JP2006040996A - Manufacture of semiconductor light emitting element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor light emitting element of forward voltage being 2V or less, of which protrusion defects on the surface of current dispersion layer are reduced and failure due to reverse voltage or leak current is reduced, solving the problem in process. <P>SOLUTION: An electrode is formed on an n-type semiconductor substrate 1, a light emitting part in which an active layer 5 between an n-type clad layer 4 and a p-type clad layer 6, a p-type connection layer 7 formed on the light emitting part, a p-type current dispersion player 8 laminated on the p-type connection layer 7, a part of the surface of the p-type current dispersion layer 8, and the entire or partial rear surface of the semiconductor substrate. A temperature history is so set that a growth temperature T2 of the p-type connection layer 7 is lower than a growth temperature T1 of the light emitting part, a growth start temperature T3 of the p-type current dispersion layer 8 is equal to the growth temperature T2 of the p-type connection layer 7, and a growth completion temperature T3 of the p-type current dispersion layer 8 is higher than the growth temperature T1 of the light emitting part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a semiconductor light emitting device having a low forward voltage, high luminance, and high reliability.

  Recently, the demand for high-intensity red and yellow light-emitting diodes manufactured using AlGaInP-based epitaxial wafers has increased significantly. The main demand is traffic signals, automobile brake lamps, fog lights and so on.

  FIG. 7 shows a typical structure of a red band AlGaInP light emitting diode formed by metal organic vapor phase epitaxy (MOVPE).

  As shown in FIG. 7, a conventional AlGaInP-based light emitting diode includes an n-type buffer layer 22 made of GaAs, an n-type cladding layer 23 made of AlGaInP, and an AlGaInP film on an n-type semiconductor substrate 21 made of GaAs by MOVPE. An undoped active layer 24 composed of AlGaInP, a p-type cladding layer 25 composed of AlGaInP, and a p-type current distribution layer 26 composed of GaP are sequentially stacked, and a surface electrode (p side) as a first electrode is formed on a part of the surface of the p-type current distribution layer 26. Ohmic contact electrode) 28, and a back electrode (n-side common electrode) 27 as a second electrode is provided on the entire back surface of the n-type substrate 21. 23 to 25 form an AlGaInP quaternary double heterostructure part (light emitting part).

  In order to increase the brightness of the light emitting diode, a layer for dispersing current, that is, the second conductivity type current distribution layer 26 is generally provided on the second conductivity type cladding layer (p-type cladding layer 25). Is. Further, the second conductivity type current spreading layer 26 plays a role of dispersing current, and also has a role of a window layer. That is, the second conductivity type current spreading layer 26 is required to be transparent to the emitted light. Currently, GaP, GaAsP, or AlGaAs is used as the second conductivity type current spreading layer 26 that satisfies these conditions. Among these, GaP is mentioned as a material having the most transparency and capable of reducing the resistance. For this reason, in a light emitting diode using an AlGaInP-based material, GaP is most often used as the second conductivity type current spreading layer 26.

  When GaP is used for the second conductivity type current spreading layer 26, the forward voltage of the light emitting diode is increased due to the band discontinuity between the second conductivity type current spreading layer 26 made of GaP and the second conductivity type cladding layer 25. There is a problem of becoming.

  In order to solve this problem, an intervening layer having a band gap energy smaller than that of the second conductivity type cladding layer 25 is interposed between the second conductivity type current spreading layer 26 and the second conductivity type cladding layer 25 made of GaP. A method of providing a directional voltage reduction layer is disclosed (see Patent Document 1).

However, with the method of Patent Document 1 described above, the forward voltage can be reduced to some extent, but it does not reach a desired forward voltage (for example, a forward voltage of 2 V or less). Further, when the current spreading layer is grown at the same growth temperature as that of the light emitting portion, many convex defects appear on the surface, which causes a process problem. In addition, the reverse voltage of the light emitting diode is reduced, and a leak current is also generated.
JP 2000-312030 A (FIG. 1)

  As described above, the structure of the light-emitting diode disclosed in Patent Document 1 has a problem in that the forward voltage is not high yet, and the forward voltage is high.

