second electrode in the vertical direction.
In paragraph 6, A method for manufacturing a micro LED characterized by additionally depositing an etching stop layer on the ohmic electrode layer deposited in the second deposition process.
Micro LED manufactured according to the manufacturing method of paragraph 6 or 7.
Substrate; A buffer layer deposited on the above substrate; n-type semiconductor layer, active layer, and p-type semiconductor layer deposited sequentially on the above buffer layer; First and second ohmic electrode layers respectively deposited on the n-type semiconductor layer and the p-type semiconductor layer; A passivation layer applied to the upper or side of the substrate, the buffer layer, the n-type semiconductor layer, the active layer, the p-type semiconductor layer, and the ohmic electrode layer to protect and insulate each component from the outside; and It includes first and second electrodes disposed on each ohmic electrode layer and supplying power to the n-type semiconductor layer and the p-type semiconductor layer, respectively. Mesa etching is performed on a number of percent of the total area of the p-type semiconductor layer or the n-type semiconductor layer from the p-type semiconductor layer to a position in the vertical direction of the n-type semiconductor layer while tilted by a preset angle range from the vertical axis, wherein the mesa etching is performed only on one corner in the area direction of the p-type semiconductor layer and the n-type semiconductor layer. The second ohmic electrode layer is deposited at a position located at a predetermined radius away from the area where mesa etching was performed on the top of the p-type semiconductor layer, and The second electrode is disposed on the second ohmic electrode and is implemented on the top of the p-type semiconductor layer, and A micro LED characterized in that the first electrode is deposited from the first ohmic electrode layer along a mesa etching plane to the top of the p-type semiconductor layer, and is positioned in an area on the top of the p-type semiconductor layer where the second electrode is not located, thereby being implemented to be positioned at the same height as the second electrode in the vertical direction.
In Paragraph 9, The angle range previously set above is, A micro LED characterized by being 5 to 35°.
In Paragraph 9, A micro LED characterized in that, when the above mesa etching is performed, the area from the n-type semiconductor layer to the p-type semiconductor layer in the mesa etched region has an obliquely inclined shape.
A first deposition process in which a buffer layer, an n-type semiconductor layer, an active layer, and a p-type semiconductor layer are grown or deposited on a substrate; A first etching process in which a number of percent of the total area of the p-type semiconductor layer or the n-type semiconductor layer is etched in a vertical direction from the p-type semiconductor layer to a position in the vertical direction of the n-type semiconductor layer while tilted by a predetermined angle range from the vertical axis; A second deposition process in which a first and a second ohmic electrode layer are respectively deposited on the upper surface of the n-type semiconductor layer exposed by the above etching process and on the p-type semiconductor layer; A third deposition process in which a passivation layer is deposited on the upper or side surface of each layer; A second etching process in which the passivation layer is etched by an area of each ohmic electrode layer until each ohmic electrode layer is exposed; and A fourth deposition process in which first and second electrodes are deposited from each ohmic electrode layer onto the p-type semiconductor layer, wherein The above mesa etching is performed only at one corner in the area direction of the p-type semiconductor layer and the n-type semiconductor layer, and The second ohmic electrode layer is deposited at a position located at a predetermined radius away from the area where mesa etching was performed on the top of the p-type semiconductor layer, and The second electrode is disposed on the second ohmic electrode and is implemented on the top of the p-type semiconductor layer, and A method for manufacturing a micro LED characterized in that the first electrode is deposited from the first ohmic electrode layer along a mesa etching plane to the top of the p-type semiconductor layer, and is positioned in an area on the top of the p-type semiconductor layer where the second electrode is not located, thereby being implemented to be positioned at the same height as the second electrode in the vertical direction.
In Paragraph 12, A method for manufacturing a micro LED characterized by additionally depositing an etching stop layer on the ohmic electrode layer deposited in the second deposition process.
In Paragraph 12, The above second etching process is, A method for manufacturing a micro LED characterized by proceeding on the upper surface of each ohmic electrode layer.
In Paragraph 13, The above etching stop layer is, A method for manufacturing a micro LED characterized by minimizing damage to each ohmic electrode layer that may occur during the above-mentioned second etching process.
A micro LED manufactured according to the manufacturing method of any one of paragraphs 12 to 15.

Description

Micro LED with Horizontal Electrode Structure and Manufacturing Method thereof The present invention relates to a micro LED having a horizontal electrode structure and a method for manufacturing the same. The content described in this section merely provides background information regarding the present embodiment and does not constitute prior art. LEDs (Light Emitting Diodes) are inorganic light sources widely used in various fields, such as display devices, automotive lamps, and general lighting. Due to their advantages of long lifespan, low power consumption, and fast response speed, LEDs are rapidly replacing conventional light sources. LEDs can generally produce various colors by utilizing a mixture of blue, green, and red. Light-emitting diodes used in various devices include multiple pixels to produce various images or colors, and each pixel is equipped with blue, green, and red subpixels; the color of a specific pixel is determined by the colors of these subpixels, and an image can be produced through a combination of these pixels. Recently, micro LEDs with a side length of 100㎛ or less are being developed, and micro LEDs are attracting attention as light-emitting devices for next-generation displays because they have a faster response speed, lower power consumption, and higher brightness compared to conventional LEDs. The structure of a conventional general micro LED is shown in Fig. 11. Figure 11 is a diagram illustrating the structure of a conventional micro LED. Referring to FIG. 11, a conventional micro LED (1110) has a shape that includes a step (1120) to implement electrodes. That is, one electrode is placed on the top layer, and an additional electrode is placed on the bottom layer. To this end, etching is performed in a mesa structure so that an additional electrode is placed on the bottom layer as well, and a step (1120) is formed. However, since the conventional micro LED (1110) includes a step (1120) as described above, in order to electrically connect with other components (e.g., a control board such as a PCB) as an electrode, a bump (1130) for overcoming the step must be placed at the location where the step (1120) is formed. Accordingly, the conventional micro LED (1110) requires an additional bump (1130) separate from the LED manufacturing process, and there is an inconvenience in that an additional process must be performed to place the bump (1130). In addition, since the conventional micro LED (1110) includes a step (1120), etching must be performed to implement the step (1120). As a result, the area of the light-generating active layer within the conventional micro LED (1110) is reduced accordingly, causing a decrease in light output amount or output efficiency. FIG. 1 is a diagram illustrating the configuration of a micro LED according to one embodiment of the present invention. FIGS. 2 to 9 are drawings illustrating the manufacturing process of a micro LED according to one embodiment of the present invention. FIG. 10 is a flowchart illustrating a method for manufacturing a micro LED according to one embodiment of the present invention. Figure 11 is a diagram illustrating the structure of a conventional micro LED. The present invention is susceptible to various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the invention to specific embodiments, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention. Similar reference numerals have been used for similar components in the description of each drawing. Terms such as first, second, A, B, etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and/or" includes a combination of a plurality of related described items or any of a plurality of related described items. When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "h