CN1192057A - Semiconductor light emitting element and method for fabricating the same - Google Patents
Semiconductor light emitting element and method for fabricating the same Download PDFInfo
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- CN1192057A CN1192057A CN98106264A CN98106264A CN1192057A CN 1192057 A CN1192057 A CN 1192057A CN 98106264 A CN98106264 A CN 98106264A CN 98106264 A CN98106264 A CN 98106264A CN 1192057 A CN1192057 A CN 1192057A
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- 239000004065 semiconductor Substances 0.000 title claims abstract description 206
- 238000000034 method Methods 0.000 title claims description 9
- 239000000758 substrate Substances 0.000 claims abstract description 61
- 239000000463 material Substances 0.000 claims abstract description 18
- 239000010410 layer Substances 0.000 claims description 380
- 238000009792 diffusion process Methods 0.000 claims description 176
- 230000004888 barrier function Effects 0.000 claims description 98
- 230000002093 peripheral effect Effects 0.000 claims description 25
- 238000005530 etching Methods 0.000 claims description 18
- 239000011241 protective layer Substances 0.000 claims description 18
- 150000001875 compounds Chemical class 0.000 claims description 13
- 238000004519 manufacturing process Methods 0.000 claims description 13
- 230000015572 biosynthetic process Effects 0.000 claims description 8
- 229910052782 aluminium Inorganic materials 0.000 claims description 7
- 229910052733 gallium Inorganic materials 0.000 claims description 7
- 238000003780 insertion Methods 0.000 claims description 3
- 230000037431 insertion Effects 0.000 claims description 3
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 45
- 239000013078 crystal Substances 0.000 description 31
- 230000007547 defect Effects 0.000 description 21
- 239000011248 coating agent Substances 0.000 description 20
- 238000000576 coating method Methods 0.000 description 20
- 125000004429 atom Chemical group 0.000 description 11
- 238000010276 construction Methods 0.000 description 9
- 230000008859 change Effects 0.000 description 7
- 230000031700 light absorption Effects 0.000 description 7
- 229910052738 indium Inorganic materials 0.000 description 6
- 230000007704 transition Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 4
- 125000004437 phosphorous atom Chemical group 0.000 description 4
- 230000005012 migration Effects 0.000 description 3
- 238000013508 migration Methods 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 239000004411 aluminium Substances 0.000 description 2
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 239000011810 insulating material Substances 0.000 description 2
- 229910000980 Aluminium gallium arsenide Inorganic materials 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
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- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
- H01L33/14—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
- H01L33/14—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
- H01L33/145—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure with a current-blocking structure
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Abstract
A semiconductor luminescent element comprises a substrate, a semiconductor multilayer structure which at least comprises a first conductive type first covering layer, an active layer and a second conductive type second covering layer which are formed at the substrate according to the sequence, a current diffuse layer which is made from a material comprising a second conductive type Ga <1>-<x>In<x>P (x is more than 0 and less than 1) which is formed at the semiconductor multilayer structure.
Description
The present invention relates to a kind of semiconductor light-emitting elements, light-emitting diode for example, and relate to the manufacture method of this element.
Owing to multiple reason, will be used as the visible light light-emitting component with the semiconductor light-emitting elements that the AlGaInP semi-conducting material is made usually.In other words, the AlGaInP material has and can mate with the GaAs substrate lattice, and the advantageous characteristic of maximum direct transition band gap is arranged in the III-V compound semiconductor, and similar characteristics.Particularly, sending 550 by direct transition in the light-emitting diode (LED) of the light of 690nm scope, can obtain high emission effciency.
Yet, the conventional surface emission type semiconductor light emitting element of making by the AlGaInP material, existing problems aspect light output efficiency.This problem will illustrate as an example with conventional LED shown in Figure 12.
Conventional LED shown in Figure 12 comprises semiconductor multilayer structure 1212, and this structure is by n-type AlGaInP first covering 123 that forms on n-type GaAs substrate 121, and GaInP active layer 124 and p-type AlGaInP second covering 125 constitute.On the middle body of p-type covering 125, be formed with p-lateral electrode 1211, and on the back side of n-type substrate 121, be formed with n-lateral electrode 1210.
Light radiating portion at LED is the light that produces in the GaInP active layer 124, and the surface portion that does not form p-lateral electrode 1211 on p-type covering 125 sends.For improving the emission effciency of this LED, need make the current expansion that flows out from p-lateral electrode 1211 to whole GaInP active layer 124.Yet in fact, because the resistivity of p-type AlGaInP covering 125 is big, electric current only expands to a little scope of p-type covering 125, and therefore only be positioned at p-lateral electrode 1211 under GaInP active layer 124 parts luminous.As a result, in conventional LED shown in Figure 12, extremely low through the light output efficiency of LED upper surface.
For overcoming the problems referred to above, the U.S. Patent No. 5008718 of R.M.Fletcher etc. proposes a kind of semiconductor light-emitting elements, and the GaP current-diffusion layer wherein is provided, and makes electric current can expand to wideer scope.With reference to Figure 13, with the semiconductor light-emitting elements that proposes in the open text above being described in.
This semiconductor light-emitting elements is a kind of LED, and it comprises semiconductor multilayer structure 1312, and this structure is by n-type AlGaInP first covering 133 that forms on n-type GaAs substrate 131, and GaInP active layer 134 and p-type AlGaInP second covering 135 constitute.On semiconductor multilayer structure 1312, be formed with p-type GaP current-diffusion layer 136.The middle body of p-type GaP current-diffusion layer 136 is provided with p-lateral electrode 1311, and the whole back side of n-type substrate 131 is provided with n-lateral electrode 1310.
In this semiconductor light-emitting elements, the resistivity of p-type GaP current-diffusion layer 136 is less than the resistivity of p-type AlGaInP second covering 135, and therefore electric current can be expanded in p-type current-diffusion layer.Thereby in the more wide region of GaInP active layer 134, obtain the light emission, improved emission effciency.In addition, the band gap of p-type GaP current-diffusion layer 136 is greater than the band gap of p-type AlGaInP second covering 135.Therefore, will be when p-lateral electrode 1,311 one sides to be exported when the light that in active layer 134, produces, the light of being launched passes p-type current-diffusion layer 136 and is not absorbed.This has further improved emission effciency.
Yet in conventional semiconductor light-emitting elements shown in Figure 13, the use of current-diffusion layer GaP causes following point.
First problem is the degree of crystallinity that the GaP layer can not provide.Because the strong bonded of Ga atom and P atom in the GaP crystal, the Ga atom has small diffusion (migration) on the growing surface of crystal, cause the island growth of crystal, but not good layer growth.This certainly will produce crystal defect, reduces the degree of crystallinity of GaP layer, thereby and increases its resistivity.As a result, the emission effciency of the semiconductor light-emitting elements that is obtained and reliability decrease.
The lattice constant that second problem is the GaP layer obviously be different from the GaAs substrate and with the AlGaInP semiconductor layer of GaAs substrate lattice coupling.The lattice of GaAs often is 5.65A, and the lattice constant of GaP is 5.45A, causes-3.54% lattice mismatch.This lattice mismatch causes above-mentioned first problem.That is, in the GaP crystal, produce crystal defect, and therefore reduced degree of crystallinity.As a result, as described for first problem, the emission effciency of the semiconductor light-emitting elements that is obtained and reliability decrease.
The 3rd problem is abovely as the GaP of second problem description and the lattice mismatch of GaAs the light radiating portion to be produced harmful effect.Because the dislocation that the lattice mismatch because of-3.45% produces at the active layer as the light radiating portion, crystal defect occurs in covering and the similar layer.This causes the generation in non-emission complex centre.As a result, the emission effciency of the semiconductor light-emitting elements that is obtained and reliability significantly descend.
