CN207800631U - Novel gaN base LED device structure - Google Patents

Abstract

The utility model is related to a kind of novel GaN base LED device structures.The device architecture includes：Conductive substrates；Reflective layer is set in the conductive substrates；Metal electrode layer is set on the reflective layer；Multiple blue light epitaxial layers and multiple GaN ultraviolet lights epitaxial layers, are sequentially arranged at intervals and are set on the metal electrode layer；Wherein, the GaN blue lights epitaxial layer 10 includes the GaN barrier layer 104a and InGaN quantum well layers 104b of period stacked distribution successively, and the GaN ultraviolet lights epitaxial layer 20 includes the Al of period stacked distribution successively_{1‑ y}Ga_yN barrier layers 204a and Al_1‑xGa_xN quantum well layers 204b；First cathode electrode is set on the blue light epitaxial layer；Second cathode electrode is set on the GaN ultraviolet lights epitaxial layer；Anode electrode is set under the conductive substrates.GaN epitaxy piece is transferred to from Sapphire Substrate on good electric, thermal conductivity characteristic substrate material by the utility model, can be promoted the radiating efficiency of device, be extended the service life of device.

Description

Novel GaN base LED device structure

Technical field

The utility model is related to technical field of integrated circuits, more particularly to a kind of novel GaN base LED device structure.

Background technology

LED (LightingEmittingDiode) i.e. light emitting diodes are a kind of semiconducting solid luminescent devices.It is Using solid semiconductor chip as luminescent material, draw by the compound energy for releasing surplus occurs for carrier in the semiconductors Photon transmitting is played, red, yellow, blue, green light is directly sent out.LED is a kind of novel solid state light emitter, with small, hair Light efficiency is high, low energy consumption, long lifespan, without mercury pollution, all solid state, response is rapid, operating voltage is low, all various aspects such as safe and reliable The advantages of.

Using the principle of three primary colours, fluorescent powder is added when LED component encapsulates, the light of random color can be sent out, therefore can To be illuminated as light source using LED.In the prior art, the mode of LED coating fluorescent powders mainly has：Fluorescent powder is far from core Piece, fluorescent powder are evenly distributed on encapsulating material and fluorescent powder is close to the packaged type of chip surface.Wherein fluorescent powder is uniformly distributed It is easy to operate in the packaged type of encapsulating material, but the launching efficiency of the packaged type fluorescent powder is relatively low；Since fluorescent powder is separate The cumbersome of chip and uncontrollable industrialized production also unrealized so far；The packaged type that fluorescent powder is close to chip be by Intermediary's encapsulating material is bonded together with chip, and defect is that the refractive index of intermediary's encapsulating material is relatively low, and the light that chip is sent out is easy It generates total reflection and heat is caused to be assembled, reduce the light extraction efficiency of chip instead and influence the excitation of fluorescent powder (residing for fluorescent powder Excitation temperature it is relatively high).Fluorescent powder is directly coated on the semi-finished product of die bond bonding wire, this can cause the big of fluorescent powder again Amount waste.Therefore, a kind of novel LED how is designed, reducing the coating of fluorescent powder just becomes of crucial importance.

Utility model content

Therefore, to solve technological deficiency and deficiency of the existing technology, the utility model proposes a kind of novel GaN bases LED device structure.

Specifically, a kind of novel GaN base LED device structure that the utility model one embodiment proposes, including：

Conductive substrates 410；

Reflective layer 40 is set in the conductive substrates 410；

Metal electrode layer 407 is set on the reflective layer 40；

Multiple GaN blue lights epitaxial layers 10 and multiple GaN ultraviolet lights epitaxial layers 20, are sequentially arranged at intervals and are set to the metal On electrode layer；Wherein, the GaN blue lights epitaxial layer 10 includes GaN barrier layer 104a and the InGaN amounts of period stacked distribution successively Sub- well layer 104b, the GaN ultraviolet lights epitaxial layer 20 include the Al of period stacked distribution successively_1-yGa_yN barrier layers 204a and Al_1-xGa_xN quantum well layers 204b；

First cathode electrode 51 is set on the GaN blue lights epitaxial layer 10；

Second cathode electrode 52 is set on the GaN ultraviolet lights epitaxial layer 20；

Anode electrode 53 is set under the conductive substrates 410.

