Light-emitting device

Abstract

A light-emitting element includes a semiconductor stack and a substrate. The substrate includes an upper surface supporting the semiconductor stack, a lower surface opposite the upper surface, and a plurality of side surfaces surrounding and connected between the upper and lower surfaces. One of the plurality of side surfaces includes an upper modified region near the upper surface and a lower modified region near the lower surface. The upper modified region includes a plurality of upper modified portions. The lower modified region includes a plurality of lower modified portions. Each upper modified portion includes a plurality of upper modified marks. Each lower modified portion includes a plurality of lower modified marks. Each upper modified mark includes a first end facing the upper surface and a second end facing the lower surface, the second end being a pointed tip compared to the first end. Each lower modified mark includes a third end facing the upper surface and a fourth end facing the lower surface, the third end being a pointed tip compared to the fourth end.

Description

Technical Field

[0001] The present disclosure relates to a light-emitting element and a method for manufacturing the same, and more particularly to a light-emitting element and a method for manufacturing the same by laser cutting a substrate. Prior Art

[0002] Solid-state semiconductor elements such as light-emitting diodes (LEDs) have the advantages of low power consumption, low heat generation, long working life, shock resistance, small size, fast response speed, and good optoelectronic characteristics such as a stable emission wavelength due to the characteristics of the semiconductor constituent materials. Therefore, light-emitting diodes are widely used in household appliances, device indicators, and optoelectronic products, etc. Summary of the Invention

[0003] A light-emitting element includes a semiconductor stack and a substrate. The substrate includes an upper surface for carrying the semiconductor stack, a lower surface opposite to the upper surface, and a plurality of side surfaces surrounding and connecting between the upper surface and the lower surface. The horizontal direction is parallel to the upper surface, and the vertical direction is perpendicular to the upper surface. One of the plurality of side surfaces includes an upper modification region close to the upper surface in the vertical direction and a lower modification region close to the lower surface in the vertical direction. The upper modification region includes a plurality of upper modification portions. The lower modification region includes a plurality of lower modification portions. Each upper modification portion includes a plurality of upper modification marks arranged in the horizontal direction, and each lower modification portion includes a plurality of lower modification marks arranged in the horizontal direction. Each upper modification mark includes a first end facing the upper surface and a second end facing the lower surface. The second end is a tip compared to the first end. Each lower modification mark includes a third end facing the upper surface and a fourth end facing the lower surface. The third end is a tip compared to the fourth end. Brief Description of the Drawings

[0004] FIG. 1 shows a top view schematic diagram of an embodiment of a light-emitting element according to the present disclosure. FIG. 2 shows a side view schematic diagram of FIG. 1 at side S1. FIGS. 3A to 3F show schematic diagrams of a method for manufacturing a light-emitting element according to the present disclosure. FIG. 4 is a schematic diagram of a semiconductor stack and electrodes of a light-emitting element according to the present disclosure. FIG. 5 is a cross-sectional schematic diagram of a light-emitting package according to some embodiments of the present disclosure. FIG. 6 is a schematic diagram of a light-emitting device according to some embodiments of the present disclosure. Embodiments

[0005] The following embodiments will be described with reference to the drawings. In the drawings or the description, similar or identical parts are denoted by the same reference numerals, and in the drawings, the shape or thickness of the elements may be enlarged or reduced. It should be noted in particular that elements not shown in the drawings or described in the specification may be in forms known to those skilled in the art. Also, some elements and / or symbols may be omitted in some of the drawings. In the drawings, similar symbols are used to indicate similar elements. The following description and the accompanying drawings are provided for illustrative purposes only and are not intended to be limiting. It is contemplated that elements and features of one embodiment can be advantageously incorporated into another embodiment without further elaboration. In addition, other layers / structures or steps may be incorporated in the following embodiments. For example, the description of "forming a second layer / structure on a first layer / structure" may include embodiments where the first layer / structure is in direct contact with the second layer / structure, or embodiments where the first layer / structure is in indirect contact with the second layer / structure, i.e., there are other layers / structures between the first layer / structure and the second layer / structure. In addition, the relative spatial relationship between the first layer / structure and the second layer / structure may change according to the operation or use of the device. The first layer / structure itself is not limited to a single layer or a single structure. The first layer may include a plurality of sub-layers, and the first structure may include a plurality of sub-structures.

[0006] In addition, with regard to the spatially related descriptive terms mentioned in this disclosure, such as: "under", "lower", "below", "above", "on", "top", "bottom" and similar terms, for the convenience of description, their usage is to describe the relative relationship between one element or feature and another element or feature in the drawings. In addition to the orientation shown in the drawings, these spatially related terms are also used to describe the possible orientations of the light-emitting element during use and operation. As the orientation of the semiconductor element varies (rotating 90 degrees or other orientations), the spatially related descriptions used to describe its orientation should be interpreted in a similar manner.

[0007] In this disclosure, if not otherwise specified, the general formula AlGaN series represents Al aGa (1-a)N, where 0 ≤ a ≤ 1; the general formula InGaN series represents In bGa (1–b)N, where 0 ≤ b ≤ 1; the general formula AlInGaN series represents Al cIn dGa (1-c-d)N, where 0 ≤ c ≤ 1, 0 ≤ d ≤ 1. Adjusting the content of the elements can achieve different purposes, such as but not limited to, adjusting the energy level or the main emission wavelength of the light-emitting element.

[0008] The composition and dopants of each layer included in the light-emitting element disclosed in this disclosure can be analyzed by any suitable method, such as a secondary ion mass spectrometer (SIMS).

[0009] The thickness of each layer included in the light-emitting element disclosed in this disclosure can be analyzed by any suitable method, such as transmission electron microscopy (TEM) or scanning electron microscopy (SEM), so as to match the depth positions of the respective layers on, for example, a SIMS spectrum.

