JP2001053388A - Semiconductor light-emitting element and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting element which facilitates external connection, and has high mechanical stability. SOLUTION: A cathode electrode 22 made from TIN and having a thin streak part 24 and an external connecting part 25 is formed on a sapphire substrate 20. On the connecting part 25, a semiconductor growth blocking insulation film is formed. A laminated semiconductor 21 for a laser diode is provided on the surface of the board 20, comprising the thin streak part 23. An anode electrode 23 composed of Au and Ni is brought into ohmic contact with a contact layer composed of p-type GaN on the upper surface of the semiconductor 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor light emitting device such as a laser diode and a method for manufacturing the same.

[0002]

2. Description of the Related Art A laser diode having a structure shown in FIG. 1 is known. This laser diode has a multiple quantum well structure (MQW structure), and includes an insulating substrate 1 made of sapphire or the like, a laminated semiconductor 2 including a large number of layers, first and second semiconductor layers. Electrodes 3 and 4. The stacked semiconductor 2 includes a buffer layer 5 made of a GaN compound semiconductor, an n-type semiconductor layer 6 made of a GaN compound semiconductor, an n-type semiconductor layer 7 made of an InGaN compound semiconductor, and an AlGaN compound semiconductor, which are sequentially formed on the upper surface of the substrate 1. A first n-type cladding layer 8, a second n-type cladding layer 9 made of a GaN compound semiconductor, an active layer 10 formed by alternately stacking a plurality of In _0.5 GaN compound semiconductor layers and In _0.2 GaN compound semiconductor layers, First p-type cladding layer 11 composed of an AlGaN compound semiconductor layer, second p-type cladding layer 12 composed of a GaN layer, p-type semiconductor layer 13 composed of an AlGaN compound semiconductor, and p-type contact layer composed of a GaN compound semiconductor Consists of fourteen. The n-type semiconductor layer 6 has a step 6a, on which no other semiconductor layers 7-14 are formed, and the first electrode (cathode electrode) 3 is an ohmic contact. It is connected. The second electrode (anode electrode) is ohmically connected to the p-type contact layer 14. The second electrode 4 is a well-known strip electrode, that is, a stripe electrode, and is formed narrower than the width of the active layer 10. Note that a protective insulating film (not shown) made of a silicon oxide film is provided on most of the side surface of the stacked semiconductor 2.

A pair of electrodes 3 of the laser diode of FIG.
When a voltage is applied between the anode electrode 4 and the anode electrode 4 that is higher than the cathode electrode 3 and a current flows between these electrodes, the n-type cladding layers 7 and 8 are activated from the n-type cladding layers 7 and 8 sides. Electrons are injected into the active layer 10, holes are injected into the active layer 10 from the p-type cladding layers 11 and 12, and carriers (electrons and holes) injected into the active layer 10 are n-type cladding layers 7 and 12. 8 and p
It is confined in the active layer 10 by the function of the shaped cladding layers 11 and 12, and is also formed by the cleavage planes at both ends of the active layer 10 (a crystal plane which is easily broken and has a good flatness and acts as a reflecting mirror). Oscillates due to resonator operation,
Output light is obtained. Also, the laser diode of FIG.
The anode electrode 4 and the p-type contact layer 13 form the active layer 10.
Since the semiconductor laser is a gain-guided stripe semiconductor laser formed in a stripe shape, that is, a stripe, which is much narrower than the width of the semiconductor layer, the current path is limited, and the oscillation operation region in the active layer 10 is limited. -The stabilization is achieved.

[0004]

The G shown in FIG.
The operating voltage of the aN semiconductor laser is relatively high for the following reasons (1) and (2). (1) The contact between the anode electrode 4 and the p-type contact layer 14
Mic contact (low-resistance contact) cannot be taken well.
That is, in the case of a GaN compound semiconductor, there is no p-side electrode having a sufficiently low ohmic resistance, and even in the case of a currently known multilayer electrode made of gold and nickel having the smallest resistance, the resistance value is 1 It is about × 10 ⁻³ Ωcm ² . (2) Contact layer 1 in contact with anode electrode 4
Since 4 has a stripe shape, the series resistance component (series resistance component) here becomes relatively high.

