WO2021129405A1

WO2021129405A1 - Semiconductor light-emitting element

Info

Publication number: WO2021129405A1
Application number: PCT/CN2020/135236
Authority: WO
Inventors: 蔡均富
Original assignee: 天津三安光电有限公司
Priority date: 2019-12-23
Filing date: 2020-12-10
Publication date: 2021-07-01
Also published as: CN211700319U

Abstract

A semiconductor light-emitting element, comprising a semiconductor barrier transistor stacked layer, which comprises a first conductive-type semiconductor layer (106, 206), a second conductive-type semiconductor layer (108, 208), and an active layer (107, 207) located between the first conductive-type semiconductor layer (106, 206) and the second conductive-type semiconductor layer (108, 208); a dielectric layer (105, 205) located on the side of the first conductive-type semiconductor layer (106, 206) away from the active layer (107, 207), wherein the dielectric layer (105, 205) is provided with a plurality of through openings; and a metal layer located on the side of the dielectric layer (105, 205) away from the first conductive-type semiconductor layer (106, 206), wherein the metal layer is electrically connected to the first conductive-type semiconductor layer (106, 206) by means of the plurality of openings of the dielectric layer (105, 205); and the plurality of through openings of the dielectric layer (105, 205) are ring-shaped. The dielectric layer (105, 205) uses a design of ring-shaped openings, such that the effect of mirror reflection can also be taken into consideration on the basis of guaranteeing current conduction and injection, thereby improving the light-emitting brightness of the semiconductor light-emitting element, and improving the light-emitting efficiency thereof.

Description

Semiconductor light-emitting element

Technical field

The invention relates to a semiconductor light-emitting element, which belongs to the field of semiconductor optoelectronic devices and technology.

Background technique

Light Emitting Diode (LED for short) has the advantages of high luminous intensity, high efficiency, small size, long service life, etc., and is considered to be one of the most potential light sources at present. In recent years, LEDs have been widely used in daily life, such as lighting, signal display, backlights, car lights, and large-screen displays. At the same time, these applications also put forward higher requirements for the brightness and luminous efficiency of LEDs.

Existing light emitting diodes include horizontal type and vertical type. The vertical type of light-emitting diode is obtained by transferring the semiconductor barrier crystal stack to other substrates such as silicon, silicon carbide or metal substrates, and removing the original epitaxially grown substrate. Compared with the horizontal type, it can effectively improve the epitaxy. The growth substrate brings about the technical problems of light absorption, current crowding, or poor heat dissipation. The transfer of the substrate generally uses a bonding process, and the bonding is mainly through metal-metal high-temperature and high-pressure bonding, that is, a metal bonding layer is formed between one side of the semiconductor barrier crystal stack and the substrate. The other side of the semiconductor barrier crystal stack provides a light-emitting side, and the light-emitting side is equipped with a wire electrode to provide current injection or flow. The substrate under the semiconductor barrier crystal stack provides current flow or flow, thereby forming a current that passes through the semiconductor vertically. A light-emitting diode with a barrier crystal stack.

In order to improve the light extraction efficiency, a metal reflective layer and a dielectric layer are usually designed to form an ODR reflective structure on one side of the metal bonding layer, and the light from the metal bonding layer is reflected to the light exit side to improve the light extraction efficiency. If the side of the first conductivity type semiconductor layer away from the active layer is the entire dielectric layer, electrical conduction cannot be formed. A common method is to form an electrical connection with the first conductive semiconductor layer through the opening of the dielectric layer. The common dielectric layer opening is designed as a circular opening. As shown in Figure 1(a), the dielectric layer has a high percentage of openings, and the contact area with the first conductivity type semiconductor layer is large. The current is easy to conduct and expand, but at the same time ODR When the mirror area is reduced, the brightness of the LED will decrease; on the contrary, as shown in Figure 1(b), the ratio of openings in the dielectric layer is low, and the area in contact with the first conductivity type semiconductor layer is small, and current conduction and expansion are limited. The voltage will increase, but the ODR mirror area will increase, and the reflection efficiency of the ODR reflection structure will increase, so that the luminous brightness of the LED will increase.