The semiconductor light-emitting elements of this example comprises: substrate; Semiconductor multilayer structure, this structure comprise first covering of first conduction type at least, second covering of the active layer and second conduction type, and they form on substrate in this order; And current-diffusion layer, this layer is by the Ga that is included in second conduction type that forms on the semiconductor multilayer structure
1-xIn
xThe material of P (0＜x＜1) is made.
In one embodiment of the invention, the In gram molecule coefficient x of current-diffusion layer is in the scope of about 0＜x＜0.49.
In another embodiment of the present invention, the In gram molecule coefficient x of current-diffusion layer is in the scope of about 0＜x＜0.27.
Perhaps, semiconductor light-emitting elements of the present invention comprises: substrate; Semiconductor multilayer structure, this structure comprise first covering of first conduction type at least, second covering of the active layer and second conduction type, and they form on substrate in this order; With the diffusion layer of electric current, this layer is by the Ga that is included in second conduction type that forms on the semiconductor multilayer structure
1-xIn
xThe material of P (0＜x＜1) is made, and wherein the In gram molecule coefficient x of current-diffusion layer changes on thickness direction.
In one embodiment of the invention, the In gram molecule coefficient x of the variation of current-diffusion layer is in the scope of about 0＜x＜0.49.
In another embodiment of the present invention, the In gram molecule coefficient x of the variation of current-diffusion layer is in the scope of about 0＜x＜0.27.
In yet another embodiment of the invention, active layer is by (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1), (Al
pGa
1-p)
zAs (≤0≤p≤1), or In
qGa
1-qAs (0≤q≤1) makes.
In another embodiment of the present invention, form pair of electrodes, this has insertion substrate therebetween to electrode, semiconductor multilayer structure, and current-diffusion layer, and the formation current barrier layer makes it in the face of an electrode in current-diffusion layer one side, and this moment, current-diffusion layer was inserted between this electrode and the current barrier layer.
In another embodiment of the present invention, form at the current-diffusion layer core at the electrode of current-diffusion layer one side, thereby through current-diffusion layer peripheral part output light.
In another embodiment of the present invention, form at the current-diffusion layer peripheral part at the electrode of current-diffusion layer one side, surround its core, thereby through the diffusion layer core output light of electric current.
In another embodiment of the present invention, current barrier layer is by comprising Ga
1-aIn
aThe material of p (0＜a＜1) is made.
In another embodiment of the present invention, current barrier layer is to be made by the compound semiconductor that contains Al.
In another embodiment of the present invention, current barrier layer is by Al
bGa
1-bAs (0≤b≤1) or (Al
cGa
1-c)
dIn
1-dP (0≤c≤1,0≤d≤1) makes.
Another program according to the present invention provides a kind of method of making semiconductor light-emitting elements.This semiconductor light-emitting elements comprises: substrate; Semiconductor multilayer structure, this structure comprise first covering of first conduction type at least, second covering of the active layer and second conduction type, and they form on substrate in this order; The current barrier layer of first conduction type, this layer forms on the part of semiconductor multilayer structure; Current-diffusion layer, this layer is by the Ga that is included in second conduction type that forms on the semiconductor multilayer structure
1-xIn
xThe material of P (0＜x＜1) is made, and covers current barrier layer; And pair of electrodes, one of electrode forms on current-diffusion layer, faces current barrier layer through the diffusion layer of overcurrent, and another electrode forms on substrate surface.This method comprises the following steps: to form semiconductor multilayer structure on substrate, and forms the protective layer of being made by the material that does not comprise Al and be used to form layer current barrier layer, that made by the compound semiconductor that comprises A1 on semiconductor multilayer structure; And be used to form the layer of current barrier layer by etching selectively, on the part of semiconductor multilayer structure, form current barrier layer.
In one embodiment of the invention, carry out the step that etching is used to form the layer of current barrier layer, on the core of semiconductor multilayer structure so that current barrier layer forms.
In another embodiment, carry out the step that etching is used to form the layer of current barrier layer,, surround its core on the peripheral part of semiconductor multilayer structure so that current barrier layer forms.
In another embodiment of the present invention, Al
bGa
1-bAs (0≤b≤1) layer or (Al
cGa
1-c)
dIn
1-dP (0≤c≤1,0≤d≤1) layer is used as current barrier layer.
Like this, the present invention described herein makes following advantage become possibility: (1) provides the semiconductor light-emitting elements that can improve element emission effciency and reliability greatly, and (2) provide the method for making this semiconductor light-emitting elements.
With reference to accompanying drawing, by reading and understanding following detailed description, to those skilled in the art, these and other advantage of the present invention will become apparent.
Fig. 1 is the semiconductor light-emitting elements cutaway view of the example 1 according to the present invention.
Fig. 2 is explanation Ga
1-xIn
xThe In gram molecule coefficient x of P and and the lattice mismatch of GaAs between the curve chart that concerns.
Fig. 3 is explanation Ga
1-xIn
xThe curve chart that concerns between the In gram molecule coefficient x of P and the band gap Eg.
Fig. 4 is the semiconductor light-emitting elements cutaway view of the example 2 according to the present invention.
Fig. 5 is the semiconductor light-emitting elements cutaway view of the example 3 according to the present invention.
Fig. 6 is the semiconductor light-emitting elements cutaway view of the example 4 according to the present invention.
Fig. 7 is the semiconductor light-emitting elements cutaway view of the example 5 according to the present invention.
Fig. 8 is the semiconductor light-emitting elements cutaway view of the example 6 according to the present invention.
Fig. 9 is the semiconductor light-emitting elements cutaway view of the example 7 according to the present invention.
Figure 10 A is the cutaway view of explanation semiconductor light-emitting elements manufacturing process of example 8 according to the present invention to 10C.
Figure 11 A is the cutaway view of explanation semiconductor light-emitting elements manufacturing process of example 9 according to the present invention to 11C.
Figure 12 is the cutaway view of conventional semiconductors light-emitting component.
Figure 13 is the cutaway view of another conventional semiconductors light-emitting component.
At first function of the present invention will be described.
According to the present invention, the Ga that electric current forms on semiconductor multilayer structure
1-xIn
xExpand in P (0＜x＜1) current-diffusion layer, make light in the wideer region generating of active layer.The GaInP current-diffusion layer comprises having the In atom bigger than P atomic radius.This big In atom stops the easy motion of P atom during the GaInP crystal growth, thereby prevents the crystal defect that is easy to generate.In addition, compare with GaP, the lattice mismatch of GaInP and GaAs substrate and the semiconductor layer that forms on the GaAs substrate is less.This has not only prevented the crystal defect that is easy to generate in current-diffusion layer itself, and at the active layer as the light radiating portion, also is like this in covering and the similar layer.
When the In of current-diffusion layer gram molecule coefficient x is 0＜x＜0.49, can passes current-diffusion layer and be not absorbed from the light of GaInP or the emission of AalGaInp active layer.In addition, can reduce because the generation of the crystal defect that causes with the lattice mismatch of GaAs substrate and the semiconductor layer that on the GaAs substrate, forms.
When the In of current-diffusion layer gram molecule coefficient x was 0＜x＜0.27, the band gap of current-diffusion layer is identical with GaP substantially.Therefore, the light from the active layer emission is not absorbed current-diffusion layer.Thereby current-diffusion layer can not degenerated because of light absorption.
By progressively change the In gram molecule coefficient x of current-diffusion layer at thickness direction, distortion of lattice progressively alleviates.Can reduce distortion of lattice in this way.
When the In gram molecule coefficient x of the current-diffusion layer that progressively changes is 0＜x＜0.49, can passes current-diffusion layer and be not absorbed from the light of GaInP or the emission of AalGaInp active layer.In addition, can reduce because the generation of the crystal defect that GaAs substrate and the lattice mismatch between the semiconductor layer that forms on the GaAs substrate cause.
