JP3556593B2 - Compound semiconductor light emitting device and method of manufacturing the same - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a compound semiconductor light emitting device and a method of manufacturing the same, and more particularly to a semiconductor laser diode and a light emitting diode capable of emitting light in a blue region.
[0002]
[Prior art]
FIG. 17 is a diagram showing a schematic cross section of a conventional AlGaN / InGaN / AlGaN-based compound semiconductor light emitting device (semiconductor laser, light emitting diode) capable of emitting light in the blue region.
[0003]
Referring to the figure, a semiconductor light emitting device includes a sapphire (0001) substrate 1, a GaN or AlN buffer layer 2, an n-type GaN layer 3, and an n-type Al_ZGa_1-ZN (0 ≦ Z ≦ 1) lower cladding layer 4, non-doped or Zn-doped In_YGa_1-YN (0 ≦ Y ≦ 1) active layer (also called light emitting layer) 5, p-type Al_ZGa_1-ZIt is composed of an N (0 ≦ Z ≦ 1) upper cladding layer 7 and a p-type GaN cap layer 8. An n-type electrode 10 is formed on the n-type GaN layer 3 and a p-type electrode 9 is formed on the p-type GaN cap layer 8.
[0004]
Such a compound semiconductor light emitting device is generally manufactured through the following steps by a metal organic chemical vapor deposition method (hereinafter, referred to as “MOCVD method”).
(1) The surface treatment of the sapphire substrate 1 is performed at a temperature of about 1050 ° C.
(2) The substrate temperature is lowered to about 510 ° C., and a thin GaN or AlN buffer layer 2 is grown.
(3) The substrate temperature is raised to 1020 ° C., and the n-type GaN layer 3 is grown.
(4) At the same temperature, the n-type AlGaN lower cladding layer 4 is grown.
(5) The substrate temperature is lowered to about 800 ° C., and the non-doped InGaN-based active layer (or Zn-doped light emitting layer) 5 is grown to a thickness of about 100 to 500 °.
(6) The substrate temperature is raised to about 1020 ° C., and the p-type AlGaN upper cladding layer 7 is grown.
(7) The p-type GaN cap layer 8 is grown at the same temperature.
(8) After the etching, the p-type electrode 9 and the n-type electrode 10 are formed.
[0005]
In the above-described steps, the temperature at which the active layer 5 containing In is grown is set to about 800 ° C. because the vapor pressure of In is relatively high. Because you can not get. The reason why the growth temperature of the AlGaN cladding layer is set to 1020 ° C. is that a film of good crystal quality cannot be formed unless the AlGaN cladding layer is grown at a temperature of 1000 ° C. or higher.
[0006]
Therefore, during the steps (4) to (6) described above, the light emitting element follows the growth temperature profile shown in FIG. In FIG. 16, the horizontal axis indicates the semiconductor growth direction, and the vertical axis indicates the growth temperature.
[0007]
[Problems to be solved by the invention]
However, when the substrate temperature is raised to about 1020 ° C. in order to grow the p-type AlGaN upper cladding layer 7, the above-described conventional method for manufacturing a compound semiconductor includes an active layer containing In formed in the previous step. (Light-Emitting Layer) There was a problem that In was liberated from 5. The release of In leads to the deterioration of the interface between the active layer 5 and the upper cladding layer 7 and the difficulty in controlling the thickness of the active layer 5 and the In crystal ratio. Was.
[0008]
The present invention has been made in order to solve the above-mentioned problems, and it is possible to minimize the release of In in the manufacturing process of a compound semiconductor light emitting device, to enable crystal growth with excellent controllability, and to improve the activity including In of high quality. It is an object of the present invention to provide a compound semiconductor light emitting device having an interface between a layer and a high quality active layer.