In flip-chip light-emitting diodes, the metal reflective layer and the dielectric layer can form an ODR reflective structure. There are also the above problems. When the opening ratio of the dielectric layer is high, the current is easy to conduct and expand, but at the same time the ODR mirror area is reduced, and the LED emits light. The brightness will decrease; on the contrary, when the opening ratio of the dielectric layer is low, the conduction and expansion of the current are limited, and the voltage increases, but the ODR mirror area increases, the reflection efficiency of the ODR reflection structure increases, and the light-emitting brightness of the LED also increases.

Technical solutions

In order to solve the above problems, the present invention adopts the annular opening design of the dielectric layer to ensure current conduction and injection, while taking into account the effect of mirror reflection, thereby improving the luminous brightness of the semiconductor light-emitting element and improving the luminous efficiency.

In order to achieve the above object, the present invention provides a semiconductor light emitting element, which includes: a semiconductor barrier crystal laminate, including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and a semiconductor layer located between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; The active layer between the semiconductor layers; the dielectric layer is located on the side of the first conductivity type semiconductor layer away from the active layer, the dielectric layer has a plurality of through openings; the metal layer is located on the side of the dielectric layer away from the first One side of a conductive semiconductor layer, the metal layer is electrically connected to the first conductive semiconductor layer through a plurality of openings of the dielectric layer; characterized in that, the plurality of through openings of the dielectric layer are ring-shaped of.

Preferably, the annular opening of the dielectric layer is circular, square, star-shaped, diamond-shaped or irregular in shape.

Preferably, the width of the annular opening of the dielectric layer is 0-15um, the outer diameter of the annular opening is 3-30um, and the area of the annular opening accounts for 10%-95% of the area of the entire dielectric layer.

Preferably, the dielectric layer is at least one layer composed of at least one material of nitride, oxide or fluoride.

Preferably, the metal layer at least includes a metal reflective layer.

More preferably, the metal reflective layer may be formed of a metal or alloy containing at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, and Hf.

Preferably, the metal reflective layer and the dielectric layer form an ODR reflective structure to reflect the light emitted by the semiconductor barrier crystal stack to the light exit side.

Preferably, the semiconductor barrier crystal stack radiates blue light, green light, red light or infrared light.

Preferably, the semiconductor light emitting element further includes a second electrode located on the upper part of the second conductivity type semiconductor layer and electrically connected to the second conductivity type semiconductor layer.

Preferably, the semiconductor light emitting element further includes a first electrode electrically connected to the metal layer.

Preferably, there is a substrate under the metal layer, the substrate is a conductive substrate, and the substrate is located between the opposite electrode and the metal layer.

Preferably, the conductive substrate is silicon, silicon carbide, or metal substrate.

More preferably, the metal substrate is preferably a copper, tungsten, or molybdenum substrate.

Preferably, the metal layer forms an ohmic contact with the first conductivity type semiconductor layer through an ohmic contact layer.

Preferably, the ohmic contact layer is a transparent conductive layer or a metal alloy.

Preferably, the semiconductor light emitting element further includes a transparent substrate located on the second conductive type semiconductor layer.

Preferably, the semiconductor light emitting element further includes a local defect area located on a part of the first conductivity type semiconductor layer and extending down to the second conductivity type semiconductor layer to form a mesa structure, and the mesa structure is exposed to emit light. Sidewall of the epitaxial structure.

Preferably, the semiconductor element further includes a first electrode and a second electrode. The first electrode is formed on the metal layer and is electrically connected to the first conductive semiconductor layer; the second electrode is formed In the local defect area, an electrical connection is formed with the second conductivity type semiconductor layer.

Beneficial effect

As mentioned above, the semiconductor light emitting element provided by the present invention has the following beneficial effects:

1. The ODR reflective structure is formed by the dielectric layer and the metal reflective layer. Compared with the conventional metal reflective layer structure or the Bragg reflective structure, the reflectivity of the semiconductor light-emitting element can be improved, and the light output efficiency can be improved;

2. Through the annular opening design of the dielectric layer, compared with the hollow opening design, it can improve the light reflection effect while ensuring the current injection and conduction, thereby improving the luminous brightness of the semiconductor light-emitting element and improving the luminous efficiency.

Description of the drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, and do not constitute a limitation to the present invention. In addition, the data in the drawings is a descriptive summary and is not drawn to scale.

FIG. 1 is a schematic diagram of the influence of the opening ratio of the dielectric layer on the current conduction and the reflection of the ODR structure in the prior art.

FIG. 2 is a schematic cross-sectional view of the semiconductor light-emitting device mentioned in Embodiment 1. FIG.