When the In gram molecule coefficient x of the current-diffusion layer that progressively changes was 0＜x＜0.27, the band gap of current-diffusion layer is identical with GaP substantially.Therefore, the light from the active layer emission is not absorbed current-diffusion layer.Thereby current-diffusion layer can not degenerated because of light absorption.
Compound semiconductor is as (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1), Al
pGa
1-pAs (0≤p≤1), and In
qGa
1-qAs (0≤q≤1) can be used as active layer.By using these materials, can obtain the light radiating portion that crystal defect reduces.
Can make the electrode of current barrier layer in the face of on current-diffusion layer, forming of formation, current-diffusion layer inserts between current barrier layer and this electrode simultaneously, this electrode is to be set to substrate, one of pair of electrodes that semiconductor multilayer structure and current-diffusion layer are clipped in the middle.With this layout, electric current does not form current barrier layer below current-diffusion layer part flows.Like this, because electric current guided into the zone of desirable active layer effectively, thereby emission effciency improves in should the zone.Owing on light emitting area, do not form electrode, thereby be improved through the light output efficiency that does not form the part of electrode on the current-diffusion layer.
For example, when the core of electrode at current-diffusion layer forms, and the current barrier layer that makes formation by current-diffusion layer and electrode surface to the time, electric current is drawn towards the peripheral part of active layer, improved the emission effciency of peripheral part, and thereby improved through there not being the light output efficiency of the peripheral part that electrode forms on the diffusion layer.
Perhaps, when the peripheral part of electrode at current-diffusion layer forms, surround its core, and the current barrier layer that makes formation by current-diffusion layer and electrode surface to the time, electric current is drawn towards the core of active layer, improved the emission effciency of core, and thereby improved through there not being the light output efficiency of the core that electrode forms on the diffusion layer.
When current barrier layer by Ga
1-aIn
aP (0＜a＜1) is when making, and the lattice mismatch of current barrier layer and GaAs substrate and the semiconductor layer that forms on the GaAs substrate reduces, thereby further reduced the generation of crystal defect.
Perhaps, current barrier layer can be by compound semiconductor that comprises Al such as Al
bGa
1-bAs (0≤b≤1) and (A1
cGa
1-c)
dIn
1-dP (0≤c≤1,0≤d≤1) makes, and this current barrier layer can form on semiconductor multilayer structure by protective layer, and this protective layer is made by the material that does not comprise Al.This makes and passes through etch protection layer and current barrier layer selectively, forms current barrier layer in the desired position and become possibility.
Below, will be by way of example, describe the present invention with reference to the accompanying drawings.
(example 1)
In example 1, description is comprised Ga
1-xIn
xThe AlGaInP semiconductor light-emitting elements of P (0＜x＜1) current-diffusion layer.Fig. 1 is the cutaway view of the semiconductor light-emitting elements of example 1.
Semiconductor light-emitting elements is a LED, comprises n-type GaAs resilient coating 2 (for example, Si concentration: 5 * 10 that form on n-type GaAs substrate 1
17Cm
-3, thick: about 0.5 μ m).Be formed with semiconductor sandwich construction 12 on the resilient coating 2, this structure is by a n-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 3 (y=0.5 for example, z=0.5, Si concentration: 5 * 10
17Cm
-3, thick: about 1.0 μ m), (an Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) active layer 4 (y=0.5 for example, z=0.5 is thick: about 0.5 μ m), and a p-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 5 (y=0.5 for example, z=0.5, Zn concentration: 5 * 10
17Cm
-3, thick: as about 1.0 μ m) to constitute.One P-type Ga
1-xIn
xP (0＜x＜1) current-diffusion layer 6 (x=0.40 for example, Zn concentration: 5 * 10
18Cm
-3, thick: as about 5.0 μ m) on semiconductor multilayer structure 12, to form.One P-lateral electrode 11 forms on the core of p-type current-diffusion layer 6.One n-lateral electrode 10 forms on the whole back side of n-type substrate 1.
Because this routine semiconductor light-emitting elements comprises Ga
1-xIn
xP (x=0.4) current-diffusion layer 6, as following described with reference to Fig. 2, distortion of lattice can be reduced.
Fig. 2 is explanation Ga
1-xIn
xIn gram molecule coefficient x and the Ga of P
1-xIn
xThe curve chart that concerns between the lattice mismatch of P for GaAs.As can be seen from Figure 2, when In gram molecule coefficient x is about 0.49, Ga
1-xIn
xThe lattice constant of P and the lattice constant match of GaAs, promptly the lattice mismatch between them is 0.(x=0.40) Ga in this example
1-xIn
xP current-diffusion layer 6 is about-0.60% with the lattice mismatch of GaAs.Therefore, compare for about-3.54% conventional semiconductors light-emitting component with the lattice mismatch of GaAs with GaP current-diffusion layer shown in Figure 13, distortion of lattice has in this example reduced about 83%.
In this routine semiconductor light-emitting elements, current-diffusion layer 6 is by Ga
1-xIn
xP (x=0.40) makes, and active layer 4 is by (Al
yGa
1-y)
zIn
1-z(y=0.5 z=0.5) makes P.By this arrangement, the light that produces in the active layer 4 is not absorbed by current-diffusion layer 6.With reference to Fig. 3 this is elaborated below.
Fig. 3 is explanation Ga
1-xIn
xIn gram molecule coefficient x and the Ga of P
1-xIn
xThe curve chart that concerns between the band gap Eg of P.As can be seen from Figure 3, work as Ga
1-xIn
xThe In gram molecule coefficient x of P is 0＜x＜0.27 o'clock, the X transition occurs, and it is an indirect transition.Thereby obtain and the essentially identical band gap of GaP.Be Eg=2.27eV.Work as Ga
1-xIn
xThe In gram molecule coefficient x of P is 0.20＜x＜1 o'clock, the Γ transition occurs, and it is direct transition.Therefore band gap is littler than GaP.Ga in this example
1-xIn
xThe band gap Eg of P (x=0.40) current-diffusion layer 6 is about 2.0eV, greater than the band gap of active layer 4, i.e. Eg=1.9eV.Like this, the light that produces in active layer 4 can be exported through the upper surface of semiconductor light-emitting elements, and is not absorbed by current-diffusion layer 6.
Like this, in this routine semiconductor light-emitting elements, the crystal defect number in the current-diffusion layer 6 can reduce, and the crystal defect number that produces owing to dislocation and similar reason as the active layer 4 of light radiating portion also can significantly reduce.This has improved the emission effciency and the reliability of element greatly.In addition, because of the light that produces in the active layer 4 is not absorbed by current-diffusion layer 6, so emission effciency do not reduce, and the semiconductor light-emitting elements performance can not degenerate because of light absorption yet.In fact, when semiconductor light-emitting elements is the red LED of 650nm wavelength, compare with traditional element, it is about 20% that emission effciency improves, and because of at 60 ℃, and 20mA drives down light intensity and drops to half required time and be increased to about 1.5 times, and reliability also is improved.
In this example, constitute n-type covering, (the Al of active layer and p-type covering
yGa
1-y)
zIn
1-zBut the gram molecule coefficient y of P and z appropriate change.This also is applicable to the example of back.In the semiconductor light-emitting elements according to the present invention example that be not limited to describe in this example and the back also with the LED that describes, and can be any other form, so long as use the surface emission type semiconductor light emitting element of the compound semiconductor materials that mates with the GaAs substrate lattice to get final product.
(example 2)
In the semiconductor light-emitting elements of example 2, Ga
1-xIn
xDifferent in the In gram molecule coefficient x of P current-diffusion layer and the example 1.Fig. 4 is the cutaway view of the semiconductor light-emitting elements of example 2.