[0010]
[Means for Solving the Problems]
Further, in the method for manufacturing a compound semiconductor light emitting device of the present invention, a first step of forming a lower clad layer and a second step of forming an active layer containing In at a first temperature on the lower clad layer A third step of forming an evaporation-preventing layer on the active layer at a second temperature higher than the first temperature; and a third temperature higher than the second temperature on the evaporation-preventing layer. And forming a fourth step of forming an upper cladding layer with.
GoodPreferably, the active layer has the formula Al_XGa_YIn_ZN (X + Y + Z = 1 and 0 ≦ XY
≦ 1, 0 <Z ≦ 1).
Preferably, the evaporation preventing layer is made of Al_XGa_1-XIt is characterized by being composed of a substance constituted by N (0 ≦ X ≦ 1).
Preferably said active layer is In_yGa_{1- y}It is characterized by being composed of a substance composed of As (0 <y ≦ 1).
Preferably, the evaporation preventing layer is made of Al_XGa_1-XIt is characterized by being composed of a substance composed of As (0 ≦ X ≦ 1).
Preferably, the evaporation prevention layer is formed using Mg or Zn as a p-type dopant.
[0013]
The compound semiconductor light emitting device of the present invention includes an evaporation preventing layer on an active layer. The presence of the evaporation prevention layer prevents the release of In in the active layer, which has conventionally occurred during the manufacture of the compound semiconductor light emitting device.
[0014]
In the method for manufacturing a compound semiconductor light emitting device of the present invention, the lower cladding layer is formed in the first step. In the second step, Al is deposited on the lower cladding layer at a first temperature._XGa_yIn_zAn active layer composed of N (X + Y + Z = 1 and 0 ≦ XY · 1, 0 <Z ≦ 1) is formed. In a third step, Al is formed on the active layer at a second temperature equal to or lower than the first temperature._XGa_1-XAn evaporation prevention layer composed of N (0 ≦ X ≦ 1) is formed.
[0015]
In the method for manufacturing a compound semiconductor light emitting device of the present invention, the lower cladding layer is formed in the first step. In the second step, Al_XGa_YIn_ZAn active layer composed of N (X + Y + Z = 1 and 0 ≦ XY · 1, 0 <Z ≦ 1) is formed. In the third step, Al is formed on the active layer at a second temperature higher than the first temperature._XGa_1-XAn evaporation prevention layer composed of N (0 ≦ X ≦ 1) is formed. In a fourth step, an upper cladding layer is formed on the evaporation prevention layer at a third temperature equal to or higher than the second temperature.
[0016]
In the method for manufacturing a compound semiconductor light emitting device of the present invention, the lower cladding layer is formed in the first step. In a second step, Al is deposited on the lower cladding layer at a first temperature._XGa_YIn_ZAn active layer composed of N (X + Y + Z = 1 and 0 ≦ XY · 1, 0 <Z ≦ 1) is formed. In the third step, Al is formed on the active layer at substantially the same temperature as the first temperature._XGa_1-XAn evaporation prevention layer composed of N (0 ≦ X ≦ 1) is formed.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in order. In the present embodiment, the growth conditions, the type of the organometallic compound gas, and the materials used are not limited to the following. In this embodiment, various changes can be made within the scope of the claims.
[0018]
(First embodiment)
In the first embodiment, the sapphire (0001) c-plane is used as a substrate, and each layer is grown by MOCVD. Also, trimethyl gallium (TMG), trimethyl aluminum (TMA) and trimethyl indium (TMI) are used as group III gas sources, and ammonia (NH₃) Is used, and monosilane (SiH) is used as an n-type dopant source.₄) Is biscyclopentadienyl magnesium (Cp₂Mg) is used, and H is used as a carrier gas.₂Is used.
[0019]
FIG. 1 is a schematic sectional view of a semiconductor laser diode according to a first embodiment of the present invention.
