TWI849988B - Light-emitting element - Google Patents

Abstract

A light-emitting element is provided, which includes a light-emitting stack, an upper electrode, a current passing region and a contact layer. The light-emitting stack has a light extraction surface and includes a plurality of semiconductor layers. The upper electrode is on the light extraction surface and includes an electrode part, a first extension part and a second extension part electrically connected to each other. The first extension part has a first width and the second extension part has a second width smaller than the first width. The current passing region is between the first extension part and the second extension part. The contact layer is between the second extension part and the light-emitting stack and has a third width smaller than or equal to the second width. A first distance is between the first extension part and the current passing region, a second distance is between the second extension part and the current passing region, and the first distance is larger than the second distance.

Description

Light emitting element

The present invention relates to a light-emitting element, and in particular to a light-emitting element with good current spreading effect.

Optoelectronic components, such as light-emitting diodes (LEDs), are now widely used in optical display devices, traffic signs, data storage devices, communication devices, lighting devices, and medical equipment. Currently, LEDs still have the problem of uneven current distribution, which results in low luminous efficiency.

The present disclosure provides a light-emitting element, including a light-emitting stack, an upper electrode, a current channel region and a contact layer. The light-emitting stack has a light-emitting surface. The light-emitting stack includes a plurality of semiconductor layers. The upper electrode is located on the light-emitting surface and includes an electrode portion, a first extension portion and a second extension portion electrically connected to each other. The first extension portion has a first width, and the second extension portion has a second width. The first width is greater than the second width. The current channel region is located between the first extension portion and the second extension portion. The contact layer is located between the second extension portion and the light-emitting stack, and has a third width that is less than or equal to the second width. There is a first distance between the current channel area and the first extension portion, there is a second distance between the current channel area and the second extension portion, and the first distance is greater than the second distance.

The present disclosure provides a light-emitting element, comprising a substrate, a light-emitting stack, an upper electrode, a contact structure and a contact layer. The light-emitting stack is located on the substrate, has a light-emitting surface and comprises a plurality of semiconductor layers. The upper electrode is located on the light-emitting surface. The upper electrode comprises an electrode portion, a first extension portion and a plurality of second extension portions. The electrode portion comprises a first electrode portion having a first width and a second electrode portion. The first extension portion is electrically connected to the electrode portion and has a second width. One of the plurality of second extension portions is connected to the first extension portion, the first electrode portion or the second electrode portion and has a third width, and the second width is between the first width and the third width. The contact structure is located between the light-emitting stack and the substrate. The contact layer includes III-V semiconductor material and is located between the upper electrode and the light-emitting stack. A current channel region is defined at a position on the light-emitting surface corresponding to the contact structure. The current channel region is located between two adjacent second extensions and the first extension. The contact layer has an end, and there is a shortest distance s1 between the end and the current channel region. There is a shortest distance s2 between the current channel region and the contact layer, and the range of s1/s2 is greater than 0 and less than 5.

The present disclosure provides a packaging structure, including a carrier, a light-emitting element, and a packaging material layer. The light-emitting element is located on the carrier. The packaging material layer covers the light-emitting element.

The present disclosure provides an optoelectronic system, including a base plate, a light-emitting element, and a control module. The light-emitting element is located on the base plate. The control module is electrically connected to the base plate.

100~800: Light-emitting element

1S: Light-emitting surface

1031: First side

1032: Second side

1033: Third side

1034: Fourth side

103: Substrate

111: First window layer

112: Second window layer

120: Luminous layer

121: First semiconductor layer

122: Active layer

123: Second semiconductor layer

130: Contact structure

13: Extended electrode

131: First extension part

1311~1313: Line segment

132: Second extension

132’: First end

132”: Second end

140: First contact layer

140b: Current channel area

140b1~140b3: Current channel area

140c: Current channel

140c’: Area

140c”: Area

140e: Hole

145: Insulation layer

150:Reflective layer

160: Conductive adhesive layer

170: Current spreading layer

171:Electrode part

171a: first electrode part

171b: Second electrode part

172: Back electrode

180: Protective layer

190: Second contact layer

190a’: side surface

190e: End

I, II, III, IV: Regions

X, Y: direction

b1: first area

b2: Second area

b3: The third area

b4: The fourth area

D ₁ ~D ₇ : Distance

b61: Top bottom

b62: bottom

b6’, b6”: waist

P ₁₁ , P ₁₂ : Endpoints

P ₂₁ , P ₂₂ : Endpoints

W ₀ ~W ₄ : Width

H1: Distance

60:Semiconductor components

61:Packaging substrate

62:Through hole

63: Carrier

63a, 190a: Part I

63b, 190b: Part II

65:Joining line

66: Contact structure

66a: First contact pad

66b: Second contact pad

68: Packaging material layer

4b: Optoelectronic system

49: Base plate

40’: Pixels

49’: Control module

40b: Light-emitting element

d, d’: distance

L ₁ ~L ₄ : Side length

s1~s3: distance

C ₁ , C ₂ : Area

FIG. 1A shows a top view of a light-emitting element of an embodiment; FIG. 1B shows an enlarged view of the light-emitting element in FIG. 1A; FIG. 1C to FIG. 1H show a top view of a current channel; FIG. 2 shows a cross-sectional view of the light-emitting element along line A-A’ in FIG. 1B; FIG. 3 shows a schematic diagram of the internal current distribution of the light-emitting element; FIG. 4 shows a top view of a light-emitting element according to an embodiment; FIG. 5A shows a top view of a light-emitting element according to another embodiment; FIG. 5B shows an enlarged view of the light-emitting element in FIG. 5A; FIG. 6A shows a top view of a light-emitting element according to an embodiment; FIG. 6B shows a partial enlarged view of the light-emitting element in FIG. 5A; FIG. 7 shows a top view of a light-emitting element according to an embodiment; FIG. 8 is a top view of a light-emitting element according to an embodiment; FIG. 9A is a top view of a light-emitting element according to an embodiment; FIG. 9B is a partial enlarged view of the light-emitting element in FIG. 9A; FIG. 9C is a cross-sectional view of a light-emitting element in an embodiment along line B-B’ in FIG. 9B; FIG. 9D is a cross-sectional view of a light-emitting element in an embodiment along line C-C’ in FIG. 9B; FIG. 9E is a partial enlarged view of a light-emitting element in another embodiment; FIG. 9F is a partial enlarged view of a light-emitting element in another embodiment; FIG. 9G is a top view of a light-emitting element in another embodiment; FIG. 10 is a schematic diagram of a semiconductor element packaging structure; FIG. 11 is a schematic diagram of an optoelectronic system.