This routine semiconductor light-emitting elements is a LED, comprises n-type GaAs resilient coating 22 (for example, Si concentration: 5 * 10 that form on n-type GaAs substrate 21
17Cm
-3, thick: about 0.5 μ m).Be formed with semiconductor sandwich construction 212 on the resilient coating 22, this structure is by a n-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 23 (y=1.0 for example, z=0.5, Si concentration: 5 * 10
17Cm
-3, thick: about 1.0 μ m), (an Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) active layer 24 (y=0.45 for example, z=0.5 is thick: about 0.5 μ m) and a p-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 25 (y=1.0 for example, z=0.5, Zn concentration: 5 * 10
17Cm
-3, thick: as about 1.0 μ m) to constitute.One P-type Ga
1-xIn
xP (0＜x＜1) current-diffusion layer 26 (x=0.2 for example, Zn concentration: 5 * 10
18Cm
-3, thick: as about 5.0 μ m) on semiconductor multilayer structure 212, to form.One P-lateral electrode 211 forms on the core of p-type current-diffusion layer 26.One n-lateral electrode 210 forms on the whole back side of n-type substrate 21.
As can be seen from Figure 2, because this routine semiconductor light-emitting elements comprises Ga
1-xIn
xP (x=0.2) current-diffusion layer 26, lattice mismatch is about-2.1%.This means with the lattice mismatch of GaP current-diffusion layer shown in Figure 13 and GaAs and compare that this routine distortion of lattice has reduced about 40% for the situation of the conventional semiconductors light-emitting component of pact-3.54%.
Though the effect that reduces distortion of lattice in this example is less than the effect that is obtained in the example 1, the band gap of current-diffusion layer can be done greater than the band gap in the example 1 in this example.As can be seen from Figure 3, Ga
1-xIn
xThe band gap Eg of P (x=0.2) current-diffusion layer 26 and the band gap of GaP are basic identical, i.e. 2.27eV, and this is greater than the band gap Eg of active layer 24, i.e. 2.18eV.Like this, the green glow that produces in active layer 24 is not absorbed by current-diffusion layer 26, but exports through the upper surface of semiconductor light-emitting elements.
Like this, in this routine semiconductor light-emitting elements, the generation of the crystal defect in the current-diffusion layer 26 can reduce.This has improved the emission effciency and the reliability of element greatly.In addition, because of the green glow that produces in the active layer 24 is not absorbed by current-diffusion layer 26, so emission effciency do not reduce, and the semiconductor light-emitting elements performance can not degenerate because of light absorption yet.In fact, when semiconductor light-emitting elements is the green LED of 550nm wavelength, compare with traditional element, it is about 30% that emission effciency improves, and because of at 60 ℃, and 20mA drives down light intensity and drops to half required time and be increased to about twice, and reliability also is improved.
(example 3)
In the semiconductor light-emitting elements of example 3, Ga
1-xIn
xDifferent in the In gram molecule coefficient x of P current-diffusion layer and example 1 and 2.Fig. 5 is the cutaway view of the semiconductor light-emitting elements of example 3.
This routine semiconductor light-emitting elements is a LED, comprises n-type GaAs resilient coating 32 (for example, Si concentration: 5 * 10 that form on n-type GaAs substrate 21
17Cm
-3, thick: about 0.5 μ m).Be formed with semiconductor sandwich construction 312 on the resilient coating 32, this structure is by a n-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 33 (y=1.0 for example, z=0.5, Si concentration: 5 * 10
17Cm
-3, thick: about 1.0 μ m), (an Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) active layer 34 (y=0.30 for example, z=0.5 is thick: about 0.5 μ m) and a p-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 35 (y=1.0 for example, z=0.5, Zn concentration: 5 * 10
17Cm
-3, thick: as about 1.0 μ m) to constitute.One P-type Ga
1-xIn
xP (0＜x＜1) current-diffusion layer 36 (x=0.01 for example, Zn concentration: 5 * 10
18Cm
-3, thick: as about 5.0 μ m) on semiconductor multilayer structure 312, to form.P-lateral electrode 311 forms on the core of p-type current-diffusion layer 36.N-lateral electrode 310 forms on the whole back side of n-type substrate 31.
As can be seen from Figure 2, because this routine semiconductor light-emitting elements comprises Ga
1-xIn
xP (x=0.01) current-diffusion layer 36 is the situation of-3.54% conventional semiconductors light-emitting component approximately with respect to the lattice mismatch of GaP current-diffusion layer shown in Figure 13 and GaAs, and distortion of lattice has minimizing slightly.But compare with the use of GaP layer, in this example Ga
1-xIn
xThe effect that improves degree of crystallinity is played in the use of P (x=0.01) current-diffusion layer 36, and its reason illustrates below.
In the GaP layer, because the Ga atom combines securely with the P atom in the GaP crystal, the Ga atom only has small diffusion (migration) on crystal growing surface, cause the island growth of crystal, rather than good layer growth, and this certainly will produce crystal defect.On the contrary, in comprising the GaInP layer of In atom, even the In atomic quantity is little, the generation of crystal defect also still significantly reduces.This is because the binding energy of In atom and P atom is faint, makes the In atom can spread (migration) on crystal growing surface.Because this diffusion of In atom, the Ga atom also certainly will spread.This provides good crystal layer growth, has reduced the generation of defects of crystal, and the degree of crystallinity that therefore provides.
In this routine semiconductor light-emitting elements, as can be seen from Figure 3, Ga
1-xIn
xThe band gap Eg of P (x=0.01) current-diffusion layer 36 and the band gap of GaP are basic identical, i.e. 2.27eV, and this is greater than (A1
yGa
1-y)
zIn
1-zP (y=0.30, z=0.5) band gap of active layer 34.Therefore, the gold-tinted that produces in active layer 34 is not absorbed by current-diffusion layer 36, but exports through the upper surface of semiconductor light-emitting elements.
Like this, in this routine semiconductor light-emitting elements, the generation of the crystal defect in the current-diffusion layer 36 can reduce.This has improved the emission effciency and the reliability of element greatly.In addition, because of the gold-tinted that produces in the active layer 34 is not absorbed by current-diffusion layer 36, so emission effciency do not reduce, and the semiconductor light-emitting elements performance can not degenerate because of light absorption yet.In fact, when semiconductor light-emitting elements was the yellow led of 590nm wavelength, it is about 20% that emission effciency improves, and because of at 60 ℃, and 20mA drives down light intensity and drops to half required time and be increased to about 1.5 times, and reliability also is improved.
(example 4)
In the semiconductor light-emitting elements of example 4, on thickness direction, progressively change Ga
1-xIn
xThe In gram molecule coefficient x of P current-diffusion layer, and with In
qGa
1-q(0≤0≤q) is used as active layer to As.Fig. 6 is the cutaway view of the semiconductor light-emitting elements of example 4.
This routine semiconductor light-emitting elements is a LED, comprises n-type GaAs resilient coating 62 (for example, Si concentration: 5 * 10 that form on n-type GaAs substrate 61
17Cm
-3, thick: about 0.5 μ m).Be formed with semiconductor sandwich construction 612 on the resilient coating 62, this structure is by a n-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 63 (y=0.5 for example, z=0.5, Si concentration: 5 * 10
17Cm
-3, thick: about 1.0 μ m), an In
qGa
1-qAs (0≤q≤0) active layer 64 (q=0.6 for example, thick: about 0.5 μ m) and a P-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 65 (y=0.5 for example, z=0.5, Zn concentration: 5 * 10
17Cm
-3, thick: as about 1.0 μ m) to constitute.One P-type Ga
1-xIn
xP (0＜x＜1) current-diffusion layer 66 (x=0.4 → 0.2 for example, Zn concentration: 5 * 10
18Cm
-3, thick: as about 5.0 μ m) on semiconductor multilayer structure 612, to form.One P-lateral electrode 611 forms on the core of p-type current-diffusion layer 66.One n-lateral electrode 610 forms on the whole back side of n-type substrate 61.
