This application claims priority of Taiwan Patent Application No. 111143967 filed on Nov. 17, 2022, and the entirety of which is incorporated by reference herein.
The present disclosure relates to optoelectronic semiconductor element, and in particular it relates to an optoelectronic semiconductor element including a metal layer.
Semiconductor elements are widely used, and the research and development of related materials is also continuously being carried out. For example, III-V semiconductor materials containing group III and group V elements may be applied to various optoelectronic semiconductor elements, such as light-emitting chips (for example, light-emitting diodes or laser diodes), light-absorbing chips (photodetectors or solar cells) or non-luminous chips (for example, power components of switches or rectifiers), which can be used in lighting, medical treatment, display, communication, sensing, power supply systems and other applications.
With the advancements being made in science and technology, the volume of optoelectronic semiconductor elements has gradually been miniaturized. In recent years, due to breakthroughs in the size of light-emitting diodes (LEDs), micro-LED displays, which are made by arranging light-emitting diodes in an array, are gradually gaining attention in the market. Compared with organic light-emitting diode (OLED) displays, micro-LED displays are more power-efficient, have better reliability, longer service life and better contrast performance, while being visible in sunlight.
Although existing micro-LEDs can roughly meet their original intended use, they still do not fully meet requirements in all respects. In order to make sure the micro-LED has better device characteristics, product yield, and mass transfer stability at the device application end, the improvement of micro-LEDs is still a research topic in the industry.
The present disclosure provides an optoelectronic semiconductor element. The optoelectronic semiconductor element includes a semiconductor stack and a first metal layer. The semiconductor stack includes a first portion and a second portion stacked in sequence, with the second portion including an active region. The first metal layer is located on the first portion and is electrically connected to the first portion. A top-view outline of the first portion shows a first pattern, a top-view outline of the second portion shows a second pattern, and a top-view outline of the first metal layer shows a third pattern. The area ratio of the third pattern to the first pattern is from 0.5% to 10%.
The present disclosure also provides another optoelectronic semiconductor element. The optoelectronic semiconductor element includes a semiconductor stack, a first metal layer, and a second metal layer. The semiconductor stack includes a first portion and a second portion, with the second portion including an active region. The first metal is electrically connected to the first portion. The second metal layer is electrically connected to the second portion. The semiconductor stack is located between the first metal layer and the second metal layer. A top-view outline of the first portion shows a first pattern, a top-view outline of the second portion shows a second pattern, a top-view outline of the first metal layer shows a third pattern, and a top-view outline of the second metal layer shows a fourth pattern. The area ratio of the fourth pattern to the first pattern is from 0.5% to 10%
Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion
The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.
Some embodiments of the disclosure are described. Additional operations can be provided before, during, and/or after the stages described in these embodiments. Some of the stages that are described can be replaced or eliminated for different embodiments. Additional features can be added to the semiconductor device structure. Some of the features described below can be replaced or eliminated for different embodiments. Although some embodiments are discussed with operations performed in a particular order, these operations may be performed in another logical order.
By designing the structural appearance of the optoelectronic semiconductor element according to the embodiments of the present disclosure, the accuracy of the dimension and appearance of the element can be improved. For example, it is possible to reduce the appearance abnormality of the micro-LED chip and improve the product yield. Besides, the yield and stability of the micro-LED chip during mass transfer can also be improved.
In some embodiments, as shown in
The optoelectronic semiconductor element 10 may be a micro-LED element or other suitable elements. A micro-LED refers to a light-emitting diode with a size of micron (μm) level, such as below 100 μm, below 30 μm, or even below 10 μm. In some embodiments, the second portion 120 includes a light-emitting region (such as the active region 104 in
In some embodiments, as shown in
As shown in
As shown in
In the embodiment in which the first pattern 110P has the first rounded corners 110R, the diagonals d1 and d2 are defined as diagonal connections of intersections P of extension lines of the long side (corresponding to the first length L1 of
In some embodiments, as shown in
In some embodiments, the first pattern 110P includes two long sides with a first length L1 and two short sides with a first width W1. The first width W1 may be between 0 and 80 μm. When the first width W1 is 0, it represents two adjacent rounded corners 110R directly connected. In some embodiments, there is a second shortest distance W2 between the long side of the first pattern 110P and the outline of the second pattern 120P in the Y direction. There is a fourth shortest distance W4 between the long side of the first pattern 110P and the outline of the third pattern 130P in the Y direction, and W4≥W2. The second shortest distance W2 may be between 0.2 μm and 5 μm. The fourth shortest distance W4 may be between 0.5 μm and 6 μm. The ratio of the device width W to the fourth shortest distance W4 may be between 2.5 and 30.