[0020]
Referring to the drawings, a semiconductor laser diode according to the present embodiment has a sapphire substrate 1, a GaN or AlN buffer layer 2, an n-type GaN layer 3, an n-type Al layer formed on a sapphire (0001) c-plane substrate 1 in this order._0.1Ga_0.9N lower cladding layer 4, non-doped or Si-doped In_0.2Ga_0.8N active layer (or light emitting layer) 5, thin p-type Al_0.05Ga_0.95N evaporation prevention layer 6, p-type Al_0.1Ga_0.9It is composed of an N upper cladding layer 7 and a p-type GaN cap layer 8. An n-type electrode 10 is formed on the n-type GaN layer 3, and a p-type electrode 9 is formed on the p-type GaN cap layer 8.
[0021]
The stacked state of the semiconductor differs from the conventional stacked state of the semiconductor shown in FIG. 17 in that the evaporation preventing layer 6 is provided between the active layer 5 and the upper cladding layer 7.
[0022]
The semiconductor laser shown in FIG. 1 is formed by the following steps. (1) The sapphire substrate 1 is introduced into the MOCVD apparatus, and the substrate is₂The substrate is heated at a substrate temperature of about 1050 ° C. to perform a surface treatment on the substrate.
(2) The substrate temperature is lowered to about 500 ° C., and a GaN or AlN buffer layer 2 is grown. At this time, the thickness of the buffer layer 2 is 250 ° for GaN and 500 ° for AlN.
(3) The substrate temperature is raised to about 1020 ° C., and the n-type GaN layer 3 is grown to a thickness of about 4 μm. At this point, the laminated structure shown in FIG. 3 is formed.
(4) n-type Al at the same substrate temperature_0.1Ga_0.9The N lower cladding layer 4 is grown to a thickness of about 1 μm. FIG. 4 shows the laminated state of the substrate at this time.
(5) The temperature of the substrate is lowered to about 800 ° C., and the temperature of the substrate is reduced to non-doped or Si-doped In._0.2Ga_0.8An N active layer (or light emitting layer) is grown to a thickness of about 200 °. FIG. 5 shows the laminated state of the substrate at this time.
(6) Set the substrate temperature to non-doped or Si-doped In_0.2Ga_0.8N active layer (or light emitting layer)._0.05Ga_0.95The N evaporation preventing layer 6 is grown. FIG. 6 shows the state of lamination of the substrates at this time.
(7) Raise the substrate temperature to about 1020 ° C._0.1Ga_0.9The N upper cladding layer 7 is grown with a thickness of about 1 μm.
(8) Next, at the same temperature, a p-type electrode GaN cap layer 8 is grown to a thickness of about 1 μm. FIG. 7 shows the laminated state of the substrate at this time.
[0023]
Thin p-type Al_0.05Ga_0.95The N evaporation preventing layer 6 becomes a good quality film while the substrate temperature is raised to about 1020 ° C.
[0024]
The wafer manufactured as described above has N₂Thermal annealing is performed inside. By thermal annealing, thin p-type Al_0.05Ga_0.95N evaporation prevention layer 6, p-type Al_0.1Ga_0.9The N upper cladding layer 7 and the p-type GaN cap layer 8 change to a high concentration p-type layer.
[0025]
Next, in order to perform electrode attachment, a part of the wafer is etched until the n-type GaN layer 3 is exposed. Thereafter, the p-type electrode 9 and the n-type electrode 10 are formed. Through the above steps, the AlGaN / InGaN / AlGaN-based semiconductor laser diode shown in FIG. 1 is manufactured.
[0026]
FIG. 2 is a diagram showing a crystal growth temperature profile during the formation of the lower cladding layer 4 to the upper cladding layer 7 of the semiconductor laser diode of FIG.
[0027]
As described above, in the compound semiconductor light emitting device of the present embodiment, after forming the active layer 5, the evaporation preventing layer 6 is formed at a temperature equal to or lower than the growth temperature of the active layer 5, and then the upper cladding layer 7 is formed at a substrate temperature of about 1020 ° C. It is formed. Therefore, release of In contained in the active layer 5 is prevented from occurring, whereby it is possible to provide a compound semiconductor light emitting device having an interface between an active layer containing good quality In and an active layer having good quality, and In the manufacturing process, crystal growth with excellent controllability becomes possible.