[0010] FIG. 1 shows a top view schematic diagram of an embodiment of a light-emitting element according to the present disclosure. FIG. 2 shows a side view schematic diagram of FIG. 1 from side S1. As shown in FIGS. 1 and 2, a light-emitting element 100 of an embodiment of the present disclosure includes a semiconductor stack M and a substrate 101. The substrate 101 includes an upper surface TS for carrying the semiconductor stack M and a lower surface BS opposite to the upper surface TS. The substrate 101 further includes a plurality of side surfaces, namely a first side surface S1, a second side surface S2, a third side surface S3, and a fourth side surface S4, surrounding and connecting between the upper surface TS and the lower surface BS. The first side surface S1 is opposite to the third side surface S3, and the second side surface S2 and the fourth side surface S4 are connected between the first side surface S1 and the third side surface S3. For ease of description, a horizontal direction X, Z is defined parallel to the upper surface TS and a vertical direction Y is defined perpendicular to the upper surface TS. In an embodiment, one of the plurality of side surfaces, for example, the first side surface S1 includes an upper modification region 102 and a lower modification region 103. The upper modification region 102 is disposed near the upper surface TS in the vertical direction Y and includes one or more upper modification portions 102n, where n = a, b,.... The lower modification region 103 is disposed near the lower surface BS in the vertical direction Y and includes one or more lower modification portions 103m, where m = a, b,.... Each upper modification portion 102n includes a plurality of upper modification traces 104 disposed along the horizontal direction X. Each lower modification region 103 includes a plurality of lower modification traces 105 disposed along the horizontal direction X. In an embodiment, each upper modification trace 104 includes a first end E1 facing the upper surface TS and a second end E2 facing the lower surface BS. Each lower modification trace 105 includes a third end E3 facing the upper surface TS and a fourth end E4 facing the lower surface BS. The sizes and shapes of the first end E1 and the second end E2 may be the same or different. The sizes and shapes of the third end E3 and the fourth end E4 may be the same or different. The size, for example, includes the width of the upper modification trace 104 and the lower modification trace 105 along the horizontal direction X, or the depth of the upper modification trace 104 and the lower modification trace 105 along the horizontal direction Z. In this embodiment, the first end E1 and the second end E2 have different sizes. The width of the second end E2 along the horizontal direction X is wider than that of the first end E1. In an embodiment, the first end E1 and the second end E2 have different shapes. For example, the shape of the second end E2 is a pointed tip compared to the first end E1. In this embodiment, the third end E3 and the fourth end E4 have different sizes or shapes. For example, the width of the fourth end E4 along the horizontal direction X is wider than that of the third end E3, and the shape of the third end E3 is a pointed tip compared to the fourth end E4.

[0011] The different upper modification parts 102n may have different structural features, such as dimensions, roughness, or contour features of different upper modification marks 104. The dimensions include the length, width, depth, area, or volume of the upper modification mark 104. In one embodiment, the upper modification part 102n farther away from the upper surface TS has a longer length in the vertical direction Y. For example, the upper modification part 102n may include a first upper modification part 102a and a second upper modification part 102b. The second upper modification part 102b is closer to the upper surface TS than the first upper modification part 102a. In the vertical direction Y, the first upper modification part 102a has a longer length than the second upper modification part 102b. Specifically, the average length of the plurality of upper modification marks 104 in the first upper modification part 102a is greater than the average length of the upper modification marks 104 in the second upper modification area 102b. In one embodiment, the upper modification marks 104 in the first upper modification part 102a as a whole have a more elongated shape than the upper modification marks 104 in the second upper modification part 102b. In one embodiment, each upper modification mark 104 may be a concave hole. The contour of the upper modification mark 104 closer to the upper surface TS is closer to a dot-shaped concave hole, and the contour of the upper modification mark 104 farther away from the upper surface TS is closer to a strip-shaped concave hole. In one embodiment, the depth of the concave hole of the upper modification mark 104 closer to the upper surface TS is deeper. On the contrary, the depth of the concave hole of the upper modification mark 104 farther away from the upper surface TS is shallower. In one embodiment, the upper modification part 102n closer to the upper surface TS may have a rougher surface. In one embodiment, in terms of the area range, the upper modification part 102n farther away from the upper surface TS has a larger area in the vertical direction Y.

[0012] The different lower modification parts 103m may have different structural features, such as dimensions, roughness, or contour features of different lower modification marks 105. The dimensions include the length, width, depth, area, or volume of the upper modification mark 104. In one embodiment, the lower modification part 103m farther away from the lower surface BS has a longer length in the vertical direction Y. For example, the lower modification part 103m includes a first lower modification part 103a and a second lower modification part 103b. The second lower modification part 103b is closer to the lower surface than the first lower modification part 103a. In the vertical direction Y, the first lower modification part 103a has a longer length than the second lower modification part 103b. Specifically, the average length of the plurality of lower modification marks 105 in the first lower modification part 103a is greater than the average length of the lower modification marks 105 in the second lower modification part 103b. In one embodiment, the lower modification marks 105 in the first lower modification part 103a as a whole have a more elongated shape than the lower modification marks 105 in the second lower modification part 103b. In one embodiment, each lower modification mark 105 may be a concave hole. The contour of the lower modification mark 105 in the lower modification area 103 closer to the lower surface BS is closer to a dot-shaped concave hole, and the lower modification mark 105 in the lower modification area 103 closer to the lower surface BS is closer to a strip-shaped concave hole. In one embodiment, the depth of the concave hole of the lower modification mark 105 closer to the lower surface TS is deeper. On the contrary, the depth of the concave hole of the lower modification mark 105 farther away from the lower surface BS is shallower. In one embodiment, the lower modification part 103m closer to the lower surface BS may have a rougher surface. In one embodiment, in terms of the area range, the lower modification part 103m farther away from the lower surface TS has a larger area in the vertical direction Y.