  In addition, since the current spreading layer is grown at the same growth temperature as that of the light emitting part at 650 ° C., it has been found that many convex defects appear on the surface of the current spreading layer, which causes a problem in the process. Furthermore, there is a problem in that a reverse voltage drop and a leakage current occur.

  Accordingly, an object of the present invention is to reduce the forward voltage as low as 2 V or less, reduce the convex defects on the surface of the current dispersion layer, reduce defects due to the reverse voltage and leakage current, etc. Another object of the present invention is to provide a method for manufacturing a semiconductor light emitting device that can also solve the above problem.

  That is, an object of the present invention is to provide a semiconductor light emitting device having a low forward voltage, high luminance, and high reliability by providing a method capable of reducing the forward voltage and manufacturing with high yield.

  In order to achieve the above object, the present invention is configured as follows.

  According to a first aspect of the present invention, there is provided a method for manufacturing a semiconductor light emitting device, comprising: a first conductive type semiconductor substrate; a light emitting portion in which an active layer is provided between the first conductive type cladding layer and the second conductive type cladding layer; A second conductivity type connection layer formed on the light emitting part; a second conductivity type current spreading layer laminated on the second conductivity type connection layer; and a part of the surface of the second conductivity type current spreading layer. And a method of manufacturing a semiconductor light emitting device in which electrodes are formed on the entire back surface of the semiconductor substrate or partially, a growth temperature of the second conductivity type connection layer is lower than a growth temperature of the light emitting part, and the first The growth start temperature of the second conductivity type current spreading layer is the growth temperature of the second conductivity type connection layer, and the growth end temperature of the second conductivity type current spreading layer is higher than the growth temperature of the light emitting part. Features.

According to a second aspect of the present invention, in the method for manufacturing a semiconductor light emitting device according to the first aspect, the main material for forming the first conductive type cladding layer, the active layer, and the second conductive type cladding layer is (Al _x Ga _1-x ) _Y In _1-Y P (0 ≦ X ≦ 1, 0 ≦ Y ≦ 1).

According to a third aspect of the present invention, in the method for manufacturing a semiconductor light emitting device according to the first or second aspect, the main material for forming the second conductivity type connection layer is (Al _x Ga _1-x ) _Y In _1-YP ( 0 ≦ X ≦ 1, 0 ≦ Y ≦ 1), and the band gap is smaller than the material of the second conductivity type cladding layer.

  According to a fourth aspect of the present invention, in the method for manufacturing a semiconductor light emitting device according to any one of the first to third aspects, the material of the second conductivity type current spreading layer is GaP or GaAsP.

  The invention of claim 5 is the method of manufacturing a semiconductor light emitting device according to any one of claims 1 to 4, wherein an undoped layer having a band gap greater than or equal to a band gap of the active layer is provided between the second conductivity type cladding layer and the active layer. (For example, a Zn diffusion suppression layer) is provided.

  A sixth aspect of the present invention is the method of manufacturing a semiconductor light emitting device according to any one of the first to fifth aspects, wherein a part of the second conductivity type current spreading layer is an undoped layer.

  According to a seventh aspect of the present invention, in the method for manufacturing a semiconductor light-emitting device according to any one of the first to sixth aspects, the second conductivity type determining impurity (impurity acting so that the semiconductor becomes the second conductivity type) is zinc. It is (Zn).

<Key points of the invention>
In order to achieve the above object, the inventors have intensively studied in order to solve the above-mentioned problems, and as a result, have reached the present invention.

  That is, the present inventors provide a second conductivity type connection layer between the second conductivity type current spreading layer and the second conductivity type cladding layer, and further set the growth temperature of the second conductivity type connection layer to the light emitting portion. The second conductivity type current distribution layer is grown from the growth temperature of the second conductivity type connection layer, and the growth temperature of the second conductivity type current distribution layer is gradually increased. It has been found that when the growth is continued, scattering of Zn which is an additive of the second conductivity type connection layer can be prevented and the forward voltage can be lowered.