The embodiments of the present invention will be described in detail and illustrated in the drawings, and the same or similar parts will appear in each drawing and description with the same numbers.

FIG. 1A shows a top view of a light-emitting element 100 of an embodiment, FIG. 1B shows an enlarged view of region I in FIG. 1A, and FIG. 2 shows a cross-sectional view of the light-emitting element 100 along line A-A' in FIG. 1B. In FIG. 1A, region 140c' indicates the corresponding position of current channel 140c, and the relevant description can be referred to the following paragraphs.

As shown in FIG. 1A , the light emitting element 100 includes a light emitting surface 1S and a plurality of side walls, wherein the plurality of side walls include a first side 1031, a second side 1032 opposite to the first side 1031, a third side 1033 located between the first side 1031 and the second side 1032, and a fourth side 1034 opposite to the third side 1033 and located between the first side 1031 and the second side 1032. The first side 1031, the second side 1032, the third side 1033 and the fourth side 1034 surround the light emitting surface 1S, and the first side 1031, the second side 1032, the third side 1033 and the fourth side 1034 have side lengths _L1 , _L2 , _L3 and _L4 , respectively. In this embodiment, the light emitting element 100 includes an upper electrode located on the light emitting surface 1S. The upper electrode includes two electrode portions 171 and an extended electrode 13. The material of the electrode portion 171 and the extended electrode 13 may include a single layer or multiple layers (not shown) of metal or alloy. Metals include aluminum (Al), chromium (Cr), copper (Cu), tin (Sn), gold (Au), nickel (Ni), titanium (Ti), platinum (Pt), lead (Pb), zinc (Zn), cadmium (Cd), antimony (Sb), cobalt (Co), germanium (Ge), and palladium (Pd). The alloy is an alloy containing the above metals. The electrode portion 171 is used to introduce external current, and a plurality of extended electrodes 13 are connected to the electrode portion 171 to spread the current to an area outside the electrode portion 171. The two electrode portions 171 are close to the first side 1031, and the extended electrode 13 includes a first extension portion 131 and a plurality of second extension portions 132. Compared to the second side 1032, the first extension portion 131 is closer to the first side 1031 and substantially parallel to the first side 1031. In addition, the first extension portion 131 has a first region connected to the two electrode portions 171 and two second regions extending from the two electrode portions 171 to the third side 1033 and the fourth side 1034 respectively. A plurality of second extension portions 132 are connected to the two electrode portions 171 and the first extension portion 131 and extend to the first side 1031 and the second side 1032.

As shown in FIG. 1B , in this embodiment, the first extension portion 131 and the second extension portion 132 are substantially vertically arranged, and the first extension portion 131 has a width W1, and the second extension portion has a width W2, and the width W1 is 1.5 to 3 times the width W2. Since the current density introduced into the electrode portion 171 is relatively large at the beginning, the first extension portion 131 with a relatively large width W1 can efficiently disperse the current to the third side 1033 and the fourth side 1034, and then the current is dispersed to the first side 1031 and the second side 1032 by a plurality of second extension portions 132, so that the current can be evenly dispersed on the light-emitting surface 1S.

Next, referring to the cross-sectional view of the light emitting element 100 shown in FIG. 2, the light emitting element 100 includes a substrate 103, a back electrode 172 located below the substrate 103, a conductive adhesive layer 160 located above the substrate 103, a reflective layer 150 located above the conductive adhesive layer 160, a current spreading layer 170 located above the reflective layer 150, an insulating layer 145 located above the reflective layer 150, and a first contact layer 140 located above the reflective layer 150. Between the insulating layer 145 and the current spreading layer 170, a first window layer 111 is located on the insulating layer 145, a light-emitting stack 120 is located on the first window layer 111, a second window layer 112 is located on the light-emitting stack 120, a protective layer 180 is located on the second window layer 112, a second contact layer 190 is located on the second window layer 112, and a second extension portion 132 is located on the second contact layer 190.

In this embodiment, the light-emitting stack 120 includes a first semiconductor layer 121, an active layer 122 located on the first semiconductor layer 121, and a second semiconductor layer 123 located on the active layer 122. The first semiconductor layer 121 and the second semiconductor layer 123 contain dopants to increase conductivity and have different conductivity types to provide electrons and holes for recombination in the active layer 122 to emit light. When the first semiconductor layer 121 includes a p-type III-V semiconductor material, the second semiconductor layer 123 includes an n-type III-V semiconductor material; when the second semiconductor layer 123 includes a p-type III-V semiconductor material, the first semiconductor layer 121 includes an n-type III-V semiconductor material. The first semiconductor layer 121 or the second semiconductor layer 123 has a dopant of zinc (Zn), carbon (C) or magnesium (Mg) to form a p-type III-V semiconductor material. The first semiconductor layer 121 or the second semiconductor layer 123 has a dopant of silicon (Si) or tellurium (Te) to form an n-type III-V semiconductor material. The doping concentration of the dopant is between 5x10 ¹⁶ cm ^-3 and 5x10 ¹⁹ cm ^-3 . The active layer 122 includes a plurality of well layers and barrier layers stacked alternately, and the well layers and barrier layers include III-V semiconductor materials. Depending on the composition of the well material, the active layer 122 can emit infrared light with a peak wavelength between 700nm and 1700nm, red light with a peak wavelength between 610nm and 700nm, yellow light with a peak wavelength between 530nm and 570nm, green light with a peak wavelength between 490nm and 550nm, blue light or deep blue light with a peak wavelength between 400nm and 490nm, or ultraviolet light with a peak wavelength between 250nm and 400nm.

