CN208767327U - Light emitting diode with homogeneous electrode field distribution - Google Patents

Abstract

The utility model is a kind of light emitting diode with homogeneous electrode field distribution.The diode successively includes: substrate, buffer layer, N-type semiconductor transport layer, multiple quantum well layer, P-type semiconductor transport layer, P-type heavily-doped semiconductor transport layer, current extending along epitaxial growth direction；The N-type semiconductor transport layer part exposes, and N-type Ohmic electrode is distributed on exposed N-type semiconductor transport layer；Insulator layer is distributed on current extending, P-type Ohmic electrode is covered on insulator layer；The identical hole of size is graphically distributed on the insulating layer；The P-type Ohmic electrode is divided into two parts, lower part be distributed with the matched column patterned electrodes of hole on insulating layer, top is whole layer structure, and covering is on the insulating layer.The structural improvement of the utility model Electrode Field distribution, and solve the problems, such as after Electrode Field is evenly distributed and then improve current crowding.

Description

Light emitting diode with homogeneous electrode field distribution

Technical field

The utility model relates to LED semiconductor technical fields, specifically a kind of to have homogeneous electrode electric field The LED device of distribution.

Background technique

Semiconductor material with wide forbidden band (forbidden bandwidth is greater than or equal to 2.3eV) is referred to as third generation semiconductor material, mainly Including SiC, GaN etc..It is compared with the first generation, second generation semiconductor material, third generation semiconductor material has broader forbidden band loose Degree, higher breakdown electric field, thermal conductivity and bigger electronics drift about saturated velocity the characteristics of.These characteristics allow nitride LED to send out Optical diode has obtained quick development in terms of the opto-electronic device of blue and green light and ultraviolet band in recent years, and is illuminating It is widely used on the fields such as detection, medicine phototherapy, sterilizing, chemical catalysis.However, although nitride LED shines The brightness of diode is being continuously increased, but compared with traditional lighting system, optical output power and photoelectric conversion efficiency are still It is very low.

Cause this problem one of major reason be traditional P-type Ohmic electrode setting: on the one hand, passing In the LED light emitting diode construction of system, P-type Ohmic electrode is located at the centre of optical path, and the light that a part passes through can be by P-type ohm Electrode absorbs and causes inevitable light loss.On the other hand, the fringe field of P-type Ohmic electrode is smaller than its internal electric field Many, being unevenly distributed for electric field cause electrode edge to gather a large amount of hole, LED light emitting diode regional area are made to have height Current concentration leads to the problem of Low emissivity recombination rate and current crowding, substantially reduces the efficiency of LED light emitting diode, simultaneously The localized high temperature regions as caused by current crowding can seriously affect the performance and used life of device.Therefore uniform electrode electricity Field distribution has great importance to LED light emitting diode performance is improved.Researcher is the unevenness for improving Electrode Field distribution Current crowding caused by even and the device architecture that LED light emitting diode has been transformed, are mostly transformed from the angle of electric current, than As using the nanosized SiO_2 electron barrier layer structure being placed in immediately below electrode between current extending and P-type transport layer, SiO2 Structure changes the flow path of portion of electrical current, therefore alleviates current crowding, improves the output power (Chun-Fu of device Tsai,Yan-Kuin Su,et al.Improvement in the Light Output Power of GaN-Based Light-Emitting Diodes by Natural-Cluster SiliconDioxide Nanoparticles as the Current-Blocking Layer[J].IEEE PHOTONICS TECHNOLOGY LETTERS,VOL.21,NO.14,JULY 15,(2009))；In addition, proposing a kind of LED of the graphical p-type ohmic contact structure of palladium material, palladium is embedded in Al electrode, This patterned structures reduce the light absorption of contact layer, while electric current flows between Technique of Nano Pd, keep electric current more uniform In the device of injection, meanwhile, regional spread of the part light between graphical palladium structure will be reflected back light-emitting surface by Al electrode, from And improve light output and device performance (N.Lobo, H.Rodriguez, et al.Enhancement oflight extraction in ultraviolet light-emitting diodes using nanopixel contact design withAl reflector[J].APPLIED PHYSICS LETTERS 96,081109(2010)).It is above two Although structure slows down current-crowding effect to a certain extent, the influence for Electrode Field distribution is not referred to.It is right In the first SiO2 electron barrier layer structure, SiO2 structure improves electric current point between current extending and P-type transport layer Cloth, such structure improve no obvious effect to electrode edge electric field；For second of the pole P ohmic contact layer using palladium material Structure, palladium belong to noble metal, and metal, which is embedded in metal electrode, improves no effect, and additionally expensive to electrode edge electric field Metal material also increases cost of manufacture.