FIG. 3 is a schematic diagram of the circular opening of the dielectric layer of the semiconductor light-emitting element mentioned in Embodiment 1. FIG.

4 is a schematic diagram of the photoelectric characteristic interaction of the semiconductor light-emitting element mentioned in the first embodiment with and without the annular opening when the current is injected and turned on.

FIG. 5 is a schematic diagram showing that the annular opening of the dielectric layer of the semiconductor light-emitting element mentioned in Example 2 is square.

6 is a schematic diagram of the annular opening of the dielectric layer of the semiconductor light-emitting element mentioned in Example 3 being a rhombus.

FIG. 7 is a schematic cross-sectional view of the semiconductor light-emitting device mentioned in Embodiment 4 having a flip-chip structure.

FIG. 8 is a schematic diagram of the structure of the semiconductor light-emitting element package mentioned in Embodiment 5. FIG.

In the figure: 101/201: substrate; 102: metal bonding layer; 202: metal protective layer; 103/203: metal reflective layer; 104/204: ohmic contact layer; 105/205: dielectric layer; 106/206: section A conductive semiconductor layer; 107/207: the active layer; 108/208: the second conductive semiconductor layer; 109/209: the second electrode; 110/210: the first electrode; 1051/2051: the annular opening of the dielectric layer; D1: the width of the annular opening; D2: the outer diameter of the annular opening; 2211: local defect area; 2111: the first through hole structure of the insulating protection layer; 2112: the second through hole structure of the insulating protection layer; 10: semiconductor light emitting element 30: mounting substrate; 301: first package electrode; 302: second package electrode; 303: first bonding part; 304: second bonding part; 305: sealing resin.

Embodiments of the present invention

The following describes the implementation of the present invention through specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in the present invention can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

It should be noted that the diagrams provided in this embodiment only illustrate the basic idea of the present invention in a schematic manner, so the diagrams only show the components related to the present invention instead of the number, shape, and shape of the components in actual implementation. For the size drawing, the type, quantity, and proportion of each component can be changed at will during actual implementation, and the component layout type may also be more complicated.

Example one

The present invention provides the following semiconductor light emitting element, as shown in the schematic cross-sectional view of FIG. 2, which includes the following stacked layers: 101: substrate; 102: metal bonding layer; 103: metal reflective layer; 104: ohmic contact layer; 105: Dielectric layer; 106: first conductivity type semiconductor layer; 107: active layer; 108: second conductivity type semiconductor layer; 109: second electrode; 110: first electrode; 1051: annular opening of the dielectric layer.

The following is a detailed description of the stacked layers of each structure.

The substrate 101 is a conductive substrate, and the conductive substrate may be a silicon, silicon carbide, or a metal substrate. The metal substrate is preferably a copper, tungsten or molybdenum substrate. The substrate 101 may have a thickness of about 50 μm to about 300 μm.

The metal layer may be divided into a single layer or at least two layers according to functions, and more preferably at least two functional layers, of which at least one layer may be defined as the metal bonding layer 102 according to functions. The metal bonding layer 102 is a bonding metal material used when adhering one side of the semiconductor barrier crystal stack to the substrate 101, such as gold, tin, titanium, nickel, platinum and other metals. The bonding metal layer itself may be Multi-layer material combination. The metal layer may also include a metal reflective layer 103 on the upper side of the metal bonding layer 102 and closer to the semiconductor barrier crystal stack. The metal reflective layer 103 may be composed of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg. , Zn, Pt, Au, and Hf at least one metal or alloy formed. The metal reflective layer 103 can reflect the light radiated from the semiconductor barrier crystal stack toward the side of the substrate 101 back to the semiconductor barrier crystal stack and radiate out from the light exit side.