  It has also been found that the convex defects on the surface of the second conductivity type current spreading layer can be reduced by raising the final growth temperature of the second conductivity type current spreading layer higher than that of the light emitting portion. Furthermore, it has been found that defects such as reverse voltage and leakage current can be reduced at the same time.

  That is, by finding the above manufacturing method, an epitaxial wafer for a light-emitting diode, which is easy to process, has a low forward voltage, and has high brightness and high reliability, can be manufactured with high yield. Therefore, a light emitting diode (LED) having a low forward voltage, high luminance, and high reliability can be manufactured.

  According to the present invention, the following excellent effects can be obtained.

  By using the manufacturing method of the present invention, a first conductivity type cladding layer, an active layer, a second conductivity type cladding layer, a second conductivity type connection layer, and a second conductivity type current distribution are formed on the first conductivity type semiconductor substrate. In the semiconductor light emitting device in which the layers are stacked, the growth temperature of the second conductivity type connection layer is the lowest, the initial growth of the second conductivity type current spreading layer is the same as the growth temperature of the second conductivity type connection layer, In addition, by gradually increasing the growth temperature of the second conductivity type current spreading layer and finally the highest growth temperature of the second conductivity type current spreading layer, high brightness, high reliability, low forward direction It is possible to manufacture an LED and an epitaxial wafer for LED that have good voltage and surface condition, and have little reverse voltage and leakage current failure.

  Hereinafter, the present invention will be described based on the illustrated embodiments.

[Example]
In order to manufacture a semiconductor light emitting device according to an embodiment of the present invention, an epitaxial wafer for red light emitting diodes having a structure as shown in FIG.

On the n-type semiconductor substrate 1 made of GaAs, an n-type buffer layer (film thickness 400 nm, carrier concentration 1 × 10 ¹⁸ cm ⁻³ ) 2 and n-type DBR layer 3 made of n-type (Se-doped) GaAs by the MOVPE method. , N-type (Se-doped) (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P n-type cladding layer (film thickness 300 nm, carrier concentration 1 × 10 ¹⁸ cm ⁻³ ) 4, undoped (Al _0.10 Ga _0.90 ) _0.5 In _0.5 Active layer (film thickness 600 nm) 5 made of P, p-type clad layer (film thickness 300 nm, carrier concentration 5 × 10 ¹⁷ cm ⁻³ ) 6 made of p-type (Zn-doped) (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P P-type connection layer (thickness 75 nm, carrier concentration 4 × 10 ¹⁸ cm ⁻³ ) 7 made of p-type (Zn-doped) (Al _0.3 Ga _0.7 ) _0.5 In _0.5 P, p made of p-type (Zn-doped) GaP Type current spreading layer (thickness 14000 nm, carrier A concentration of 3 × 10 ¹⁸ cm ⁻³ ) 8 was successively grown by stacking.

  FIG. 1 shows a growth temperature profile. As shown in the figure, the growth temperature in the growth by the MOVPE method is such that the growth temperature T1 from the n-type buffer layer 2 to the p-type cladding layer 6 (section A in FIG. 1) is 650 ° C., and the p-type connection layer. The growth temperature T2 in the section B where 7 is grown was 580 ° C.

  In the section C where the p-type current spreading layer 8 is grown, the growth starts from 580 ° C. (T2), which is the temperature at the end of the growth of the p-type connection layer 7, and the temperature is gradually raised. The final growth temperature T3 of the p-type current spreading layer 8 was 660 ° C. That is, the growth initial portion (section C1 in FIG. 1) closer to the light emitting portion of the p-type current spreading layer 8 is a growth layer (graded growth portion) in which the growth temperature has changed to graded from 580 ° C. to 660 ° C. It was.

  Other growth conditions were a growth pressure of 50 Torr, a growth rate of each layer of 0.3 to 1.0 nm / s, and a V / III ratio of 200. However, only the V / III ratio of the p-type current spreading layer 8 was set to 10.

Examples of raw materials used in the growth by the MOVPE method include organic metals such as trimethylgallium (TMG) or triethylgallium (TEG), trimethylaluminum (TMA), trimethylindium (TMI), arsine (AsH ₃ ), phosphine (PH ₃ ) etc., hydride gas was used.