[0013] The first side surface S1 of the light-emitting element 100 may have a plurality of cracks. In an embodiment, the cracks include, for example, a plurality of upper cracks UC and a plurality of lower cracks DC. The upper cracks UC may extend from the upper modification region 102 to the upper surface TS or the lower surface BS, and the lower cracks DC may extend from the lower modification region 103 to the lower surface BS or the lower surface BS. In an embodiment, the upper cracks UC may extend from any one or more upper modification portions 102n to the upper surface TS or the lower surface BS. For example, in any one upper modification portion 102n, the upper cracks UC may extend from one or more upper modification marks 104 to the upper surface TS, or from one or more upper modification marks 104 to the lower surface BS. Similarly, the lower cracks DC may extend from any one or more lower modification portions 103m to the lower surface BS or the upper surface TS. For example, in any one lower modification portion 103m, the lower cracks DC may extend from one or more lower modification marks 105 to the upper surface TS, or from one or more lower modification marks 105 to the lower surface BS. In any one upper modification portion 102n (or lower modification portion 103m), a plurality of transverse cracks (not shown) may also be formed to connect between the plurality of upper modification marks 104 (or lower modification marks 105).

[0014] Each upper modification portion 102n and each lower modification portion 103m may have appropriate depths relative to the upper surface TS and the lower surface BS, respectively. In an embodiment, in the vertical direction Y, the distance D between the upper surface TS and the lower surface BS may be the thickness of the substrate 100. The distance between each upper modification portion 102n (e.g., its central position) and the upper surface TS in the vertical direction Y may be less than or equal to 0.6D, and / or the distance between each lower modification portion 103m (e.g., its central position) and the lower surface BS in the vertical direction Y may be less than or equal to 0.6D, where 400 μm ≦ D ≦ 1000 μm. For example, when the distance D, that is, the thickness of the substrate 101, is 1000 μm, the distance between the central position of each upper modification portion 102n and the upper surface TS in the vertical direction Y may be less than or equal to 600 μm, and the distance between the central position of each lower modification portion 103m and the lower surface BS in the vertical direction Y may be less than or equal to 600 μm. However, when the distance D exceeds 1000 μm, the distance between the central position of each upper modification portion 102n and the upper surface TS in the vertical direction Y may still remain not exceeding 600 μm, and the distance between the central position of each lower modification portion 103m and the lower surface BS in the vertical direction Y may still remain not exceeding 600 μm. In addition, the distance between the central position of each upper modification portion 102n and the upper surface TS may be greater than or equal to 0.1D. However, when the distance D is less than 1000 μm, the distance between the central position of each upper modification portion 102n and the upper surface TS may remain greater than or equal to 100 μm.

[0015] Substrates 101 of different thicknesses may include different numbers of modified portions on a side surface, such as a first side surface S1. In an embodiment where the first side surface S1 includes an upper modified region 102 and a lower modified region 103, when the distance D is larger, the first side surface S1 may have a larger total number of modified portions, including upper modified portions 102n and lower modified regions 103m. The spacing between two adjacent upper modified portions 102n may be approximately between 90 μm and 110 μm, and the spacing between two adjacent lower modified portions 103m may be approximately between 90 μm and 110 μm.

[0016] In some embodiments, the substrate 101 includes silicon, silicon carbide (SiC), aluminum oxide (Al2O3), aluminum nitride (AlN), gallium nitride (GaN), gallium arsenide (GaAs), other suitable materials, or a combination of the foregoing materials. In one example, the substrate 101 is a sapphire substrate composed of aluminum oxide.

[0017] FIG. 4 is a schematic diagram of a semiconductor stack and electrodes of the light-emitting element shown in FIG. 2 of the present disclosure. As shown in FIGS. 4 and 2, the semiconductor stack M is, for example, a light-emitting stack, including a first semiconductor layer 110 located on the substrate 101, an active region 111 located on the first semiconductor layer 110, and a second semiconductor layer 112 located on the active region 112. Among them, the first semiconductor layer 110 has a first conductivity type and the second semiconductor layer 112 has a second conductivity type opposite to the first conductivity type. The first conductivity type is, for example, n-type so that the first semiconductor layer 110 can provide electrons to the active region 111, and the second conductivity type is, for example, p-type so that the second semiconductor layer 112 can provide holes to the active region 111, and electrons and holes are combined in the active region 111 to emit light of a specific wavelength. The first electrode 108 is located on the first semiconductor layer 110 and is electrically connected thereto; the second electrode 109 is located on the second semiconductor layer 112 and is electrically connected thereto.

