CN100461467C - Light emitting diode - Google Patents

Light emitting diode Download PDF

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Publication number
CN100461467C
CN100461467C CNB2003801008960A CN200380100896A CN100461467C CN 100461467 C CN100461467 C CN 100461467C CN B2003801008960 A CNB2003801008960 A CN B2003801008960A CN 200380100896 A CN200380100896 A CN 200380100896A CN 100461467 C CN100461467 C CN 100461467C
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light
electric current
zone
connecting portion
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CN1703784A (en
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坂本贵彦
楠濑健
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Nichia Chemical Industries Ltd
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Nichia Chemical Industries Ltd
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Abstract

A long-life light emitting diode for further making uniform light emission without an excessive current concentration and improving a light pick-up efficiency. The light emitting diode comprises, when viewed from an electrode-disposed surface side, an n-side electrode consisting of an n-side connection unit (9-1) to be connected with a conductive member and an n-side stretching unit (9-2) stretching in a longitudinal direction from the specified part of an n-side connection unit, and a p-side pad unit consisting of at least a p-side connection unit (10b-1) to be connected with a conductive member, and is further provided with an n-side connection area in which an n-side connection unit is disposed in the vicinity of one end thereof in a longitudinal direction, a p-side connection area in which a p-side connection unit is disposed in the vicinity of the other end thereof in a longitudinal direction, and an intermediate area positioned therebetween, wherein the n-side stretching unit is located in the intermediate area and stretches to face a p-side current diffusion unit in the intermediate area.

Description

Light-emitting diode
Technical field
The present invention relates to a kind ofly in layer structure, comprise nitride-based semiconductor (In XAl YGa 1-X-YN, 0≤X, 0≤Y, X+Y≤1) light-emitting diode, particularly, the 1st, relate to the light-emitting diode that makes luminenscence homogenization and improved the life-span, the 2nd, relate to and improved the light-emitting diode that takes out to the light of inspection surface side.
Background technology
Light-emitting diode for comprise nitride-based semiconductor in layer structure is widely used in the various fields such as panchromatic light-emitting diode display, traffic lights, backlight as the pure green emitting LED of high brightness, blue-light-emitting LED.
These LED are generally the structure that has stacked gradually n type nitride semiconductor layer, active layer, p type nitride semiconductor layer on substrates such as sapphire.In addition, on p type nitride semiconductor layer, dispose the p lateral electrode, on n type nitride semiconductor layer, dispose the n lateral electrode.For example, when p lateral electrode and n lateral electrode being arranged on the one side side, adopt following structure: configuration p lateral electrode on p type nitride semiconductor layer, and utilize etching etc. to remove the part of p type nitride semiconductor layer, active layer and n type nitride semiconductor layer, on the n type nitride semiconductor layer that exposes, disposed the n lateral electrode.In addition, flow through each electrode, connect electroconductive components such as the wire that constitutes by gold thread etc. and various scolding tin in order to make electric current.Electrode configuration as such LED proposes to have various schemes (for example patent documentation 1).In addition, take out, propose to have various schemes (for example patent documentation 2) as the structure of LED in order to improve light.
But,,, utilize light-emitting zone and remarkable on a large scale equably though the p lateral electrode is provided with p side electric current diffusion part in LED as the 1st problem.On the contrary,, perhaps strengthen each electrode, then produce the zone of electric current concentrations if make each electrode deformation in order to utilize light-emitting zone on a large scale.Consequently, existence always can not get luminous efficiently, and the life-span also shortens such problem.
As the 2nd problem, if, then exist resistance to become the big such problem of element characteristic deterioration that makes that waits because of LED for the light that improves LED takes out and at the position that originally is used as light-emitting zone peristome is set.
Patent documentation 1 TOHKEMY 2000-164930 communique
Patent documentation 2 W001/41219
Summary of the invention
The present invention makes in order to address this problem.The 1st purpose of the present invention is to provide that to be by shape, the allocation position that makes electrode that specific structure makes luminous more even, and does not make the electric current concentrations, and then improves the taking-up efficient and the long light-emitting diode of life-span of light.In addition, the 2nd purpose of the present invention is that by utilizing originally be not that the light that improve to the sightingpiston side in the zone of light-emitting zone takes out.
Light-emitting diode of the present invention, at least comprise n type nitride semiconductor layer (4) that has disposed the n lateral electrode and the p type nitride semiconductor layer (8) that has disposed the p lateral electrode, and disposing said n lateral electrode and above-mentioned p lateral electrode with the one side side, above-mentioned p lateral electrode comprises and being arranged on the above-mentioned p type nitride semiconductor layer and the p side electric current diffusion part (10a) of the electric current that diffusion is provided and be arranged at least a portion of p side electric current diffusion part and the p side welding disk (10b) of electric current is provided to above-mentioned p side electric current diffusion part, from electrode configuration plane side, be to have long side direction and perpendicular to the Width of above-mentioned long side direction, and the oblong-shaped that above-mentioned long side direction is long, it is characterized in that, above-mentioned light-emitting diode, from electrode configuration plane side, the said n lateral electrode comprises the n side connecting portion (9-1) that should connect electroconductive component and from the n side extension (9-2) that a predetermined part begins on long side direction and the shape that is in line extends of said n side connecting portion; And above-mentioned p side welding disk comprises the p side connecting portion (10b-1) that should connect electroconductive component at least; Also comprise near the n side connecting portion zone that has disposed said n side connecting portion the end of long side direction, near p side connecting portion zone and the therebetween zone line that the other end of long side direction, has disposed above-mentioned p side connecting portion, said n side extending part is in above-mentioned zone line, at above-mentioned zone line, said n side extension extends mutually opposed to each other with above-mentioned p side electric current diffusion part; And the end of said n side extension (9-2) is not configured in above-mentioned p side connecting portion zone, and is configured in above-mentioned zone line; At the long side direction of above-mentioned electrode configuration plane side, said n side extension (9-2) and above-mentioned p side electric current diffusion part (10a) are parallel to each other; Said n side connecting portion (9-1) is configured on the OBL diagonal.
In light-emitting diode of the present invention, above-mentioned p side welding disk also comprises from the predetermined part of above-mentioned p side connecting portion and begins the p side extension (10b-2) that extends at long side direction, at above-mentioned zone line, above-mentioned p side extension (10b-2) extends mutually opposed to each other with said n side extension, and above-mentioned p side extension (10b-2) is positioned at the side away from n side extension of above-mentioned p side electric current diffusion part.
In light-emitting diode of the present invention, the transmission of above-mentioned p side electric current diffusion part is from least a portion of the light of above-mentioned light-emitting diode.
In light-emitting diode of the present invention, above-mentioned p side electric current diffusion part has the peristome (10aa) of a plurality of transmissions from least a portion of the light of light-emitting diode.
In light-emitting diode of the present invention, above-mentioned light-emitting diode from electrode configuration plane side, has pit on the predetermined part of the above-mentioned p side electric current diffusion part of zone line, and said n side extension extends along this pit,
The said n side extension of zone line and be positioned at distance D away from the end of the above-mentioned p side electric current diffusion part of a side of n side extension, little than the Width of the above-mentioned p side electric current diffusion part in p side connecting portion zone apart from E.
In light-emitting diode of the present invention, the distance A of opposed said n side extension and above-mentioned p side electric current diffusion part is than the front end of said n side extension and little apart from B near the above-mentioned p side electric current diffusion part that is positioned at p side connecting portion area side of this front end.
In light-emitting diode of the present invention, said n side connecting portion and above-mentioned p side electric current diffusion part are put toward each other at long side direction, and the distance A of opposed said n side extension and the above-mentioned p side electric current diffusion part distance C than near said n side connecting portion of putting toward each other at long side direction the front end of p side extension (10b-2) and above-mentioned p side electric current diffusion part at least is little.
In light-emitting diode of the present invention, said n side connecting portion and above-mentioned p side connecting portion are put toward each other at long side direction.
In light-emitting diode of the present invention, on long side direction, at least a portion of above-mentioned p side electric current diffusion part is between said n side extension and above-mentioned p side welding disk.