Utility model content

The technical problem to be solved by the utility model is to provide the light emitting diode devices with homogeneous electrode field distribution Part makes p-type metal ohmic electrode contact pattern, due to patterned p-type Europe by being embedded in insulator in metal electrode bottom Electric field between the metal electrode of nurse contact position is cancelled out each other, so that higher electric field existing for the script of P-type Ohmic electrode edge Weakened, to slow down the current crowding phenomenon at the position；Patterned ohmic contact electrode also can increase dissipating for light simultaneously Effect is penetrated, to improve the luminous efficiency of light emitting diode.The structural improvement of the utility model Electrode Field distribution, and solve After Electrode Field of having determined is evenly distributed and then improve current crowding problem, than difference on two kinds of device architectures in current techniques It is even better in very big and performance；In addition, more uniform due to current distribution, the part for being conducive to alleviate light emitting diode is high Warm phenomenon extends the service life of device.

The technical solution of the utility model is:

A kind of light emitting diode with homogeneous electrode field distribution, the diode are successively wrapped along epitaxial growth direction It includes: substrate, buffer layer, N-type semiconductor transport layer, multiple quantum well layer, P-type semiconductor transport layer, P-type heavily-doped semiconductor Transport layer, current extending；The N-type semiconductor transport layer part exposes, and is distributed on exposed N-type semiconductor transport layer There is N-type Ohmic electrode；Insulator layer is distributed on current extending, P-type Ohmic electrode is covered on insulator layer；Described Hole is graphically distributed on insulating layer；The P-type Ohmic electrode is divided into two parts, lower part be distributed with on insulating layer The matched column patterned electrodes of hole, top are whole layer structure, and covering is on the insulating layer；

The graphical distribution of hole on the insulating layer is specially central symmetry, non-centrosymmetry or random distribution Irregular figure；Hole occupied area is the 50~99% of insulating layer area；The edge hole of insulating layer, the number of edge hole Amount is the 1~100% of whole pore quantities；

The figure that the figure is preferably circular, arc-shaped, annulus, ellipse or edge are round and smooth；

Hole on the insulating layer it is conveniently of circular shape, oval, the spacing between two neighboring hole is 1 ~2000nm；

The hole being graphically distributed on the insulating layer is preferably that size is identical；

The global shape of the P-type Ohmic electrode is preferably circular, and (projection of shape is identical as insulating layer, and covers it On), whole radius be 10 μm~150 μm, top entirety stratiform part with a thickness of 1~1000nm；

The material of the N-type semiconductor transport layer is Al_x1In_y1Ga_1-x1-y1N, wherein should ensure that each component coefficient 0≤ X1≤1,0≤y1≤1,1 >=1-x1-y1 >=0, with a thickness of 1~5 μm；Whole 1%~20% shared by expose portion area；

The material of the substrate is sapphire, SiC, Si, AlN, GaN or quartz glass, with a thickness of 50nm~10 μm；Institute The material for the buffer layer stated is Al_x2In_y2Ga_1-x2-y2N, in formula component x2, y2 and 1-x2-y2 of each element between 0 and 1 it Between, with a thickness of 10~50nm；The material of the multiple quantum well layer is Al_x3In_y3Ga_1-x3-y3N/Al_x4In_y4Ga_1-x4-y4N, in formula For component x3, x4, y3, y4,1-x3-y3 and 1-x4-y4 of each element between 0 and 1, quantum builds Al_x3In_y3Ga_1-x3-y3N's With a thickness of 5~50nm, Quantum Well Al_x4In_y4Ga_1-x4-y4N with a thickness of 1~15nm, and quantum builds Al_x3In_y3Ga_1-x3-y3The taboo of N Bandwidth is greater than Quantum Well Al_x4In_y4Ga_1-x4-y4The forbidden bandwidth of N；The material of the P-type semiconductor transport layer is Al_x5In_y5Ga_1-x5-y5N, component x5, y5 and 1-x5-y5 of each element are between 0 and 1 in formula, with a thickness of 50~500nm； The material of the P-type heavily-doped semiconductor transport layer is Al_x7In_y7Ga_1-x7-y7N, wherein should ensure that 0≤x7 of each component coefficient ≤ 1,0≤y7≤1,1 >=1-x7-y7 >=0, material doped is p-type heavy doping, with a thickness of 10~50nm；The current expansion The material of layer is ITO, Ni/Au, zinc oxide, graphene, aluminium or metal nanometer line, with a thickness of 10~500nm；

The material of the p-type Ohmic electrode is P-type Ohmic electrode Ni/Au, Cr/Au, Pt/Au or Ni/Al, with a thickness of 1~ 3000nm；

The material of the N-type Ohmic electrode is N-type Ohmic electrode Al/Au, Cr/Au or Ti/Al/Ti/Au, with a thickness of 1~ 3000nm, area are the 5%~95% of N-type semiconductor transport layer expose portion area；