In this example, from p-type covering 65 1 sides, on thickness direction, progressively change Ga from about 0.4 to about 0.2
1-xIn
xThe In gram molecule coefficient x of P current-diffusion layer 66.Therefore can gradually reduce the distortion of lattice that causes by lattice mismatch, thereby the appearance of distortion of lattice in the light radiating portion can be reduced to minimum.
In this routine semiconductor light-emitting elements, Ga
1-xIn
xThe band gap Eg of P (x=0.4 → 0.2) current-diffusion layer 66 is greater than In
qGa
1-qThe band gap of As (q=0.6) active layer 64.Therefore, the infrared light that produces in the active layer 64 can be exported through the upper surface of semiconductor light-emitting elements, and is not absorbed by current-diffusion layer 66.
Like this, in this routine semiconductor light-emitting elements, distortion of lattice reduces, and therefore emission effciency and reliability also significantly improve.In addition, because of the infrared light that produces in the active layer 64 is not absorbed by current-diffusion layer 66, so emission effciency do not reduce, and the semiconductor light-emitting elements performance can not degenerate because of light absorption yet.In fact, when semiconductor light-emitting elements was the infrared LED of 950mn wavelength, it is about 30% that emission effciency improves, and because of at 60 ℃, and 20mA drives down light intensity and drops to half required time and be increased to about 1.8 times, and reliability also is improved.
In this example, constitute the In of active layer
qGa
1-qBut the gram molecule coefficient q appropriate change of As.In
qGa
1-qAs (1≤q≤1) layer can be used as n-type and p-type covering.
(example 5)
In example 5, the AlGaAs semiconductor light-emitting elements will be described, Ga in this element
1-xIn
xThe In gram molecule coefficient x of P current-diffusion layer progressively changes on thickness direction.Fig. 7 is the cutaway view of the semiconductor light-emitting elements of example 5.
This routine semiconductor light-emitting elements is a LED, and it comprises n-type GaAs resilient coating 72 (for example, Si concentration: 5 * 10 that form on n-type GaAs substrate 71
17Cm
-3, thick: about 0.5 μ m).Be formed with semiconductor sandwich construction 712 on the resilient coating 72, this structure is by a n-type Al
pGa
1-pAs (0≤p≤1) covering 73 (p=0.7 for example, Si concentration: 5 * 10
17Cm
-3, thick: about 1.0 μ m), an Al
pGa
1-pAs (0≤p≤0) active layer 74 (p=0 for example, thick: about 0.5 μ m) and a P-type Al
pGa
1-pAs (0≤p≤1) covering 75 (p=0.7 for example, Zn concentration: 5 * 10
17Cm
-3, thick: as about 1.0 μ m) to constitute.One P-type Ga
1-xIn
xP (0＜x＜1) current-diffusion layer 76 (x=0.2 → 0.01 for example, Zn concentration: 5 * 10
18Cm
-3, thick: as about 5.0 μ m) on semiconductor multilayer structure 712, to form.In addition, a P-type Ga
1-xIn
xP (0＜x＜1) current-diffusion layer 77 (x=0.01 for example, Zn concentration: 5 * 10
18Cm
-3, thick: as about 2.0 μ m) on current-diffusion layer 76, to form.One p-lateral electrode 711 forms on the core of p-type current-diffusion layer 77.One n-lateral electrode 710 forms on the whole back side of n-type substrate 71.
In this example, from p-type covering 75 1 sides, from 0.2 to 0.01 progressively changes Ga on thickness direction
1-xIn
xThe In gram molecule coefficient x of the diffusion layer 76 of P electric current.Therefore distortion of lattice is gradually reduced, thereby the appearance of distortion of lattice in the light radiating portion is reduced to minimum.
In this routine semiconductor light-emitting elements, Ga
1-xIn
xThe band gap Eg of P (x=0.2 → 0.01) current-diffusion layer 76 is greater than Al
pGa
1-pThe band gap of As (p=0) active layer 74.Therefore, the infrared light that produces in the active layer 74 can be exported through the upper surface of semiconductor light-emitting elements, and is not absorbed by current-diffusion layer 76.
Like this, in this routine semiconductor light-emitting elements, distortion of lattice reduces, and therefore emission effciency and reliability raising.In addition, because of the infrared light that produces in the active layer 74 is not absorbed by current-diffusion layer 76, thereby emission effciency does not reduce, and the performance of semiconductor light-emitting elements can not degenerate because of light absorption yet.In fact, when semiconductor light-emitting elements was the infrared LED of 850nm wavelength, it is about 10% that emission effciency improves, and because of at 60 ℃, and 20mA drives down light intensity and drops to half required time and be increased to about 1.3 times, and reliability also must be listed as raising.
In this example, constitute n-type covering, the Al of active layer and p-type covering
pGa
1-pBut the gram molecule coefficient p appropriate change of As.
(example 6)
To describe the AlGaInP semiconductor light-emitting elements in example 6, current barrier layer forms on the core of semiconductor multilayer structure in this element, and Ga
1-xIn
xP (0＜x＜1) current-diffusion layer is formed on the current barrier layer.Fig. 8 is the cutaway view of the semiconductor light-emitting elements of example 6.
This routine semiconductor light-emitting elements is a LED, comprises n-type GaAs resilient coating 82 (for example, Si concentration: 5 * 10 that form on n-type GaAs substrate 81
17Cm
-3, thick: about 0.5 μ m).Be formed with semiconductor sandwich construction 812 on the resilient coating 82, this structure is by a n-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 83 (y=1.0 for example, z=0.5, Si concentration: 5 * 10
17Cm
-3, thick: about 1.0 μ m), (an Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) active layer 84 (y=0.15 for example, z=0.5 is thick: about 0.5 μ m) and a P-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 85 (y=1.0 for example, z=0.5, Zn concentration: 5 * 10
17Cm
-3, thick: as about 1.0 μ m) to constitute.
One n-type Ga
1-aIn
aP (0＜a＜1) current barrier layer 88 (a=0.2 for example, Si concentration: 5 * 10
17Cm
-3, thick: as about 0.5 μ m) on the core of semiconductor multilayer structure 812, to form.One p-type Ga
1-xIn
xP (0＜x＜1) current-diffusion layer 86 (x=0.2 for example, Zn concentration: 5 * 10
18Cm
-3, thick: as about 5.0 μ m) on semiconductor multilayer structure 812, to form, thereby cover current barrier layer 88.One P-lateral electrode 811 forms on the core of p-type current-diffusion layer 86, forms on the whole back side of n-type substrate 81 in the face of current barrier layer 88, one n-lateral electrodes 810 by current-diffusion layer 86.
In this example, current barrier layer 88 forms on the core of semiconductor multilayer structure 812, and current-diffusion layer 86 forms on current barrier layer 88.With this layout, further expand to the peripheral part of current-diffusion layer 86 from the electric current that p-lateral electrode 811 flows out.This has further improved through not forming the light output efficiency of current-diffusion layer 86 peripheral parts of p-lateral electrode 811 on it.In addition, because current barrier layer 88 is by n-type Ga
1-aIn
aP (0＜a＜1) makes, and image current diffusion layer 86 is the same, and it plays the effect that reduces distortion of lattice and improve element emission effciency and reliability.In fact, when semiconductor light-emitting elements was the orange LED of 610nm wavelength, it is about 30% that emission effciency improves, and because of at 60 ℃, and 20mA drives down light intensity and drops to half required time and be increased to about 2.5 times, and reliability also is improved.
In this example, current barrier layer forms on the core of semiconductor multilayer structure.So that block current flow flows to the core of light radiating portion.Perhaps, can partly form semiconductor multilayer structure, and can make the current barrier layer of formation hide the part of surrounding semiconductor multilayer structure in substrate center.In this example, current barrier layer conducts electricity, and has the conduction type identical with substrate.Perhaps, current barrier layer can be made by insulating material.This also is applicable to example 8 described later.