In light-emitting diode of the present invention, said n type nitride semiconductor layer (4) is from the electrode forming surface side, comprise the 1st zone that is provided with semiconductor multilayer structure with above-mentioned p lateral electrode with the 2nd different zone of above-mentioned the 1st zone, be provided with a plurality of concavo-convex in above-mentioned the 2nd zone, above-mentioned a plurality of concavo-convex top levels, on above-mentioned light-emitting diode cross section view, be positioned at p type nitride semiconductor layer (8) side of active layer, above-mentioned a plurality of concavo-convex bottom water plane, on above-mentioned light-emitting diode cross section view, be positioned at n type nitride semiconductor layer (4) side of active layer.
In light-emitting diode of the present invention, said n side extension (9-2) only extends opposed to each other at a side and above-mentioned p side electric current diffusion part (10a) and forms.
In light-emitting diode of the present invention, said n side extension (9-2) forms in the long side direction extension along OBL ora terminalis.
In light-emitting diode of the present invention, above-mentioned p side extension (10b-2) extends and to form from above-mentioned p side connecting portion (10b-1) the shape ground that is in line.In addition, above-mentioned p side connecting portion (10b-1) is configured on the OBL diagonal.
Effect of the present invention is as follows
According to light-emitting diode of the present invention, can make luminous more evenly, and do not make the electric current concentrations, and can improve the taking-up efficient of light, life-saving.
In addition, the taking-up efficient of light can be carried out the control of light directive property effectively, can further improve the performance of light-emitting component.
Description of drawings
Fig. 1 is the plane graph of the LED of the embodiment of the present invention 1 seen from electrode configuration plane side.
Fig. 2 is the profile of the II-II line of Fig. 1.
Fig. 3 is the plane graph of the LED of the embodiment of the present invention 2 seen from electrode configuration plane side.
Fig. 4 is the profile of the IV-IV line of Fig. 3.
Fig. 5 is the plane graph of the LED of the embodiment of the present invention 3 seen from electrode configuration plane side.
Fig. 6 is the plane graph of other form of the LED of expression embodiment of the present invention 3.
Fig. 7 is the plane graph of the LED of the embodiment of the present invention 4 seen from electrode configuration plane side.
Fig. 8 is the plane graph of other form of the LED of expression embodiment of the present invention 4.
Fig. 9 is the profile of the LED of expression embodiment of the present invention 5.
Figure 10 is the plane graph of the LED of the embodiment of the present invention 6 seen from electrode configuration plane side.
Figure 11 is the fragmentary cross-sectional view of the XI-XI line of Figure 10.
Figure 12 is the plane graph of the LED of the embodiment of the present invention 7 seen from electrode configuration plane side.
Figure 13 is the plane graph of the LED of the embodiment of the present invention 8 seen from electrode configuration plane side.
Embodiment
Each semiconductor layer of the light-emitting diode that the present invention relates to as formation (below, be called " LED (LightEmitting Diode) ") can use various nitride-based semiconductors.Specifically, preferably use, on substrate, formed a plurality of In by organic metal vapor growth method (MOCVD), hydride vapor growth method (HVPE) etc. XAl YGa 1-X-YN semi-conductive light-emitting diodes such as (0≤X, 0≤Y, X+Y≤1).In addition, as this layer structure, can list homogeneity structure, heterojunction structure or double-heterostructure with MIS knot, PIN knot or PN junction.In addition, can make each layer be the superlattice structure, perhaps on the film that produces quantum effect, form the single quantum well structure and the multiple quantum trap structure of active layer.
In general, LED each semiconductor layer of growing on specific substrate forms, at this moment, use the sapphire insulation substrate as substrate, when finally not removing this insulating properties substrate, usually, any one of p lateral electrode and n lateral electrode all is formed on the same one side side on the semiconductor layer.At this moment, the installation that can face up is about to semiconductor layer side and is configured in the observation side, takes out the light that sends from semiconductor layer side, and the installation that also can face down is about to substrate side and is configured in the observation side, takes out the light that sends from substrate side.Certainly, after finally having removed substrate, also can face up and install or the installation that faces down.In addition, substrate is not limited to sapphire, can also use material known such as spinelle, SiC, GaN, GaAs.
Below, embodiments of the present invention are described with reference to the accompanying drawings.But the execution mode of the following stated is just enumerated and is used for the light-emitting diode that technological thought of the present invention is specific, and light-emitting diode of the present invention is not limited to following diode.
In addition, this specification is defined in the described parts of claims the parts of execution mode anything but.Particularly, the size of the structure member of being put down in writing in the execution mode, material, shape, their relative configuration etc. are except specially appointed record, and scope of the present invention has more than and is limited to this, only simple illustrative examples.The size of each parts shown in the drawings and position relation etc. in order to offer some clarification on, are exaggerated.And then, in the following description,, represent the parts of same or homogeneity, suitably detailed for same title, symbol.In addition, constitute each key element of the present invention, can adopt with same parts to constitute a plurality of key elements,, on the contrary, also can share a functions of components and realize with a plurality of parts with a double form of doing a plurality of key elements of parts.
(execution mode 1)
LED according to Fig. 1,2 explanation execution modes 1.The LED that present embodiment relates to as shown in the figure, is at the LED that has disposed p lateral electrode and n lateral electrode with the one side side.Fig. 1 is the skeleton diagram of the LED of the present embodiment seen from electrode configuration plane side.In addition, Fig. 2 is the constructed profile of layer structure of the LED of expression present embodiment, the profile of the II-II line of presentation graphs 1.
As shown in Figure 1, the LED that embodiment of the present invention 1 relates to from electrode configuration plane side, is the long oblong-shaped of predetermined direction.In the present embodiment, be that an opposite side is than another rectangle to the length of side.And, near an end of rectangular long side direction, dispose n side connecting portion 9-1, near the other end of rectangular long side direction, relatively dispose p side connecting portion 10b-1.
As shown in Figure 2, the LED of present embodiment, for example, have on Sapphire Substrate 1, stacked gradually GaN resilient coating 2, non-impurity-doped GaN layer 3, become n type contact layer mix silicon GaN layer 4, become n type coating layer mix silicon GaN layer 5, become active layer InGaN layer 6, become mixing magnesium AlGaN layer 7, becoming the layer structure of mixing magnesium GaN layer 8 of p type contact layer of p type coating layer.And then, utilize etching etc. partly to remove to mix magnesium GaN layer 8, mix magnesium AlGaN layer 7, InGaN layer 6, mix silicon GaN layer 5, mix silicon GaN layer 4, and formed n lateral electrode 9 on the face mixing exposing of silicon GaN layer 4, on roughly whole of the upper surface of mixing magnesium GaN layer 8, be provided with p lateral electrode 10.In addition, in the present embodiment, the n type nitride semiconductor layer that claims are put down in writing is mixed silicon GaN layer 4 corresponding to what become n type contact layer, and p type nitride semiconductor layer is mixed magnesium GaN layer 8 corresponding to what become p type contact layer.
In the present embodiment, n lateral electrode 9 is to begin to stack gradually W, Al, W, Pt, Au from n contact layer side and form the n lateral electrode, also can use other material known and lit-par-lit structure.In addition, by connecting the n side connecting portion 9-1 wiry that finally becomes electroconductive component and constituting at the n side extension 9-2 that long side direction extends from its part beginning.
P lateral electrode 10 with go up the p type contact layer that forms in the zone (roughly whole face) of the ratio broad of p type contact layer and carry out ohmic contact, and comprise the p side electric current diffusion part 10a of the electric current that diffusion provides from described p side welding disk next and the p side welding disk 10b that forms in the predetermined part of p side electric current diffusion part.In the present embodiment, begin to stack gradually Ni, Au, Au and form the p lateral electrode, but also can use other material known and lit-par-lit structure from p type contact layer.At this moment, be p side electric current diffusion part by transmission from relatively Ni, the Au of thin film-stack of at least a portion of the light of LED (below, be also referred to as " light transmission ") degree, be p side welding disk by the Au of the thicker film-stack that does not have light transmission.In addition, p side welding disk 10b constitutes to the p side extension 10b-2 of the n side connecting portion 9-1 extension relative with long side direction with beginning from its part by connecting the p side connecting portion 10b-1 wiry that finally becomes electroconductive component.