The material of the insulator layer is undoped SiO₂、Al₂O₃、Si₃N₄, AlN, LiF, diamond or PMMA, it is thick Degree is 1~2999nm；

The substantive distinguishing features of the utility model are as follows:

The utility model is by studying electrode structure, i.e., side is embedded in a layer structure of graphically becoming attached under the electrodes, keeps p-type golden Belong to Ohmic contact pattern and the field distribution of electrode edge is optimized by the improvement at diode electrode edge, homogeneous electrode electricity Field distribution structure can be used on the LED device of any structure, such as inverted structure, vertical structure.This is practical new Type is related to other epitaxial layers, and the material limitation of graphical pattern and insulating layer is few, and technological process requirement is low, and material easily obtains It takes.

The beneficial effects of the utility model are:

Compared with prior art, the utility model has following substantive distinguishing features outstanding and marked improvement:

(1) LED device with homogeneous electrode field distribution in the utility model, it is characterized in that in P-type Ohmic electrode bottom is embedded in patterned insulator layer, and this structure takes full advantage of the characteristics of cancelling out each other between electric field, makes any Higher cell-edge between two electrodes is cancelled out each other, to obtain uniform Electrode Field distribution, reduces the portion The current-crowding effect of position, so that performance when enhancing LED operation, improves the efficiency of light emitting diode.

(2) different with the refractive index of electrode due to insulating layer, patterned ohmic contact electrode can increase the dispersion effect of light, The light emission being more absorbed by the electrode is set to go out device, to improve the light extraction efficiency of diode.

(3) in addition, the device design structure alleviates current-crowding effect in LED component to a certain extent, to reduce The influence of device degradation caused by being increased as device junction temperature, and then extend the service life of device.

(4) in addition, the device uses round, oval structure, round and smooth edge can avoid point discharge phenomenon.

(5) in the utility model with homogeneous electrode field distribution LED device, with similar in effect other Device is compared, and the utility model is only more the step of etching to P-type Ohmic electrode, and does not cause shadow to normal working voltage It rings, manufacture craft is simple, and easily operated, repeatability is strong, and precision required by the thickness of insulator growth is not high, and material is easy It obtains, selectivity is more, and production cost is low.

Detailed description of the invention

Explanation further is made to the utility model with reference to the accompanying drawing.

Fig. 1 is standard light emitting diode epitaxial slice structure main view in the prior art.

Fig. 2 is to grow insulator layer in epi-layer surface, and on insulator layer, pass through photoetching in embodiment 1,2,3,4 Step is made with dry etch process, exposes the epitaxial slice structure schematic diagram of N-type semiconductor transport layer.

Fig. 3 is the pattern dielectric body layer structural representation that is etched by photoetching and ICP in the method for the utility model Figure.

Fig. 4 is to be uniformly coated with the structural schematic diagram of photoresist in insulator layer surface in embodiment 1,2,3,4.

Fig. 5 is to place photolithography plate in embodiment 1,2,3,4 and carry out the schematic diagram after exposure-processed.

Fig. 6 is that the schematic diagram of electrode is made by evaporation metal in embodiment 1,2,3,4.

Fig. 7 is to remove obtained after extra metal and photoresist to have homogeneous electrode electric field in embodiment 1,2,3,4 The epitaxial slice structure main view of the light emitting diode of distribution.

Fig. 8 and Fig. 9 is respectively to carry out photoetching in embodiment 1 and 3 to insulator layer and dry etch process makes figure, The structure top view of the cylindrical-array shape, peripheral cylindrical array shape that are showed.

Figure 10 is any two in the LED P-type Ohmic electrode for have in embodiment 1,3 homogeneous electrode field distribution The comparison diagram of the field strength distribution of field strength distribution and standard light emitting diode P-type Ohmic electrode between a electrode.

Figure 11 is LED P-type Ohmic electrode marginal position in embodiment 1,3 with homogeneous electrode field distribution The hole concentration of the last one quantum hydrazine and standard light emitting diode P-type Ohmic electrode edge contrast scheme.

Figure 12 is that LED P-type Ohmic electrode bottom in embodiment 1,3 with homogeneous electrode field distribution has absolutely The hole concentration figure of the last one quantum hydrazine of edge body position.

Wherein, 101. substrate, 102. buffer layers, 103.N- type semiconductor transport layer, 104. multiple quantum well layers, 105.P- type Semiconductor transport layer, 106.P- type heavily-doped semiconductor transport layer, 107. current extendings, 108.P- type Ohmic electrode, 109.N- type Ohmic electrode, 110. insulator layers, 111. photoresist layers.

Specific embodiment

Below with reference to examples and drawings, the utility model is described in further detail, but not in this, as to the application right The restriction of claimed range.