In some embodiments, the first rounded corner 110R of the first pattern 110P is located between the long side and the short side. There is a first distance D1 between a first midpoint M1 of the first rounded corner 110R and a third midpoint M3 of the third rounded corner 130R. There is second distance D2 between the first midpoint M1 of the first rounded corner 110R and a second midpoint M2 of the second rounded corner 120R, and D2≥D1>0. The first curvature radius R1 of the first rounded corner 110R may be between 0.5 μm and 5 μm.
In some embodiments, the first rounded corner 110R of the first pattern 110P and the second rounded corner 120R of the second pattern 120P are staggered. In some embodiments, the first rounded corner 110R of the first pattern 110P and the third rounded corner 130R of the third pattern 130P are staggered. The so-called “staggered” here means that the extension of the connection line of the midpoints of two rounded corners of the pattern is not perpendicular to any of the two rounded corners of the other pattern. For example, the extension of the connection line of the first midpoint M1 and the second midpoint M2 is not perpendicular to any of the first rounded corner 110R and the second rounded corner 120R. The extension of the connection line of the first midpoints M1 and the third midpoint M3 is not perpendicular to any of the first rounded corner 110R and the third rounded corners 130R.
In some embodiments, the second pattern 120P has two long sides and two short sides, the long sides and the short sides are respectively parallel to the X direction and the Y direction, and the second rounded corner 120R of the second pattern 120P is between the long and short sides. The second curvature radius R2 of the second rounded corner 120R may be between 0.2 μm and 2 μm. In some embodiments, there is a third shortest distance W3 between the extension line of the long side of the second pattern 120P and the outline of the third pattern 130P in the Y direction, and W3≥W2. The ratio of the device width W to the second shortest distance W2 (W/W2) may be between 3 and 80. A preferable ratio of the device width W to the second shortest distance W2 is between about 15 and 30.
In some embodiments, the third pattern 130P has two long sides and two short sides, the long sides and the short sides are respectively parallel to the X direction and the Y direction, and the third rounded corner 130R is located between the long and short sides of the third pattern 130P. In some embodiments, the second pattern 120P has a sixth width W6, the third pattern 130P has a fifth width W5, and W6≥W5. In some embodiments, W>W6≥W1. The ratio of the device width W to the fifth width W5 (W/W5) may be between 1.1 and 10.
In some embodiments, the substrate 150 includes an insulating material or a non-insulating material. The insulating material includes sapphire, glass, or ceramic material. Non-insulating materials include elemental semiconductors (such as silicon or germanium), compound semiconductors (such as silicon carbide, gallium arsenide, gallium nitride, aluminum nitride, aluminum gallium nitride, or combinations thereof), metals (such as copper, molybdenum, or copper tungsten), or a combination thereof. The substrate 150 may also be a multi-layered substrate, such as a silicon-on-insulator (SOI) substrate.
As shown in
The materials of the first-type semiconductor layer 102, the active region 104, and the second-type semiconductor layer 106 include III-V group semiconductor materials, such as AlxInyGa(1-x-y)N, AlxInyGa(1-x-y)As or AlxInyGa(1-x-y)P, wherein 0≤x, y≤1, and (x+y)≤1. When the material of the active region 104 is InGaP or AlInGaP, the active region 104 can emit red light with a wavelength between 610 nm and 700 nm, or emit yellow light or green light with a wavelength between 510 nm and 600 nm. When the material of the active region 104 is InGaN, the active region 104 can emit blue light or deep blue light with a wavelength between 400 nm and 490 nm, or emit green light with a wavelength between 490 nm and 550 nm. When the material of the active region 104 is AlGaN or AlGaInN, the active region 104 can emit ultraviolet light with a wavelength between 250 nm and 400 nm. When the material of the active region 104 is InGaAs, InGaAsP, AlGaAs, or AlGaInAs, the active region 104 can emit infrared light with a wavelength between 700 nm and 1700 nm. The semiconductor stack 100 may include a single heterostructure (SH), a double heterostructure (DH), a double-side double heterostructure (DDH), or a multi-quantum well (MQW) material structure. The material of the active region 104 may be a semiconductor doped with p-type dopant, doped with n-type dopant, or without dopant. The p-type or n-type dopant may be magnesium (Mg), zinc (Zn), silicon (Si), carbon (C) or tellurium (Te).