The material of the first window layer 111 includes at least one element selected from the group consisting of aluminum (Al), gallium (Ga), indium (In), arsenic (As), phosphorus (P) and nitrogen (N), such as semiconductor compounds such as GaN, AlGaInP, AlInP, AlGaAs, GaP, etc. The first window layer 111 and the first semiconductor layer 121 include dopants and have the same conductivity type, such as p-type conductivity type. The doping concentration of the first window layer 111 is greater than the doping concentration of the first semiconductor layer 121, so the first window layer 111 has a higher conductivity. The thickness of the first window layer 111 is between 0.5μm and 10μm to provide the function of lateral diffusion of current, avoid the current being confined to a local area of the light-emitting element 100, and help light to be emitted from multiple side walls of the light-emitting element 100.

The material of the second window layer 112 includes at least one element of a group consisting of aluminum (Al), gallium (Ga), indium (In), arsenic (As), phosphorus (P) and nitrogen (N), such as semiconductor compounds such as GaN, AlGaInP, AlInP, AlGaAs, GaP, etc. The second window layer 112 includes at least one material different from the second semiconductor layer 123. Preferably, the second window layer 112 includes dopants and has the same conductivity type as the second semiconductor layer 123, such as an n-type conductivity type. The light-emitting surface 1S of the light-emitting element 100 is a surface of the second window layer 112 and can be a roughened surface to reduce total reflection and improve the light-emitting efficiency of the light-emitting element 100. The protective layer 180 conformally covers the roughened surface of the second window layer 112. In some embodiments, the material of the protective layer 180 includes silicon (Si) nitride or oxide, such as SiO ₂ or SiN _x . In this embodiment, the thickness of the second window layer 112 is greater than that of the first window layer 111 . The thickness of the second window layer 112 is between 1 μm and 20 μm, so as to provide the function of lateral current diffusion and improve the light extraction efficiency of the light emitting element 100 .

Referring to FIGS. 1A to 1H and FIG. 2, the second contact layer 190 is located between the second window layer 112 and the extended electrode 13, and the contact resistance between the second contact layer 190 and the extended electrode 13 is less than ^10-2 Ω- ^cm2 , preferably less than ^10-4 Ω- ^cm2 , for conducting current from the extended electrode 13 to the second window layer 112. In this embodiment, the second contact layer 190 is only located under the extended electrode 13 and is not formed under the electrode portion 171. When viewed from above, the second contact layer 190 and the extended electrode 13 have the same pattern. The material of the second contact layer 190 includes a III-V semiconductor material, such as GaAs, AlGaAs or InGaP. The second contact layer 190 includes dopants and has the same conductivity type as the second window layer 112, such as n-type conductivity type. The second contact layer 190 has a doping concentration greater than 10 ¹⁸ /cm ³ , preferably between 10 ¹⁹ /cm ³ and 5*10 ²⁰ /cm ³ .

The substrate 103 includes a metal, such as molybdenum, or a semiconductor material, such as germanium and silicon. The back electrode 172 is connected to the substrate 103 and is used to conduct current into the light-emitting element 100. The back electrode 172 includes a single layer or multiple layers (not shown) of metal or alloy. Metals include aluminum (Al), chromium (Cr), copper (Cu), tin (Sn), gold (Au), nickel (Ni), titanium (Ti), platinum (Pt), lead (Pb), zinc (Zn), cadmium (Cd), antimony (Sb), cobalt (Co), germanium (Ge), and palladium (Pd). The alloy is an alloy containing the above metals. The conductive adhesive layer 160 is used to bond the reflective layer 150 and the substrate 103 and provide a good conductive path. The material of the conductive adhesive layer 160 includes gold, tin, lead, indium or their alloys.

The material of the reflective layer 150 includes a metal element, such as silver or gold, whose reflectivity for light with a peak wavelength (Wp) between 600nm and 2000nm is greater than 90%, and is used to reflect the light emitted by the light-emitting stack 120. The current spreading layer 170 is electrically connected to the reflective layer 150. The current spreading layer 170 includes a metal oxide, such as 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), gallium zinc oxide (GZO), zinc oxide (ZnO), indium zinc oxide (IZO) or indium tungsten oxide (IWO). In this embodiment, the current spreading layer 170 is indium zinc oxide (IZO). The material of the insulating layer 145 includes insulating materials, such as silicon nitride (SiNx), aluminum oxide (AlOx), silicon oxide (SiOx) or magnesium fluoride (MgFx). The refractive index of the insulating layer 145 is at least 1 less than that of the first window layer 111, thereby increasing the percentage of light reflected from the light-emitting stack 120.

As shown in FIG. 2 , the insulating layer 145 includes a first window layer 111 that exposes a portion of a plurality of holes 140e. The first contact layer 140 conformally covers the other side of the insulating layer 145 opposite to the first window layer 111, fills the plurality of holes 140e, and is electrically connected to the portion of the first window layer 111 exposed in the holes 140e to form a plurality of current channels 140c for current to flow through. The material of the first contact layer 140 is selected from metal oxide materials, such as 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), gallium zinc oxide (GZO), zinc oxide (ZnO), indium zinc oxide (IZO) or indium tungsten oxide (IWO). In this embodiment, the material of the first contact layer 140 is selected from indium tin oxide (ITO) that can form a low contact resistance with the first window layer 111.