The utility model has the advantages that：

1) by the material preparation of multicolour in same LED component, single LED chip can generate a variety of the utility model The light of color, therefore greatly reduce the coating of fluorescent powder；

2) for the utility model by the material preparation of multicolour in same LED component, device integration is high, reduces LED Production cost；

3) the utility model is shone by preparing the LED of the electrode control different color material of different color material respectively, The luminescent color of LED can be adjusted more flexiblely；

4) the utility model uses substrate slice bonding to be combined GaN epitaxy piece with laser lift-off technique in the fabrication process It is transferred to from Sapphire Substrate on good electric, thermal conductivity characteristic substrate material, the radiating efficiency of device can be promoted, extended The service life of device；

5) the utility model proposes device electrode above and below vertical distribution, thoroughly solve formal dress, inverted structure LED chip In because electrode plane distribution, electric current laterally injection caused by such as radiate, even, reliability of current distribution is uneven etc. is a series of to ask Topic.

Through the following detailed description with reference to the accompanying drawings, the other aspects and feature of the utility model become apparent.But it answers When knowing, which is only the purpose design explained, not as the restriction of the scope of the utility model, this is because its It should refer to appended claims.It should also be noted that unless otherwise noted, it is not necessary to which scale attached drawing, they are only Try hard to conceptually illustrate structure and flow described herein.

Description of the drawings

Below in conjunction with attached drawing, specific embodiment of the present utility model is described in detail.

Fig. 1 is a kind of novel GaN base LED device structure schematic diagram that the utility model embodiment provides；

Fig. 2 is a kind of growth schematic diagram for GaN blue lights epitaxial layer that the utility model embodiment provides；

Fig. 3 is a kind of growth schematic diagram for first active layer that the utility model embodiment provides；

A kind of ultraviolet light wick slot that Fig. 4 provides for the utility model embodiment prepares schematic diagram；

Fig. 5 is a kind of growth schematic diagram for GaN ultraviolet lights epitaxial layer that the utility model embodiment provides；

Fig. 6 is a kind of growth schematic diagram for second active layer that the utility model embodiment provides；

A kind of conductive substrates that Fig. 7 provides for the utility model embodiment prepare schematic diagram；

Fig. 8 is a kind of electrode fabrication schematic top plan view that the utility model embodiment provides；

Fig. 9 is a kind of electrode fabrication diagrammatic cross-section that the utility model embodiment provides.

Specific implementation mode

To keep the above objects, features, and advantages of the utility model more obvious and easy to understand, below in conjunction with the accompanying drawings to this The specific implementation mode of utility model is described in detail.

Embodiment one

Fig. 1 is referred to, Fig. 1 is a kind of novel GaN base LED device structure schematic diagram that the utility model embodiment provides. The device architecture includes：

Conductive substrates 410；

Reflective layer 40 is set in the conductive substrates 410；

Metal electrode layer 407 is set on the reflective layer 40；

Multiple GaN blue lights epitaxial layers 10 and multiple GaN ultraviolet lights epitaxial layers 20, are sequentially arranged at intervals and are set to the metal On electrode layer；

First cathode electrode 51 is set on the GaN blue lights epitaxial layer 10；

Second cathode electrode 52 is set on the GaN ultraviolet lights epitaxial layer 20；

Anode electrode 53 is set under the conductive substrates 410.

Wherein, the conductive substrates 410 are doping Si pieces, aluminium sheet or copper sheet.

Wherein, the GaN blue lights epitaxial layer 10 includes the first GaN buffer layers 101, the first GaN stabilized zones 102, the first N-shaped GaN layer 103, the first active layer 104, the first barrier layers AlGaN 105 and the first p-type GaN layer 106.

Wherein, first active layer 104 includes GaN barrier layer 104a and the InGaN quantum of period stacked distribution successively Well layer 104b.

Wherein, the stacking periods of the GaN barrier layers 104a and InGaN quantum well layer 104b are 8~30, the InGaN In contents in quantum well layer 104b are 10~20%.

Wherein, the GaN ultraviolet lights epitaxial layer 20 includes the 2nd GaN buffer layers 201, the 2nd GaN stabilized zones 202, the 2nd n Type GaN layer 203, the second active layer 204, the 2nd barrier layers AlGaN 205, the second p-type GaN layer 206.

Wherein, second active layer 204 includes：The Al of period stacked distribution successively_1-yGa_yN barrier layers 204a and Al_{1- x}Ga_xN quantum well layers 204b.

Wherein, the Al_1-yGa_yThe N barrier layers 204a and Al_1-xGa_xThe stacking periods of N quantum well layers 204b be 8~ 30, the Al_1-xGa_xAl content in N quantum well layers 204b is 10~50%.

Further, device further includes separation layer 12, is set to the surrounding of the GaN ultraviolet lights epitaxial layer 20.

Wherein, the material of the separation layer 12 is SiO₂。

The present embodiment generates the light of multiple color by being arranged the material of multicolour in same LED component, can be with Solving LED packagings coating fluorescent powder in the prior art leads to the defect that LED component luminous efficiency is low, integrated level is low.