[0018] In some embodiments, the first semiconductor layer 110 and the second semiconductor layer 112 can serve as confinement layers, carrier supply layers, or contact layers. The active region 111 can serve as a light-emitting structure. The first semiconductor layer 110 and the second semiconductor layer 112 can include semiconductor materials of different doping types to supply carriers. For example, the first semiconductor layer 110 includes an n-type semiconductor layer, and the second semiconductor layer 112 includes a p-type semiconductor layer to respectively provide electrons and holes, or the first semiconductor layer 110 includes a p-type semiconductor layer, and the second semiconductor layer 112 includes an n-type semiconductor layer to respectively provide holes and electrons. The first semiconductor layer 110, the active region 111, and the second semiconductor layer 112 can include III-V group compound semiconductor materials of the same series, such as the AlInGaAs series, the AlGaInP series, the InGaAsP series, the AlGaN series, or the AlInGaN series. Among them, the AlInGaAs series can be expressed as (Al x1In (1-x1)) 1-x2Ga x2As, the AlInGaP series can be expressed as (Al x1In (1-x1)) 1-x2Ga x2P, the InGaAsP series can be expressed as In x1Ga 1-x1As x2P 1-x2, where 0≦x1≦1, 0≦x2≦1, the AlInGaN series can be expressed as (Al x1In (1-x1)) 1-x2Ga x2N, the AlGaN series can be expressed as Al x3Ga 1-x3N, the InGaN series can be expressed as In X3Ga 1-X3N, where 0≦x3≦1, 0≦x4≦1. The wavelength of the light emitted by the light-emitting element 100 depends on the material composition of the active region 111. Specifically, the material of the active region 111 can include the AlInGaAs series, the InGaAsP series, the AlGaInP series, the InGaN series, or the AlGaN series. When the material of the active region 104 is the AlGaInP series or the InGaN series material, red light with a wavelength between 610 nm and 650 nm, or green light with a wavelength between 530 nm and 570 nm can be emitted. When the material of the active region 111 is the InGaN series material, blue light with a wavelength between 400 nm and 490 nm, cyan light with a wavelength between 490 nm and 530 nm, or green light with a wavelength between 530 nm and 570 nm can be emitted. The material of the active region 111 can be the AlGaN series or the AlInGaN series material. When the material of the active region 104 is the AlGaN-containing material in the AlGaN series material, the active region 111 can emit medium-wave ultraviolet light (UV-B) and short-wave ultraviolet light (UV-C) with a wavelength generally between 320 nm and 220 nm.When the material of the active region 111 is AlInGaN or InGaN material of the AlInGaN series, near-ultraviolet light (UV-A) with a wavelength approximately between 420 nm and 320 nm can be emitted. In some embodiments, the active region 111 may include a single heterostructure, a double heterostructure, a single quantum well structure, or multiple quantum wells (MQW). In some embodiments, the active region 111 includes one or more quantum well layers and one or more barrier layers that are alternately stacked one or more times, and the energy barrier of the barrier layer is greater than that of the quantum well layer to restrict the carrier distribution. In addition, the plurality of quantum well layers may have the same or different material compositions and energy barriers between each other, and this application does not limit this. In some embodiments, the material of the active region 111 may be an i-type, p-type, or n-type semiconductor. The first electrode 108 and the second electrode 109 include a single-layer or multi-layer metal structure. The first electrode 108 and the second electrode 109 include at least one material selected from the group consisting of nickel (Ni), titanium (Ti), platinum (Pt), palladium (Pd), silver (Ag), gold (Au), aluminum (Al), and copper (Cu).

[0019] In one embodiment, the light-emitting element 100 may be an ultraviolet light-emitting diode with a wavelength less than 320 nm, that is, a so-called UV-B light-emitting diode or UV-C light-emitting diode. In some embodiments, the material of the semiconductor stack M may be of the AlGaN series. For example, when it is AlGaN, its average aluminum component is between 0.1 and 1. The conductor stack M can emit light with a wavelength less than 320 nm, and the light-emitting element 100 is an ultraviolet light-emitting diode, such as a deep ultraviolet (Deep UV) light-emitting diode or a UV-C light-emitting diode with a wavelength less than 285 nm.

[0020] In some embodiments, the light-emitting element 100 may be in a flip chip package form, so that the light emitted therefrom exits through the substrate 101. In the light-emitting elements of some comparative examples, the substrate is entirely flat, for example, it is a rectangular body with a thickness less than 250 μm, and the light emitted by the semiconductor stack M will generate total internal reflection in the substrate. Especially when the light-emitting element is an ultraviolet light-emitting diode, due to the shorter wavelength, a higher proportion of the light will be totally internally reflected inside the substrate (such as sapphire). If the thickness of the substrate is insufficient, the light will be difficult to exit from the substrate, resulting in poor light extraction efficiency.

[0021] In some embodiments of the present disclosure, the substrate 101 of the light-emitting element 100 has a specific thickness, for example, greater than 400 μm. The light emitted by the semiconductor stack M can be reflected multiple times in the substrate 101 to increase the probability of extraction, thereby enhancing the brightness. In some embodiments of the present disclosure, the substrate 101 has a three-dimensional geometric structure, such as a columnar body, including a cube, or a cylinder. As shown in FIGS. 1 and 2, the substrate 101 is a rectangular body. When viewed from the side of the semiconductor stack M, it includes a length L and a width W parallel to the horizontal directions X and Z respectively. The distance D between the upper surface TS and the lower surface BS in the vertical direction Y is the thickness of the substrate 101, where W ≦ L ≦ D, or W ≦ D ≦ L. Embodiments of the present disclosure increase the light extraction efficiency by having the substrate 101 with a specific thickness, for example, greater than 400 μm. The substrate 101 of the embodiments of the present disclosure has a specific thickness. Compared with the length L and the width W of the substrate 101, the thickness (distance D) may not be the minimum value. In some embodiments, the side surface of the substrate 101 can be an inclined surface, and the above-mentioned distances on the side surface of the substrate 101 are the projected distances in the vertical direction Y.

[0022] FIGS. 3A to 3F show schematic diagrams of a manufacturing method of the light-emitting element 100 of the present disclosure. Among them, FIGS. 3A to 3D show side views in the manufacturing method, and FIGS. 3E to 3F show top views in the manufacturing method and their corresponding cross-sectional side views.

[0023] As shown in FIG. 3A, Step 1: Provide a substrate wafer: Provide a substrate wafer 1000, where the substrate wafer 1000 includes a wafer upper surface 1000S and a wafer lower surface 1000B. The wafer upper surface 1000S and the wafer lower surface 1000B are separated by a distance D'.

[0024] As shown in FIG. 3B, Step 2: Grow a semiconductor thin film: Epitaxially grow a semiconductor thin film 2000 on the wafer upper surface 1000S of the substrate wafer 1000.