[0028]
FIG. 8 is a schematic sectional view of a light emitting diode which is a modification of the present embodiment. Referring to FIG. 8, the light emitting diode differs from the semiconductor laser diode shown in FIG. 1 in that p-type electrode 9 is formed small. This is because the light emitted by the active layer 5 is also output upward through the upper cladding layer 7 and the cap layer 8.
[0029]
(Second embodiment)
FIG. 9 is a diagram showing a growth temperature profile from the lower cladding layer to the upper cladding layer of the compound semiconductor light emitting device according to the second embodiment of the present invention.
[0030]
Since the laminated structure of the compound semiconductor light emitting device in this embodiment is the same as that of the first embodiment shown in FIGS. 1 and 8, description thereof will not be repeated here. The compound semiconductor light emitting device according to the second embodiment is characterized in that the evaporation preventing layer is formed at a substrate temperature not lower than the growth temperature of the active layer containing In and not higher than the growth temperature of the upper cladding layer.
[0031]
In the second embodiment, MOCVD is used for crystal growth, and a sapphire (0001) c-plane is used as a substrate. Also, trimethyl gallium (TMG), trimethyl aluminum (TMA) and trimethyl indium (TMI) are used as group III gas sources, and ammonia (NH₃) Is used. Monosilane (SiH) is used as an n-type dopant source.₄) Is biscyclopentadienyl magnesium (Cp₂Mg) as a carrier gas₂Is used. The manufacturing process will be described below.
(1) A sapphire substrate is introduced into the MOCVD apparatus, and the substrate is H₂The substrate is heated at a substrate temperature of about 1050 ° C. to perform a surface treatment on the substrate.
(2) Lower the substrate temperature to about 500 ° C. and form a GaN or AlN buffer layer. At this time, the thickness of the buffer layer is 250 ° for GaN and 500 ° for AlN.
(3) The substrate temperature is raised to about 1020 ° C., and an n-type GaN layer is grown to about 4 μm.
(4) n-type Al at the same substrate temperature_0.1Ga_0.9The N lower cladding layer 4 is grown to about 1 μm.
(5) The substrate temperature is lowered to about 800 ° C., and the non-doped or Si-doped In_0.2Ga_0.8An N active layer (or “light emitting layer”) is grown to a thickness of about 200 °.
(6) Set the substrate temperature to non-doped or Si-doped In_0.2Ga_0.8N-type active layer growth temperature or higher and p-type Al_0.1Ga_0.9A thin p-type Al at about 900 ° C. which is lower than the growth temperature of the N upper cladding layer._0.05Ga_0.95A N evaporation prevention layer is grown.
(7) Raise the substrate temperature to about 1020 ° C._0.1Ga_0.9The N upper cladding layer is grown to about 1 μm.
(8) Growing a p-type electrode GaN cap layer by about 1 μm. Thin p-type Al_0.05Ga_0.95The N evaporation preventing layer becomes a good quality film while the substrate temperature is raised to about 1020 ° C.
[0032]
After crystal growth, the wafer is subjected to thermal annealing and etching, and then electrodes are formed. Since these steps are the same as those in the first embodiment, description thereof will not be repeated here.
[0033]
As described above, in this embodiment, after the formation of the active layer containing In, the evaporation prevention layer is formed at a growth temperature of the active layer or higher and a growth temperature of the upper cladding layer or lower. As a result, crystal growth with excellent controllability becomes possible, and it becomes possible to provide an active layer containing high quality In and an interface between the active layers.
[0034]
(Third embodiment)
The laminated state of the compound semiconductor light emitting device manufactured in the third embodiment is the same as the laminated state of the compound semiconductor light emitting device in the first embodiment shown in FIGS. 1 and 8, and therefore, description thereof will not be repeated. .