In this embodiment, the thickness of the insulating layer 145 is between 500Å and 5000Å, preferably between 1000Å and 2000Å; the thickness of the first contact layer 140 is between 20Å and 200Å; the thickness of the current spreading layer 170 is between 1000Å and 5000Å, preferably between 1500Å and 3500Å. The insulating layer 145, the first contact layer 140, the current spreading layer 170 and the reflective layer 150 form an omnidirectional reflector (ODR), which can improve the reflectivity of light directed to the omnidirectional reflector to exceed 95%.

The portion where the first contact layer 140 directly contacts the first window layer 111 forms a current channel 140c. The current channel 140c has a width W3 between 1μm and 100μm, preferably between 5μm and 30μm. In the cross-sectional view of FIG. 2, the current channel 140c does not overlap with the extended electrode 13 and the electrode portion 171 in a direction (X) perpendicular to the light-emitting stack 120. In addition, the relative position of the current channel 140c corresponding to the light-emitting surface 1S is defined as region 140c', therefore, a plurality of regions 140c' are shown in FIG. 1A and are staggered from each other (i.e., they do not overlap in the X direction). Furthermore, the region 140c' and the extended electrode 13 and the electrode portion 171 are also staggered, that is, the region 140c' and the extended electrode 13 and the electrode portion 171 do not overlap in the X direction (refer to Figure 2). The plurality of regions 140c' may be arranged in a dot array in the top view. In this embodiment, the top view of each current channel 140c is a circle, so the region 140c' is also a circle. In other embodiments, as shown in Figures 1C to 1F, the top view of the current channel 140c (or region 140c') includes but is not limited to a rectangle, a triangle, a diamond or a combination thereof.

As shown in FIG. 1A , there is a current channel region 140b between any two adjacent second extensions 132 and first extensions 131, and the current channel region 140b is a range defined by a common tangent line of a plurality of regions 140c′ closest to the extension electrode 13, and there is no region 140c′ between the current channel region 140b and the extension electrode 13. In other words, between two adjacent second extensions 132 and first extensions 131, the current channel region 140b is a polygon surrounding all regions 140c′, and each side of the current channel region 140b is tangent to at least two regions 140c′. In FIG. 1A, the current channel region 140b is a quadrilateral (e.g., a rectangle) and only one is drawn as an example. The light-emitting element may include multiple current channel regions.

As shown in Figures 1C to 1G, when the region 140c' is in other shapes, the current channel region 140b is defined by the vertices (such as Figure 1D or 1F), sides (such as Figure 1C or 1E), or at least two of the above (such as Figure 1G) of the region 140c' closest to the extended electrode 13. In Figure 1C or 1E, the region 140c' is a square, and the current channel region 140b is a quadrilateral; in Figure 1D or 1F, the region 140c' is a triangle and a rhombus, respectively, and the current channel region 140b is a quadrilateral; in Figure 1G, the region 140c' includes at least two different shapes, and the current channel region 140b is a quadrilateral. As shown in Figures 1B and 1H, the current channel region 140b has the same shape, which is a hexagon. In FIG. 1B, in addition to the area 140c' defining the current channel area 140b, there are still other areas 140c' surrounded therein, which means that some areas 140c' are not used to define the current channel area 140b. In FIG. 1H, the current channel area 140b is defined by all areas 140c'.

As shown in FIG. 1B , there is a shortest distance D ₁ between the current channel region 140b and the first extension portion 131, and a shortest distance D ₂ between the current channel region 140b and the second extension portion 132, and the distance D ₁ is greater than the distance D ₂ . Since the width W ₁ of the first extension portion 131 is 1.5 to 3 times the width W ₂ of the second extension portion 132, and the first extension portion 131 is directly connected to the electrode portion 171, and the second extension portion 132 is directly connected to the first extension portion 131, when the light-emitting device 100 is in normal operation, the current flowing through the first extension portion 131 is greater than the current flowing through the second extension portion 132, as shown in FIG. 3 is a schematic diagram of the internal current distribution of the light-emitting device 100. The direction of the current 9 in the figure is only for illustration. According to the electrical design of the light-emitting stack 120, the direction of the current 9 may be opposite. The current 9 flows through the first window layer 111, the light-emitting stack 120 and the second window layer 112 between the current channel 140c and the first extension portion 131 and the second extension portion 132. Since the current flowing through the first extension portion 131 is greater than the current flowing through the second extension portion 132, when the current 9 flows through the area between the current channel 140c and the first extension portion 131 and the second extension portion 132, a larger portion of the current 9 flows through the area _C2 between the current channel 140c and the first extension portion 131, and a smaller portion of the current 9 flows through the area _C1 between the current channel 140c and the second extension portion 132 to the second extension portion 132. In addition, since the distance between the current channel region 140b and the first extension portion 131 is designed to be greater than the distance between the current channel region 140b and the second extension portion 132 ( _D1 > _D2 ), the current in region _C2 is more dispersed and the current in region _C1 is more concentrated; since the current in region _C2 is more but more dispersed, and the current in region _C1 is less but more concentrated, the current density passing through the active layer 122 in region _C1 is close to the current density passing through the active layer 122 in region _C2 , thereby achieving the purpose of uniformly dispersing the current.

In this embodiment, the width _W1 of the first extension portion 131 is between 3 μm and 50 μm, preferably between 10 μm and 20 μm, and the width _W2 of the second extension portion 132 is between 2 μm and 33 μm, preferably between 5 μm and 10 μm. There is a ratio R1 (= _D1 / _W1 ) between the distance _D1 and the width _W1 , and there is a ratio R2 (= _D2 / _W2 ) between the distance _D2 and the width _W2 . The ranges of R1 and R2 are 2≦R1≦3.5 and 2≦R2≦3.5, respectively. Therefore, the preferred range of the distance _D1 is between 20 μm and 70 μm, and the distance D2 is between 20 μm and 70 μm. The preferred range of ₂ is between 10 μm and 35 μm. When the width of the first extension portion 131 is gradual, the maximum width is defined as W1 and the above ratio R1 is calculated.