The dielectric layer 105 is located on a side of the first conductivity type semiconductor layer 106 away from the active layer 107, and the dielectric layer 105 has a plurality of through openings. The plurality of through openings of the dielectric layer 105 are ring-shaped, and the openings may be uniformly or non-uniformly distributed on one side of the semiconductor barrier crystal stack. As shown in FIG. 2, the circled part is the annular opening 1051 of the dielectric layer 105. The width of the annular opening 1051 of the dielectric layer is D1, and its range is 0~15um; the outer diameter of the annular opening is D2, and its range is 3~30um, and the area of the annular opening accounts for 10%~95 of the area of the entire dielectric layer. %. The dielectric layer 105 may be formed of an insulating material having a conductivity smaller than that of the metal reflective layer 103 or the ohmic contact layer 104, a material having low conductivity, or a material that is Schottky contacting the first conductivity type semiconductor layer 106. For example, the dielectric layer 105 may be composed of at least one of fluoride, nitride, or oxide, such as ZnO, SiO ₂ , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ , TiO _x , At least one of MgF or GaF is formed. The dielectric layer 105 is formed by a combination of at least one layer of composition or multiple layers of dielectric layer materials with different refractive indexes. The dielectric layer 105 is more preferably a light-transmitting dielectric layer, and at least 50% of light can pass through the dielectric layer. More preferably, the refractive index of the dielectric layer 105 is lower than the refractive index of the semiconductor barrier crystal stack. In this embodiment, the pattern of the annular opening is preferably circular. As shown in FIG. 3, D1 is the width of the annular opening, and its range is preferably 0~15μm, and D2 is the width of the outer diameter of the annular opening, and its range is preferably 3~30μm.

An ohmic contact layer 104 may be included between the metal reflective layer 103 and the dielectric layer 105. The ohmic contact layer 104 forms a plurality of regions to ohmically contact the first conductive type semiconductor layer 106 by filling at least the plurality of annular openings of the dielectric layer 105 to transfer current from The metal layer (including the metal reflective layer 103 and the bonding layer 102) is uniformly transferred to the semiconductor barrier crystal stack, so the ohmic contact layer 104 does not contact the side of the first conductive type semiconductor layer 106 in the form of an entire surface. The ohmic contact layer 104 may be formed of a transparent conductive layer such as at least one of ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, and ATO. The ohmic contact layer 104 may alternatively use a light-transmitting conductive layer and metal. The metal is preferably an alloy material, such as gold zinc, gold germanium, gold germanium nickel, or gold beryllium. The ohmic contact layer 104 may have a single-layer or multi-layer structure.

The metal reflective layer 103 and the dielectric layer 105 form an ODR reflective structure, which returns the light radiated from the semiconductor barrier crystal stack toward the substrate 101 to the semiconductor barrier crystal stack and radiates out from the light exit side to improve light extraction efficiency. The dielectric layer 105 of the present invention has a plurality of through annular openings. On the one hand, the ohmic contact layer 104 is electrically connected to the first conductivity type semiconductor layer through the annular openings to ensure current injection and conduction. On the other hand, as shown in the figure As shown in 4, compared with the hollow design of the dielectric layer, it can be found that after the opening position of the dielectric layer adopts the annular opening design of the inner ring and the outer ring, the strongest current injection has the strongest luminous intensity, and the dielectric layer of the inner ring and the outer ring The reflection effect of (ODR) can be enhanced internally and externally. It can be seen that there is a better ODR reflection effect, and the interaction between electrical and optical characteristics is enhanced. After adopting the annular opening design of the dielectric layer, the LED can maintain the same working voltage, increase the luminous brightness, and improve the overall luminous efficiency.

The semiconductor barrier crystal stack is a semiconductor barrier crystal stack obtained by MOCVD or other growth methods. The semiconductor barrier crystal stack is a semiconductor material that can provide conventional radiation such as ultraviolet, blue, green, yellow, red, and infrared light. , The specific material can be 200~950nm, such as common nitride, specific such as gallium nitride-based semiconductor barrier crystal stack, gallium nitride-based barrier crystal stack is usually doped with aluminum, indium and other elements, mainly to provide Radiation in the 200~550nm band; or the common aluminum gallium indium phosphorus-based or aluminum gallium arsenic-based semiconductor barrier crystal stack, which mainly provides radiation in the 550~950nm band.