In order to solve the above problem, it is conceivable to increase the width of the stripe of the anode electrode 4. However, when this method is adopted, the stabilization of the lateral mode is hindered. That is, one of the purposes of adopting the stripe shape of the anode electrode 4 is to reduce the operating current and to limit the light emitting spot position. And the advantage of adopting the stripe shape is lost. Further, abnormal relaxation oscillation occurs in the transient response characteristic of the optical output with respect to the pulse current, and a fluctuation phenomenon (noise) of the optical output at the time of DC driving is caused. When the width of the anode electrode 4 and / or the contact layer 13 is increased,
Astigmatism occurs. That is, the position where the width of the laser light is most narrowed, that is, the distance between the position of the beam waste and the end face of the active layer is called astigmatic difference. When the stripe width is increased, the astigmatic difference easily occurs. When astigmatism occurs, it becomes difficult to obtain a beam or a small spot with good parallelism with a single lens. In addition, there is a demand for a laser diode which can be easily connected to an external device and has high mechanical stability.

Accordingly, a first object of the present invention is to provide a semiconductor light emitting device which can be easily connected externally and has high mechanical stability. A second object of the present invention is to provide a semiconductor light emitting device capable of meeting a demand for a reduction in operating voltage without impairing various characteristics such as stabilization of a lateral mode and a function of reducing astigmatism, and a method of manufacturing the same. Is to provide.

[0007]

SUMMARY OF THE INVENTION In order to achieve the first object, the present invention provides an insulating substrate, a strip arranged on one main surface of the substrate, and a connecting portion connected to the strip. A first electrode having at least a first conductive type clad layer, an active layer, and a second conductive type clad layer, wherein the strip portion is covered but the external connection portion is provided. A semiconductor disposed on the substrate having the first electrode so as not to cover, and disposed on a surface of the semiconductor;
And a second electrode having a width wider than the narrow portion.

In order to achieve the first and second objects, the first electrode is a cathode electrode made of titanium nitride, and the second electrode is an anode electrode. It can be. Further, in order to achieve the second object, a configuration in which the insulating substrate of the second aspect is omitted can be adopted as described in the third aspect. According to a fourth aspect of the present invention, in order to form the semiconductor on the substrate in a limited manner, the external connection portion of the first electrode may be covered with a substance such as a silicon oxide film which prevents the growth of the semiconductor. it can.

[0009]

According to the first and fourth aspects of the present invention, the strip portion of the first electrode that contacts the semiconductor and the external connection portion that does not contact the semiconductor are provided on the substrate. And mechanical stability is increased.
Further, since the second polarity is widened, the voltage drop here is reduced, and external connection to the second electrode is facilitated. According to the second and third aspects of the present invention, in the GaN or GaN-based light emitting device, it is difficult to obtain good ohmic contact of the anode electrode, but in the present application, the area of the anode electrode is increased. Thereby lowering the voltage drop here. Therefore, the operating voltage of the semiconductor light emitting device can be reduced. Since the cathode electrode is in the form of stripes, the effect of limiting the active region in the active layer occurs in the same manner as in the case where the conventional anode electrode is formed as a stripe. Also, the G of the cathode electrode
Since the ohmic contact to aN can be obtained better than in the case of the anode electrode, the operating voltage can be lower than in the case where the conventional anode electrode is formed as a stripe. According to the invention of claim 4, it is possible to easily achieve limited formation of a semiconductor on a substrate.

[0010]

Embodiments and Examples Next, embodiments and examples of the present invention will be described with reference to FIGS.

A laser diode having a multiple quantum well structure (MQW structure) according to an embodiment of the present invention shown in FIGS. 1 and 2 has a sapphire substrate 20 as an insulating substrate and a laminated semiconductor 21.
And a cathode electrode 22 as a first electrode and an anode electrode 23 as a second electrode. The stacked semiconductor 21 including the light emitting layer, that is, the active layer, is not formed on the entire one main surface 20a of the semiconductor substrate 20, but is formed only on the right side in FIG. In FIG. 2, for simplicity of illustration, the stacked semiconductor 21 is shown in one block without being divided into a number of layers.

The cathode electrode 22 made of a titanium nitride (TiN) film includes a narrow portion 24 disposed at the center of the right side portion of the substrate 20 and an external connection portion 25 wider than the narrow portion 24. The strip portion 24 of the cathode electrode 22 is ohmic (low resistance) connected to the lower surface of the laminated semiconductor 21.
The anode electrode 23 is formed wider than the narrow portion 24 of the cathode electrode 22 and is ohmically connected to almost the entire upper surface of the stacked semiconductor 21. Note that the side surfaces 26 and 27 of the stacked semiconductor 21 are cleaved surfaces, from which light output can be obtained. Therefore, the laser diode of this embodiment is different from the conventional laser diode of FIG. 1 in the following points. (1) The cathode electrode 22 has a strip portion 24, which is arranged between the semiconductor 21 and the substrate 20. (2) The cathode electrode 22 is formed of titanium nitride (TiN). (3) The anode electrode 23 is formed on the entire upper surface of the semiconductor 21. (4) The external connection portion 25 of the cathode electrode 22 is
0.