For example, hydrogen selenide (H ₂ Se) is used as a raw material (hereinafter referred to as additive raw material) for adding an n-type layer conductivity type determining impurity such as an n-type GaAs n-type buffer layer 2. It was. Further, diethyl zinc (DEZn) was used as an additive material for a p-type layer such as the p-type cladding layer 6 made of p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P. However, silane (SiH ₄ ), diethyl tellurium (DETe), and dimethyl tellurium (DMTe) can also be used as the additive material for the n-type layer. In addition, dimethyl zinc (DMZn) can also be used as an additive material for the p-type layer.

  The surface of the epitaxial wafer manufactured under the growth conditions as described above was a mirror surface without convex defects.

  On the upper surface of the epitaxial wafer, a circular surface electrode 9 having a diameter of 110 μm was formed by evaporation in a matrix form. As the surface electrode 9, gold, beryllium, nickel, and gold were deposited in the order of 40 nm, 10 nm, and 1000 nm, respectively. Further, a back electrode 10 was formed on the entire bottom surface of the epitaxial wafer. As this back electrode 10, gold, germanium, nickel, and gold were vapor-deposited in the order of 60 nm, 10 nm, and 500 nm, respectively, and then alloying of the electrode was performed at 400 ° C. for 5 minutes in a nitrogen gas atmosphere.

  Thereafter, the LED epitaxial wafer with an electrode configured as described above was cut so that the circular surface electrode 9 was at the center, and a light emitting diode bare chip having a chip size of 300 μm square was produced. Further, this light emitting diode bare chip was mounted (die bonding) on a TO-18 stem, and then wire bonding was further performed on the mounted light emitting diode bare chip to produce a light emitting diode (LED) element.

  The light emission output of the LED element when energized with 20 mA was 1.96 mW, and the forward voltage at 20 mA was 1.94 V. That is, a forward voltage of 2 V or less could be achieved.

  Moreover, when the reliability test of the test condition: 25 ° C. and 50 mA energization was performed, the relative output after the 168 hr energization test (relative output: luminescence output after 168 hr energization test / initial emission output) was 98%.

  Incidentally, the current value at the time of reliability evaluation is 20 mA. Furthermore, defects due to reverse voltage and leakage current could be eliminated.

[Comparative Example 1]
As Comparative Example 1, an epitaxial wafer for a red light emitting diode having a structure as shown in FIG.

  The epitaxial growth method, the epitaxial layer thickness, the epitaxial structure, the electrode formation method, and the LED element manufacturing method in Comparative Example 1 were basically the same as those in the above example. However, as shown in FIG. 4, the growth temperature of all epitaxial layers is fixed at 650 ° C. with T1 = T2 = T3.

  The surface of the epitaxial wafer manufactured under the growth conditions as described above had many convex defects.

  When an LED element was manufactured using this epitaxial wafer, the epitaxial wafer was cracked in a process step, and the number of acquired LED elements was reduced.

  Moreover, as a result of evaluating the characteristics of the LED element manufactured by attaching an electrode to the epitaxial wafer, the light emission output was 1.86 mW when energized with 20 mA. The forward voltage was 2.02 V, and a forward voltage of 2 V or less could not be achieved. Furthermore, reverse voltage and leakage current failures frequently occurred. For this reason, it was not possible to manufacture LED elements with high brightness and low forward voltage with high yield.

[Comparative Example 2]
As Comparative Example 2, an epitaxial wafer for red light emitting diodes having an emission wavelength of about 630 nm and having the structure shown in FIG.

The epitaxial growth method, epitaxial layer thickness, epitaxial structure, electrode forming method, and LED element manufacturing method of Comparative Example 2 were basically the same as those in the above example. However, as shown in FIG. 5, the growth temperature is the growth temperature T1 from the n-type buffer layer 2 made of n-type GaAs to the p-type connection layer 7 made of p-type (Al _0.3 Ga _0.7 ) _0.5 In _0.5 P. = T2 was set to 650 ° C., and the growth temperature T3 of the p-type current dispersion layer 8 made of p-type GaP was set to 660 ° C.