In addition, as shown in Figure 1, the LED of embodiment of the present invention 1 is divided into the n side connecting portion zone that comprises n side connecting portion 9-1, p side connecting portion zone and the therebetween zone line that comprises p side connecting portion 10b-1.At this, establish each zone for LED being carried out the zone cut apart with the direction of long side direction approximate vertical.
In zone line, disposed n side extension 9-2, regional therebetween, n side extension 9-2 and p lateral electrode diffusion part 10a relatively extend.That is, n side extension is not invaded p side connecting portion zone, and only is configured in zone line, Qu Yu inside therebetween, and n side extension 9-2 and p side electric current diffusion part 10a relatively are configured.
By such formation,, can provide electric current equably to n side extension 9-2 from p side electric current diffusion part 10a in the n of zone line side extension 9-2 and the relative zone of p side electric current diffusion part 10a.In addition, n side extension 9-2 is configured in the zone line, therefore can alleviate electric current and concentrate from the p side electric current diffusion part 10a of n side extension around p side connecting portion.
That is, electroconductive component directly is connected on the p side connecting portion 10b-1, so becomes the high zone of current density certainly easily around it.But the LED of embodiment of the present invention 1, n side extension do not extend to p side connecting portion zone always, therefore can alleviate current concentration significantly near p side connecting portion, and can provide electric current to wideer zone more equably at zone line.
In addition, shown in present embodiment, if p side electric current diffusion part 10a adopts the structure with light transmission, then p side connecting portion 10b-1 preferably has p side extension 10b-2.That is, have light transmission, need form the thin film of its Film Thickness Ratio in order to make p side electric current diffusion part 10a.But, be film if make p side electric current diffusion part 10a with light transmission degree, then resistance must become greatly, is difficult to make the current expansion that is provided by p side welding disk to whole p side electric current diffusion part 10a.Therefore, constitute p side welding disk 10b, make p side extension 10b-2 begin to extend from the less p side connecting portion 10b-1 of resistance ratio, and make current expansion to p side extension 10b-2, afterwards electric current is offered p side electric current diffusion part 10a, thus, the easier electric current that makes is diffused into whole p side electric current diffusion part 10a.
In addition, the LED of present embodiment is at zone line, n side extension 9-2 and p side extension 10b-2 be approximately perpendicular to the direction of long side direction (below, be called " Width ") each other at a distance of configuration relatively further, thus, can electric current be offered whole LED with wider.
On the other hand, in general, from the inner light that produces of LED, the limit is by all boundary reflections such as semiconductor layer and semiconductor layer, semiconductor layer and electrode, directive LED outside, limit.When reverberation, be not to reflect fully, the part of light is absorbed by each parts.At this,, then can reduce the number of times of light absorption automatically if can reduce the number of times of light reflection.In view of such situation, from the electrode configuration plane side of LED,, light absorption can be suppressed to Min. thus in Width its profile of attenuate as far as possible, can improve taking-up simultaneously from the light of Width.In addition, by attenuate, can light be taken out from a thin side concentrated area.As such shape, an opposite side is arranged than another rectangle or parallelogram, ellipses etc., but as practical problem, if consider rate of finished products etc., then rectangle is best to the length of side.
Like this, LED is from electrode configuration plane side, and what a direction is thin.But for electroconductive component the most at last is connected to each electrode, p side connecting portion 10b-1 and n side connecting portion 9-1 need area to a certain degree.People consider, from electrode configuration plane side, if make the profile of LED be thinned to the limit, make then can maximally utilise the taking-up of light by the thickness that stays the Width that can connect electroconductive component, but are difficult to dispose effectively n side extension.
Therefore, the LED of present embodiment as shown in Figure 1, at zone line, has pit on the predetermined part of p side electric current diffusion part 10a.And, along this pit configuration n side extension 9-2.At this moment, preferably make the n side extension of zone line and p side electric current diffusion part apart from little than the Width of the p side electric current diffusion part in p side connecting portion zone of the distance D of n side extension end far away apart from E.Thus, can guarantee the area that the electroconductive component of p side connecting portion can connect, can dispose n side extension simultaneously, and can make the Width of LED thinner.
In addition, than apart from E hour, the distance A of n side extension respect to one another and p side electric current diffusion part cans be compared to the front end of n side extension and little apart from B near the p side electric current diffusion part that is positioned at p side connecting portion area side of front end most in distance D.In addition, the p lateral electrode diffusion part that is positioned at p side connecting portion area side of the front end of so-called close n side extension just, refers near the p side electric current diffusion part in p side connecting portion zone of the non-relative region that n side extension is not relative with p side electric current diffusion part.In Fig. 1, p side electric current diffusion part begins along with the curve of releiving extends from p side connecting portion, therefore, is the distance of n side extension and this curve of releiving apart from B.
That is, as mentioned above, electroconductive component directly is connected on the p side connecting portion 10b-1, therefore, its periphery is the highest zone of current density certainly, and still, as described in present embodiment, distance A is than little apart from B, therefore, between B, can alleviate concentrating of electric current, and, between A, can provide more uniform electric current.
In addition, the LED of present embodiment, as shown in Figure 1, n side connecting portion and p side electric current diffusion part are at long side direction toward each other.And the distance A of relative n side connecting portion and p side electric current diffusion part is preferably less than the relative n side connecting portion and the distance C of p side electric current diffusion part near the front end of p side extension at least.That is, adjacent near the front end of p side extension with n side connecting portion, so become the zone that current density increases easily around it certainly, but, as described in present embodiment, by making distance A less than distance C, can between C, alleviate concentrating of electric current, and more uniform electric current can be provided between A.
In addition, in the present embodiment, illustrated that p side electric current diffusion part has spread the situation of electric current fully, but, under the inadequate situation of electric current diffusion function of p side electric current diffusion part, by changing the shape of the p side welding disk that constitutes by p side connecting portion and p side extension itself, can substantially increase and decrease distance A, B, C.Specifically, for example, wanting to strengthen under the situation of distance A, can adopt further refinement p side extension, making it to leave the structure of n side extension; Under the situation of wanting to strengthen apart from B, can adopt an angle that makes roughly tetragonal p side connecting portion shown in Figure 1 to become circle, make it to leave the structure of n side extension.Equally, wanting to strengthen under the situation of distance C, can adopt and shorten p side extension, making it structure away from n side connecting portion.
And, under the inadequate situation of electric current diffusion function of p side electric current diffusion part, distance C, the closer to the front end of p side extension, the above-mentioned effect of being brought by the relation of distance A and distance C is remarkable more, and along with the front end that leaves p side extension, its effect is also more little.Therefore, for example, in order to increase light-emitting area, can be along with the distance that reduces p side electric current diffusion part and the n side connecting portion relative of leaving with long side direction from the front end of p side extension.
In addition,, on the position lower, have n side extension, make and do not block the light that penetrates from the active layer that becomes the light injection part in side surface direction than light injection part at this.In the present embodiment, from electrode configuration plane side, because to make the profile of LED be rectangle, so light mainly penetrates from Width, rather than penetrates from long side direction, and such structure is effective especially.And at this, making component construction is DH (double heterojunction) structure, and therefore the InGaN layer 6 as active layer is equivalent to the light injection part.Certainly, when component construction was the pn knot, its interface was called the light injection part.
In addition, facing up when the LED of present embodiment is installed, mainly using the wire that constitutes by gold thread etc.,, using scolding tin etc. as electroconductive component facing down when installing as electroconductive component.
At this, adopted to make p side electric current diffusion part be relatively thinner film, the structure of the part of the light of the transmissive LED of p side electric current diffusion part own still, also can adopt the structure that makes p side electric current diffusion part not make the LED light transmission for thicker film thus.Particularly, when facing down installation,, make p side electric current diffusion part reverberation, can improve taking-up to the light of observing side by with the predetermined stacked Rh of thickness, various metal partss such as Al, Ag.At this moment, need on the predetermined part of p side electric current diffusion part, p side welding disk be set, just can similarly constitute integratedly with the n electrode.