As shown in an enlarged scale in FIG. 3, a laminated semiconductor 21 includes a substrate 20 including a strip portion 24 of a cathode electrode 22.
GaN sequentially laminated on one main surface 20a of
Buffer layer 31 made of (potassium nitride) compound semiconductor
And an n-type semiconductor layer 32 made of a GaN compound semiconductor;
An n-type cladding layer 33 made of AIGaN (aluminum / gallium / nitrogen) compound semiconductor;
An n-side light guide layer 34 made of an N compound semiconductor;
_An active layer 35 in which a plurality of _0.5 GaN compound semiconductor layers and In _0.15 GaN compound semiconductor layers are alternately stacked, a p-side optical guide layer 36 made of a non-doped GaN compound semiconductor layer, and a p-type clad layer made of an AIGaN layer 37,
And a p-type contact layer 38 made of a GaN compound semiconductor. Strip portion 2 of cathode electrode 22 made of TiN
4 is ohmically connected to the n-type semiconductor layer 32 via the GaN buffer layer 31. Note that the buffer layer 31 and n
Either one or both of the semiconductor layer 32 may be referred to as an n-side contact layer.

Next, details of the structure of the laser diode shown in FIG. 2 and a method of manufacturing the same will be described. First, the AI ₂ shown in FIG.
A substrate 20 made of artificial sapphire containing O ₃ as a main component is prepared. After sapphire substrate 20 is subjected to organic cleaning and acid cleaning, it is placed in a chamber (reaction chamber) of a MOCVD (metal organic chemical vapor deposition) apparatus, and is placed at 1100 ° C., 10 ° C. in a hydrogen gas atmosphere. A heat treatment for about one minute is performed to remove the natural oxide film on the surface. Note that it is possible to use a substrate other than a sapphire substrate as the substrate 20,
The sapphire substrate is most practical in consideration of the difference in lattice constant from the GaN-based compound semiconductor formed on the upper surface. This sapphire substrate 20 is, as described later,
On the upper surface thereof, there are provided a semiconductor formation region where the buffer layer 31 and the like are formed, and an electrode formation region where the cathode electrode 22 is formed. In the present embodiment, the thickness of the substrate 20 is set to about 350 μm so as to function well as a support such as the buffer layer 31 thereon.

Next, as shown in FIG. 5, a titanium nitride film 22a is formed on the entire upper surface of the substrate 20 by a known reactive sputtering method. That is, a target made of titanium is sputtered in an atmosphere of a mixed gas of nitrogen and argon, and titanium and nitrogen in the gas are reacted to deposit titanium nitride as a compound thereof on the upper surface of the substrate 20.
The titanium nitride film 22a can be formed by a method other than the reactive sputtering. For example, a sputtering method using titanium nitride as a target, a method in which a metal film made of titanium is formed on the upper surface of a substrate by a sputtering method and the like, and then the metal film is nitrided by a heat treatment in an atmosphere of NH ₃ , are used. It can also be formed. In the present embodiment, the thickness of the titanium nitride film 22a is set to 100 to 2000 (angstrom). The titanium nitride film 22a is likely to be oriented in the <111> direction because the (111) plane is the densest surface with the minimum surface energy. Sapphire has a hexagonal crystal structure, and if a TiN film is formed on a hexagonal (0001) plane, <11
The orientation in the direction of 1> can be improved. For this reason,
The titanium nitride film 22a satisfactorily inherits the crystal orientation of the lower low-resistance substrate and is well oriented in the <111> direction.
The specific resistance of this titanium nitride film 22a is 25 to 250 μΩc.
m. In this embodiment, the thickness of the titanium nitride film 22a is set in the range of 50 to 2,000 angstroms.
For this reason, the titanium nitride film 22a is substantially a conductive film or a low-resistance film.
1 can be used as the cathode electrode 22 in good low-resistance contact.

Next, the titanium nitride film 22a is subjected to a well-known selective etching to form a narrow portion 24 of the cathode electrode 22 on the upper surface of the semiconductor formation region of the sapphire substrate 20, as shown in FIG. A substantially square external connection portion 25 is formed in the electrode formation region 20. In addition,
In this embodiment, in order to obtain a good effect of stabilizing the transverse mode of the laser diode, the narrow portion 24 made of titanium nitride
Is about 3 to 5 μm.