The semiconductor barrier layer stack mainly includes a first conductivity type semiconductor layer 106, a second conductivity type semiconductor layer 108, and an active layer 107 between the first conductivity type semiconductor layer 106 and the second conductivity type semiconductor layer 108. The first conductive type semiconductor layer 106 and the second conductive type semiconductor layer 108 may be respectively n-type doped or p-type doped to realize a material layer that at least provides electrons or holes, respectively. The n-type semiconductor layer may be doped with n-type dopants such as Si, Ge, or Sn, and the p-type semiconductor layer may be doped with p-type dopants such as Mg, Zn, Ca, Sr, or Ba. The first conductive semiconductor layer 106, the active layer 107, and the second conductive semiconductor layer 108 may specifically be aluminum gallium indium nitride, gallium nitride, aluminum gallium nitride, aluminum indium phosphorus, aluminum gallium indium phosphorus, or gallium arsenide or aluminum gallium. Made of arsenic and other materials. The first conductive type semiconductor layer 106 or the second conductive type semiconductor layer 108 includes a covering layer that provides electrons or holes, and may include other layer materials such as a current spreading layer, a window layer, or an ohmic contact layer, etc., depending on the doping concentration or The content of the components is different, and it is set to different multi-layers. The active layer 107 is a region where electrons and holes are recombined to provide light radiation. Different materials can be selected according to different emission wavelengths. The active layer 107 may be a periodic structure of single quantum well or multiple quantum wells. By adjusting the composition ratio of the semiconductor materials in the active layer 107, light of different wavelengths is expected to be radiated.

The second electrode 109 is arranged on the light emitting side of the semiconductor barrier crystal stack, and forms an electrical connection with the second conductivity type semiconductor layer. The second electrode 109 mainly includes a pad portion, and the pad portion is mainly used for external wiring during packaging. The pads of the second electrode can be designed in different shapes according to actual wire bonding requirements, such as cylindrical or square or other polygonal shapes. As a preferred embodiment, the second electrode may further include an extension part extending from the pad, the extension part may be formed in a predetermined pattern shape, and the extension part may have various shapes, such as a strip shape.

The semiconductor light emitting element further includes a first electrode 110, and the first electrode 110 is electrically connected to the first conductive semiconductor layer through the metal layer. The first electrode 110 described in this embodiment is formed on the back side of the substrate 101 in the form of a whole surface. The substrate of this embodiment is a conductive support substrate, and the second electrode 109 and the first electrode 110 are formed on both sides of the support substrate 101 Side, in order to realize that the current flows vertically through the semiconductor barrier crystal stack to provide a uniform current density.

The second electrode 109 and the first electrode 110 are preferably made of metal materials. At least the pad portion and the extension portion of the second electrode 109 may also include a metal material for forming a good ohmic contact with the semiconductor light emitting sequence.

The present invention also prepared a sample of a comparative example. The opening of the dielectric layer in the comparative example was a conventional circular opening. In addition, the semiconductor light-emitting element was fabricated under the same conditions as in Example 1, and the comparative example and the dielectric in Example 1 The area of the layer openings accounts for the same proportion.

The photoelectric performance test of the semiconductor light-emitting element of the above-mentioned comparative example and Example 1 was carried out, and the characteristic results are shown in Table 1 below.

Table 1

In the comparative example, a current was passed between the first electrode and the second electrode, and infrared light with a peak emission wavelength of 944 nm was emitted. In addition, as shown in Table 1, in the comparative example, when a current of 350 milliamperes (mA) was passed in the _{forward direction, the forward voltage Vf 1 was 2.98V.} _{The luminous output power (P 0} ) when the forward current is set to 350 mA is 350 mW. The semiconductor light-emitting element in Example 1 was tested, and when the forward current was 350 mA, its luminous output power (P ₀ ) and forward voltage (Vf1) were 365 mW and 2.97V, respectively. Experimental results show that, in the case where the assurance of the dielectric layer of the same area proportion of the openings, the dielectric layer having an opening using ring opening, for example, a Vf of ₁ ₁ has the same comparative Vf of the embodiment, but the emission output power compared to Comparative enhance 3.75% .

It can be seen from this that, under the condition that the area of the opening of the dielectric layer is guaranteed, compared with the hollow design of the dielectric layer, the annular opening of the dielectric layer can improve the semiconductor light-emitting element while ensuring the conduction and injection of current. Reflectivity, thereby improving the luminous efficiency of semiconductor light-emitting elements.

Example two

This embodiment, as shown in FIG. 5, differs from the first embodiment in that the shape of the annular opening of the dielectric layer 105 in the first embodiment is circular, while the shape of the annular opening of the dielectric layer 105 in this embodiment is square of.

Example three

This embodiment, as shown in FIG. 6, differs from the first embodiment in that the shape of the annular opening of the dielectric layer 105 in the first embodiment is circular, while the shape of the annular opening of the dielectric layer 105 in this embodiment is a rhombus. of.