(example 7)
To describe the AlGaInp semiconductor light-emitting elements in example 7, current barrier layer forms on the peripheral part of semiconductor multilayer structure in this element, surrounds its core, and Ga
1-xIn
xP (0＜x＜1) current-diffusion layer is formed on the current barrier layer.Fig. 9 is the cutaway view of the semiconductor light-emitting elements of example 7.
This routine semiconductor light-emitting elements is a LED, comprises n-type GaAs resilient coating 92 (for example, Si concentration: 5 * 10 that form on n-type GaAs substrate 91
17Cm
-3, thick: about 0.5 μ m).Be formed with semiconductor sandwich construction 912 on the resilient coating 92, this structure is by a n-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 93 (y=1.0 for example, z=0.5, Si concentration: 5 * 10
17Cm
-3, thick: about 1.0 μ m), (an Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) active layer 94 (y=0.4 for example, z=0.5 is thick: about 0.5 μ m) and a P-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 95 (y=1.0 for example, z=0.5, Zn concentration: 5 * 10
17Cm
-3, thick: as about 1.0 μ m) to constitute.
One n-type Ga
1-aIn
aP (0＜a＜1) current barrier layer 98 (a=0.2 for example, Si concentration: 5 * 10
17Cm
-3, thick: as about 0.5 μ m) on the peripheral part of semiconductor multilayer structure 912, to form, surround its core.One p-type Ga
1-xIn
xP (0＜x＜1) current-diffusion layer 96 (x=0.2 for example, Zn concentration: 5 * 10
18Cm
-3, thick: as about 5.0 μ m) on semiconductor multilayer structure 912, to form, thereby cover current barrier layer 98.One P-lateral electrode 911 forms on the peripheral part of p-type current-diffusion layer 96, surrounds its core, and a n-lateral electrode 910 forms on the whole back side of n-type substrate 91.
In this example, current barrier layer 98 forms on the peripheral part of semiconductor multilayer structure 912, surrounds its core, and current-diffusion layer 96 forms on current barrier layer 98.With this layout, the current concentration that flows out from p-lateral electrode 911 is at the core of current-diffusion layer 96.This has further improved through not forming the light output efficiency of current-diffusion layer 96 cores of p-lateral electrode 911 on it.In addition, because current barrier layer 98 is by n-type Ga
1-aIn
aP (0＜a＜1) makes, and image current diffusion layer 96 is the same, and it plays the effect that reduces distortion of lattice and improve element emission effciency and reliability.In fact, when semiconductor light-emitting elements was the green LED of 550nm wavelength, it is about 35% that emission effciency improves, and because of at 60 ℃, and 20mA drives down light intensity and drops to half required time and be increased to about 2.7 times, and reliability also is improved.
In this example, current barrier layer forms on the peripheral part of semiconductor multilayer structure.Surround its core, so that block current flow flows to the peripheral part of light radiating portion.Perhaps, can form semiconductor multilayer structure, surround its core, and can make the current barrier layer of formation hide the part that semiconductor multilayer structure surrounded at substrate peripheral portion.In this example, current barrier layer conducts electricity, and has the conduction type identical with substrate.Perhaps, current barrier layer can be made by insulating material.This also is applicable to example 9 described later.
(example 8)
To describe the AlGaInP semiconductor light-emitting elements in example 8, current barrier layer is by the compound semiconductor that comprises Al, as (Al in this element
cGa
1-c)
dIn
1-dP (0≤c≤1,0≤d≤1) makes, is formed on the core of semiconductor multilayer structure, and Ga
1-xIn
xP (0＜x＜1) current-diffusion layer is formed on the current barrier layer.Figure 10 C is the cutaway view of the semiconductor light-emitting elements of example 8.
This routine semiconductor light-emitting elements is a LED, comprises n-type GaAs resilient coating 102 (for example, Si concentration: 5 * 10 that form on n-type GaAs substrate 101
17Cm
-3, thick: about 0.5 μ m).Be formed with semiconductor sandwich construction 1012 on the resilient coating 102, this structure is by a n-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 103 (y=1.0 for example, z=0.5, Si concentration: 5 * 10
17Cm
-3, thick: about 1.0 μ m), (an Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) active layer 104 (y=0.45 for example, z=0.5 is thick: about 0.5 μ m) and a P-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 105 (routine y=1.0, z=0.5, Zn concentration: 5 * 10
17Cm
-3, thick: as about 1.0 μ m) to constitute.
On semiconductor multilayer structure 1012, form a p-type Ga
1-rIn
rP (0＜r＜1) protective layer 109 (r=0.2 for example, Zn concentration: 5 * 10
18Cm
-3, thick: as about 0.5 μ m), on protective layer 109, to form a n-type (Al
cGa
1-c)
dIn
1-dP (0≤c≤1,0≤d≤1) current barrier layer 108 (c=0.2 for example, d=0.5, Si concentration: 5 * 10
17Cm
-3, thick: as about 5.0 μ m), on semiconductor multilayer structure 1012, to form a p-type Ga
1-xIn
xP (0＜x＜1) current-diffusion layer 106 (x=0.2 for example, Zn concentration: 5 * 10
18Cm
-3, thick: as about 5.0 μ m), to cover current barrier layer 108.One p-lateral electrode 1011 forms on the core of p-type current-diffusion layer 106.On the whole back side of n-type substrate 101, form in the face of current barrier layer 108, one n-lateral electrodes 1010 by current-diffusion layer 106.
This routine semiconductor light-emitting elements is for example made in following mode.
At first shown in Figure 10 A, n-type GaAs resilient coating 102, n-type (Al
yGa
1-y)
zIn
1-zP covering 103, (Al
yGa
1-y)
zIn
1-zP active layer 104, p-type (Al
yGa
1-y)
zIn
1-zP covering 105, p-type Ga
1-rIn
rP protective layer 109 and being used to form by n-type (Al
cGa
1-c)
dIn
1-dThe layer 108a of the current barrier layer that P makes is formed on the n-type GaAs substrate 101 in proper order.
Shown in Figure 10 B, etching is used to form the layer 108a of current barrier layer, so that only stay the part that is positioned at protective layer 109 cores, forms current barrier layer 108 thus then.In this etching, the use etching speed depends on the etchant of Al, for example phosphoric acid (H
3PO
4) etchant.By using this etchant, etching layer 108a that made by the compound semiconductor that comprises Al, that be used to form current barrier layer, and the protective layer of being made by the material that does not comprise Al 109 selectively stops etching when arriving protective layer 109 with box lunch.
Afterwards, shown in Figure 10 C, growth p-type Ga on the structure that is obtained
1-xIn
xP current-diffusion layer 106, and form n-lateral electrode 1010 and p-lateral electrode 1011, thus make semiconductor light-emitting elements.
Like this, in this routine semiconductor light-emitting elements, current barrier layer 108 is by (the Al that contains Al
cGa
1-c)
dIn
1-d(c=0.2 d=0.5) makes P.Therefore might be at current barrier layer 108 and Ga
1-rIn
rCarry out selectable etching between P (r=0.2) protective layer 109.This has significantly improved the output in the manufacturing process, and has reduced cost.
(example 9)
To describe the AlGInP semiconductor light-emitting elements in example 9, current barrier layer is by the compound semiconductor that comprises Al, as Al in this element
bGa
1-bAs (0≤b≤1) makes, and is formed on the peripheral part of semiconductor multilayer structure, surrounds its core, and Ga
1-xIn
xP (0＜x＜1) current-diffusion layer is formed on the current barrier layer.Figure 11 C is the cutaway view of the semiconductor light-emitting elements of example 9.