Incidentally, the growth temperature T3 of the p-type current spreading layer 8 made of p-type GaP from the temperature at the end of the growth of the p-type connection layer 7 made of p-type (Al _0.3 Ga _0.7 ) _0.5 In _0.5 P (T2 = 650 ° C.). In the section C1 until the temperature rises to 660 ° C., the p-type current distribution layer 8 is not grown, and after the temperature is stabilized at 660 ° C., the p-type current distribution layer 8 is grown ( Section C2 in FIG.

  The surface of the epitaxial wafer manufactured under the growth conditions as described above was a mirror surface without convex defects.

  Using this epitaxial wafer, the characteristics of the LED element manufactured with electrodes were evaluated. As a result, the light emission output was 1.79 mW when energized with 20 mA. The forward voltage was 2,04V, and a forward voltage of 2V or less could not be achieved. For this reason, an LED element having a high luminance and a low forward voltage could not be manufactured. Incidentally, there was no reverse voltage and leakage current failure.

[Comparative Example 3]
As Comparative Example 3, an epitaxial wafer for red light-emitting diodes having a structure as shown in FIG.

The epitaxial growth method, epitaxial layer film thickness, epitaxial structure, electrode forming method, and LED element manufacturing method of Comparative Example 3 were basically the same as those in the above example. However, as shown in FIG. 6, the growth temperature is a growth temperature T1 from the n-type buffer layer 2 made of n-type GaAs to the p-type cladding layer 6 made of p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P. The growth temperature T2 of the p-type connection layer 7 made of p-type (Al _0.3 Ga _0.7 ) _0.5 In _0.5 P is 580 ° C., and the growth temperature T3 of the p-type current spreading layer 8 made of p-type GaP is The temperature was 660 ° C. Incidentally, from the temperature 580 ° C. at the end of the growth of the p-type connection layer 7 made of the p-type (Al _0.3 Ga _0.7 ) _0.5 In _0.5 P to 660 ° C. which is the growth temperature of the p-type current spreading layer 8 made of the p-type GaP. In the section C1 until the temperature rises (section C1 in FIG. 6), the p-type current distribution layer 8 made of p-type GaP is not grown, and after the temperature is stabilized at 660 ° C., the p-type GaP The p-type current spreading layer 8 was grown (section C2 in FIG. 6).

  The surface of the epitaxial wafer manufactured under the growth conditions as described above was a mirror surface without convex defects.

  Using this epitaxial wafer, the characteristics of the LED element manufactured with electrodes were evaluated. As a result, the light emission output was 1.80 mW when energized with 20 mA. The forward voltage was 2.01 V, and a forward voltage of 2 V or less could not be achieved. For this reason, an LED element with high luminance and low forward voltage could not be manufactured. Incidentally, there was no reverse voltage and leakage current failure.

<Reason for optimal conditions>
First, when the growth temperature T3 of the second conductivity type current spreading layer 8 made of GaP is 650 ° C. or less, many convex defects appear on the surface of the second conductivity type current spreading layer 8. For this reason, problems such as epitaxial wafer cracking in the process steps arise. Further, if this convex defect exists, the reverse voltage failure and the leakage current failure frequently occur, although the reason is not clear. Currently, the growth temperature T3 of the second-conductivity-type current spreading layer 8 made of GaP is probably low, which causes reverse voltage failure and leakage current failure due to the amount of carbon (C), that is, auto-doped C. I think that.

  Further, when the growth temperature T3 of the second conductive type current spreading layer 8 made of GaP becomes 670 ° C. or more, the surface of the second conductive type current spreading layer 8 made of GaP has no convex defect and becomes a mirror surface. . However, since the doping efficiency of Zn, which is an additive, is reduced, current dispersion is deteriorated and the light emission output is lowered. Furthermore, when the growth temperature T3 increases, the diffusion of Zn increases and the reliability decreases. Therefore, the growth temperature T3 of the second conductivity type current spreading layer 8 is preferably 655 to 665 ° C., more preferably 660 ° C.