Standard light emitting diode epitaxial slice structure in the prior art as shown in Figure 1, its along epitaxial growth direction successively Include: substrate 101, buffer layer 102, N-type semiconductor transport layer 103, multiple quantum well layer 104, P-type semiconductor transport layer 105, P-type heavily-doped semiconductor transport layer 106, current extending 107, P-type Ohmic electrode 108, N-type Ohmic electrode 109.

Embodiment illustrated in fig. 2 shows in the method for the utility model, grows insulator layer on current extending 107 110, and on insulator layer 110, step is made by photoetching and dry etch process, exposes N-type semiconductor transport layer 103 epitaxial slice structure successively includes: substrate 101, buffer layer 102, N-type semiconductor transport layer along epitaxial growth direction 103, multiple quantum well layer 104, P-type semiconductor transport layer 105, P-type heavily-doped semiconductor transport layer 106, current extending 107, insulator layer 110.

Embodiment illustrated in fig. 3 shows in the method for the utility model, passes through photoetching and ICP etching processing insulator layer 110 Structure afterwards, insulator layer 110 present graphically, along epitaxial growth direction successively include: substrate 101, buffer layer 102, N-type semiconductor transport layer 103, multiple quantum well layer 104, P-type semiconductor transport layer 105, P-type heavily-doped semiconductor transport layer 106, current extending 107, insulator layer 110.

Embodiment illustrated in fig. 4 shows in the method for the utility model, in the uniform resist coating 111 of insulator layer surface Structure successively includes: substrate 101, buffer layer 102, N-type semiconductor transport layer 103, Multiple-quantum along epitaxial growth direction Well layer 104, P-type semiconductor transport layer 105, P-type heavily-doped semiconductor transport layer 106, current extending 107, insulator layer 110 and photoresist layer 111.

Embodiment illustrated in fig. 5 shows in the method for the utility model, is exposed what treated by placing photolithography plate Structure successively includes: substrate 101, buffer layer 102, N-type semiconductor transport layer 103, Multiple-quantum along epitaxial growth direction Well layer 104, P-type semiconductor transport layer 105, P-type heavily-doped semiconductor transport layer 106, current extending 107, insulator layer 110 and photoresist layer 111.

Embodiment illustrated in fig. 6 shows in the method for the utility model, passes on 110 surface of insulator layer and N-type semiconductor Defeated 103 surface evaporation metal of layer and the structure for forming electrode, successively include: substrate 101, buffer layer along epitaxial growth direction 102, N-type semiconductor transport layer 103, multiple quantum well layer 104, P-type semiconductor transport layer 105, P-type heavily-doped semiconductor pass Defeated layer 106, current extending 107, P-type Ohmic electrode 108, N-type Ohmic electrode 109, insulator layer 110 and photoresist layer 111。

Embodiment illustrated in fig. 7 shows that the utility model has the epitaxial wafer of the light emitting diode of homogeneous electrode field distribution Structure successively includes: substrate 101, buffer layer 102, N-type semiconductor transport layer 103, Multiple-quantum along epitaxial growth direction Well layer 104, P-type semiconductor transport layer 105, P-type heavily-doped semiconductor transport layer 106, current extending 107, P-type ohm Electrode 108, N-type Ohmic electrode 109, insulator layer 110.

Fig. 8 and embodiment illustrated in fig. 9 show in the method for the utility model, pass through photoetching and dry etching insulator layer The vertical view of the epitaxial slice structure of the P-type Ohmic electrode of the 110 cylindrical-array shape figures produced and peripheral cylindrical array shape figure Figure, successively includes: substrate 101, buffer layer 102, N-type semiconductor transport layer 103, multiple quantum wells along epitaxial growth direction Layer 104, P-type semiconductor transport layer 105, P-type heavily-doped semiconductor transport layer 106, current extending 107 and insulator layer 110。

Embodiment 1

The LED device with homogeneous electrode field distribution of the present embodiment is as shown in fig. 7, along epitaxial growth Direction successively includes: epitaxial layer (substrate 101, buffer layer 102, N-type semiconductor transport layer 103, multiple quantum well layer 104, P-type Semiconductor transport layer 105, P-type heavily-doped semiconductor transport layer 106, current extending 107), the N-type semiconductor pass 103 part of layer expose, and N-type Ohmic electrode 109 is distributed on exposed N-type semiconductor transport layer 103；Current extending 107 On insulator layer 110 is distributed with, P-type Ohmic electrode 108 is covered on insulator layer 110；Figure on the insulating layer 110 The identical hole of size is distributed in change, with a thickness of 5nm；The P-type Ohmic electrode 108 divides for two parts, lower part be distributed with The matched column patterned electrodes of hole on insulating layer 110, top are whole layer structure, are covered on insulating layer 110, thick Degree is 10nm；