Embodiment two

Fig. 2~Fig. 9 is referred to, Fig. 2 is a kind of growth signal for GaN blue lights epitaxial layer that the utility model embodiment provides Figure；Fig. 3 is a kind of growth schematic diagram for first active layer that the utility model embodiment provides；Fig. 4 is implemented for the utility model A kind of ultraviolet light wick slot that example provides prepares schematic diagram；Fig. 5 is a kind of GaN ultraviolet lights that the utility model embodiment provides The growth schematic diagram of epitaxial layer；Fig. 6 is a kind of growth schematic diagram for second active layer that the utility model embodiment provides；Fig. 7 A kind of conductive substrates provided for the utility model embodiment prepare schematic diagram；Fig. 8 is what the utility model embodiment provided A kind of electrode fabrication schematic top plan view；Fig. 9 is a kind of electrode fabrication diagrammatic cross-section that the utility model embodiment provides, this reality To in more detail the technological process of the utility model be introduced by applying example.This method includes：

The growth of S10, GaN blue light epitaxial layer, as shown in Figures 2 and 3

S101, Sapphire Substrate 11 is chosen, wherein sapphire crystal face is (0001), the growth regulation in Sapphire Substrate 11 The thickness of one GaN buffer layers 101, the first GaN buffer layers 101 is 3000~5000 nanometers, and growth temperature is 400~600 DEG C；

Preferably, the thickness of the first GaN buffer layers 101 is 4000 nanometers；

Preferably, the growth temperature of the first GaN buffer layers 101 is 500 DEG C.

S102,900~1050 DEG C are raised the temperature to, the one GaN stabilized zones of growth regulation on the first GaN buffer layers 101 102, the thickness of the first GaN stabilized zones 102 is 500~1500 nanometers；

Preferably, the thickness of the first GaN stabilized zones 102 is 1000 nanometers；

Preferably, the growth temperature of the first GaN stabilized zones 102 is 1000 DEG C.

Temperature-resistant, one n-type GaN layer 103 of growth regulation on the first GaN stabilized zones 102 in S103, holding S102, the The thickness of one n-type GaN layer 103 is 200~1000 nanometers, impurity Si, doping concentration 1x10¹⁸~5x10¹⁹cm^-3；

Preferably, the growth temperature of the first n-type GaN layer 103 is 1000 DEG C；

Preferably, the thickness of the first n-type GaN layer 103 is 400 nanometers；

Preferably, the doping concentration of the first n-type GaN layer 103 is 1x10¹⁹cm^-3。

S104, one multiple quantum well layer 104 of growth regulation in the first n-type GaN layer 103, the first multiple quantum well layer 104 are InGaN/GaN multi-quantum pit structures.Specifically, InGaN/GaN multi-quantum pit structures are InGaN quantum well layer 104b and GaN gesture The period is laminated to be formed barrier layer 104a successively, and stacking periods are 8~30.The growth temperature of InGaN quantum well layers 104b be 650~ 750 DEG C, thickness is 1.5~3.5 nanometers, and the content that wherein content of In is about 10~20%, In is fixed according to optical wavelength, and content is got over High optical wavelength is longer.The growth temperature of GaN barrier layers 104a is 750~850 DEG C, and thickness is 5~10 nanometers；

Preferably, the growth temperature of InGaN quantum well layers 104b is 750 DEG C；

Preferably, the thickness of InGaN quantum well layers 104b is 2.8 nanometers；

Preferably, the growth temperature of GaN barrier layers 104a is 850 DEG C；

Preferably, the thickness of GaN barrier layers 104a is 5 nanometers；

Preferably, the stacking periods of InGaN quantum well layers 104b and GaN barrier layer 104a are 20.

S105,850~950 DEG C are raised the temperature to, p-type the first AlGaN blockings is grown on the first multiple quantum well layer 104 The thickness of layer 105, the first barrier layers AlGaN 105 is 10~40 nanometers；

Preferably, the growth temperature on the first barrier layers AlGaN 105 is 900 DEG C；

Preferably, the growth temperature on the first barrier layers AlGaN 105 is 20 nanometers.

S106, one p-type GaN layer 106 of growth regulation on the first barrier layers AlGaN 105 are used, the first p-type GaN as contact The thickness of layer 106 is 100~300 nanometers；

Preferably, the growth temperature of the first p-type GaN layer 106 is 900 DEG C；

Preferably, the thickness of the first p-type GaN layer 106 is 200 nanometers.