This routine semiconductor light-emitting elements is a LED, comprises n-type GaAs resilient coating 112 (for example, Si concentration: 5 * 10 that form on n-type GaAs substrate 111
17Cm
-3, thick: about 0.5 μ m).Be formed with semiconductor sandwich construction 1112 on the resilient coating 112, this structure is by a n-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 113 (y=1.0 for example, z=0.5, Si concentration: 5 * 10
17Cm
-3, thick: about 1.0 μ m), (an Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) active layer 114 (y=0.4 for example, z=0.5 is thick: about 0.5 μ m) and a P-type (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1) covering 115 (y=1.0 for example, z=0.5, Zn concentration: 5 * 10
17Cm
-3, thick: as about 1.0 μ m) to constitute.
One p-type Ga
1-rIn
rP (0＜r＜1) protective layer 119 (r=0.2 for example, Zn concentration: 5 * 10
18Cm
-3, thick: as about 0.5 μ m) on semiconductor multilayer structure 1112, to form.One n-type Al
bGa
1-bAs (0≤b≤1) current barrier layer 118 (b=0.2 for example, Si concentration: 5 * 10
17Cm
-3, thick: as about 0.5 μ m) to be formed on the peripheral part of protective layer 119, to surround its core.One p-type Ga
1-xIn
xP (0＜x＜1) current-diffusion layer 116 (x=0.2 for example, Zn concentration: 5 * 10
18m
-3, thick: as about 5.0 μ m), on semiconductor multilayer structure 1112, to form, cover current barrier layer 118.One p-lateral electrode 1111 forms on the peripheral part of p-type current-diffusion layer 116, surrounds its core, forms on the whole back side of n-type substrate 111 in the face of current barrier layer 118, one n-lateral electrodes 1110 by current-diffusion layer 116.
This routine semiconductor light-emitting elements is for example made in following mode.
At first shown in Figure 11 A, n-type GaAs resilient coating 112, n-type (Al
yGa
1-y)
zIn
1-zP covering 113, (Al
yGa
1-y)
zIn
1-zP active layer 114, p-type (Al
yGa
1-y)
zIn
1-zP covering 115, p-type Ga
1-rIn
rP protective layer 119 and being used to form by n-type Al
bGa
1-bThe layer 118a of the current barrier layer that As makes is formed on the n-type GaAs substrate 111 in proper order.
Shown in Figure 11 B, the layer 118a that etching is used to form current barrier layer so that only stay the part that is positioned at protective layer 119 peripheral parts, surrounds its core, forms current barrier layer 118 thus then.In this etching, the use etching speed depends on the etchant of Al, for example phosphoric acid (H
3PO
4) etchant.By using this etchant, etching layer 118a that made by the compound semiconductor that comprises Al, that be used to form current barrier layer, and the protective layer of being made by the material that does not comprise Al 119 selectively stops etching when arriving protective layer 119 with box lunch.
Afterwards, shown in Figure 11 C, growth p-type Ga on the structure that is obtained
1-xIn
xP current-diffusion layer 116, and form n-lateral electrode 1110 and p-lateral electrode 1111, thus make semiconductor light-emitting elements.
In this routine semiconductor light-emitting elements, current barrier layer 118 is by the Al that contains A1
bGa
1-bAs (b=0.2) makes.Therefore might be at current barrier layer 118 that contains aluminium and the Ga that does not contain aluminium
1-rIn
rCarry out selectable etching between P (r=0.2) protective layer 119.This has significantly improved the output in the manufacturing process, and has reduced cost.
As mentioned above, according to the present invention, the distortion of lattice in the current-diffusion layer can be reduced.This not only can reduce the generation of crystal defect in the current-diffusion layer itself, and can prevent the generation of crystal defect in the light radiating portion of active layer and the similar layer.The result has significantly improved emission effciency and reliability.
Be set to o＜x＜0.49 by current-diffusion layer In gram molecule coefficient, can pass current-diffusion layer and be not absorbed from the light of GaInP layer or AlGaInP layer emission.Simultaneously, the generation of crystal defect also is lowered in the current-diffusion layer.The emission effciency reliability further improves as a result.
In gram molecule coefficient by current-diffusion layer is set to 0＜x＜0.27, and light is not absorbed in current-diffusion layer, and the degree of crystallinity of current-diffusion layer improves.Emission effciency and reliability further improve as a result.
By on thickness direction, progressively changing the In gram molecule coefficient x of current-diffusion layer, distortion of lattice is alleviated gradually.This has further reduced distortion of lattice, thereby improves emission effciency and reliability.
By on 0＜x＜0.49 scope, progressively changing the In gram molecule coefficient x of current-diffusion layer, can pass current-diffusion layer and be not absorbed from the light of GaInP layer or the emission of AlGaInP layer.The generation of crystal defect simultaneously also reduces.Emission effciency and reliability further improve as a result.
By progressively change the In gram molecule coefficient x of current-diffusion layer on 0＜x＜0.27 scope, light is not absorbed in current-diffusion layer, and the degree of crystallinity of current-diffusion layer improves.Emission effciency and reliability further improve as a result.
For comprising by (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1), Al
pGa
1-pzAs (0≤p≤1), In
qGa
1-qThe optical semiconductor radiated element of the light radiating portion that As (0≤q≤1) or similar substance are made by using above-mentioned current-diffusion layer, has prevented that the light radiating portion from producing crystal defect.This has improved the emission effciency of element.
By forming by the current barrier layer of current-diffusion layer in the face of electrode, electric current is guided into the part that does not form current barrier layer below the current-diffusion layer effectively.The efficient that this has improved emission effciency and has exported through the part light that does not form electrode on the current-diffusion layer.
For example, can on the current-diffusion layer core, form electrode, and can form by the current barrier layer of current-diffusion layer in the face of electrode.In this case, be improved by the light output efficiency that does not form the peripheral part of electrode on the current-diffusion layer.
Perhaps, can on the current-diffusion layer peripheral part, form electrode, surround its core, and can form by the current barrier layer of current-diffusion layer in the face of electrode.In this case, be improved through the light output efficiency that does not form the core of electrode on the current-diffusion layer.
By with Ga
1-aIn
aP (0＜a＜1) is used as current barrier layer, and the distortion of lattice in the current barrier layer reduces.This has improved the emission effciency and the reliability of element.
By comprising the compound semiconductor of Al, as Al
bGa
1-bAs (0≤b≤1) and (Al
cGa
1-c)
dIn
1-dP (0≤c≤1,0≤d≤1) is used for current barrier layer, can form current barrier layer by selectively being etched in the position that needs.This has obviously improved the output in the manufacturing process, and has reduced production cost.
To those skilled in the art, various other modifications are apparent and make easily, and do not depart from the spirit and scope of the invention.Therefore, the description that the scope of claims is not limited to here to be done, but opposite, should understand in a wide range claim.
Claims (18)
1. a semiconductor light-emitting elements comprises:
Substrate;
Semiconductor multilayer structure, this structure comprise first covering of first conduction type at least, second covering of the active layer and second conduction type, and they form on substrate in this order; With
Current-diffusion layer, this layer is by the Ga that is included in second conduction type that forms on the semiconductor multilayer structure
1-xIn
xThe material of P (0＜x＜1) is made.
2. semiconductor light-emitting elements as claimed in claim 1, the In gram molecule coefficient x that it is characterized in that current-diffusion layer is in the scope of about 0＜x＜0.49.
3. semiconductor light-emitting elements as claimed in claim 1, the In gram molecule coefficient x that it is characterized in that current-diffusion layer is in the scope of about 0＜x＜0.27.
4. a semiconductor light-emitting elements comprises:
Substrate;
Semiconductor multilayer structure, this structure comprise first covering of first conduction type at least, second covering of the active layer and second conduction type, and they form on substrate in this order; With
Current-diffusion layer, this layer is by the Ga that is included in second conduction type that forms on the semiconductor multilayer structure
1-xIn
xThe material of P (0＜x＜1) is made, and wherein the In gram molecule coefficient x of current-diffusion layer changes on thickness direction.
5. semiconductor light-emitting elements as claimed in claim 4, the In gram molecule coefficient x of variation that it is characterized in that current-diffusion layer is in the scope of about 0＜x＜0.49.