The material of the patterned insulator layer 110 is undoped SiO₂；

The substrate 101 uses Sapphire Substrate, and the material of buffer layer 102 is GaN, with a thickness of 15nm；N-type is partly led The material of body transport layer 103 is GaN, with a thickness of 3 μm；The structure of multiple quantum well layer 104 is the In in 5 periods_0.07Ga_0.93N/GaN Layer, the thickness that wherein quantum builds GaN are set as 8nm, Quantum Well In_0.07Ga_0.93The thickness of N is set as 4nm；P-type semiconductor passes The material of defeated layer 105 is GaN, with a thickness of 50nm；The material of P-type heavily-doped semiconductor transport layer 106 is GaN, with a thickness of 10nm；The material of current extending 107 is ITO, with a thickness of 10nm；The material of P-type Ohmic electrode 108 is Cr/Au；N-type-Europe The material of nurse electrode 109 is Cr/Au, symmetrical cylindrical-array shape figure (such as Fig. 8) centered on patterned insulator layer, insulator layer 108 material is undoped SiO₂；

The above-mentioned LED device epitaxial structure with homogeneous electrode field distribution, preparation method are as follows:

The first step, in MOCVD (i.e. metallo-organic compound chemical gaseous phase deposition) reacting furnace, grown epitaxial layer: in indigo plant Jewel substrate 101 is toasted under 1200 DEG C of progress environment, then epitaxial growth buffer on substrate surface after treatment 102, material GaN, with a thickness of 15nm (so that dislocation defects are filtered and release the stress of lattice mismatch generation It puts)；Next N-type semiconductor transport layer 103, material GaN, with a thickness of 3 μm are successively grown on buffer layer 102；Multiple-quantum Well layer 104, structure are the In in 5 periods_0.07Ga_0.93N/GaN layers, the thickness that wherein quantum builds GaN is set as 8nm, Quantum Well In_0.07Ga_0.93The thickness of N is set as 4nm；P-type semiconductor transport layer 105, material GaN, with a thickness of 50nm；P-type heavy doping Semiconductor transport layer 106, material GaN, with a thickness of 10nm；Current extending 107, material ITO, with a thickness of 10nm；

Second step, it is raw on the epitaxial layer top layer current extending 107 that obtains in the first step in PECVD reacting furnace Long insulator layer 110, with a thickness of 100nm, used material is undoped SiO₂；

Third step makes platform by photoetching and dry etch process on the right side for the insulator layer 110 that second step obtains Rank exposes a part of N-type semiconductor transport layer 103, the N-type semiconductor transport layer 103 exposed, is 90 degree of sector, 5% (fan-shaped radius is 100 μm) of the gross area is accounted for, as shown in Figure 2；

4th step, in the SiO that third step obtains₂Photoetching is carried out on layer 110, that is, retains the rounded portions that a diameter is 50 μm Point, the other parts other than circle are etched away, then again in remaining circle SiO₂It is performed etching on layer, first in circle in etching The center of circle of shape part etches hollow cylinder that a radius is 9.9 μm (until manifest the upper of following current extending 107 Surface), then centered on it, first lap (quantity is 12) is etched, and then etch the second circle hollow cylinder (quantity again It is 25), the equal radius of the hollow cylinder is identical, is uniformly distributed, and the distance between two neighboring cylinder is 200nm (hole Occupied area is the 90% of insulating layer area)；Finally obtain graphical SiO₂Layer；Graphical SiO₂Main view such as Fig. 3 institute of layer Show, top view is as shown in Figure 8 (for Fig. 8 Hole quantity because length is limited, quantity only takes part as signal)；Wherein, absolutely The point of contact (a bit of most outer) of the outer of the outermost hole of edge layer is located at edge (the i.e. insulating layer edge hole of insulating layer The electrode of distribution, the lower electrode and upper layer that make the P-type Ohmic electrode becomes an entirety, so that it is defeated to be conducive to electronics Fortune)；" the edge hole of insulating layer " described in the utility model, it can such as the present embodiment in this way, the hole at edge has been It is whole, be also possible to hole across insulating layer edge (it is beyond insulating layer partially due to insulating layer itself is limited, be only capable of etching Some perforations out, but remaining part can be in the vapor deposition of 108 lower part of P-type Ohmic electrode, according to the outer of insulating layer still Shape keeps round and smooth outer)；

5th step, in the graphical SiO that the 4th step obtains₂Layer 110 and its all current extendings 107 exposed of surrounding On uniformly coat a layer photoresist 111, on photoresist 111 place band just like the figure that hole described in the 4th step is distributed The photolithography plate of change is exposed processing, as shown in Figure 4；

6th step after exposure-processed, removes reticle, it is most upper to be exposed epitaxial layer by decomposing after illumination for photoresist 111 The current extending 107 and insulator SiO of layer₂Layer 110, as shown in Figure 5；