Example four

As shown in FIG. 7, different from the first embodiment, this embodiment provides another semiconductor light-emitting element, a flip-chip light-emitting diode, which includes the following stacked layers: 201: a substrate; 202: a metal protective layer; 203: metal reflective layer; 204: ohmic contact layer; 205: dielectric layer; 206: first conductivity type semiconductor layer; 207: active layer; 208: second conductivity type semiconductor layer; 209: second pole; 210: first Electrode; 2051: ring-shaped opening of the dielectric layer; 211: insulating protective layer.

The substrate 201 is a transparent substrate. The transparent substrate 201 may be a growth substrate used for the growth of a semiconductor barrier crystal stack, or it may be a transparent substrate combined with a semiconductor barrier crystal stack through a transparent adhesive layer, specifically including a planar type. Sapphire substrate, patterned sapphire substrate, silicon carbide substrate, gallium nitride substrate, etc. In this embodiment, the transparent substrate 201 is selected as a patterned sapphire substrate. In other embodiments, the substrate can be thinned or removed to form a thin-film LED chip.

The semiconductor barrier crystal stack is located on the transparent substrate 201 and includes a first conductivity type semiconductor layer 206, an active layer 207, and a second conductivity type semiconductor layer 208 stacked in sequence. In one of the preferred embodiments, the first conductivity type semiconductor layer 206 and the second conductivity type semiconductor layer 208 may be p-type GaN or N-type GaN, respectively, and the active layer 207 may be a GaN-based quantum well layer. Of course, other types of epitaxial structures can also be selected according to actual needs, and are not limited to the examples listed here.

The local defect region 2211 is located on a part of the first conductivity type semiconductor layer 206 and extends downward to the second conductivity type semiconductor layer 208 to form a mesa structure. The mesa structure exposes the sidewalls of the epitaxial structure, specifically The mesa structure reveals the mesa of the second conductivity type semiconductor layer 208 and the sidewalls of the first conductivity type semiconductor layer 206, the active layer 207, and the second conductivity type semiconductor layer 208. It should be noted that the number of locally defective regions 1211 is at least one, and it can also be increased according to the structure and area of the LED chip.

The ohmic contact layer 204 is located on the first conductive type semiconductor layer 206, and the ohmic contact layer 204 may be formed of a transparent conductive layer such as at least one of ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, and ATO. The ohmic contact layer 204 may alternatively use a light-transmitting conductive layer and metal. The metal is preferably an alloy material, such as gold zinc, gold germanium, gold germanium nickel, or gold beryllium. The ohmic contact layer 204 may have a single-layer or multi-layer structure. The ohmic contact layer is in ohmic contact with the first conductivity type semiconductor layer 206.

The dielectric layer 205 wraps the sidewalls of the ohmic contact layer and covers the sidewalls of the adjacent light-emitting epitaxial structure, wherein the dielectric layer 205 that wraps the sidewalls of the ohmic contact layer 204 is mainly used for ohmic contact The layer 204 and the metal reflective layer 203 constitute an omnidirectional reflective layer (ODR) structure. The dielectric layer 205 covering the sidewalls of the adjacent light-emitting epitaxial structure mainly serves as electrical insulation; further, the dielectric layer has a A series of annular opening structure, as shown in FIG. 7, 2051 is the annular opening of the dielectric layer.

A dielectric layer 205 having a ring-shaped opening structure is formed on part of the surface of the epitaxial structure. The dielectric layer 205 may be a low refractive index material, such as a silicon dioxide layer, magnesium fluoride, etc., or a high refractive index material, such as Titanium dioxide or the like, or the dielectric layer 205 may also be a distributed Bragg reflector (DBR) layer including high and low refractive index materials, and is not limited to the examples listed here.

A metal layer is formed on the surface of the dielectric layer 205, and the metal layer may include a multilayer structure, such as a metal reflective layer 203, a metal protective layer 202, etc., and is not limited to the examples listed here. As an example, when the metal reflective layer 203 is made of Al or Ag highly reflective metal as a mirror (mirror), the metal protective layer 202 (Barrier) is made of TiW alloy, etc., and the metal protective layer 202 can be completely wrapped around the metal reflective layer 203. To protect the metal reflective layer.