  Secondly, the lower the growth temperature T2 of the second conductivity type connection layer 7, the lower the forward voltage. However, if it is too low, the crystallinity is deteriorated and the diffusion of Zn increases. For this reason, reliability deteriorates. Further, when the growth temperature T2 of the second conductivity type connection layer 7 is increased, the doping efficiency of Zn decreases, and the second conductivity type current spreading layer 8 made of GaP which is the effect of the second conductivity type connection layer 7 and the first The effect of relaxing the band discontinuity of the two-conductivity-type cladding layer 6 is reduced, and the forward voltage is not lowered. For this reason, the growth temperature T2 of the second conductivity type connection layer 7 has an optimum value. Therefore, the growth temperature T2 of the second conductivity type connection layer 7 is preferably 550 ° C. to 630 ° C., and more preferably 570 ° C. to 600 ° C.

  Third, if the band gap of the second conductivity type connection layer 7 is too large, the second conductivity type current spreading layer 8 made of GaP which is the effect of the second conductivity type connection layer 7 and the second conductivity type. The effect of relaxing the band discontinuity of the cladding layer 6 is reduced. Furthermore, the doping efficiency of Zn decreases. For this reason, a forward voltage becomes high.

  On the other hand, if the band gap of the second conductivity type connection layer 7 is too small, it becomes an absorption layer for the emitted light, and the light emission output is lowered.

  For this reason, the band gap of the second conductivity type connection layer 7 has an optimum value. Therefore, the band gap of the second conductivity type connection layer 7 is preferably equal to or greater than the band gap equivalent to the emitted light, and preferably equal to or less than the band gap of the second conductivity type cladding layer 6.

  However, even if the band gap of the second conductivity type connection layer 7 is smaller than the emitted light, if the film thickness is reduced, light absorption can be minimized. For this reason, a material having a smaller band gap than the emitted light can be used for the second conductivity type connection layer 7. In this case, the film thickness of the second conductivity type connection layer 7 is preferably 30 nm to 200 nm. More preferably, it is 50 to 100 nm. This is because when a material having a smaller band gap than the emitted light is used for the second conductivity type connection layer 7, the light absorption is large when the film thickness is 200 nm or more.

  In the present invention, the growth temperature is defined, but the growth temperature varies depending on each device. For this reason, it is difficult to define it in general. For this reason, a second conductivity type connection layer 7, which is a material having a band gap smaller than that of the second conductivity type cladding layer 6, is provided between the second conductivity type cladding layer 6 and the GaP current spreading layer 8, and the second The growth temperature T2 of the conductive type connection layer 7 is lower than the growth temperature T1 from the first conductive type buffer layer 2 to the second conductive type cladding layer 6, and further, a second conductive type current spreading layer made of GaP. 8 is started from the same temperature T2 as that of the second conductivity type connection layer 7, and the final growth temperature T3 of the second conductivity type current spreading layer 8 made of GaP is changed from the first conductivity type buffer layer 2 to the first temperature. The purpose of the present invention is to make the temperature higher than the growth temperature T 1 up to the two-conductivity-type cladding layer 6. For this reason, it is important to obtain the temperature history as described above rather than the absolute temperature of each layer.

<Other embodiments and modifications>
[Modification 1]
It is possible to adopt a structure in which a diffusion suppression layer for suppressing the diffusion of Zn is provided between the active layer 5 and the second conductivity type cladding layer 6, and it can be easily analogized that the same effect can be obtained even under this structure. . This diffusion suppression layer is configured as an undoped layer, for example, but may be configured as a low concentration first conductivity type or a low concentration second conductivity type. However, if the diffusion suppression layer is too thick, the series resistance increases and the forward voltage increases. In addition, the manufacturing cost increases.

  Therefore, when this diffusion suppression layer is provided, the thickness is preferably 1500 nm or less. In any case, it is easily inferred that the present invention can be applied regardless of the presence or absence of the diffusion suppressing layer.

[Modification 2]
In the embodiment, a red LED having a light emission wavelength of 630 nm is used, but a similar effect can be obtained even with an LED having a light emission wavelength of 560 to 650 nm manufactured using the same AlGaInP-based material.