In addition, concavo-convex by on the predetermined part of LED, being provided with, the energy scattered light, the result can improve the taking-up efficient of light.For example, be provided with by surface at n type contact layer with n lateral electrode concavo-convex, perhaps on the interface of Sapphire Substrate and epitaxial loayer, be provided with concavo-convex, scattered light more effectively.
Particularly, the LED of embodiment of the present invention 1, from electrode configuration plane side, be oblong-shaped, so light does not just penetrate from vertical (semiconductor multilayer direction) effectively, also penetrate effectively from horizontal (particularly Width), but, concavo-convex by being provided with on for example surface of n type contact layer, except improving ejaculation from horizontal light, can also improve from the ejaculation of light longitudinally, further can obtain the luminous of solid.In addition, for the surface at n type contact layer forms concavo-convex, for example, can utilize opening of the surface of n type contact layer formation the mask of the mouth of predetermined shape such as circle, triangle, quadrangle, the recess that this predetermined shape is set with RIE (reactive ion etching) forms.In addition, remove other parts by staying this predetermined shape, can form concavo-convex, i.e. protuberance.When formation is concavo-convex on n type contact layer, outside the interface of n lateral electrode and n type contact layer, also can on this interface, form concavo-convex certainly.
In addition, also can form concavo-convex operation and the operation of exposing the face that is used for stacked n lateral electrode in the lump.Promptly, for example, after stacked p type contact layer, the coating resist film, expose into desired figure, the resist film that stays is used as mask, at the position of the luminescent layer that has stayed the light-emitting component effect, the position of the final configuration n lateral electrode on n type contact layer surface can form and comprises the convex column of n type contact layer to p type contact layer on the n type contact layer.Thus, form the face that exposes of n lateral electrode, and form the convex column simultaneously, therefore can simplify working process.Like this, forming concavo-convex operation in the lump and when exposing the operation of the face that is used for stacked n lateral electrode, the convex column must be formed on the position than active floor height.The light that can will be propagated in n type contact layer by this convex column reflexes to the sightingpiston side, and be fetched into the outside, and from the light of active layer directive side surface direction directly by the convex column with going direction changing to the sightingpiston side, therefore, become more effective to the taking-up efficient of the light of sightingpiston side.The convex column can adopt as required from luminous sightingpiston side and be seen as different shapes such as circle, rhombus, triangle or hexagon.And then the convex column preferably is tapered from n type contact layer side direction p type contact layer side.Thus, can further improve taking-up to the light of sightingpiston side.
In addition, self-evident, the concavo-convex effect of explanation so far is not the LED of present embodiment, and is applicable for the LED of other structure yet.
On the other hand, under above-mentioned arbitrary situation, the end face of the concaveconvex shape of seeing from luminous sightingpiston or the shape of convex column if having the limit that has angle, preferably is vertically formed with light emitting end surface, then can be fetched into the outside with the light that penetrates effectively.Particularly, what make concavo-convex or convex column is shaped as triangle from what luminous inspection surface side was seen, and make this leg-of-mutton angle relative with light emitting end surface, and, leg-of-mutton one side relative with this angle is positioned at away from light emitting end surface one side, and makes it and the light emitting end surface almost parallel, thus, can make one side relative form greatlyyer, so this is desirable with light emitting end surface with having angle.That is, can make each triangle become configuration radially, make that each leg-of-mutton angle is relative with light emitting end surface with respect to light emitting end surface.In addition, triangle is isosceles triangle or equilateral triangle preferably, and at this moment, an above-mentioned angle is preferably two angles that the limit forms by equal in length.Thus, can take out light more equably.In addition, so-called light emitting end surface, be have finally be provided electric current and luminous n type contact layer to the end face of the duplexer of p type contact layer.
In addition, for the light that effectively active layer is sent is fetched into the outside, light is preferably the least possible at the number of times of semiconductor multilayer structure internal reflection.Therefore, for example, use sapphire to do substrate, making the semiconductor multilayer constructing analog is GaN, the refractive index of sapphire refractive index, GaN approximately is 1.77 and 2.5, therefore according to Si Nieer (Snell) law, the critical angle at its interface is about 45 degree, and the designer can at random set light reflects and inject to the outside in the semiconductor multilayer structure reflection of light number of times.Specifically, for example, can be the distance of light primary event with the distance setting of the Width of the semiconductor multilayer structure of the active layer end face of the zone line of pie graph 1.Thus, can further improve the taking-up of the light of Width.Certainly, can only not be applied to constitute the distance design of Width of semiconductor multilayer structure of the active layer end face of zone line, and can also be applied to various distance designs.
(execution mode 2)
The LED of execution mode 2 is described according to Fig. 3, Fig. 4.Fig. 3 is the skeleton diagram of the LED of the present embodiment seen from electrode configuration plane side.Fig. 4 is the constructed profile of layer structure of the LED of expression execution mode 2, the section of the IV-IV line of presentation graphs 3.In addition, give prosign for the parts that have an identical function with execution mode 1.
The LED of present embodiment, 10a has a plurality of peristome 10aa except p side electric current diffusion part, adopts and the same structure of execution mode 1 described LED.In addition, p side welding disk does not have p side extension, and by such formation, the light that penetrates from active layer can not blocked by p side extension, is desirable from light taking-up aspect therefore.Certainly, if consider the expansion of electric current, then also can adopt structure with p side extension.Pay attention to which effect, can select arbitrarily by the designer.
P lateral electrode 10 with go up the p type contact layer that forms in the zone (roughly whole face) of the ratio broad of p type contact layer and carry out ohmic contact, and, comprise the p side electric current diffusion part 10a of the electric current that diffusion is provided by the p side welding disk of next describing and the p side welding disk 10b that on the predetermined part of p side electric current diffusion part, forms.At this, the p current-diffusion layer has a plurality of peristomes that expose the p contact layer in fact.At least a portion from the light of LED is fetched into the outside from this peristome.
In the present embodiment, begin to stack gradually Rh, Ir, Au as the p lateral electrode, but also can use other material known and lit-par-lit structure from p type contact layer.At this moment, stacked continuously Rh, Ir are p side electric current diffusion parts, and Au is a p side welding disk.In the present embodiment, finally should connect the p side connecting portion 10b of electroconductive component corresponding to p side welding disk itself.
In addition, resemble present embodiment like this, if the p current-diffusion layer has a plurality of peristomes, then p side connecting portion also can not have p side extension.That is, when forming peristome on the p current-diffusion layer, make it form the thicker film of Film Thickness Ratio, making does not have light transmission.This is because form thicker film, will reduce resistance, and the electric current that is provided by p side welding disk is spread easily.But if make the thick film of p current-diffusion layer for not having the light transmission degree, then light is difficult to take out from p side electric current diffusion part.Therefore,, resistance can be reduced, the taking-up of light can be carried out simultaneously by on p side electric current diffusion part, a plurality of peristomes being set.
As shown in Figure 4, also can not form configuration p side welding disk on the p side electric current diffusion part of peristome, but, also can have configuration p side connecting portion on the p side electric current diffusion part of peristome as alternate manner.That is, by having peristome, can constitute at section is the upper surface and the recess internal configurations p side welding disk of concavo-convex p current-diffusion layer.Thus, can improve, therefore can improve the fluid-tight engagement of p side welding disk and p current-diffusion layer, and can provide electric current effectively to the p current-diffusion layer from p side welding disk from the contact area of p side welding disk to the p current-diffusion layer.
In addition, self-evident, can at random set shape, size, allocation position of peristome etc.And then, owing to have peristome at the n side extension side end of p side electric current diffusion part, so its end is out of line, because of peristome becomes concavo-convex, even in this case, as a whole, n side extension and p side electric current diffusion part also can be toward each other.
In addition, at this, as Fig. 1 or shown in Figure 3, for example, relative n side extension is distinguished almost parallel each other with p side electric current diffusion part, relative n side extension with p side extension, relative n side connecting portion and p side electric current diffusion part, still, self-evident, not parallel also passable.At this moment, distance A, B, C, D, E become the beeline in the corresponding region.