The optoelectronic semiconductor element 10 may further include an insulating layer 160 disposed on the semiconductor stack 100, and there are at least two openings in the insulating layer 160 for exposing the first metal layer 130 and the second metal layer 140. Referring to
The material of the insulating layer 160 may include a non-conductive material. Non-conductive material includes organic material, inorganic material or dielectric material. Organic material includes benzocyclobutene (BCB), perfluorocyclobutane (PFCB), epoxy resin, acrylic resin, cycloolefin polymer (COC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polyetherimide, fluorocarbon polymer. Inorganic material includes silicone and glass. Dielectric material includes aluminum oxide (Al2O3), silicon nitride (SiNx), silicon oxide (SiOx), titanium oxide (TiOx), magnesium fluoride (MgFx).
The optoelectronic semiconductor element 10 may further include a first electrode 171 electrically connected to the first metal layer 130 and a second electrode 172 electrically connected to the second metal layer 140. The top surfaces of the first electrode 171 and the second electrode 172 may substantially be the same elevation.
The first electrode 171 and the second electrode 172 may be a single-layer or multi-layer structure. The material of the first electrode 171 and the second electrode 172 may include conductive material, such as metal, metal compound, or a combination thereof. The metal includes, for example, gold, nickel, platinum, palladium, iridium, titanium, chromium, tungsten, aluminum, copper, silver, tin, indium, alloys thereof, or combinations thereof. The metal compound includes metal oxide (such as indium tin oxide (ITO)) or other light-transmitting conductive materials.
In some embodiments, as shown in
With the structural appearance of the optoelectronic semiconductor element 10 according to the above embodiments, the accuracy of the dimension and appearance of each component can be improved. For example, the abnormal appearance of the optoelectronic semiconductor element 10 produced by lithography and etching processes can be reduced, and the product yield can be therefore improved. At the same time, the yield and stability of the optoelectronic semiconductor element during subsequent mass transfer can also be enhanced.
Referring to
By disposing the first metal layer 130 and the second metal layer 140 on opposite sides of the semiconductor stack 100 to form a vertical type optoelectronic semiconductor element 20, the ratio of the active region 104 to be removed can be reduced so a larger luminous area can be preserved. By controlling the second area ratio of the fourth pattern 140P to the first pattern 110P, the abnormal appearance of the optoelectronic semiconductor element 20 produced by the lithography and etching process can be reduced and the product yield can be improved. At the same time, the yield and stability of the optoelectronic semiconductor element 20 during subsequent mass transfer can be enhanced.
In some embodiments, as shown in
When any of the first pattern 110P, the second pattern 120P, the third pattern 130P, and the fourth pattern 140P is substantially circular, its corresponding curvature radius R1, R2, R3, or R4 is a fixed value everywhere on the pattern. When any of the above patterns is substantially elliptical, its corresponding curvature radius R1, R2, R3, or R4 is a variable value on the pattern. In some embodiments, as shown in
Referring to
Referring to
In
In summary, the present disclosure provides optoelectronic semiconductor elements with various configurations, which are used to solve the problems derived from the influence of the original dimensional design and manufacturing process of the micro-LED elements during the manufacturing process. By designing the structural appearance of the optoelectronic semiconductor element according to the embodiments of the present disclosure, the accuracy of the dimension and appearance of the element can be improved. For example, the appearance abnormality of the micro-LED chip can be reduced and the product yield can be improved. At the same time, the yield and stability of the micro-LED chip during mass transfer can also be enhanced.
The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.
Number | Date | Country | Kind |
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111143967 | Nov 2022 | TW | national |