[0035]
FIG. 10 is a diagram showing a temperature profile during the formation of the lower cladding layer to the upper cladding layer of the compound semiconductor light emitting device according to the third embodiment of the present invention.
[0036]
The manufacturing process of the compound semiconductor light emitting device in the present embodiment is characterized in that the growth temperature of the evaporation prevention layer is made substantially the same as the growth temperature of the active layer containing In.
[0037]
In this embodiment, an MOCVD method is used as a method for manufacturing a compound semiconductor light emitting device. A sapphire (0001) c-plane is used as a substrate, trimethylgallium (TMG), trimethylaluminum (TMA) and trimethylindium (TMI) are used as group III gas sources, and ammonia (NH 3) is used as a group V gas source.₃) Is used, and monosilane (SiH) is used as an n-type dopant source.₄) Is biscyclopentadienyl magnesium (Cp₂Mg) as a carrier gas₂Is used. The manufacturing process will be described below.
(1) A sapphire substrate is introduced into the MOCVD apparatus, and the substrate is H₂The substrate is heated at a substrate temperature of about 1050 ° C. to perform a surface treatment on the substrate.
(2) Lower the substrate temperature to about 500 ° C. and grow a GaN or AlN buffer layer. At this time, the thickness of the buffer layer is 250 ° for GaN and 500 ° for AlN.
(3) The substrate temperature is raised to about 1020 ° C., and an n-type GaN layer is grown to about 4 μm.
(4) n-type Al at the same substrate temperature_0.1Ga_0.9The N lower cladding layer is grown to about 1 μm.
(5) Reduce the substrate temperature to about 800 ° C._0.2Ga_0.8An N active layer is grown with a thickness of about 200 °.
(6) Non-doped or Si-doped In_0.2Ga_0.8At a growth temperature substantially equal to the growth temperature of the N active layer, a thin p-type Al_0.05Ga_0.95A N evaporation prevention layer is grown.
(7) Raise the substrate temperature to about 1020 ° C._0.1Ga_0.9The N upper cladding layer is grown to about 1 μm.
(8) A p-type GaN cap layer is grown to about 1 μm. Thin p-type Al_0.05Ga_0.95The N evaporation preventing layer becomes a good quality film while the substrate temperature is raised to about 1020 ° C.
[0038]
The manufactured wafer is subjected to thermal annealing, etching, and electrode forming steps to be formed into devices such as a semiconductor laser and a light emitting diode. Since these steps are substantially the same as those in the first embodiment, description thereof will not be repeated.
[0039]
(Fourth embodiment)
FIG. 11 is a schematic sectional view of a compound semiconductor light emitting device according to a fourth embodiment of the present invention.
[0040]
Referring to the drawings, a compound semiconductor light emitting device according to the present embodiment has a stacked n-type electrode 10, an n-type GaAs substrate 11, an n-type GaAs buffer layer 12, an n-type Al_0.8Ga_0.2As lower cladding layer 13, active layer 20, p-type (Mg-doped) Al_0.8Ga_0.2It comprises an As upper cladding layer 17, an insulating layer 18, a p-type GaAs cap layer 19, and a p-type electrode 9. In addition, the active layer 20 includes a non-doped GaAs layer 14, a non-doped In_0.15Ga_0.85It is composed of a compound semiconductor in which an As strained quantum well active layer 15 and a non-doped GaAs evaporation prevention layer 16 are laminated in this order.
[0041]
FIG. 12 shows the energy levels near the active layer. In the compound semiconductor light emitting device of this embodiment, a ridge waveguide structure having a width of 3 μm is formed by photolithography and wet etching.
[0042]
The compound semiconductor light emitting device in this embodiment is formed by the MOCVD method. In this embodiment, GaAs is used as the substrate, trimethylgallium (TMG), trimethylaluminum (TMA) and trimethylindium (TMI) are used as the group III gas source, and arsine (AsH) is used as the group V gas source.₃), Se as an n-type dopant source, Mg and Zn as a p-type dopant source, and H as a carrier gas.₂Is used. The compound semiconductor light emitting device in this embodiment is manufactured by the following steps.