At this, in execution mode 1 and 2, as shown in figures 1 and 3, adopt p side electric current diffusion part not to be arranged in n side connecting portion zone, that is, p side electric current diffusion part is positioned at the structure of zone line.For example, as Fig. 5～shown in Figure 8, also can constitute p side electric current diffusion part and be contained in the n side connecting portion zone.At this moment, for example, shown in each figure, preferably adopt n side welding disk and p face down bonding disc portion not to be configured in as the structure on the diagonal of rectangle and OBL light-emitting diode.In addition, at this moment, n side connecting portion zone, zone line, p side connecting portion zone are respectively the zones that generally perpendicularly demarcates with long side direction.Below, according to Fig. 5～Fig. 8 execution mode 3,4 is described.
(execution mode 3)
The LED of present embodiment is described according to Fig. 5, Fig. 6.In addition, give prosign to the parts that have an identical function with execution mode 1.The LED of present embodiment except following structure difference, adopts the structure identical with the LED of execution mode 1 basically.
That is, the LED of present embodiment as mentioned above, forms p side electric current diffusion part 10a and arrives n side connecting portion zone, and n side welding disk 9-1 and p side welding disk 10b-1 from electrode configuration plane side, are configured in respectively on the diagonal as rectangular LED.In addition, n side extension 9-2 is relative with p side extension 10b-2 part.And, in the zone of the n type that the is exposed to contact layer 4 that exposes in order to form the n lateral electrode, have a plurality of protuberances 11 that are used to improve the taking-up of light, make the semiconductor laminated structure that will comprise active layer fence up.
Fig. 5 be the protuberance 11 seen from electrode configuration plane side be shaped as rhombus the time example, Fig. 6 be the protuberance 11 seen from electrode configuration plane side be shaped as triangle the time example.Like this, by the protuberance 11 that closely disposes reservation shape, can improve the taking-up that faces up when installing to the light of observing side.Though its reason is uncertain, but be considered to, the light of propagating in the n type contact layer of (rear side among the figure) below protuberance 11 is by the root diffuse reflection of protuberance 11, and perhaps the light of propagating in n type contact layer enters protuberance 11 inside, thus, the taking-up efficient to the light of observing side improves.In addition, also be considered to, from the LED side, concavo-convex top is than the position height (being positioned at the p side) of active layer, directly runs into forming concavo-convex protuberance from the light that penetrates end face, can be with the going direction changing of light to the sightingpiston side.
In addition, preferably disposing each protuberance, make and necessarily meet certain protuberance 11 from the light that penetrates end face, that is, is not to inject to the LED outside with a straight line from the light that penetrates end face.Specifically, at all predetermined at least one protuberances of straight lines configuration, can realize that thus bigger light takes out from having considered that ejaculation end face that light passes through begins to extend.
In addition, in order to simplify working process, protuberance can form in the operation that is exposed to the n side contact layer in order to dispose the n lateral electrode.At this moment, each protuberance adopts the structure that has begun to stack gradually n side contact layer 4 to p side contact layer 8 from substrate side.Utilizing etching etc. to form under the situation of protuberance, the top shape of the protuberance of seeing from electrode configuration plane side, unfilled corner rather than certain sometimes for example, but, the most important thing is that the protuberance than active floor height is formed on its top, therefore, even under these circumstances, also can improve the taking-up efficient of light.
(execution mode 4)
The LED of present embodiment is described according to Fig. 7, Fig. 8.Have with the parts of execution mode 1 identical function and give prosign.The LED of present embodiment adopts basically and the identical structure of execution mode 1 described LED except following structure difference.
That is, the LED of present embodiment as mentioned above, forms p side electric current diffusion part 10a and arrives n side connecting portion zone, n side welding disk 9-1 and p side welding disk 10b-1, and from electrode configuration plane side, being configured in respectively is on the diagonal of rectangular LED.In addition, n side extension 9-2 is relative with p side extension 10b-2 part.And, in the zone of the n type that the is exposed to contact layer 4 that exposes in order to form the n lateral electrode, have a plurality of protuberances 11 that are used to improve the taking-up of light, about protuberance 11, Fig. 7 is the same with Fig. 5, and Fig. 8 is identical with Fig. 6.
(execution mode 5)
The LED of present embodiment is described according to Fig. 9.Have with the parts of execution mode 1 identical function and give prosign.The LED of present embodiment except following structure difference, adopts basically and the identical structure of execution mode 1 described LED.
That is, the LED of present embodiment as shown in Figure 9, begins to tilt to the face that is provided with n lateral electrode 9 of n type contact layer 4 always from the interface of Sapphire Substrate 1 and resilient coating 2.By having the inclined plane like this, can further improve the taking-up when facing up installation and facing down installation to the light of observing side.
Specifically,, be under the situations of 64 degree for example making angle of inclination shown in Figure 9 facing down when installing, can make taking-up to the light of observing side is angle of inclination roughly 1.1 times when being the execution mode 1 of 90 degree.In addition, be 34 degree making the angle of inclination, thereby make under the more slow situation of inclination that can make the taking-up to the light of observing side is that the angle of inclination is roughly 1.6 times under 90 situations about spending.
In addition, in the present embodiment, adopted the structure the inclined plane begins to tilt to the face that is provided with n lateral electrode 9 of n type contact layer 4 always from the interface of Sapphire Substrate 1 and resilient coating 2 till, but the inclined plane can be arranged in other zone also.That is, can make at least a portion of the side of LED have the inclined plane.For example, except said structure, also can be that the face that is provided with n lateral electrode 9 from n type contact layer 4 begins to tilt to till the face that is provided with p lateral electrode 10 of p type contact layer always.No matter which adopts, by in bigger side regions the inclined plane being set, above-mentioned effect all can be bigger.
In addition, with known insulating properties control of material such as aluminium oxide, aluminium nitride, silica, yittrium oxide, titanium oxide, zirconia, ITO, indium oxide, tin oxide thickness etc., make transmission or reflection from the light of LED inside, and individual layer or multilayer insulation material be set on the inclined plane, thus, under the installation that faces up, the arbitrary situation of installing that faces down, can both further improve taking-up to the light of observing side.In addition, in the present embodiment, basic component construction is identical with execution mode, and other component construction by the inclined plane is set, can improve the taking-up to the light of observing side certainly.
(execution mode 6)
The LED of execution mode 6 then, is described according to Figure 10, Figure 11.Figure 10 is the plane graph of the LED of the present embodiment seen from the electrode forming surface side.Figure 11 is near the profile the welding disk 20b (below be also referred to as " p side welding disk ") of p lateral electrode 20 of XI-XI line of Figure 10, and the position relation of the configured and disposed protuberance 11 on 2nd zone different with the 1st zone of semiconductor multilayer in the 1st zone that is provided with p lateral electrode 20 is shown.
The LED of present embodiment, p lateral electrode 20 and n lateral electrode 19 are arranged on the one side side, are to be the structure from the bright dipping of electrode forming surface side-draw of electrode forming surface side with the sightingpiston side.Constitute the semiconductor multilayer structure of LED, the same with execution mode 1, have following layer structure: promptly, on Sapphire Substrate 1, stacked gradually GaN resilient coating 2, non-impurity-doped GaN layer 3, become n type contact layer mix silicon GaN layer 4, become n type coating layer mix silicon GaN layer 5, become active layer InGaN layer 6, become p type coating layer mix magnesium AlGaN layer 7, become p type contact layer mix magnesium GaN layer 8.And then, utilize etching etc. partly to remove to mix magnesium GaN layer 8, mix magnesium AlGaN layer 7, InGaN layer 6, mix silicon GaN layer 5, mix silicon GaN layer 4, and formed n lateral electrode 19 on the face mixing exposing of silicon GaN layer 4, be provided with p lateral electrode 20 mixing on the magnesium GaN layer 8.N lateral electrode 19 begins to have stacked gradually W, Pt, Au from n type contact layer side.The electric current diffusion part 20a of p lateral electrode 20 (below be also referred to as " p side electric current diffusion part "), be formed on roughly whole of p type contact layer, and from p type contact layer side begun to stack gradually Ni, Au (the perhaps alloy of Ni and Au), 20b is the same with the n lateral electrode for p side welding disk, has stacked gradually W, Pt, Au.Like this, be same structure by making p side welding disk 20b and n lateral electrode 19, the formation operation that can make p side welding disk 20b and n lateral electrode 19 is an operation.In addition, in the present embodiment, in order to ensure light-emitting zone (the 1st zone), p side electric current diffusion part 20a partly fences up n lateral electrode 19.