FIG. 4 shows a top view of a light-emitting device 200 according to another embodiment. The light-emitting device 200 is similar to the light-emitting device 100, and the same or similar structures can be referred to above, and will not be described again here. The light-emitting device 200 is different from the light-emitting device 100 in that the distribution of the region 140c' in the current channel region 140b is different, that is, the distribution of the current channel 140c of the light-emitting device 200 is different from that of the current channel 140c of the light-emitting device 100. In the light-emitting device 200, the density of the current channel region 140b increases gradually from the first side 1031 to the second side 1032. In detail, the current channel region 140b of the light-emitting element 200 includes a first region b1 and a second region b2. The first region b1 is closer to the electrode portion 171 than the second region b2. The number of regions 140c' per unit area in the first region b1 is smaller than the number of regions 140c' per unit area in the second region b2. In other words, the density (number/area) of the region 140c' in the first region b1 is smaller than the density of the region 140c' in the second region b2, that is, the density of the current channel 140c in the first region b1 is smaller than the density of the current channel 140c in the second region b2. Therefore, under the same area, the total contact area of the first contact layer 140 and the first window layer 111 in the first region b1 is smaller than the total contact area of the first contact layer 140 and the first window layer 111 in the second region b2. In this way, the current The total contact resistance through the interface between the first contact layer 140 and the first window layer 111 in the second region b2 is smaller than the total contact resistance through the interface between the first contact layer 140 and the first window layer 111 in the first region b1, that is, the current is easier to pass through the interface between the first contact layer 140 and the first window layer 111 in the second region b2, thereby driving the current that originally needs to pass through the current channel 140c in the first region b1 to flow to the current channel 140c in the second region b2, so that the current distribution in the light-emitting element 200 is more uniform.

FIG. 5A shows a top view of a light-emitting element 300 according to another embodiment, and FIG. 5B shows an enlarged view of region II in FIG. 5A. The light-emitting element 300 is similar to the light-emitting element 100, and the same or similar structures can be referred to above, and will not be described again here. The difference between the light-emitting element 300 and the light-emitting element 100 is that the shortest distance between the current channel region 140b and the first extension portion 131 is different, that is, the shortest distance between the current channel 140c and the first extension portion 131 in the light-emitting element 300 is different from the shortest distance between the current channel 140c and the first extension portion 131 in the light-emitting element 100. The details are as follows. As shown in FIG. 5B, the light-emitting element 300 includes a plurality of current channel regions 140b1, 140b2, and 140b3. The shortest distances between the current channel region 140b1, the current channel region 140b2, and the current channel region 140b3 and the line segment 1311, the line segment 1312, and the line segment 1313 of the first extension portion 131 are respectively a distance D ₃ , a distance D ₄ , and a distance D ₅ , wherein the distance D ₃ is greater than the distance D ₄ , and the distance D ₄ is greater than the distance D _5. In this embodiment, the line segment 1311 is closest to the electrode portion 171, the line segment 1312 is next, and the line segment 1313 is farthest from the electrode portion 171. On the first extension portion 131, the closer to the electrode portion 171, the higher the current density is, and the farther from the electrode portion 171, the lower the current density is, so the current density of the line segment 1311 is the highest, the line segment 1312 is the second, and the line segment 1313 is the lowest. Similar to FIG. 3, by designing that the distance _D3 is greater than the distance _D4 , and the distance _D4 is greater than the distance _D5 , the current density between the line segment 1311 and the current channel area 140b1, between the line segment 1312 and the current channel area 140b2, and between the line segment 1313 and the current channel 140b3 can be close, thereby achieving the purpose of evenly dispersing the current. The optimal range of distance D ₃ is between 80μm and 130μm, the optimal range of distance D ₄ is between 50μm and 100μm, and the optimal range of distance D ₅ is between 20μm and 70μm.

FIG. 6A shows a top view of a light-emitting element 400 according to another embodiment, and FIG. 6B shows an enlarged view of region III in FIG. 6A. The light-emitting element 400 is similar to the light-emitting element 200, and the same or similar structure can be referred to above, and will not be described here. The difference between the light-emitting element 400 and the light-emitting element 200 is that the distribution of the region 140c' in the current channel region 140b is different, that is, the distribution of the current channel 140c of the light-emitting element 400 is different from that of the current channel 140c of the light-emitting element 200. In addition, the current channel region 140b is not a rectangle but a hexagon. In detail, the current channel region 140b of the light-emitting element 400 includes a second region b2 and a third region b3. The second region b2 can refer to the description in the previous paragraph, and the third region b3 is described as follows.

As shown in FIG. 6B , the shape of the third region b3 is an isosceles trapezoid having an upper base b61, a lower base b62, and two waists b6′ and b6″ having the same length connecting the upper base b61 and the lower base b62. There is a distance D ₆ between the end points P ₁₁ and P ₁₂ of the isosceles trapezoid closest to the first extension portion 131 and the adjacent second extension portion 132; there is a distance D ₇ between the end points P ₂₁ and P ₂₂ of the isosceles trapezoid farthest from the first extension portion 131 and the adjacent second extension portion 132, and the distance D ₆ is greater than the distance D _7. . The distance between the region 140c' and the second extension portion 132 closest to it gradually decreases from the lower bottom b62 to the upper bottom b61. In detail, from the vicinity of the lower bottom b62 to the vicinity of the upper bottom b61, the distance between the waist b6' or the waist b6" and the second extension portion 132 gradually decreases from the distance _D6 to the distance _D7 . The preferred range of distance _D7 is between 10μm and 35μm, and the preferred range of distance _D6 is between 35μm and 100μm. The closer the part of the second extension portion 132 is to the first extension portion 131, the higher the current density, that is, the current density of the second extension portion 132 close to the lower bottom b62 is higher than the current density close to the upper bottom b61. Similar to Figure 3, by designing that the distance _D6 gradually decreases to the distance _D7 , the current density between the end point _P11 to the end point _P21 and the adjacent (closest) second extension portion 132 in the third area b3 can be made close, or the current density between the end point _P12 to the end point _P22 and the adjacent second extension portion 132 can be made close, thereby achieving the purpose of uniformly dispersing the current.