(1) An n-type (100) GaAs substrate 11 is introduced into an MOCVD apparatus, the substrate temperature is raised to about 800 ° C., and a GaAs buffer layer 12 is grown. The thickness of the GaAs buffer layer is 0.5 μm.
(2) n-type Al at the same temperature_0.8Ga_0.2An As lower cladding layer 13 is grown to a thickness of about 1.4 μm.
(3) A non-doped GaAs layer 14 is grown by about 100 °.
(4) Lower the substrate temperature to about 630 ° C._0.15Ga_0.85An As strained quantum well active layer 15 is grown to a thickness of about 110 °.
(5) The non-doped GaAs evaporation preventing layer 16 is grown to a thickness of about 100 °. The temperature of the substrate in growing the evaporation preventing layer can be determined by any of the growth temperature profiles shown in FIGS. That is, in FIG. 13, the evaporation preventing layer is formed at about 550 ° C. which is lower than 630 ° C. which is the growth temperature of the strained quantum well active layer. In FIG. 14, the evaporation preventing layer can be grown at a temperature of about 630 ° C., which is the growth temperature of the strained quantum well active layer, and about 700 ° C., which is a temperature of about 800 ° C. or less, which is the growth temperature of the upper cladding layer. In FIG. 15, the evaporation preventing layer can be grown at about 630 ° C., which is almost the same as the growth temperature of the strained quantum well active layer.
(6) p-type (Mg-doped) Al_0.8Ga_0.2An As upper cladding layer 17 is grown to a thickness of about 1.4 μm.
(7) A p-type (Zn-doped) GaAs cap layer 19 is grown to a thickness of about 1 μm.
[0043]
The ridge waveguide structure having a width of 3 μm shown in FIG. 11 is formed on the wafer having undergone the above steps by using the conventional techniques of photolithography and wet etching. On the wafer on which the ridge waveguide structure is formed, p-type and n-type electrodes are formed and elements are formed.
[0044]
(Fifth embodiment)
The laminated state of the compound semiconductor light emitting device formed in the fifth embodiment is the same as the laminated structure of the compound semiconductor light emitting device in the first embodiment shown in FIGS. 1 and 8, and therefore, description thereof will not be repeated. . The fifth embodiment is characterized in that Al is used as a material for forming an evaporation prevention layer._0.4Ga_0.6N is used. This makes it possible to make a clear difference in the chemical composition of the substance between the evaporation prevention layer and the upper cladding layer, thereby facilitating verification of the evaporation prevention layer after the device is manufactured.
[0045]
The MOCVD method is used for manufacturing the compound semiconductor light emitting device in this embodiment, and a sapphire (0001) c-plane is used as a substrate. Also, trimethyl gallium (TMG), trimethyl aluminum (TMA) and trimethyl indium (TMI) are used as group III gas sources, and ammonia (NH₃) Is used. Monosilane (SiH) is used as an n-type dopant source.₄) Is biscyclopentadienyl magnesium (Cp₂Mg) as a carrier gas₂Is used.
[0046]
The compound semiconductor light emitting device in this embodiment is formed through the following steps.
(1) A sapphire substrate is introduced into the MOCVD apparatus, and the substrate temperature is set to H.₂The substrate is heated at a substrate temperature of about 1050 ° C. to perform a surface treatment on the substrate.
(2) Lower the substrate temperature to about 500 ° C. and grow a GaN or AlN buffer layer. At this time, the thickness of the buffer layer is 250 ° for GaN and 500 ° for AlN.
(3) Raise the substrate temperature to about 1020 ° C. and grow an n-type GaN layer with a layer thickness of about 4 μm.
(4) n-type Al at the same substrate temperature_0.1Ga_0.9An N lower cladding layer is grown to a thickness of about 1 μm.