S11, ultraviolet light wick slot is made in the devices, as shown in figure 4, ultraviolet light wick slot is in GaN blue light epitaxial layers In spaced groove, quantity determines according to demand, and Fig. 4 is described so that the quantity of ultraviolet light wick slot is 3 as an example：

S111, using pecvd process in 106 surface deposition layer of oxide layer (i.e. SiO of the first p-type GaN₂Layer), thickness is 300~800 nanometers, preferably SiO₂The thickness of layer is 500 nanometers；

S112, using wet-etching technology in SiO₂A rectangular window, the length of rectangular window and wide difference are etched on layer More than 50 microns, it is less than 300 microns, it is preferable that the length and width of rectangular window are 100 microns；

S113, SiO is etched using dry etch process₂Material under rectangular window etches into always Sapphire Substrate, shape At ultraviolet light wick slot；

S114, the SiO for removing device surface₂Layer；

S115, one layer of SiO is deposited again in entire device upper surface₂Layer, thickness are 20~100 nanometers, preferably SiO₂Layer Thickness be 50 nanometers；

S116, dry etch process etched features surface SiO is utilized₂Layer forms separation layer in ultraviolet light wick slot surrounding 12。

The growth of S12, GaN ultraviolet light epitaxial layer, as shown in Figure 5 and Figure 6；

S121, the two GaN buffer layers 201 of growth regulation in ultraviolet light wick slot, the thickness of the 2nd GaN buffer layers 201 are 3000~5000 nanometers, growth temperature is 400~600 DEG C；

Preferably, the thickness of the 2nd GaN buffer layers 301 is 4000 nanometers；

Preferably, the temperature of the 2nd GaN buffer layers 301 is 500 DEG C.

S122,900-1050 DEG C is raised the temperature to, the two GaN stabilized zones 202 of growth regulation on the 2nd GaN buffer layers 201, The thickness of 2nd GaN stabilized zones 202 is 500~1500 nanometers；

Preferably, the thickness of the 2nd GaN stabilized zones 202 is 1000 nanometers；

Preferably, the growth temperature of the 2nd GaN stabilized zones 202 is 1000 DEG C.

Temperature-resistant, two n-type GaN layer 203 of growth regulation on the 2nd GaN stabilized zones 202 in S123, holding S122, the The thickness of two n-type GaN layers 203 is 200~1000 nanometers, impurity Si, doping concentration 1x10¹⁸~5x10¹⁹cm^-3；

Preferably, the growth temperature of the second n-type GaN layer 203 is 1000 DEG C；

Preferably, the thickness of the second n-type GaN layer 203 is 400 nanometers；

Preferably, the doping concentration of the second n-type GaN layer 203 is 1x10¹⁹cm^-3。

S124, two active layer 204 of growth regulation in the second n-type GaN layer 203, the second active layer 204 are Al_1-xGa_xN/ Al_1-yGa_yN multi-quantum pit structures.Specifically, Al_1-xGa_xN/Al_1-yGa_yN multi-quantum pit structures are Al_1-xGa_xN quantum well layers 204b and Al_1-yGa_yThe period is laminated to be formed N barrier layers 204a successively, and stacking periods are 8~30.Al_1-xGa_xN quantum well layers 204b Growth temperature be 850~950 DEG C, thickness is 1.5~3.5 nanometers, and the wherein content of Al is about 10~50%, Al content according to Fixed according to optical wavelength, content is higher, and optical wavelength is shorter.Al_1-yGa_yThe growth temperature of N potential barriers 204a is 750~900 DEG C, and thickness is equal It is 5~10 nanometers；

Preferably, Al_1-xGa_xThe growth temperature of N quantum well layers 204b is 900 DEG C；

Preferably, Al_1-xGa_xThe thickness of N quantum well layers 204b is 2.8 nanometers；

Preferably, Al_1-yGa_yThe growth temperature of N barrier layers 204a is 850 DEG C；

Preferably, Al_1-yGa_yThe thickness of N barrier layers 204a is 5 nanometers；

Preferably, Al_1-xGa_xN quantum well layers 204b and Al_1-yGa_yThe stacking periods of N barrier layers 204a are 20.

S125,850~950 DEG C are raised the temperature to, the 2nd barrier layers AlGaN of p-type is grown on the second active layer 204 205, the thickness on the 2nd barrier layers AlGaN 205 is 10~40 nanometers；

Preferably, the growth temperature on the 2nd barrier layers AlGaN 205 is 900 DEG C；

Preferably, the growth temperature on the 2nd barrier layers AlGaN 205 is 20 nanometers；

Preferably, the component of the Al on the 2nd barrier layers AlGaN 205 is more than 70%.