In this embodiment, the metal reflective layer 203 and the dielectric layer 205 form an ODR reflective structure, which returns the light radiated from the semiconductor barrier crystal stack toward the substrate 201 side to the semiconductor barrier crystal stack and radiates out from the transparent substrate 201 side. Improve light output efficiency. The dielectric layer 205 has a plurality of through annular openings, and the metal layer is electrically connected to the first conductive semiconductor layer 206 through the annular openings 2051 to ensure current injection and conduction. On the other hand, as shown in FIG. 4 It is shown that compared with the hollow design of the dielectric layer, it can be found that after the opening position of the dielectric layer adopts the annular opening design of the inner ring and the outer ring, the strongest current injection has the strongest luminous intensity, and the dielectric layer of the inner ring and the outer ring (ODR The reflection effect of) can be strengthened internally and externally. It can be seen that there is a better ODR reflection effect, and the interaction between electrical and optical characteristics is enhanced. After adopting the annular opening design of the dielectric layer, the semiconductor light-emitting element can maintain the same working voltage, improve the luminous brightness, and improve the overall luminous efficiency.

The semiconductor light-emitting element may also include an insulating protection layer 211 formed on the metal protection layer 202 and the local defect region 2211, and the first via structure 2111 and the insulating protection layer 211 of the insulating protection layer 211 are formed in the insulating protection layer 211 The second through-hole structure 2112. The first through-hole structure 2111 serves as a reserved window for the first electrode, and the second through-hole structure 2112 serves as a reserved window for the second electrode. The first electrode 210 is formed in the reserved window of the first electrode to realize the electrical connection between the first electrode and the first conductivity type semiconductor layer; the second electrode 209 is formed in the reserved window of the second electrode, In order to realize the electrical connection between the second electrode and the second conductivity type semiconductor layer.

As an example, the insulating protection layer 211 can be a low refractive index material, such as a silicon dioxide layer, magnesium fluoride, etc., or a high refractive index material, such as titanium dioxide, etc., or the insulating protection layer 211 can also be a distributed Bragg reflector. Layer (DBR), and is not limited to the examples listed here.

It should be noted that, according to needs, after the first and second electrodes are fabricated, a third insulating layer (not shown in the figure) can be formed on the first and second electrodes, and a through hole structure can be formed. As the electrode window, the third and fourth electrodes are finally formed in the electrode window.

In this embodiment, an omnidirectional reflector (ODR) structure is formed by a low-refractive-index dielectric layer and a metal reflective layer, and its reflection effect is better than that of a conventional metal reflective layer or a distributed Bragg reflective layer structure, which enhances the probability of external light extraction of the semiconductor light-emitting element. Improve the brightness of the LED device; by forming a ring-shaped opening structure on the dielectric layer, the metal layer and the ohmic contact layer are electrically connected, so as to maintain the voltage (VF) of the semiconductor light-emitting element not rising; by adopting the ring-shaped opening design for the dielectric layer, it is guaranteed In the case of the proportion of the opening area of the dielectric layer, the injection and conduction of current can be ensured, while the light reflection effect is improved, and the luminous efficiency of the semiconductor light-emitting element is improved.

Example five

The semiconductor light-emitting element provided by the present invention can be widely used in display or backlight packages or applications, and can especially meet the high-brightness requirements of backlight products.

Specifically, this embodiment provides a package as shown in FIG. 8, the package including a mounting substrate 30, a semiconductor light emitting element 10 and a sealing resin 305. At least one semiconductor light-emitting element in the foregoing embodiments is mounted on the mounting substrate 30. The mounting substrate 30 is an insulating substrate, such as a package module substrate for RGB display screen or a module substrate for backlight display. One surface of the mounting substrate 30 There is a first electrode terminal 301 and a second electrode terminal 302 that are electrically isolated. The semiconductor light-emitting element is located on one surface of the mounting substrate 30. The first electrode 210 and the second electrode 209 of the semiconductor light-emitting element pass through the first coupling portion 303 and the second coupling portion 304, respectively, and the first electrode terminal 301 and the second electrode terminal 302. connection. The first bonding portion 303 and the second bonding portion 304 include but are not limited to solder, such as eutectic solder or reflow solder.