At this, the LED of present embodiment, form a plurality of each concavo-convex protuberance 11 be trapped among the 1st zone around.That is, the LED of present embodiment, with protuberance be trapped among the 1st luminous when driving zone around, thus, can effectively utilize the electrode forming surface side surface area of LED, carry out the control that light takes out efficient and light directive property.In general, LED makes the presumptive area filming stacked behind the various semiconductor layers on the substrates such as sapphire, is divided into each LED by this film zone.The present application also can be provided for forming the special zone of protuberance, still, for example, cuts apart the film zone of wafer or form a plurality of protuberances around electrode, can suppress the increase of operation thus.That is, preferably on the desired zone on the n type contact layer plane that only is arranged at the electrode forming surface side originally, form the protuberance of the present application.
At this, n type contact layer from the electrode forming surface side, is made of with 2nd zone different with the 1st zone the 1st zone that is provided with the semiconductor multilayer structure with p lateral electrode, and the 2nd zone is provided with n electrode 19 and a plurality of protuberance 11.As shown in figure 11, be arranged on the top of each protuberance on the 2nd zone, on the LED section, constitute in p type contact layer side and be higher than active layer, preferably height is identical in fact with p type contact layer.That is, the top of protuberance forms than active floor height.In addition, concavo-convex bottom forms lowlyer than active layer.The LED of present embodiment is a DH structure, and therefore concavo-convex top can be higher than the interface of active layer and adjacent with it n side layer at least, and still better is is higher than the interface of active layer and adjacent with it p side layer.In addition, concavo-convex bottom can be lower than the interface of active layer and adjacent with it p side layer at least, and still, better is is lower than the interface of active layer and adjacent with it n side layer.And then, be not limited to the DH structure, for example, active layer uses the quantum well structure, being clipped in the structure of this active layer by n side layer and p side layer, also can form same protuberance.That is, concavo-convex top is higher than the interface of active layer and n side layer, preferably is higher than the interface of active layer and p side layer.In addition, concavo-convex bottom is lower than the interface of active layer and p side layer, is preferably lower than the interface of active layer and n side layer.
By such formation, can make taking-up efficient to the light of observing side for example improve 10～20%.Though its reason is also indeterminate, can consider following reason 1～3.That is, 1. the light of propagating in n type contact layer is taken into protuberance inside from n type contact layer, light from the top of protuberance or its midway part be fetched into the sightingpiston side.The light that injects to lateral outer from the active layer end face by a plurality of protuberances reflect, scattering, light is fetched to the sightingpiston side.3. the light of propagating in n type contact layer is by the root of protuberance (coupling part of n type contact layer and protuberance) diffuse reflection, and light is fetched to the sightingpiston side.
In addition, by a plurality of protuberances are set, can carry out uniform light in whole sightingpiston side and take out.And then, constitute protuberance owing to comprise p type contact layer ground, so the height at their top is roughly the same, therefore can not had the 1st regional occlusion that is provided with the semiconductor multilayer structure of p lateral electrode, can effectively light be fetched into the sightingpiston side from the protuberance top.And, by being constituted, protuberance is higher than p type contact layer, preferably be higher than p type electrode, can more effectively light be taken out.
In addition, on the protuberance section, protuberance from the semiconductor multilayer direction, be the n type contact layer side direction p type contact layer side crustal inclination that is tapered, above-mentioned thus effect is bigger.That is, intentionally have angle by making protuberance, make from the light of active layer by protuberance surface total reflection, perhaps make the light scattering of propagating in n type contact layer, the result can carry out taking out to the light of sightingpiston side effectively.The inclination angle of protuberance is preferably 30 degree～80 degree, and better is 40 degree～70 degree.
The shape of protuberance section can be various shapes such as circular cone, semicircle, but preferably trapezoidal, i.e. protuberance truncated cone shape preferably itself.By such formation, the control of the directive property of light becomes easier, and as a whole, can carry out more uniform light and take out.Taking out light from p type contact layer, and when being sightingpiston, can think that the sightingpiston side of protuberance comprises the plane, do not comprising the summit, can obtain such effect thus with the p side contact layer.
In addition, when being shaped as of protuberance section was trapezoidal, (p side) can also have recess in trapezoidal top.Thus, when the light of propagating in n type contact layer invaded protuberance inside, light injected to the sightingpiston side easily because of the recess that the top at protuberance forms, and this is desirable.
The LED of the present application, on the direction of the ejaculation end face that is being approximately perpendicular to the semiconductor multilayer structure that forms in the 1st zone of n type contact layer, best more than 2, it is desirable to the protuberance repeated configuration at least in part more than 3.Thus, from the light in the 1st zone with high probability by protuberance, therefore can more easily obtain above-mentioned effect.
The protuberance of present embodiment when in order to form the n lateral electrode, to be preferably in n type contact layer being exposed, forms simultaneously.Promptly, the LED of present embodiment is with the structure of one side side with p lateral electrode and n lateral electrode, therefore stacked behind the p type contact layer on the substrate, be necessary to remove corresponding with the n lateral electrode at least zone, make n type contact layer expose from the p side of semiconductor multilayer structure.In detail, for example, stacked behind the p type contact layer, the coating resist film, and expose into desired figure, use the resist film that stays as mask, afterwards, utilize etching to remove part except the position (the 1st zone) that the p lateral electrode is set and the position (part in the 2nd zone) that should form protuberance, expose up to n type contact layer.Thus, can form the face that exposes of n lateral electrode, and can form protuberance simultaneously, therefore can simplify working process.At this, use resist film as mask, but also can be with SiO 2Deng dielectric film as mask.
The protuberance of Xing Chenging like this, have with the 1st zone in the identical lit-par-lit structure of semiconductor multilayer structure.But the active layer that the 1st zone is comprised works as luminescent layer, but the active layer that protuberance comprised in the 2nd zone does not play luminescent layer.This is because the 1st zone has the p lateral electrode, and is relative therewith, does not form the p lateral electrode on the 2nd zone (protuberance).That is, the active layer in the 1st zone can be provided charge carrier (hole and electronics) because of energising, and is relative therewith, and the active layer of the protuberance that is provided with is gone up in the 2nd zone, is not provided charge carrier because of energising.Like this, the protuberance of the present application, itself can not be luminous.
In addition, in the inside in the 1st zone the peristome that is surrounded by the 1st zone fully can be set on every side, in each peristome, can be provided with can not be luminous a plurality of protuberances, but this moment, peristome hinders current path sometimes, just component resistance does not rise, and can not obtain luminous tendency uniformly in addition, is not desirable therefore.Therefore, the present application, in zone (the 1st zone) that originally should be luminous, the preferably similarly stacked luminous required type of n at least contact layer, active layer, p type contact layer, and equally luminous, preferably only on original non-luminous zone (the 2nd zone), a plurality of protuberances are set.No matter adopt which structure, the obvious characteristic of the present application all is: in original non-luminous zone a plurality of protuberances are set, by effectively utilizing original non-luminous zone, can obtain above-mentioned effect.
Resemble the protuberance that forms above-mentioned, for the identical lit-par-lit structure of semiconductor multilayer structure in the 1st zone, in other words, protuberance is made of the different a plurality of layers of material.If the material difference, then the refractive index of each layer is inevitable also different, and therefore the light that is taken into protuberance is easily by each boundary reflection, and the result is to think that the light that helps to improve to the sightingpiston side takes out.