[0025] As shown in FIG. 3C, Step 3: Form a dicing channel: Remove a part of the semiconductor thin film 2000 to form a plurality of separated semiconductor stacks M and expose a part of the surface of the wafer upper surface 1000S. The exposed area of the substrate wafer 1000 serves as a dicing channel 11 for subsequent dicing of the substrate wafer 1000.

[0026] As shown in FIG. 3D, Step Four, forming electrodes: Form a first electrode 108 and a second electrode 109 on the semiconductor stack M. The top view shape of the semiconductor stack M can be a geometric shape, such as a polygon, a circle, or other alternative shapes. The polygon can include a triangle, a quadrilateral, or a hexagon. The quadrilateral can include a parallelogram, a rectangle, or a square. In this embodiment, the top view shape of each semiconductor stack M is a rectangle and each has a pair of long sides and a pair of short sides. The first electrode 108 and the second electrode 109 are used to electrically connect to other components or an external power source. The top view of the formed structure is shown in FIG. 3E or FIG. 3F.

[0027] In one embodiment, the substrate wafer 1000 can be an epitaxial substrate for epitaxially growing a semiconductor thin film 2000 through, for example, metalorganic chemical vapor deposition (MOCVD). In one embodiment, a plurality of separated protrusions (not shown in the figure) are provided on the wafer upper surface 1000S of the substrate wafer 1000 to change the traveling path of light to increase the light extraction efficiency. In one embodiment, the protrusions are formed by directly patterning the surface of the substrate wafer 1000 to a certain depth, and thus have the same composition material as the substrate wafer 1000. In another embodiment, after forming a light-transmitting material layer on the wafer upper surface 1000S of the substrate wafer 1000, the light-transmitting material layer is patterned to form the protrusions, wherein the protrusions and the substrate wafer 1000 have different composition materials. In one embodiment, the protrusions can be formed only between the semiconductor stack M and the substrate wafer 1000, and not on the scribe line 11 of the substrate wafer 1000. For example, protrusions can be originally formed on the entire surface of the wafer upper surface 1000S, and after step three, the protrusions formed on the scribe line 11 can be planarized or the protruding size can be reduced. In one embodiment, protrusions can be formed on the wafer lower surface 1000B. The protrusions on the wafer lower surface 1000B can be used to change the traveling path of light to increase the light extraction efficiency. Similar to the foregoing embodiment, the protrusions are formed only in the region where the semiconductor stack M is orthogonally projected onto the lower surface 1000B, and not in the region where the scribe line 11 is orthogonally projected onto the lower surface 1000B. Alternatively, the substrate wafer 100 can be a bonding carrier substrate. A bonding layer (not shown) can be further included between the substrate wafer 1000 and the semiconductor thin film 2000. The semiconductor thin film 2000 originally epitaxially grown on the epitaxial substrate can be bonded to the substrate 1000 through the bonding layer by using wafer bonding technology. The bonding layer is transparent to the light emitted by the semiconductor stack M, and its material can be an insulating material and / or a conductive material. The insulating materials include polyimide (PI), benzocyclobutene (BCB), perfluorocyclobutane (PFCB), magnesium oxide (MgO), Su8, epoxy resin, acrylic resin, cycloolefin polymer (COC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polyetherimide, fluorocarbon polymer, glass, aluminum oxide (Al2O3), silicon oxide (SiOx), titanium oxide (TiO2), silicon nitride (SiNx), or spin-on glass (SOG).The conductive materials include indium tin oxide (ITO), indium oxide (InO), tin oxide (SnO), cadmium tin oxide (CTO), antimony tin oxide (ATO), aluminum zinc oxide (AZO), zinc tin oxide (ZTO), zinc oxide (ZnO), indium zinc oxide (IZO), tantalum pentoxide (Ta2O5), diamond-like carbon film (DLC), or gallium zinc oxide (GZO), etc. In one embodiment, the scribe line 11 exposes the bonding layer, and the following scribing steps further include first scribing the bonding layer with a UV laser and then performing the following scribing steps to scribe the substrate wafer 1000. In some embodiments, before the scribing step, the lower surface 1000B of the wafer can be selectively polished. After polishing, the distance between the lower surface 1000B and the upper surface 1000S of the wafer is slightly reduced from the distance D' to the distance D. However, in some embodiments, the scribing step can also be performed without polishing the lower surface 1000B of the wafer. At this time, the distance D between the upper and lower surfaces of the substrate wafer 1000 is equal to the distance D'. In addition, in embodiments where there are protrusions on the upper surface 1000S or the lower surface 1000B of the wafer, the distance D between the upper surface 1000S and the lower surface 1000B of the wafer, or the distance or thickness based on the upper surface 1000S or the lower surface 1000B of the wafer, is measured from a reference plane that does not include the protrusions on the upper surface 1000S or the lower surface 1000B of the wafer.