7th step, evaporation metal carries out production P-type Ohmic electrode 108, material in the patterned structures that the 6th step obtains It (is that SiO is filled by vapor deposition first for Cr/Au₂Graphical hole in layer 110, under lower formation P-type Ohmic electrode 108 Portion then proceedes to the top of vapor deposition P-type Ohmic electrode 108, with a thickness of 10nm.Finally obtain the projection of P-type Ohmic electrode 108 Area is identical as insulating layer 110), evaporation metal carries out production N-type Ohmic electrode on 103 surface of N-type semiconductor transport layer 109, material Cr/Au；Device after vapor deposition generates as shown in fig. 6, wherein removing vapor deposition with adhesive tape on remaining photoresist surface On a small amount of metal, then successively using go glue, acetone, ethanol solution remove P-type Ohmic electrode 108 on photoresist；Finally By the N-type Ohmic electrode 109 (circle that the radius of N-type Ohmic electrode 109 is 50 μm, the thickness that are lithographically derived required shape For 10nm), (108 projection of shape of P-type Ohmic electrode and the insulation as shown in Figure 7 of the finally obtained epitaxial slice structure of the utility model Layer 110 is identical, i.e., outer is concordant)；

Thus the LED device with homogeneous electrode field distribution of the utility model is made.

Embodiment 2

The LED device with homogeneous electrode field distribution of the present embodiment is as shown in fig. 7, along epitaxial growth Direction successively includes: epitaxial layer (substrate 101, buffer layer 102, N-type semiconductor transport layer 103, multiple quantum well layer 104, P-type Semiconductor transport layer 105, P-type heavily-doped semiconductor transport layer 106, current extending 107), the N-type semiconductor pass 103 part of layer expose, and N-type Ohmic electrode 109 is distributed on exposed N-type semiconductor transport layer 103；Current extending 107 On insulator layer 110 is distributed with, P-type Ohmic electrode 108 is covered on insulator layer 110；Figure on the insulating layer 110 The identical hole of size is distributed in change, with a thickness of 5nm；The P-type Ohmic electrode 108 divides for two parts, lower part be distributed with The matched column patterned electrodes of hole on insulating layer 110, top are whole layer structure, are covered on insulating layer 110, thick Degree is 15nm；

The material of the patterned insulator layer 110 is undoped Al₂O₃；

The substrate 101 uses Sapphire Substrate, and the material of buffer layer 102 is AlN, with a thickness of 15nm；N-type is partly led The material of body transport layer 103 is Al_0.60Ga_0.40N, with a thickness of 4 μm；The structure of multiple quantum well layer 104 is 5 periods Al_0.53Ga_0.47N/Al_0.44Ga_0.56N layers, wherein quantum builds Al_0.53Ga_0.47The thickness of N is set as 11nm, Quantum Well Al_0.44Ga_0.56The thickness of N is set as 3nm；The material of P-type semiconductor transport layer 105 is Al_0.40Ga_0.60N, with a thickness of 10nm； The material of P-type heavily-doped semiconductor transport layer 106 is GaN, with a thickness of 15nm；The material of current extending 107 is ITO, thickness For 10nm；The material of P-type Ohmic electrode 108 is Ni/Au；The material of N-type-Ohmic electrode 109 is Ni/Au, patterned insulator layer Centered on symmetrical cylindroid array shape figure, the material of insulator layer 108 is undoped Al₂O₃；

The above-mentioned LED device epitaxial structure with homogeneous electrode field distribution, preparation method are as follows:

The first step, in MOCVD (i.e. metallo-organic compound chemical gaseous phase deposition) reacting furnace, grown epitaxial layer: in indigo plant On jewel substrate 101, grown buffer layer 102, material AlN, with a thickness of 15nm；Then N-type semiconductor transport layer is successively grown 103, material Al_0.60Ga_0.40N, with a thickness of 4 μm；Multiple quantum well layer 104, structure are the Al in 5 periods_0.53Ga_0.47N/ Al_0.44Ga_0.56N layers, wherein quantum builds Al_0.53Ga_0.47The thickness of N is set as 11nm, Quantum Well Al_0.44Ga_0.56The thickness of N is arranged For 3nm；P-type semiconductor transport layer 105, material Al_0.40Ga_0.60N, with a thickness of 10nm；P-type heavily-doped semiconductor transport layer 106, material GaN, with a thickness of 15nm；Current extending 107, material ITO, with a thickness of 10nm；

Second step is grown on the epitaxial layer top layer current extending 107 that obtains in the first step in ALD reacting furnace Insulator layer 110, with a thickness of 50nm, used material is undoped Al₂O₃；