The quantity of the protuberance of the present application, density etc. are not particularly limited, and still according to inventor's experiment, can form more than at least 100 in the 2nd zone, it is desirable to more than 200, and better is more than 300, it would be desirable more than 500.Like this, can further improve above-mentioned effect.From the electrode forming surface side, the ratio of the area that the protuberance in the 2nd zone is shared (at length saying the ratio that the area at the interface in protuberance and the 2nd zone accounts in the 2nd zone) can it is desirable to more than 30% for more than 20%, and better is more than 40%.In addition, the area at the interface in 1 protuberance and the 2nd zone can be 3～300 μ m 2, it is desirable to 6～80 μ m 2, that better is 12～50 μ m 2
By in the 2nd zone protuberance 11 being set, light is reflected, scattering, improves thereby take out efficient.At this, protuberance 11 shown in Figure 11, it is concavo-convex that n type contact layer 4 is provided with exposing, and form pit, so each protuberance 11 has and the 1st regional identical layer structure as light-emitting zone.Therefore, protuberance 11 also has the active layer part.But, it is believed that, when intactly relatively the active layer part of the active layer in the 1st zone of light and protuberance 11 was penetrated in configuration, the light that penetrates from the active layer in the 1st zone was partially absorbed a part by the active layer of protuberance 11, and the light utilization ratio reduces because of this part.On the other hand, the light that penetrates owing to the active layer from the 1st zone spreads and ejaculation, so the active layer part of not only shining protuberance 11, and coating layer is partly also illuminated.When from the coating layer partial reflection of the relative protuberance 11 of the luminous quilt of active layer, scattering, the utilization ratio of light improves.Therefore, spread ejaculation easily by adopting the light that penetrates from the active layer in the 1st zone, and this light can improve the utilization ratio of light easily by the shape of the reflection of the coating layer of protuberance 11, scattering.According to such reason, can think that the taking-up efficient of light can be improved because of the structure of above-mentioned protuberance.
According to the explanation of doing so far, the LED of the present application reduces the laterally light of (side surface direction of LED) of directive, selectively directive top (sightingpiston side).Particularly, have among the LED of the low layer of refractive index at least one side (preferably upside or p side layer) of the levels that clips active layer, light is easily by the low layer reflection of this refractive index, in any case, and side surface direction only main.The present application is effective especially to such element.
LED when reality is used, in general, uses the potting resin that is made of for example organic resin such as epoxy resin, silicones to seal around it and use.The present application even use like this, also can alleviate the resin deterioration that is caused by light significantly.This is considered to, and does not focus on the potting resin that is positioned at the active layer side from the light of active layer side, and light disperses because of a plurality of protuberances.Particularly, epoxy resin to light a little less than, so the application the 2nd invention is to being that the LED of potting resin is effective especially with epoxy resin.Similarly, even when on the supporter that constitutes by organic resin (for example nylon-based resin), having disposed LED, also can prolong the life-span of its supporter itself.That is,, can alleviate the light deterioration of supporter significantly because of penetrating from the LED side by using the LED of the present application.Certainly, supporting body surface is the closer to LED, and such effect is remarkable more.
In addition, the LED of present embodiment does not form protuberance between n lateral electrode 19 and the 1st zone, still, can form protuberance in this zone as execution mode 7 and execution mode 8 yet.N lateral electrode 19 peripheries, luminous more intense, therefore by between n lateral electrode 19 and p side electric current diffusion part 20a, protuberance being set, can further improve above-mentioned effect.In addition, for example, also can a plurality of protuberances be set to high-density near the luminous more intense zone n electrode and the 1st zone, the luminous more weak regional low-density in the zone different with it a plurality of protuberances are set.The zone that light-emitting zone is strong, weak zone are different because of the structure of LED, but no matter which adopts, consider the intensity of light-emitting zone, by changing the density of a plurality of protuberances, can carry out that more effective light takes out and directive property is controlled.
(execution mode 7)
The LED of present embodiment is described according to Figure 12.The formation zone of the shape of the shape that the LED of present embodiment constructs except the semiconductor multilayer in the 1st zone, p side electric current diffusion part 20a correspondingly and protuberance was different, structure was identical with the LED of execution mode 6.
That is, the LED of present embodiment, from electrode configuration plane side, the 1st zone between n lateral electrode 19 and p lateral electrode 20 has necking section, and is formed with a plurality of protuberances at this necking section.Promptly, from electrode configuration plane side, be set in place the semiconductor multilayer structure on the 1st zone between the welding disk of n lateral electrode and p lateral electrode, on direction perpendicular to the straight line of the welding disk that connects n lateral electrode and p lateral electrode, the both sides in the 1st zone have necking section, and necking section has a plurality of protuberances.Thus, can carry out effectively taking out to the light of luminous and sightingpiston side.
At length say, the LED of present embodiment, the welding disk 20b and the n lateral electrode 19 of p lateral electrode are configured on the straight line X-X.And as shown in figure 12, from the electrode forming surface side, p side electric current diffusion part 20a forms the oblong-shaped along straight line X-X, and correspondingly, the shape of LED itself also is the oblong-shaped along straight line X-X.In addition, flow to the electric current of n lateral electrode 19, mainly flow, make that its path is the shortest along straight line X-X from the welding disk 20b of p lateral electrode.But, the inventor finds, on the zone among the electric current diffusion part 20a of 19 of the welding disk 20b of p lateral electrode and n lateral electrodes away from 3 positions of straight line X-X, p side welding disk 20b, n lateral electrode 19, be difficult to provide electric current, consequently, compare with other zone, luminous a little less than, thereby the invention present embodiment.
The LED of present embodiment, consider above-mentioned situation, on the 1st zone between the welding disk 20b of n lateral electrode 19 and p lateral electrode, necking section is being set, the semiconductor multilayer structure in the zone that this necking section of removing and originally should be luminous is corresponding, and form a plurality of protuberances at this necking section, thus, the result can realize that good light takes out.This is to consider, remove the luminous weak zone suitable with necking section, in this zone of having removed protuberance is set, the strong thus luminous lateral outer that intactly injects to, this ejaculation strong luminous via the protuberance conversion direction, directive sightingpiston side, so the controlled raising of sensing of the taking-up of light, light.
(execution mode 8)
The LED of present embodiment is described according to Figure 13.The formation zone of the shape of the shape that the LED of present embodiment constructs except the semiconductor multilayer in the 1st zone, p side electric current diffusion part 20a correspondingly and protuberance was different, structure was identical with the LED of execution mode 6.
Promptly, the LED of present embodiment, from electrode configuration plane side, be set in place the semiconductor multilayer structure on the 1st zone between the welding disk of n lateral electrode and p lateral electrode, on the straight line X-X of the welding disk that connects n lateral electrode and p lateral electrode, begin to have necking section from n lateral electrode side, and necking section have a plurality of protuberances.Thus, the light that can further improve light takes out, the sensing of light is controlled, as mentioned above, electric current mainly flows along straight line X-X, but, by the part on the straight line X-X that removes the 1st zone, and on this removal zone a plurality of protuberances are set, the result is the directive property control that can improve the taking-up efficient of light, light effectively.This is to consider, by removing the part on the straight line X-X, can make current expansion arrive the wideer zone of semiconductor multilayer structure, and can effectively the more intense light of constructing the end face ejaculation from semiconductor multilayer be fetched into the sightingpiston side, this semiconductor multilayer structure end face is positioned at from the zone that straight line X-X removes, comprises active layer.
In addition, the inventor finds, a plurality of protuberances is set by resembling the 2nd invention on the 2nd zone, can see the tendency that the electrostatic withstand voltage of forward and reverse both direction improves.Though its reason and indeterminate can be thought substantially and a plurality of protuberances are set, thereby the surface area increase is relevant.
In addition, the LED of present embodiment is best and the structure of the LED of execution mode 7 and usefulness.That is, the necking section by the LED that makes present embodiment has execution mode 7 can further improve above-mentioned effect.The size of execution mode 7 and 8 necking section, shape etc. can be set arbitrarily.
In addition, the semiconductor multilayer of the LED of each execution mode structure is not limited to above-mentioned.The mixed crystal material of each semiconductor layer and mixed crystal ratio, stacked number, lamination order etc. can at random be set by the producer.P lateral electrode, n lateral electrode can be set its lamination order, structural material, thickness etc. arbitrarily too.
In execution mode 6,7,8, from the electrode forming surface side, be rectangular profile, and then constitute the welding disk that disposes n electrode and p electrode in the substantial middle at the two ends of its long side direction respectively that still, the present invention is not limited to this.Except the structure of the described LED of this specification, for example, also can adopt the welding disk that on tetragonal diagonal, disposes n electrode and p electrode respectively.