6. semiconductor light-emitting elements as claimed in claim 4, the In gram molecule coefficient x of variation that it is characterized in that current-diffusion layer is in the scope of about 0＜x＜0.27.
7. semiconductor light-emitting elements as claimed in claim 1 is characterized in that active layer is by (Al
yGa
1-y)
zIn
1-zP (0≤y≤1,0≤z≤1), (Al
pGa
1-p)
zAs (0≤p≤1), or In
qGa
1-qAs (0≤q≤1) makes.
8. semiconductor light-emitting elements as claimed in claim 1, it is characterized in that forming pair of electrodes, this has insertion substrate therebetween to electrode, semiconductor multilayer structure, and current-diffusion layer, and the formation current barrier layer makes it in the face of an electrode in current-diffusion layer one side, and this moment, current-diffusion layer was inserted between this electrode and the current barrier layer.
9. semiconductor light-emitting elements as claimed in claim 4, it is characterized in that forming pair of electrodes, this has insertion substrate therebetween to electrode, semiconductor multilayer structure, and current-diffusion layer, and the formation current barrier layer makes it in the face of an electrode in current-diffusion layer one side, and this moment, current-diffusion layer was inserted between this electrode and the current barrier layer.
10. semiconductor light-emitting elements as claimed in claim 8 is characterized in that forming at the current-diffusion layer core at the electrode of current-diffusion layer one side, thereby through current-diffusion layer peripheral part output light.
11. semiconductor light-emitting elements as claimed in claim 8 is characterized in that forming at the current-diffusion layer peripheral part at the electrode of current-diffusion layer one side, surrounds its core, thereby through current-diffusion layer core output light.
12. semiconductor light-emitting elements as claimed in claim 8 is characterized in that current barrier layer is by comprising Ga
1-aIn
aThe material of P (0＜a＜1) is made.
13. semiconductor light-emitting elements as claimed in claim 8 is characterized in that current barrier layer is to be made by the compound semiconductor that contains Al.
14., it is characterized in that current barrier layer is by Al as the semiconductor light-emitting elements of claim 13
bGa
1-bAs (0≤b≤1) or (Al
cGa
1-c)
dIn
1-dP (0≤c≤1,0≤d≤1) makes.
15. a method of making semiconductor light-emitting elements, this semiconductor light-emitting elements comprises: substrate; Semiconductor multilayer structure, this structure comprise first covering of first conduction type at least, second covering of the active layer and second conduction type, and they form on substrate in this order; The current barrier layer of first conduction type, this layer forms on the part of semiconductor multilayer structure; Current-diffusion layer, this layer is by the Ga that is included in second conduction type that forms on the semiconductor multilayer structure
1-xIn
xThe material of P (0＜x＜1) is made, and covers current barrier layer; And pair of electrodes, one of electrode forms on current-diffusion layer, and in the face of current barrier layer, another electrode forms on substrate surface by current-diffusion layer, and this method comprises the following steps:
On substrate, form semiconductor multilayer structure, and on semiconductor multilayer structure, form the protective layer of making by the material that does not comprise Al and be used to form layer current barrier layer, that make by the compound semiconductor that comprises AL; And
Be used to form the layer of current barrier layer by etching selectively, on the part of semiconductor multilayer structure, form current barrier layer.
16., it is characterized in that carrying out the step that etching is used to form the layer of current barrier layer, so that current barrier layer forms on the core of semiconductor multilayer structure as the method for the manufacturing semiconductor light-emitting elements of claim 15.
17. as the method for the manufacturing semiconductor light-emitting elements of claim 15, it is characterized in that carrying out the step that etching is used to form the layer of current barrier layer,, surround its core on the peripheral part of semiconductor multilayer structure so that current barrier layer forms.
18. the method as the manufacturing semiconductor light-emitting elements of claim 15 is characterized in that an Al
bGa
1-bAs (0≤b≤a 1) layer or (an Al
cGa
1-c)
dIn
1-dP (0≤c≤1,0≤d≤1) layer is as current barrier layer.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP46337/97 | 1997-02-28 | ||
| JP46337/1997 | 1997-02-28 | ||
| JP4633797A JP3332785B2 (en) | 1997-02-28 | 1997-02-28 | Semiconductor light emitting device and method of manufacturing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1192057A true CN1192057A (en) | 1998-09-02 |
| CN1151562C CN1151562C (en) | 2004-05-26 |
Family
ID=12744331
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB981062644A Expired - Lifetime CN1151562C (en) | 1997-02-28 | 1998-02-28 | Semiconductor light emitting element and method for fabricating the same |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JP3332785B2 (en) |
| KR (1) | KR100329054B1 (en) |
| CN (1) | CN1151562C (en) |
| DE (1) | DE19808446C2 (en) |
| TW (1) | TW472399B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106057998A (en) * | 2016-08-10 | 2016-10-26 | 山东浪潮华光光电子股份有限公司 | GaAs-based light emitting diode chip possessing current blocking layer and current extension layer and manufacturing method thereof |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000068554A (en) | 1998-08-21 | 2000-03-03 | Sharp Corp | Semiconductor light emitting element |
| JP3472714B2 (en) * | 1999-01-25 | 2003-12-02 | シャープ株式会社 | Method for manufacturing semiconductor light emitting device |
| DE10306309A1 (en) * | 2003-02-14 | 2004-09-09 | Osram Opto Semiconductors Gmbh | Simple and cost effective process for preparation of a radiation emitting semiconductor chip based on AlGaInP useful in production of light emitting diodes (LED) |
| JP5326538B2 (en) * | 2008-12-12 | 2013-10-30 | 信越半導体株式会社 | Compound semiconductor substrate, light emitting element, compound semiconductor substrate manufacturing method, and light emitting element manufacturing method |
| KR101633814B1 (en) * | 2010-09-03 | 2016-06-27 | 엘지이노텍 주식회사 | light emitting device |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2685209B2 (en) * | 1988-03-25 | 1997-12-03 | 株式会社東芝 | Semiconductor device and semiconductor light emitting device |
| JP2831667B2 (en) * | 1988-12-14 | 1998-12-02 | 株式会社東芝 | Semiconductor laser device and method of manufacturing the same |
| US5008718A (en) * | 1989-12-18 | 1991-04-16 | Fletcher Robert M | Light-emitting diode with an electrically conductive window |
| JPH0715038A (en) * | 1993-06-21 | 1995-01-17 | Toshiba Corp | Semiconductor light emitting device |
| JP3143040B2 (en) * | 1995-06-06 | 2001-03-07 | 三菱化学株式会社 | Epitaxial wafer and method for manufacturing the same |
-
1997
- 1997-02-28 JP JP4633797A patent/JP3332785B2/en not_active Expired - Lifetime
-
1998
- 1998-02-25 TW TW087102739A patent/TW472399B/en not_active IP Right Cessation
- 1998-02-27 DE DE19808446A patent/DE19808446C2/en not_active Expired - Lifetime
- 1998-02-28 CN CNB981062644A patent/CN1151562C/en not_active Expired - Lifetime
- 1998-02-28 KR KR1019980006570A patent/KR100329054B1/en not_active IP Right Cessation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106057998A (en) * | 2016-08-10 | 2016-10-26 | 山东浪潮华光光电子股份有限公司 | GaAs-based light emitting diode chip possessing current blocking layer and current extension layer and manufacturing method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH10242510A (en) | 1998-09-11 |
| DE19808446A1 (en) | 1998-09-10 |
| TW472399B (en) | 2002-01-11 |
| KR100329054B1 (en) | 2002-08-17 |
| KR19980071848A (en) | 1998-10-26 |
| CN1151562C (en) | 2004-05-26 |
| DE19808446C2 (en) | 2003-03-13 |
| JP3332785B2 (en) | 2002-10-07 |
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