FIG. 7 shows a top view of a light-emitting element 500 according to another embodiment. The light-emitting element 500 is similar to the light-emitting element 200. The same or similar structures can be referred to above and will not be described again here. The light-emitting element 500 differs from the light-emitting element 200 in that the width of the second extension portion 132 gradually changes. Specifically, the second extension portion 132 has a first end 132' close to the first side 1031 and a second end 132" close to the second side 1032. The first end 132' is closer to the first extension portion 131 than the second end 132", and the width of the second extension portion 132 gradually decreases from the first end 132' to the second end 132". The second end 132" is the end of the second extension portion 132, and the current flows from the first end 132 to the second end 132. ’ is dispersed to the second end 132”, the current will gradually decrease, so the current near the second end 132” does not need to flow through the same width electrode as the current near the first end 132’, and the same current density can be maintained without causing the phenomenon of current concentration. In addition, as mentioned above, since the density of the second area b2 is greater than that of the first area b1, the current is driven to flow to the second area b2, thereby making the current more evenly dispersed.

In another embodiment, the width of the second extension portion 132 of the light-emitting element 500 gradually increases from the first end 132' to the second end 132" (not shown), so that the current on the second extension portion 132 can be more easily diffused from the first end 132' to the second end 132", thereby achieving the purpose of evenly dispersing the current.

FIG. 8 shows a top view of a light-emitting element 600 according to another embodiment. The light-emitting element 600 is similar to the light-emitting element 200, and the same or similar structures can be referred to above and will not be described again here. The light-emitting element 600 includes a first region b1 and a fourth region b4. The first region b1 can be referred to the description in the previous paragraph. The difference between the first region b1 and the fourth region b4 lies in the area of the region 140c’ (140c”), and the area of each region 140c” in the fourth region b4 is larger than the area of each region 140c’ in the first region b1 to increase the uniformity of current distribution. Specifically, under the same area and the same number of regions (140c', 140c") in the first region b1 and the fourth region b4, when the area of region 140c' is larger than that of region 140c' (i.e., the distance between regions 140c' is larger than the distance between regions 140c'), the total area of the first contact layer 140 and the first window layer 111 in the fourth region b4 will be larger than the total area of the first contact layer 140 and the first window layer 111 in the first region b1. The total contact area of the fourth region b4 and the first region b1, the total contact resistance of the current corresponding to the bottom through the first contact layer 140 and the first window layer 111 in the fourth region b4 is less than the total contact resistance through the first contact layer 140 and the first window layer 111 in the first region b1, thereby driving the current that originally needs to pass through the current channel 140c in the first region b1 to flow to the current channel 140c in the fourth region b4, so that the current distribution in the light-emitting element 600 is more uniform.

In another embodiment, the light-emitting element (not shown) differs from the aforementioned light-emitting elements 100, 200, 300, 400, 500, 600 in that the width W1 of the first extension portion 131 connecting the two electrode portions 171 (refer to FIG. 1B ) is gradually changed. Specifically, the width W1 of the first extension portion 131 gradually decreases from the electrode portion 171 toward the third side 1033 or the fourth side 1034. In another embodiment, the width W1 of the first extension portion 131 gradually increases from the electrode portion 171 toward the third side 1033 or the fourth side 1034.

FIG. 9A shows a top view of a light-emitting element 700 according to another embodiment, and FIG. 9B shows a partial enlarged view of region IV of the light-emitting element 700 in FIG. 9A. The light-emitting element 700 is similar to the light-emitting element 100, and its same or similar structure can be referred to above, and will not be described here.

In the present embodiment, the upper electrode includes an electrode portion 171 and an extension electrode 13. The electrode portion 171 includes a first electrode portion 171a and a second electrode portion 171b. Among the plurality of sidewalls of the light-emitting element 700, the first electrode portion 171a is closest to the first side 1031, and the second electrode portion 171b is closest to the second side 1032. The extension electrode 13 may include two first extension portions 131a, 131b and a plurality of second extension portions 132. In the present embodiment, the first extension portion 131a extends along the first side 1031 and is connected to the first electrode portion 171a, and the first extension portion 131b extends along the second side 1032 and is connected to the second electrode portion 171b. Each second extension portion 132 may be connected to the first extension portion 131a and the first extension portion 131b, or connected to the first electrode portion 171a and the second electrode portion 171b. Each second extension portion 132 may be substantially parallel to the third side 1033 or the fourth side 1034.

As shown in FIG. 9A and FIG. 9B , the first electrode portion 171a and the second electrode portion 171b have a width W ₀ , the first extension portion 131a and the first extension portion 131b have a width W ₁ , and the second extension portion 132 has a width W ₂ . In this embodiment, the width W ₁ is between the width W ₀ and the width W ₂ , and the width W ₁ is greater than the width W ₂ .

As shown in Figures 9A to 9C, the second contact layer 190 preferably does not overlap with the current channel region 140b in the direction (X) perpendicular to the light-emitting stack 120. As shown in the upper view of Figure 9B, the second contact layer 190 may have an end 190e. In this embodiment, the end 190e is the intersection of the second contact layer 190 and the first extension portion 131. There is a shortest distance s1 between the end 190e and the current channel region 140b, and there is a shortest distance s2 between the current channel region 140b and the second contact layer 190. In one embodiment, the range of s1/s2 can be greater than 0 and less than 5, preferably greater than 1 and less than 3. There is a shortest distance D ₁ between the first extension portion 131 and the current channel region 140 b , and preferably the distance D ₁ is greater than the distance s2 . In this embodiment, the second contact layer 190 may have a width W ₄ , and preferably the width W ₄ is smaller than the width W ₂ of the second extension portion 132 .