Third step makes platform by photoetching and dry etch process on the right side for the insulator layer 110 that second step obtains Rank exposes a part of N-type semiconductor transport layer 103, the N-type semiconductor transport layer 103 exposed, is 90 degree of sector, The 5% of the gross area is accounted for, as shown in Figure 2；

4th step, in the Al that third step obtains₂O₃Photoetching is carried out on layer 110, that is, retains the rounded portions that a diameter is 50 μm Point, the other parts other than circle are etched away, then again in remaining circle Al₂O₃It is performed etching on layer, first in circle in etching The center of circle of shape part etches a hollow ellipse column, and the transverse of cylindroid upper and lower surface is 5 μm, and short axle is 4 μm, then Centered on it, first lap is etched, and then etches the second circle hollow ellipse column again, ellipsoid in the hollow ellipse column Long axis short axle it is all the same, be uniformly distributed, the distance between two neighboring cylinder be 150nm；Finally obtain graphical Al₂O₃Layer； Graphical Al₂O₃The main view of layer is as shown in Figure 3；

5th step, in the graphical Al that the 4th step obtains₂O₃Layer 110 and its all current extendings 107 exposed of surrounding On uniformly coat a layer photoresist 111, on photoresist 111 place band just like the figure that hole described in the 4th step is distributed The photolithography plate of change is exposed processing, as shown in Figure 4；

6th step after exposure-processed, removes reticle, it is most upper to be exposed epitaxial layer by decomposing after illumination for photoresist 111 The current extending 107 and insulator Al of layer₂O₃Layer 110, as shown in Figure 5；

7th step, evaporation metal carries out production P-type Ohmic electrode 108, material in the patterned structures that the 6th step obtains For Ni/Au, evaporation metal carries out production N-type Ohmic electrode 109 on 103 surface of N-type semiconductor transport layer, and material is NiAu；Device after vapor deposition generates a small amount of gold on remaining photoresist surface as shown in fig. 6, wherein removing vapor deposition with adhesive tape Belong to, then successively using go glue, acetone, ethanol solution remove P-type Ohmic electrode 108 on photoresist；It is obtained finally by photoetching To the N-type Ohmic electrode 109 of required shape, the finally obtained epitaxial slice structure of the utility model is as shown in Figure 7；

Thus the LED device with homogeneous electrode field distribution of the utility model is made.

Embodiment 3

Except the material that current extending 107 uses is graphene；Insulator layer 110 first makes a radius by lithography in centre 40 μm of cylindrical cavity then makes a circle cylindrical cavity by lithography at 110 edge of insulator layer, on edge every two cylindrical cavity it Between distance be 200nm, it be 200nm (top view such as Fig. 9) that radius, which be at a distance from 9.9 μm, with centered cylinder hole, other together reality Apply example 1.

Embodiment 4

Except the material that current extending 107 uses is aluminium；It is 35 μm that insulator layer 110, which first makes a radius by lithography in centre, Cylindrical cavity, then make a circle cylindroid hole by lithography at 110 edge of insulator layer, on edge every two cylindroid hole it Between distance be 150nm, the transverse of cylindroid upper and lower surface is 5 μm, and short axle is at a distance from 4 μm, with centered cylinder hole For 200nm, other are the same as embodiment 2.

Figure 10, Figure 11 and Figure 12 are emulated using APSYS, are suitable for example 1 and 3

Curve shown in Figure 10 shows that the field strength between two electrodes of light emitting diode with homogeneous electrode field distribution is bright Aobvious to be less than standard light emitting diode, as the distance of two electrodes is closer, electric field is more uniform, this is because mutually supporting between electric field The effect to disappear.And so on, when electrode edge is divided into many small electrodes, the field strength of electrode edge entirety can reduce.P- Type Ohmic electrode cell-edge reduces, and the hole concentration at the position can be caused to be reduced, and then to the electricity of electrode edge Stream crowding phenomenon plays the role of alleviation, and has obtained better current expansion effect.

Curve shown in Figure 11 shows the light emitting diode with homogeneous electrode field distribution, P-type Ohmic electrode edge Hole concentration be less than the electrode edge of standard light emitting diode, it is that current expansion effect is good that hole concentration, which reduces, and two Distance is nearlyr (width of insulating layer is narrower) between electrode, and hole concentration is lower, and current expansion effect is better.

Curve shown in Figure 12 shows the light emitting diode with homogeneous electrode field distribution, P-type Ohmic electrode bottom Hole concentration at insertion insulating layer reduces (width of insulating layer narrows) with distance between two electrodes and becomes uniformly, thus Improve current crowding.

The above-mentioned LED device with homogeneous electrode field distribution, related raw material can pass through generality Approach obtains, and the operating procedure in preparation method is that those skilled in the art are had.

The utility model unaccomplished matter is well-known technique.