(5) Reduce the substrate temperature to about 800 ° C._0.2Ga_0.8An N active layer (also referred to as a light emitting layer) is grown to a thickness of about 200 °.
(6) Thin p-type Al_0.4Ga_0.6A N evaporation prevention layer is grown. The substrate temperature at this time can be arbitrarily selected from about 600 ° C. to about 900 ° C. For example, about 600 ° C., about 800 ° C., about 900 ° C., and the like can be selected.
(7) Raise the substrate temperature to about 1020 ° C._0.1Ga_0.9An N upper cladding layer is grown to a thickness of about 1 μm.
(8) A p-type GaN cap layer is grown to a thickness of about 1 μm. Thin p-type Al_0.4Ga_0.6The N evaporation preventing layer becomes a good quality film while the substrate temperature is raised to about 1020 ° C.
[0047]
At about 700 ° C., N₂Thermal annealing is performed inside. Thin p-type Al by thermal annealing_0.4Ga_0.6N evaporation prevention layer, p-type Al_0.1Ga_0.9The N upper cladding layer and the p-type GaN cap layer change to a high concentration p-type layer.
[0048]
Next, in order to form an n-type electrode, etching is performed until the n-type GaN layer is exposed, and p-type and n-type electrodes are respectively formed on the etched wafer.
[0049]
In the description of the embodiment, the MOCVD method is used for growing crystals, but an MBE method (molecular beam epitaxial growth method) or the like can be used as a growing method. Further, within the scope of the claims, materials used, growth conditions, and the like can be changed.
[0050]
Further, in the first to third and fifth embodiments, the sapphire (0001) c-plane is used as the substrate, but the substrate is made of SiC, MgO, ZnO or MgAl.₂O₄Etc. can be used.
[0051]
Further, the substance used as the buffer layer has the chemical formula_XGa_1-XA substance such as N (0 <X <1) can be used.
[0052]
Further, the active layer has the formula Al_XGa_YIn_ZAny substance can be used as long as it is a substance constituted by N (X + Y + Z = 1 and 0 ≦ XY · 1, 0 <Z ≦ 1).
[0053]
Further, n-type Al_ZGa_1-ZN (0 ≦ Z ≦ 1) can be used, and a p-type Al_ZGa_1-ZA substance constituted by N (0 ≦ Z ≦ 1) can be used.
[0054]
Further, non-doped Al is used as a material constituting the non-doped GaAs layer 14 in the fourth embodiment._XGa_1-XA material composed of As (0 ≦ X ≦ 1) can be used._0.15Ga_0.85As a material constituting the As strained quantum well active layer, non-doped In_yGa_1-yAs (0 <y ≦ 1) can be used. Further, in the fourth embodiment, p-type Al_XGa_1-XA substance composed of As (0 ≦ X ≦ 1) can be used.
[0055]
【The invention's effect】
According to the compound semiconductor light emitting device of the present invention, since the compound semiconductor light emitting device is provided with the evaporation preventing layer, the release of In can be suppressed to the utmost, the crystal growth with excellent controllability can be achieved, and the active layer (light emitting layer) containing high quality In and It is possible to provide a compound semiconductor light emitting device including an interface of an active layer.
[0056]
Further, according to the method for manufacturing a compound semiconductor light emitting device of the present invention, the release of In contained in the active layer can be suppressed as much as possible. It is possible to provide an interface between the layer and the active layer.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a semiconductor laser diode according to an embodiment of the present invention.
FIG. 2 is a diagram showing a growth temperature profile of the compound semiconductor light emitting device according to the first embodiment of the present invention.
FIG. 3 is a first diagram showing a manufacturing process of the compound semiconductor light emitting device.
FIG. 4 is a second diagram showing the manufacturing process of the compound semiconductor light emitting device.
FIG. 5 is a third diagram showing the manufacturing process of the compound semiconductor light emitting device.