The semiconductor light emitting element package emits light having blue light or mixed colors (for example, white). For example, the semiconductor light emitting element chip emits light in the blue wavelength band, such as light with a peak wavelength of 450 nm, and the package further includes a transparent sealing resin 306 for protecting the semiconductor light emitting element chip, and also provides light radiation in the corresponding blue wavelength band. Or, in order to emit white light, the package may include a fluorescence conversion material for wavelength conversion of light emitted from the semiconductor light emitting element chip. The fluorescence conversion material may be provided in the sealing resin 306. The sealing resin 306 may be applied to at least one side of the semiconductor light-emitting element chip by dispensing or pasting, but is not limited thereto. The fluorescence conversion material may be a fluorescence conversion material in which red and green are combined, or a yellow phosphor or a fluorescence conversion material in which red, yellow and green are combined. Since the semiconductor light emitting element has an ODR structure with high reflection efficiency in the present invention, the light emitting efficiency of the semiconductor light emitting element can be improved, so that the light emitting efficiency of the entire semiconductor light emitting element package can be improved.

It should be noted that the above embodiments are only used to illustrate the present invention, but not to limit the present invention. Those skilled in the art can make various modifications to the present invention without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention, and the scope of patent protection of the present invention should be defined in accordance with the scope of the claims.

Claims

A semiconductor light emitting element, comprising: a semiconductor barrier crystal stack, including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an activity located between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer The dielectric layer is located on the side of the first conductivity type semiconductor layer away from the active layer, and the dielectric layer has a plurality of through openings; the metal layer is located on the side of the dielectric layer away from the first conductivity type semiconductor layer On one side, the metal layer is electrically connected to the first conductivity type semiconductor layer through a plurality of openings of the dielectric layer; wherein the plurality of through openings of the dielectric layer are ring-shaped.
The semiconductor light-emitting element according to claim 1, wherein the annular opening of the dielectric layer is circular, square, star-shaped, diamond-shaped or irregular in shape.
The semiconductor light-emitting element according to claim 1, wherein the width of the annular opening of the dielectric layer is 0-15um, the outer diameter of the annular opening is 3-30um, and the area of the annular opening occupies the entire dielectric layer. The proportion of area is 10%~95%.
The semiconductor light-emitting element according to claim 1, wherein the dielectric layer has a single-layer or multi-layer structure and is composed of at least one of nitride, oxide, or fluoride.
The semiconductor light-emitting element according to claim 1, wherein the metal layer at least includes a metal reflective layer.
The semiconductor light-emitting element according to claim 5, wherein the metal reflective layer can be at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, and Hf. A kind of metal or alloy is formed.
7. The semiconductor light emitting element according to claim 6, wherein the metal reflective layer and the dielectric layer form an ODR reflective structure to reflect the light emitted by the semiconductor barrier crystal stack to the light emitting side.
The semiconductor light emitting element according to claim 1, wherein the semiconductor barrier crystal laminate radiates blue light, green light, red light or infrared light.
The semiconductor light-emitting element according to claim 1, further comprising a second electrode located on the upper part of the second conductivity type semiconductor layer and electrically connected to the second conductivity type semiconductor layer.
The semiconductor light emitting device of claim 1, further comprising a first electrode electrically connected to the metal layer.
10. The semiconductor light emitting device according to claim 10, wherein a substrate is provided under the metal layer, the substrate is a conductive substrate, and the substrate is located between the first electrode and the metal layer.
The semiconductor light-emitting element according to claim 11, wherein the conductive substrate is silicon, silicon carbide, or metal substrate.
The semiconductor light-emitting element according to claim 12, wherein the metal substrate is a copper, tungsten or molybdenum substrate.
The semiconductor light-emitting element according to claim 1, wherein the metal layer forms an ohmic contact with the first conductive semiconductor layer through an ohmic contact layer.
The semiconductor light-emitting element according to claim 14, wherein the ohmic contact layer is a transparent conductive layer or a metal alloy.
The semiconductor light emitting device according to claim 1, further comprising a transparent substrate on the second conductivity type semiconductor layer.
The semiconductor light-emitting element according to claim 16, further comprising a local defect area, which is located on a part of the first conductivity type semiconductor layer and extends down to the second conductivity type semiconductor layer to form a mesa Structure, the mesa structure has exposed sidewalls of the light-emitting epitaxial structure.
The semiconductor light-emitting element according to claim 17, further comprising a first electrode and a second electrode, the first electrode is formed on the metal layer and forms an electrical connection with the first conductivity type semiconductor layer. The second electrode; is formed in the local defect area to form an electrical connection with the second conductivity type semiconductor layer.