S126, two p-type GaN layer 206 of growth regulation on the 2nd barrier layers AlGaN 205 are used, the second p-type GaN as contact The thickness of layer 206 is 100~300 nanometers；

Preferably, the growth temperature of the second p-type GaN layer 206 is 900 DEG C；

Preferably, the thickness of the second p-type GaN layer 206 is 200 nanometers.

S13, bonding, electrode fabrication, as shown in Figure 7, Figure 8 and Figure 9；

S131, in device surface, i.e., on the first p-type GaN layer 106 and 206 surface of the second p-type GaN layer using sputtering or The technique of evaporation prepares the alloy-layer of layer of Ni metal layer or Au metal layers or Ni/Au and other metals, forms metal The thickness of electrode layer 407, metal electrode layer 407 is 100~1000nm；

S132, on 407 surface of metal electrode layer, using the technique of sputtering or evaporation prepare layer of Ni metal layer or Pb metal layers or the good metal or metal alloy of the giving out light property such as Ni/Pb metal layers or Al metal layers form the first reflective layer 408, the thickness of the first reflective layer 408 is 300~1500nm；

S133, choose a heavy doping Si piece either aluminium sheet or copper sheet conductive substrates 410 using sputtering or evaporator man Skill prepares the second reflective layer 409 in conductive substrates 410, and the preparation process of the second reflective layer 409 is with reference in step S182 first The preparation process of reflective layer 408,409 thickness of the second reflective layer are 500~2500nm；

S134, the first reflective layer 408 prepared in S182, S183 and the second reflective layer 409 are close together, 300 It in~500 DEG C of environment, places 15~120 minutes, realizes the first reflective layer 408 and the bonding of the second reflective layer 409, formed reflective Layer 40；

Optionally, conductive substrates can be by forming in reflective layer electroplating surface metal Cu, and this method can be reduced effectively Chip warpage, stress caused by high temperature in bonding technology increase reliability.

S135, Sapphire Substrate 11 is removed with excimer laser, GaN buffer layers is exposed, i.e., are delayed the first GaN It rushes layer 101 and the 2nd GaN buffer layers 201 is exposed；

S136, photoetching process progress roughing in surface is utilized on exposed GaN buffer layers；

Surface roughening techniques are the total reflections for overcoming light from optically denser medium to optically thinner medium, improve LED luminous efficiencies A key technology.For the LED of positive light extraction, since p-type GaN is resistive formation, and than relatively thin, roughing in surface will likely be destroyed Active layer, and it is more difficult to make prepared by p-type Ohmic contact, therefore, using laser lift-off, it is thick then to carry out the surfaces N-shaped GaN Change, can preferably solve the above problems.

S137, cathode electrode is prepared on coarse GaN buffer layers, specially prepares first in the first GaN buffer layers 101 Cathode electrode 51 prepares the second cathode electrode 52 in the 2nd GaN buffer layers 201；

S138, in conductive substrates 410 using sputtering or evaporation technique prepare one layer of metal Al or Ni or The metal of other good conductivities forms anode electrode 53 after etching.

The LED that the present embodiment controls different color material by preparing the electrode of different color material respectively shines, can be with The luminescent color of LED is adjusted more flexiblely.

In conclusion specific case used herein is to original of the utility model based on novel GaN base LED device structure Reason and embodiment are expounded, and the explanation of above example is only intended to methods and its core that help understands the utility model Thought is thought；Meanwhile those of ordinary skill in the art in specific implementation mode and are answered according to the thought of the utility model With there will be changes in range, in conclusion the content of the present specification should not be construed as a limitation of the present invention, this reality It should be subject to the attached claims with novel protection domain.

Claims (1)

1. a kind of novel GaN base LED device structure, which is characterized in that including：

Conductive substrates (410)；

Reflective layer (40) is set in the conductive substrates (410)；

Metal electrode layer (407) is set on the reflective layer (40)；

Multiple GaN blue lights epitaxial layers (10) and multiple GaN ultraviolet lights epitaxial layers (20), are sequentially arranged at intervals and are set to the metal On electrode layer；Wherein, the GaN blue lights epitaxial layer (10) include period stacked distribution successively GaN barrier layers (104a) and InGaN quantum well layers (104b), the GaN ultraviolet lights epitaxial layer (20) include the Al of period stacked distribution successively_1-yGa_yN potential barriers Layer (204a) and Al_1-xGa_xN quantum well layers (204b)；

First cathode electrode (51) is set on the GaN blue lights epitaxial layer (10)；

Second cathode electrode (52) is set on the GaN ultraviolet lights epitaxial layer (20)；

Anode electrode (53) is set under the conductive substrates (410).