[0028] Step Five: Cut the substrate wafer 1000. In the cutting step of the substrate wafer 1000, the laser light can first be incident from either surface side of the substrate wafer 1000 (the upper surface 1000S side or the lower surface 1000B side of the wafer), and upper or lower modified points are formed in the substrate wafer 1000. And the laser light is incident from the other surface side of the substrate wafer 1000 (the lower surface 1000B side or the upper surface 1000S side of the wafer), and lower or upper modified points are formed in the substrate wafer 1000. In an embodiment, laser cutting, such as Stealth Laser Dicing (SLD), is used to focus the laser beam and the focused laser beam of the stealth laser cutting along the cutting track 11 from the upper surface 1000S side of the substrate wafer 1000 into the substrate wafer 1000 to form a plurality of upper modified points USP. As shown in FIG. 3E and with reference to FIG. 2, taking the extension direction along the long side of the semiconductor stack M as an example, first, perform the first cutting step R1. From the upper surface 1000S side of the wafer, along a plurality of cutting lines A-A' in the long side direction of the semiconductor stack M, focus the laser beam of the stealth laser cutting at the first depth D1 in the substrate wafer 1000, so that physical and / or chemical changes occur at the laser light focusing position inside the substrate wafer 1000 to form a plurality of upper modified points USP. The upper modified points USP correspond to the laser beam focusing positions and are also arranged along the long side direction of the semiconductor stack M. The first depth D1 is less than or equal to 0.6D. However, when the distance D is greater than 1000 μm, the first depth D1 is less than or equal to 600 μm. Then, perform the second cutting step R2. Similarly, from the upper surface 1000S side of the wafer, along the cutting line B-B' in the short side direction of the semiconductor stack M, focus the laser beam of the stealth laser cutting at the first depth D1 in the substrate wafer 1000, so that physical and / or chemical changes occur at the laser light focusing position inside the substrate wafer 1000 to form a plurality of upper modified points USP. The upper modified points USP correspond to the laser beam focusing positions and are also arranged along the short side direction of the semiconductor stack M. Then, similar to the first cutting step R1 and the second cutting step R2, perform the third cutting step R3 and the fourth cutting step R4 respectively with a second depth D2 less than the first depth D1, and then perform the fifth cutting step R5 and the sixth cutting step R6 respectively with a third depth D3 less than the second depth D2. The third depth D3 can be greater than or equal to 0.1D or 100 μm. The laser beams used in the fifth cutting step R5 and the sixth cutting step R6 are focused at the third depth D3, and the focusing depth is shallower, so that the focusing points of the laser beams are more concentrated. As a result, the upper modified points USP formed have a shorter length and a more obvious contour.Conversely, the laser beams used in the first cutting step R1 and the second cutting step R2 are focused at the first depth D1, and the relatively deep focusing depth causes the focal points of the laser beams to be dispersed, so that the upper modified points USP formed have a longer length and a less obvious profile. In another embodiment, after performing the first cutting step R1, the third cutting step R3, and the fifth cutting step R5 along the long side direction of the semiconductor stack M, it is also possible to switch to the short side direction of the semiconductor stack M to complete the first cutting step R1, the third cutting step R3, and the fifth cutting step R5.

[0029] As shown in FIG. 3F and with reference to FIG. 2, in one embodiment, by laser cutting, such as Stealth Laser Dicing (SLD), a laser beam of the stealth laser cutting and a focused laser beam are incident from the side of the wafer lower surface 1000B of the substrate wafer 1000 along the dicing lane 11 into the substrate wafer 1000 to form a plurality of lower modified points BSP. As shown in FIG. 3F and with reference to FIG. 2, taking the extension direction along the long side of the semiconductor stack M as an example, first, perform the seventh cutting step R7. From the side of the wafer lower surface 1000B, along a plurality of cutting lines A-A' in the long side direction of the semiconductor stack M, focus the laser beam of the stealth laser cutting at the fourth depth D4 in the substrate wafer 1000, so that physical and / or chemical changes occur at the laser beam focusing position inside the substrate wafer 1000 to form a plurality of lower modified points BSP. The lower modified points BSP correspond to the laser beam focusing positions and are also arranged along the long side direction of the semiconductor stack M. The fourth depth D4 can be less than or equal to 0.6D. When the distance D is greater than 1000 μm, the fourth depth D4 is less than or equal to 600 μm. Then, perform the eighth cutting step R8. Similarly, from the side of the wafer lower surface 1000B, along the cutting line B-B' in the short side direction of the semiconductor stack M, focus the laser beam of the stealth laser cutting at the fourth depth D1 in the substrate wafer 1000, so that physical and / or chemical changes occur at the laser beam focusing position inside the substrate wafer 1000 to form a plurality of lower modified points BSP. The lower modified points BSP correspond to the laser beam focusing positions and are also arranged along the short side direction of the semiconductor stack M. Then, similar to the seventh cutting step R7 and the eighth cutting step R8, perform the ninth cutting step R9 and the tenth cutting step R10 respectively at a fifth depth D5 less than the fourth depth D4, and then perform the eleventh cutting step R11 and the twelfth cutting step R12 respectively at a sixth depth D6 less than the fifth depth D5. Finally, perform the thirteenth cutting step R13 and the fourteenth cutting step R14 respectively at a seventh depth D7 less than the sixth depth D6. In order to reduce the damage of the laser beam to the semiconductor stack M, the number of times of focusing the laser beam from the side of the wafer lower surface 1000B can be greater than the number of times of focusing the laser beam from the side of the wafer upper surface 1000S. The laser beams used in the thirteenth cutting step R13 and the fourteenth cutting step R14 are focused at the seventh depth D7, and the focusing depth is relatively shallow, so that the focusing points of the laser beams are more concentrated. Therefore, the formed lower modified points BSP have a shorter length and a more obvious contour. On the contrary, the laser beams used in the seventh cutting step R7 and the eighth cutting step R8 are focused at the fourth depth D4, and the relatively deep focusing depth makes the focusing points of the laser beams dispersed. Therefore, the formed lower modified points BSP have a longer length and a less obvious contour.In another embodiment, after performing the seventh cutting step R9, ninth cutting step R9, 11th cutting step R11, and 13th cutting step R3 along the long side direction of the semiconductor stack M, the cutting direction can be switched to the short side direction of the semiconductor stack M to complete the eighth cutting step R8, tenth cutting step R10, 12th cutting step R12, and 14th cutting step R14. However, the present disclosure is not limited thereto. The user can select the number and depth of the modified points formed by irradiating laser beams from the upper surface 1000S and the lower surface 1000B of the wafer according to the capabilities of the cutting machine and the thickness of the object to be divided. The order of irradiating laser beams from the upper surface 1000S and the lower surface 1000B of the wafer is not limited by the above disclosure either, and the upper surface 1000S and the lower surface 1000B of the wafer can be alternately irradiated with laser beams.