FIG. 9C shows a cross-sectional view along the B-B’ line in FIG. 9B, and FIG. 9D shows a cross-sectional view along the C-C’ line in FIG. 9B. As shown in FIG. 9C, the second extension portion 132 can cover the side surface 190a’ and the upper surface 190s of the second contact layer 190, so that the second contact layer 190 is covered by the second extension portion 132 and is not exposed.

As shown in FIG. 9C and FIG. 9D , the light emitting element 700 does not have the first window layer 111. In this embodiment, the insulating layer 145 is adjacent to the first semiconductor layer 121, and further includes a contact structure 130 below the first semiconductor layer 121. As shown in FIG. 9C , the contact structure 130 may be adjacent to the first semiconductor layer 121 and located in a plurality of holes 140e of the insulating layer 145. The material of the contact structure 130 includes a III-V semiconductor material. In one embodiment, the III-V semiconductor material may be a binary III-V semiconductor material, such as GaAs or GaP. The contact structure 130 includes dopants such as zinc (Zn), carbon (C) or magnesium (Mg), and may have the same conductivity type as the first semiconductor layer 121, for example, p-type. In one embodiment, the thickness of the contact structure 130 is greater than the thickness of the insulating layer 145. As shown in FIG. 9C , the first contact layer 140 covers the sidewalls of the insulating layer 145 and the contact structure 130 exposed in the hole 140e. In this embodiment, a plurality of current channels 140c are formed by setting the contact structure 130 to allow current to flow. As shown in FIG. 9C , there is a distance H1 between the second contact layer 190 and the contact structure 130 in the vertical direction (X direction). In one embodiment, the distance s2 is greater than the distance H1, and preferably the distance s2 is greater than twice the distance H1 (s2>2H1).

In this embodiment, the second contact layer 190 is only located below the second extension portion 132. As shown in FIG. 9B and FIG. 9D, the second contact layer 190 does not overlap with the electrode portion 171 and the first extension portion 131 in the vertical direction (X direction). Since the second contact layer 190 is only located below the second extension portion 132, the chance of light generated by the active layer 122 being absorbed by the first extension portion 131 can be reduced, thereby improving the light emitting efficiency.

FIG. 9E and FIG. 9F respectively show partial enlarged views of the light emitting element of other embodiments. In one embodiment, the second contact layer 190 may be located only below a portion of the second extension portion 132 without being connected to the first extension portion 131. As shown in FIG. 9E, there is also a distance s3 between the end 190e of the second contact layer 190 and the first extension portion 131. The distance s3 may be in the range of 10 μm to 50 μm, for example, about 20 μm, 25 μm, 30 μm, 35 μm or 40 μm. In some embodiments, by separating the second contact layer 190 from the first extension portion 131 by a distance, the chance of light generated by the active layer 122 being absorbed by the first extension portion 131 can be further reduced, thereby improving the light-emitting efficiency of the light-emitting element.

In another embodiment, the second contact layer 190 may be extended and disposed below a portion of the first extension portion 131. As shown in FIG. 9F, the second contact layer 190 may have a first portion 190a and a second portion 190b, the first portion 190a being disposed below the second extension portion 132, and the second portion 190b being disposed below an edge of the first extension portion 131 close to a side of the current channel region 140b. The second portion 190b may be connected to the first portion 190a. In the vertical direction (X direction), the second portion 190b substantially overlaps with the first extension portion 131. Specifically, in the vertical direction (X direction), a side of the second portion 190b substantially overlaps with a side of the first extension portion 131 close to the current channel region 140b. In the top view, the area of the second portion 190b is preferably less than 1/2 of the area of the first extension portion 131, and more preferably less than 1/3. The second portion 190b is preferably not overlapped with the electrode portion 171 in the vertical direction (X direction). By extending the second contact layer 190 below a portion of the first extension portion 131, it is beneficial to improve the contact resistance between the first extension portion 131 and the second window layer 112 below (refer to Figure 9D), which can further reduce the forward voltage value of the light-emitting element.

FIG. 9G shows a top view of a light-emitting element 800 according to another embodiment. The main difference between the light-emitting element 800 and the light-emitting element 700 is the configuration of the electrode portion 171. Other identical or similar structures can be referred to above and will not be described here. As shown in FIG. 9G, in this embodiment, the first electrode portion 171a and the second electrode portion 171b of the electrode portion 171 do not overlap in the horizontal direction (Y direction). In addition, in this embodiment, the first electrode portion 171a and the second electrode portion 171b are respectively connected to different second extension portions 132, but are not limited thereto. In another embodiment, the first electrode portion 171a and the second electrode portion 171b may also be connected to the same second extension portion 132, and do not overlap in the horizontal direction (Y direction). In some embodiments, by making the first electrode portion 171a and the second electrode portion 171b non-overlapping in the horizontal direction (Y direction), the current distribution can be made more uniform, which is beneficial to improving the uniformity of the light emission of the device.