In execution mode 6～8, illustrated from the electrode forming surface side, utilize a plurality of protuberances that concavo-convex example is set on the 2nd zone, but also can be that it is concavo-convex to utilize a plurality of recesses to be provided with on the 2nd zone from the electrode forming surface side.So can improve the taking-up efficient of light, but because therefore operating difficulties not desirable yet.That is,,, be preferably in the 1st zone groove is set on every side, make and temporarily expose n type contact layer in order to prevent electric leakage (leak) even be provided with on the 2nd zone under the situation of recess.This is because if do not form groove around the 1st zone, then becomes the state that the 1st zone and the 2nd zone have coupled together, and for example, when finally cutting into each chip, if cut surface has dust etc., then may produce the cause of electric leakage.When being provided with groove like this, concavo-convex area can be set must be reduced, and is not desirable therefore.
From electrode forming surface, be provided with on the 2nd zone under the situation of a plurality of recesses, the quantity of recess can it is desirable to more than 200 more than 100 at least, and better is more than 300, it would be desirable more than 500.
In each above execution mode, the explanation of having omitted diaphragm, when still reality is used LED, the most handy SiO 2, SiN XCover at least a portion on LED surface Deng dielectric film.For example, can with dielectric film cover except the zone that connects each electroconductive component on p, each welding disk of n side, can observed zone from the electrode forming surface side.At this moment, each is concavo-convexly also covered by dielectric film.
(industrial utilizability)
The present invention can be used for backlight, the letter of illumination light source, light-emitting diode display, portable phone etc. Number machine, light switch, vehicle mounted brake lamp, various sensor and various indicator lamps etc.

Claims (14)

1. light-emitting diode, at least comprise n type nitride semiconductor layer (4) that has disposed the n lateral electrode and the p type nitride semiconductor layer (8) that has disposed the p lateral electrode, and disposing said n lateral electrode and above-mentioned p lateral electrode with the one side side, above-mentioned p lateral electrode comprises and being arranged on the above-mentioned p type nitride semiconductor layer and the p side electric current diffusion part (10a) of the electric current that diffusion is provided and be arranged at least a portion of p side electric current diffusion part and the p side welding disk (10b) of electric current is provided to above-mentioned p side electric current diffusion part, from electrode configuration plane side, be to have long side direction and perpendicular to the Width of above-mentioned long side direction, and the oblong-shaped that above-mentioned long side direction is long, it is characterized in that
Above-mentioned light-emitting diode, from electrode configuration plane side,
The said n lateral electrode comprises the n side connecting portion (9-1) that should connect electroconductive component and from the n side extension (9-2) that a predetermined part begins on long side direction and the shape that is in line extends of said n side connecting portion; And above-mentioned p side welding disk comprises the p side connecting portion (10b-1) that should connect electroconductive component at least;
Also comprise near the n side connecting portion zone that has disposed said n side connecting portion the end of long side direction, near p side connecting portion zone and the therebetween zone line that the other end of long side direction, has disposed above-mentioned p side connecting portion,
Said n side extending part is in above-mentioned zone line, and at above-mentioned zone line, said n side extension extends mutually opposed to each other with above-mentioned p side electric current diffusion part; And
The end of said n side extension (9-2) is not configured in above-mentioned p side connecting portion zone, and is configured in above-mentioned zone line;
At the long side direction of above-mentioned electrode configuration plane side, said n side extension (9-2) and above-mentioned p side electric current diffusion part (10a) are parallel to each other;
Said n side connecting portion (9-1) is configured on the OBL diagonal.
2. light-emitting diode as claimed in claim 1 is characterized in that,
Above-mentioned p side welding disk also comprises from the predetermined part of above-mentioned p side connecting portion and begins the p side extension (10b-2) that extends at long side direction, at above-mentioned zone line, and above-mentioned p side extension (10b-2) and the extension opposed to each other mutually of said n side extension,
Above-mentioned p side extension (10b-2) is positioned at the side away from n side extension of above-mentioned p side electric current diffusion part.
3. as claim 1 or 2 described light-emitting diodes, it is characterized in that,
The transmission of above-mentioned p side electric current diffusion part is from least a portion of the light of above-mentioned light-emitting diode.
4. as claim 1 or 2 described light-emitting diodes, it is characterized in that,
Above-mentioned p side electric current diffusion part has the peristome (10aa) of a plurality of transmissions from least a portion of the light of light-emitting diode.
5. as each described light-emitting diode of claim 1 or 2, it is characterized in that,
Above-mentioned light-emitting diode from electrode configuration plane side, has pit on the predetermined part of the above-mentioned p side electric current diffusion part of zone line, said n side extension extends along this pit,
The said n side extension of zone line and be positioned at distance D away from the end of the above-mentioned p side electric current diffusion part of a side of n side extension, little than the Width of the above-mentioned p side electric current diffusion part in p side connecting portion zone apart from E.
6. light-emitting diode as claimed in claim 5 is characterized in that,
The distance A of opposed said n side extension and above-mentioned p side electric current diffusion part is than the front end of said n side extension and little apart from B near the above-mentioned p side electric current diffusion part that is positioned at p side connecting portion area side of this front end.
7. each described light-emitting diode as claimed in claim 2 is characterized in that,
Said n side connecting portion and above-mentioned p side electric current diffusion part are put toward each other at long side direction,
The distance A of opposed said n side extension and the above-mentioned p side electric current diffusion part distance C than near said n side connecting portion of putting toward each other at long side direction the front end of p side extension (10b-2) and above-mentioned p side electric current diffusion part at least is little.
8. as each described light-emitting diode of claim 1 or 2, it is characterized in that,
Said n side connecting portion and above-mentioned p side connecting portion are put toward each other at long side direction.
9. light-emitting diode as claimed in claim 1 is characterized in that,
On long side direction, at least a portion of above-mentioned p side electric current diffusion part is between said n side extension and above-mentioned p side welding disk.
10. light-emitting diode as claimed in claim 1 is characterized in that,
Said n type nitride semiconductor layer (4) is from the electrode forming surface side, comprise the 1st zone that is provided with semiconductor multilayer structure with above-mentioned p lateral electrode with the 2nd different zone of above-mentioned the 1st zone,
Be provided with in above-mentioned the 2nd zone a plurality of concavo-convex,
Above-mentioned a plurality of concavo-convex top levels on above-mentioned light-emitting diode cross section view, is positioned at p type nitride semiconductor layer (8) side of active layer,
Above-mentioned a plurality of concavo-convex bottom water plane on above-mentioned light-emitting diode cross section view, is positioned at n type nitride semiconductor layer (4) side of active layer.
11. light-emitting diode as claimed in claim 1 is characterized in that,
Said n side extension (9-2) only extends opposed to each other at a side and above-mentioned p side electric current diffusion part (10a) and forms.
12. light-emitting diode as claimed in claim 1 is characterized in that,
Said n side extension (9-2) forms in the long side direction extension along OBL ora terminalis.
13. light-emitting diode as claimed in claim 2 is characterized in that,
Above-mentioned p side extension (10b-2) extends and to form from above-mentioned p side connecting portion (10b-1) the shape ground that is in line.
14. light-emitting diode as claimed in claim 1 is characterized in that,
Above-mentioned p side connecting portion (10b-1) is configured on the OBL diagonal.
CNB2003801008960A 2002-10-03 2003-10-02 Light emitting diode Expired - Fee Related CN100461467C (en)

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CN101859836B (en) * 2009-04-07 2014-05-28 江苏璨扬光电有限公司 Light-conducting type light-emitting diode and manufacturing method thereof
CN102376833B (en) * 2010-08-06 2014-01-01 晶元光电股份有限公司 Array-type light-emitting element, light source generation device and backlight module
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CN102832302A (en) * 2012-08-31 2012-12-19 扬州中科半导体照明有限公司 Method for manufacturing N electrode of GaN-based light-emitting diode (LED)
CN103227261B (en) * 2013-04-26 2015-10-07 东莞市福地电子材料有限公司 Led flip chip
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