[0030] As shown in FIGS. 3E, 3F, 1, and 2, in step six, perform the separation step: Apply a separation force to the substrate wafer 1000 so that the substrate wafer 1000 is separated along the cutting lines A-A' and B-B' into a plurality of light-emitting elements 100 as shown in FIGS. 1 and 2 by the upper modified points USP and the lower modified points BSP in the substrate wafer 1000. Among them, the substrate wafer 1000 is split and separated along the upper modified points USP and the lower modified points BSP corresponding to the cutting line A-A' to form the first side surface S1 and the third side surface S3 of the substrate 101 of the light-emitting element 100, and the substrate wafer 1000 is split and separated along the upper modified points USP and the lower modified points BSP corresponding to the cutting line B-B' to form the second side surface S2 and the fourth side surface S4 of the substrate 101 of the light-emitting element 100. As shown in FIG. 2, after separation, the upper modified region 102 and the lower modified region 103 are respectively formed on the first side surface S1 and other side surfaces of the substrate 101 of the light-emitting element 100. As shown in FIG. 2, the upper modified region 102 has one or more upper modified parts 102n with different depths, such as the first upper modified part 102a, the second upper modified part 102b, and the third upper modified part 102c. Each upper modified part 102n has a plurality of upper modified marks 104 formed by the upper modified points USP. The lower modified region 103 has one or more lower modified parts 103m with different depths, such as the first lower modified part 103a, the second lower modified part 103b, the third lower modified part 103c, and the fourth lower modified part 103d. Each lower modified part 103m has a plurality of lower modified marks 105 formed by the lower modified points BSP. The aforementioned laser cutting and / or separation steps can form cracks inside the substrate wafer 1000, so that cracks appear on the side surfaces of the separated substrate 101. For example, the upper crack UC extends from the upper modified region 102 to the upper surface TS or the lower surface BS, and the lower crack DC extends from the lower modified region 103 to the lower surface BS or the lower surface BS.

[0031] In another embodiment, the separation step may not be performed. After the cutting step, the substrate wafer 1000 can be separated into a plurality of light-emitting elements 100 along the cutting line, for example, due to the internal stress in the modified cutting area.

[0032] In a comparative example, all the modified marks are formed by performing hidden laser cutting from the side of the lower surface 1000B of the wafer. When the focusing depth of the laser beam is too deep, for example, greater than 600 μm, the focused range of the laser beam will be too large to accumulate enough energy, and thus it is impossible to form modified points that can cause sufficient damage to the substrate wafer 1000, such as forming an amorphous region in a sapphire substrate. It is difficult to smoothly separate the substrate wafer 1000 into the substrates 101 of a plurality of light-emitting elements 100 during the separation step, and thus it is impossible to separate and form a plurality of light-emitting elements 100.

[0033] In this embodiment, the focusing depth of the laser beam of the hidden laser corresponding to each upper modified point USP or lower modified point BSP in each cutting step is less than a certain depth. In an embodiment where the distance D is less than 1000 μm, the focusing depth is less than or equal to 0.6D. In an embodiment where the distance D is greater than 1000 μm, the focusing depth is less than or equal to 600 μm. Therefore, the laser beam can be well focused in the substrate wafer 1000 to form sufficient physical and / or chemical changes, such as forming an amorphous region in a sapphire substrate, so as to smoothly separate the substrate wafer 1000 into the substrates 101 of a plurality of light-emitting elements 100 during the separation step.

[0034] In an embodiment, after completing one cutting step along the long side or the short side, the direction of the hidden laser cutting is immediately switched to the other side, and upper modified points USP or lower modified points BSP are formed with the same laser focusing depth, so that the modified points in the two directions can be substantially staggered, thereby reducing the difficulty of separating the substrate wafer 1000 and improving the component yield. For example, as can be seen from the appearance of the light-emitting element 100, the upper modified portion 102n on the first side S1 can be substantially at the same height as the upper modified portion 102n on the second side S2 in the vertical direction Y, and / or the lower modified portion 103m on the first side S1 and the lower modified portion 103m on the second side S2 are substantially at the same height in the vertical direction Y. Similarly, in another embodiment, all the upper modified points USP or lower modified points BSP can also be formed along one side of the long side and the short side of the substrate wafer 1000 first, and then switched to the other side to form the upper modified points USP or lower modified points BSP.

[0035] FIG. 5 shows a cross-sectional schematic view of a light-emitting package 1P according to some embodiments of the present application. As shown in FIG. 5, a light-transmitting body 102P covers the upper surface of a reflective cavity 104P, a circuit board 106P is disposed on the lower surface of the reflective cavity 104P, and a light-emitting element 100P is electrically connected to the circuit board 106P by metal bumps 108a and 108b, wherein the light-emitting element 100P can be the light-emitting element 100 in the foregoing embodiments.

[0036] FIG. 6 shows a schematic view of a light-emitting device 1A according to some embodiments of the present application. The light-emitting device 1A includes a light-emitting unit 50 mounted on an electrical connection element 52, and the electrical connection element 52 is in the shape of a long flat plate. A plurality of light-emitting units 52 are disposed on one side of the electrical connection element 52 and arranged at intervals along the longitudinal direction of the electrical connection element. A heat sink 58 is disposed on the other side of the electrical connection element 52 for dissipating the heat generated by the light-emitting unit 50, and a transparent cover 56 is disposed on the side where the light-emitting unit 50 is disposed and is made of a material that allows the light emitted by the light-emitting unit 50 to easily penetrate. In addition, terminals 54 are disposed at both ends of the light-emitting device to connect to a power source to supply electrical energy to the electrical connection element 52. The plurality of light-emitting units 50 can be the light-emitting element 100 or the light-emitting package 1P in the foregoing embodiments.