[Modification 3]
Even in a structure without the buffer layer and the DBR layer which is a light reflecting layer, the same effect as the present invention can be obtained.

[Modification 4]
In the embodiment, Zn is used as the second conductivity type determining impurity, but the same effect can be obtained when magnesium (Mg) is used.

[Modification 5]
In the embodiment, the shape of the surface electrode is circular, but the same effect can be obtained by using an irregular shape such as a square, a rhombus, or a polygon.

It is the figure which showed the growth temperature program of AlGaInP type | system | group red LED concerning one Example of this invention. It is the figure which showed the cross-section of AlGaInP type | system | group red LED concerning one Example of this invention. It is the figure which compared and showed the forward voltage of the AlGaInP type | system | group red LED concerning the Example and comparative example of this invention. It is the figure which showed the growth temperature program concerning the comparative example 1. FIG. It is the figure which showed the growth temperature program concerning the comparative example 2. FIG. It is the figure which showed the growth temperature program concerning the comparative example 3. FIG. It is the figure which showed the cross-section of AlGaInP type | system | group red LED concerning a prior art.

Explanation of symbols

1 n-type semiconductor substrate (first conductivity type semiconductor substrate)
2 n-type buffer layer (first conductivity type buffer layer)
3 n-type DBR layer 4 n-type cladding layer (first conductivity type cladding layer)
5 active layer 6 p-type cladding layer (second conductivity type cladding layer)
7 p-type connection layer (second conductivity type connection layer)
8 p-type current spreading layer (second conductivity type current spreading layer)
9 Front electrode 10 Back electrode

Claims (7)

A first conductivity type semiconductor substrate; a light emitting portion in which an active layer is provided between the first conductivity type cladding layer and the second conductivity type cladding layer; and a second conductivity type connection layer formed on the light emission portion A second conductivity type current spreading layer laminated on the second conductivity type connection layer, a part of the surface of the second conductivity type current spreading layer, and the whole or part of the back surface of the semiconductor substrate. In the method of manufacturing a semiconductor light emitting device in which is formed,
The growth temperature of the second conductivity type connection layer is lower than the growth temperature of the light emitting portion, and the growth start temperature of the second conductivity type current spreading layer is the growth temperature of the second conductivity type connection layer, A method of manufacturing a semiconductor light emitting element, wherein a growth end temperature of the second conductivity type current spreading layer is higher than a growth temperature of the light emitting part. In the manufacturing method of the semiconductor light-emitting device according to claim 1,
The main material for forming the first conductivity type cladding layer, the active layer, and the second conductivity type cladding layer is (Al _x Ga _{1 -x} ) _Y In _1-Y P (0 ≦ X ≦ 1, 0 ≦ Y ≦ 1) A method for producing a semiconductor light emitting device, wherein In the manufacturing method of the semiconductor light-emitting device according to claim 1 or 2,
The main material is the _{(Al x Ga 1-x)} Y In 1-Y P (0 ≦ X ≦ 1,0 ≦ Y ≦ 1), and said second conductivity type cladding forming the second conductivity type connection layer A method for manufacturing a semiconductor light emitting device, wherein the band gap is smaller than that of a layer material. In the manufacturing method of the semiconductor light-emitting device according to any one of claims 1 to 3,
A method of manufacturing a semiconductor light emitting device, wherein the material of the second conductivity type current spreading layer is GaP or GaAsP. In the manufacturing method of the semiconductor light-emitting device according to any one of claims 1 to 4,
A method of manufacturing a semiconductor light emitting device, comprising providing an undoped layer having a band gap greater than that of an active layer between the second conductivity type cladding layer and the active layer. In the manufacturing method of the semiconductor light-emitting device according to claim 1,
A method of manufacturing a semiconductor light emitting device, wherein a part of the second conductivity type current spreading layer is an undoped layer. In the manufacturing method of the semiconductor light-emitting device according to any one of claims 1 to 6,
The method of manufacturing a semiconductor light emitting device, wherein the second conductivity type determining impurity is zinc.

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