FIG. 6 is a fourth diagram showing the manufacturing process of the compound semiconductor light emitting device.
FIG. 7 is a fifth diagram showing the manufacturing process of the compound semiconductor light emitting device.
FIG. 8 is a schematic sectional view of a light emitting diode according to one embodiment of the present invention.
FIG. 9 is a diagram showing a growth temperature profile of a compound semiconductor light emitting device according to a second embodiment of the present invention.
FIG. 10 is a diagram showing a growth temperature profile of a compound semiconductor light emitting device according to a third example of the present invention.
FIG. 11 is a schematic sectional view of a semiconductor laser diode according to a fourth embodiment of the present invention.
FIG. 12 is a diagram showing an energy level near an active layer in FIG. 11;
FIG. 13 is a first diagram showing a temperature profile in a process of manufacturing the laser diode of FIG. 11;
FIG. 14 is a second diagram illustrating a temperature profile in a process of manufacturing the laser diode of FIG. 11;
FIG. 15 is a third diagram showing a temperature profile in a process of manufacturing the laser diode of FIG. 11;
FIG. 16 is a diagram showing a temperature profile in a manufacturing process of a conventional compound semiconductor light emitting device.
FIG. 17 is a schematic sectional view of a conventional compound semiconductor light emitting device.
[Explanation of symbols]
1 Sapphire (0001) substrate
2 GaN or AlN buffer layer
3 n-type GaN layer
4 n-type Al_ZGa_1-ZN (0 ≦ Z ≦ 1) lower cladding layer
5 non-doped or Si-doped In_YGa_1-YN (0 <Y ≦ 1) active layer (or light emitting layer)
6 Thin layer p-type Al_XGa_1-XN (0 ≦ X ≦ 1) evaporation prevention layer
7 p-type Al_ZGa_1-ZN (0 ≦ Z ≦ 1) upper cladding layer
8 p-type GaN cap layer
9 p-type electrode
10 n-type electrode
11 n-type GaAs substrate
12 n-type GaAs buffer layer
13 n-type Al_ZGa_1-ZAs (0 ≦ Z ≦ 1) lower cladding layer
14 Non-doped Al_XGa_1-XAs (0 ≦ X ≦ 1) layer
15 Non-doped In_YGa_1-YAs (0 <Y ≦ 1) strained quantum well active layer
16 p-type Al_XGa_1-XAs (0 ≦ X ≦ 1) evaporation prevention layer
17 p-type Al_ZGa_1-ZAs (0 ≦ Z ≦ 1) upper cladding layer
18 Insulating layer
19 p-type GaAs cap layer
20 Active layer

Claims (6)

A first step of forming a lower cladding layer;
A second step of forming an active layer containing In at a first temperature on the lower cladding layer;
A third step of forming an anti-evaporation layer on the active layer at a second temperature higher than the first temperature;
Forming a top cladding layer at a third temperature higher than the second temperature on the evaporation preventing layer. The active layer has a chemical formula of Al _X Ga _Y In _Z N (X + Y + Z = 1 and 0 ≦ X
2. The method for manufacturing a compound semiconductor light-emitting device according to claim 1, wherein the method comprises a substance constituted by Y ≦ 1, 0 <Z ≦ 1). 3. The method according to claim 2 , wherein the evaporation prevention layer is made of a material composed of Al _x Ga ₁ -xN (0 ≦ X ≦ 1). 4. The active layer is characterized by comprising a composed material by _{In y Ga 1- y As (0} <y ≦ 1), the production method of a compound semiconductor light-emitting device according to claim 1. The evaporation prevention layer is characterized by comprising a composed material by _{Al X Ga 1-X As (} 0 ≦ X ≦ 1), the production method of a compound semiconductor light-emitting device according to claim 4. The evaporation prevention layer is characterized by being formed using Mg or Zn as p-type dopant, a manufacturing method of a compound semiconductor light-emitting device according to claim 3 or 5.

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