FIG. 10 is a schematic diagram of a semiconductor device package structure of an embodiment of the present disclosure. The package structure includes a semiconductor device 60, a package substrate 61, a carrier 63, a bonding wire 65, a contact structure 66, and a package material layer 68. The package substrate 61 may include a ceramic or glass material. The package substrate 61 has a plurality of through holes 62. The through holes 62 may be filled with conductive materials such as metals to facilitate electrical conduction and/or heat dissipation. The carrier 63 is located on the surface of one side of the package substrate 61 and also includes conductive materials such as metals. The contact structure 66 is located on the surface of the other side of the package substrate 61. In the present embodiment, the contact structure 66 includes a first contact pad 66a and a second contact pad 66b, and the first contact pad 66a and the second contact pad 66b can be electrically connected to the carrier 63 through the through hole 62. In one embodiment, the contact structure 66 can further include a thermal pad (not shown), for example, located between the first contact pad 66a and the second contact pad 66b. The semiconductor element 60 is located on the carrier 63 and can be a light-emitting element described in any embodiment of the present disclosure. In the present embodiment, the carrier 63 includes a first portion 63a and a second portion 63b, and the semiconductor element 60 is electrically connected to the second portion 63b of the carrier 63 through a bonding wire 65. The material of the bonding wire 65 may include metal, such as gold, silver, copper, aluminum, or an alloy containing at least one of the above elements. The packaging material layer 68 covers the semiconductor element 60 and has the effect of protecting the semiconductor element 60. Specifically, the packaging material layer 68 may include resin materials such as epoxy, silicone, etc. The packaging material layer 68 may further include a plurality of wavelength conversion particles (not shown) to convert the first light emitted by the semiconductor element 60 into a second light. The wavelength of the second light is greater than the wavelength of the first light.

The light-emitting element or packaging structure disclosed herein can be applied to products in the fields of lighting, medical treatment, display, communication, sensing, power supply system, etc., such as lamps, monitors, mobile phones, tablet computers, car dashboards, televisions, computers, wearable devices (such as watches, bracelets, necklaces, etc.), traffic signs, outdoor displays, medical equipment, etc.

FIG. 11 is a schematic diagram of an optoelectronic system 4b. The optoelectronic system 4b includes a base plate 49, a plurality of pixels 40', and a control module 49'. The plurality of pixels 40' are located on the base plate 49 and electrically connected to the base plate 49. A control module 49' is electrically connected to the base plate 49 to control the plurality of pixels 40'. One of the plurality of pixels 40' includes one or more light-emitting elements 40b, and the light-emitting element 40b includes the light-emitting element 100, 200, 300, 400, 500, 600, 700, 800 disclosed in any of the aforementioned embodiments, and each light-emitting element 40b can be individually controlled by the control module 49'. In one embodiment, each pixel 40' includes a light-emitting unit for emitting red light, a light-emitting unit for emitting blue light, and a light-emitting unit for emitting green light, and at least one of the light-emitting units includes a light-emitting element 40b. In one embodiment, the plurality of light-emitting elements 40b on the base plate 49 can be placed into a matrix with rows/columns, or have an asymmetric polygonal outer contour. In one embodiment, preferably, the distance d between two adjacent pixels 40' is between 100μm and 5mm, or the distance d' between two adjacent light-emitting elements 40b is between 100μm and 500μm.

It should be noted that the various embodiments proposed above are used to illustrate the present invention, but do not limit the scope of the present invention. Similar or identical elements in each embodiment or elements with the same schematic symbols in different embodiments may have the same chemical or physical properties. In addition, the elements shown in different embodiments may be combined or replaced with each other under appropriate circumstances, and the element connection relationship in one embodiment may also be applied to another embodiment. The above embodiments may be modified in any possible way without departing from the technical principles and spirit of the present invention, and are all covered by the present invention and protected by the scope of the patent application described below.

100: Light-emitting element

1S: Light-emitting surface

103: Substrate

1031: First side

1032: Second side

1033: Third side

1034: Fourth side

13: Extension electrode

131: First extension part

132: Second extension

140b: Current channel area

140c’: Area

171:Electrode part

L ₁ ~L ₄ : Side length

I: Region

Claims (10)

A light-emitting element comprises: a substrate; a light-emitting stack located on the substrate, having a light-emitting surface and comprising a plurality of semiconductor layers; an upper electrode located on the light-emitting surface, the upper electrode comprising: an electrode portion, comprising a first electrode portion having a first width and a second electrode portion; a first extension portion electrically connected to the electrode portion and having a second width; and a plurality of second extension portions, one of which is connected to the first extension portion, the first electrode portion or the second electrode portion and having a third width, and the second width is between the first width and the third width; a contact structure located between the light-emitting stack and the substrate; and A contact layer, comprising a III-V semiconductor material and located between the upper electrode and the light-emitting stack; wherein a current channel region is defined at a position on the light-emitting surface corresponding to the contact structure, the current channel region is located between two adjacent second extensions and the first extension, the contact layer has an end, the end has a shortest distance s1 from the current channel region, the current channel region has a shortest distance s2 from the contact layer, and the range of s1/s2 is greater than 0 and less than 5. The light-emitting element as described in claim 1, wherein the current channel region is a polygon. The light-emitting element as described in claim 1, wherein there is a shortest distance D1 between the first extension portion and the current channel region, and the distance D1 is greater than the distance s2. The light-emitting element as described in claim 1, wherein the contact layer has a fourth width that is smaller than the third width. The light-emitting element as described in claim 1, wherein in a direction perpendicular to the light-emitting stack, there is a distance H1 between the contact layer and the contact structure, and the distance s2 is greater than the distance H1. A light-emitting element as described in claim 1, wherein the contact layer does not overlap with the first extension portion in a direction perpendicular to the light-emitting stack. A light-emitting element as described in claim 1, wherein the width of the first extension portion is gradual, and the second width is the maximum width of the first extension portion. A light-emitting element as described in claim 1, wherein the first electrode portion and the second electrode portion do not overlap in a horizontal direction. A packaging structure comprises: a carrier; a light-emitting element as described in any one of claim 1 to claim 8, located on the carrier; and a packaging material layer covering the light-emitting element. A photoelectric system comprises a baseboard; a light-emitting element as described in any one of claim 1 to claim 8, located on the baseboard; and a control module, electrically connected to the baseboard.