Claims (8)

1. a kind of light emitting diode with homogeneous electrode field distribution, it is characterized in that the diode along epitaxial growth direction according to Secondary includes: substrate, buffer layer, N-type semiconductor transport layer, multiple quantum well layer, P-type semiconductor transport layer, P-type heavy doping half Conductor propagation layer, current extending；The N-type semiconductor transport layer part exposes, on exposed N-type semiconductor transport layer N-type Ohmic electrode is distributed with；Insulator layer is distributed on current extending, P-type Ohmic electrode is covered on insulator layer；Institute Hole is graphically distributed on the insulator layer stated；The P-type Ohmic electrode is divided into two parts, and lower part is distributed with and insulate The matched column patterned electrodes of hole on body layer, top are whole layer structure, are covered on insulator layer；

Graphical distribution specially central symmetry, non-centrosymmetry or the random distribution of hole on the insulator layer are not Regular figure；Hole occupied area is the 50 ~ 99% of insulator layer area；The edge hole of insulator layer, the number of edge hole Amount is the 1 ~ 100% of whole pore quantities；

The figure is round, arc-shaped, annulus, the round and smooth figure of ellipse or edge.

2. as described in claim 1 with the light emitting diode of homogeneous electrode field distribution, it is characterized in that the insulator The shape of hole on layer is round, ellipse, and the spacing between two neighboring hole is 1~2000nm.

3. as described in claim 1 with the light emitting diode of homogeneous electrode field distribution, it is characterized in that the insulator The hole size being graphically distributed on layer is identical.

4. as described in claim 1 with the light emitting diode of homogeneous electrode field distribution, it is characterized in that the P-type Europe The global shape of nurse electrode is circle, and projection of shape is identical as insulator layer, and is covered thereon；Whole radius is 10 μm ~ 150 μm, top entirety stratiform part with a thickness of 1 ~ 1000nm.

5. as described in claim 1 with the light emitting diode of homogeneous electrode field distribution, it is characterized in that described P-type ohm The material of electrode is Ni/Au, Cr/Au, Pt/Au or Ni/Al, with a thickness of 1 ~ 3000nm.

6. as described in claim 1 with the light emitting diode of homogeneous electrode field distribution, it is characterized in that described N-type ohm The material of electrode is Al/Au, Cr/Au or Ti/Al/Ti/Au, and with a thickness of 1 ~ 3000nm, area is N-type semiconductor transport layer The 5% ~ 95% of expose portion area.

7. as described in claim 1 with the light emitting diode of homogeneous electrode field distribution, it is characterized in that the insulator The material of layer is undoped SiO₂、Al₂O₃、Si₃N₄, AlN, LiF, diamond or PMMA, with a thickness of 1 ~ 2999nm.

8. as described in claim 1 with the light emitting diode of homogeneous electrode field distribution, it is characterized in that the N-type half The material of conductor propagation layer is Al_x1In_y1Ga_1-x1-y1N, wherein should ensure that each component coefficient 0≤x1≤1,0≤y1≤1,1 >=1- X1-y1 >=0, with a thickness of 1~5 μm；Whole 1% ~ 20% shared by expose portion area；

The material of the substrate is sapphire, SiC, Si, AlN, GaN or quartz glass, with a thickness of 50nm ~ 10 μm；

The material of the buffer layer is Al_x2In_y2Ga_1-x2-y2N, component x2, y2 and 1-x2-y2 of each element are between 0 in formula And between 1, with a thickness of 10~50 nm；

The material of the multiple quantum well layer is Al_x3In_y3Ga_1-x3-y3N/Al_x4In_y4Ga_1-x4-y4N, the component x3 of each element in formula, Between 0 and 1, quantum builds Al by x4, y3, y4,1-x3-y3 and 1-x4-y4_x3In_y3Ga_1-x3-y3N with a thickness of 5~50 nm, Quantum Well Al_x4In_y4Ga_1-x4-y4N with a thickness of 1~15 nm, and quantum builds Al_x3In_y3Ga_1-x3-y3The forbidden bandwidth of N is greater than amount Sub- trap Al_x4In_y4Ga_1-x4-y4The forbidden bandwidth of N；

The material of the P-type semiconductor transport layer is Al_x5In_y5Ga_1-x5-y5N, component x5, y5 and 1-x5- of each element in formula Y5 is between 0 and 1, with a thickness of 50~500 nm；

The material of the P-type heavily-doped semiconductor transport layer is Al_x7In_y7Ga_1-x7-y7N, wherein should ensure that each component coefficient 0 ≤ x7≤1,0≤y7≤1,1 >=1-x7-y7 >=0, material doped is p-type heavy doping, with a thickness of 10~50nm；

The material of the current extending is ITO, Ni/Au, zinc oxide, graphene, aluminium or metal nanometer line, with a thickness of 10~ 500nm。