[0037] However, the above embodiments are only illustrative of the principles and effects of the present disclosure and are not intended to limit the present disclosure. Any person with ordinary knowledge in the technical field to which the present disclosure pertains can modify and vary the above embodiments without departing from the technical principles and spirit of the present disclosure. Therefore, the scope of the rights protected by the present disclosure is as set forth in the following claims for patent application.

[0038] 100, 100P: Light-emitting element 1000: Substrate wafer 1000S: Upper surface of the wafer 1000B: Lower surface of the wafer 101: Substrate 102: Upper modification region 102n: Upper modification part 102a: First upper modification part 102b: Second upper modification part 102c: Third upper modification part 103: Lower modification region 103m: Modification part 103a: First lower modification part 103b: Second lower modification part 103c Third lower modification part 103d: Fourth lower modification part 104: Upper modification mark 105: Lower modification mark 11: Scoring channel 110: First semiconductor layer 111: Active region 112: Second semiconductor layer S1: First side S2: Second side S3: Third side S4: Fourth side 108: First electrode 109: Second electrode 2000: Semiconductor thin film A-A’, B-B’: Cutting line D, D’: Distance D1: First depth D2: Second depth D3: Third depth D4: Fourth depth D5: Fifth depth D6: Sixth depth D7: Seventh depth E1: First end E2: Second end E3: Third end E4: Fourth end TS: Upper surface BS: Lower surface M: Semiconductor stack R1: First cutting step R2: Second cutting step R3: Third cutting step R4: Fourth cutting step R5: Fifth cutting step R6: Sixth cutting step R7: Seventh cutting step R8: Eighth cutting step R9: Ninth cutting step R10: Tenth cutting step R11: Eleventh cutting step R12: Twelfth cutting step R13: Thirteenth cutting step R14: Fourteenth cutting step UC: Upper crack DC: Lower crack X, Z: Horizontal direction Y: Vertical direction 1P: Light-emitting package 102P: Translucent body 104P: Reflective cavity 106P: Circuit board 108a, 108b: Metal bumps 1A: Light-emitting device 50: Light-emitting unit 52: Electrical connection component 54: Terminal 56: Transparent cover 58: Heat sink L: Length W: Width USP: Upper modified point BSP: Lower modified point

Claims

1. A light-emitting element, comprising: a semiconductor stack; and a substrate, including an upper surface supporting the semiconductor stack, a lower surface opposite the upper surface, and a plurality of side surfaces surrounding and connected between the upper surface and the lower surface, a vertical direction perpendicular to the upper surface; wherein one of the side surfaces includes an upper modified region adjacent to the upper surface in the vertical direction and a lower modified region adjacent to the lower surface in the vertical direction, the upper modified region including a plurality of upper modified portions, the lower modified region including a plurality of lower modified portions, each upper modified portion including a plurality of upper modified traces disposed along a horizontal direction parallel to the upper surface, each lower modified portion including a plurality of lower modified traces disposed along the horizontal direction; wherein each upper modified trace includes a first end adjacent to the upper surface and a second end adjacent to the lower surface, the width of the second end being smaller than the width of the first end; wherein each lower modified trace includes a third end adjacent to the upper surface and a fourth end adjacent to the lower surface, the width of the fourth end being larger than the width of the third end.

2. The light-emitting element as claimed in claim 1, wherein the modified portions include a first modified portion and a second modified portion, the second modified portion being closer to the upper surface than the first modified portion, and the first modified portion having a longer length than the second modified portion in the vertical direction.

3. The light-emitting element as claimed in claim 1, wherein the modified portions include a first modified portion and a second modified portion, the second modified portion being closer to the lower surface than the first modified portion, and the first modified portion having a longer length than the second modified portion in the vertical direction.

4. The light-emitting element as claimed in claim 1, further comprising a plurality of upper cracks and a plurality of lower cracks, the upper cracks extending between the upper modified portions and the upper surface, and / or the lower cracks extending between the lower modified portions and the lower surface.

5. The light-emitting element as claimed in claim 1, wherein the distance between the upper surface and the lower surface in the vertical direction is the thickness of the substrate, denoted as D, the distance between each of the upper modified regions and the upper surface in the vertical direction is less than or equal to 0.6D, and / or the distance between each of the lower modified regions and the lower surface in the vertical direction is less than or equal to 0.6D.

6. The light-emitting element as claimed in claim 5, wherein the distance between each of the modified regions and the upper surface is greater than 0.1D.

7. The light-emitting element as described in claim 5 or 6, wherein 400 μm ≤ D ≤ 1000 μm.

8. The light-emitting element as claimed in claim 1, wherein the number of the upper modified portions is less than the number of the lower modified portions.

9. The light-emitting element as claimed in claim 1, wherein each of the sides includes the upper modified portions and the lower modified portions, the sides including a first side, a second side, a third side and a fourth side, the first side being opposite to the third side, the second side and the fourth side being connected between the first side and the third side, the upper modified portions of the first side and the upper modified portions of the second side being substantially at the same height in the vertical direction, and / or the lower modified portions of the first side and the lower modified portions of the second side being substantially at the same height in the vertical direction.

10. The light-emitting element as claimed in claim 1, wherein the substrate is a rectangular body, the upper surface includes a length denoted by L and a width denoted by W, the distance between the upper surface and the lower surface in the vertical direction is the thickness of the substrate denoted by D, wherein W ≦ L ≦ D, or W ≦ D ≦ L.

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