Next, as shown in FIG.
5, an insulating film 39 for preventing semiconductor growth, which is made of a silicon oxide film or the like, is formed. The insulating film 39 functions as a mask for selectively vapor-growing the buffer layer 31 and the like on the upper surface of the region where the semiconductor is to be formed on the upper surface of the sapphire substrate 20, as described later. That is, the sapphire substrate 2
The semiconductor can be vapor-phase grown on the upper surface of the sapphire substrate 20 and the thin strip portion 24 where the insulating film 39 is not formed on the upper surface of the insulating film 39, but the semiconductor is formed on the upper surface of the insulating film 39 by vapor-phase growth. Can not do it. In this embodiment, the insulating film 39 is formed by a known chemical vapor deposition method and etching.

Next, on the upper surface of the sapphire substrate 20 on which the cathode electrode 22 made of a titanium nitride film and the insulating film 39 are formed, a buffer layer 31 made of a GaN compound semiconductor,
N-type semiconductor layer 32 made of GaN compound semiconductor, AIG
n-type cladding layer 33 made of aN compound semiconductor, n-side light guide layer 3 made of non-doped GaN compound semiconductor
4. An active layer 3 in which a plurality of In _0.5 GaN compound semiconductor layers and a plurality of In _0.15 GaN compound semiconductor layers are alternately laminated.
5. N-side light guide layer 36 made of a non-doped GaN compound semiconductor layer, p-type clad layer 3 made of an AIGaN layer
7 and a p-type contact layer 38 made of a GaN compound semiconductor by well-known MOCVD (metal organic chemical vapor deposition).
Are sequentially formed. That is, the sapphire substrate 20 on which the cathode electrode 22 made of a titanium nitride film and the insulating film 39 are formed is placed in a reaction chamber of a MOCVD apparatus, and first, trimertilgallium gas (hereinafter, referred to as TMG gas) and ammonia gas are placed in the reaction chamber. By supplying (NH ₃ ), a buffer layer 31 is formed on the upper surface of the sapphire substrate 20 and the narrow portion 24 made of a titanium nitride film. The buffer layer 31 is formed at a lower temperature than the n-type semiconductor layer 32 and the like formed thereon. That is, in the present embodiment, after the heating temperature of the sapphire substrate 20 is set to 600 ° C., the flow rate of the TMG gas, that is, the supply rate of Ga is set to about 4.3 μmol / min and NH ₃
The buffer layer 31 was formed at a gas supply of about 17.9 mmol / min. In the present embodiment, the buffer layer 3
1 had a thickness of about 250 Å. In the laser diode of the present embodiment, the buffer layer 31 can be formed uniformly and with good crystallinity above the narrow portion 24 made of a titanium nitride film, similarly to the upper surface of the sapphire substrate 20. Note that the buffer layer 31 is not formed on the upper surface of the insulating film 39.

Next, the heating temperature of the sapphire
The temperature was raised to 40 ° C., and the supply amount of TMG gas was increased to about 4.3 μmo.
1 / min, the supply amount of NH ₃ gas is about 53.6 mmol /
The supply amount of silane gas (SiH ₄ ) is about 1.5 nm
An n-type semiconductor layer 32 made of a GaN compound semiconductor was formed at 1 / min. The carrier concentration of this n-type semiconductor layer 32 is 3 × 10 ¹⁸ cm ⁻³ , and its thickness is 2 μm.

Next, the heating temperature of the sapphire substrate 20 is set to 1
While maintaining the temperature at 040 ° C., the supply amount of TMG gas was set to about 4.3 μM.
mol / min, the supply amount of NH ₃ gas is about 53.6 mmol.
/ Min, the supply amount of trimethylaluminum gas (hereinafter referred to as TMA gas) is about 2.0 μmol / min, and the supply amount of silane gas (SiH ₄ ) is about 3 nmol / min.
An n-type cladding layer 33 made of an aN compound semiconductor was formed. The carrier concentration of this n-type cladding layer 33 is 3 × 10
¹⁸ cm ^-3 and the thickness is 0.3 μm.

Next, the heating temperature of the sapphire substrate 20 is set to 1
While maintaining the temperature at 040 ° C., the supply amount of TMG gas was set to about 4.3 μM.
mol / min, the supply amount of NH ₃ gas is about 53.6 mmol.
/ Min made of a non-doped GaN compound semiconductor
The side light guide layer 34 was formed. This n-side light guide layer 34
Has a thickness of 1000 angstroms.

Next, the heating temperature of the sapphire substrate 20 is set to 8
The temperature was lowered to 00 ° C., and the supply amount of TMA gas was reduced to about 1.1 μmo.
l / min, the supply amount of NH ₃ gas is about 67 mmol / min, T
The supply amount of MI (trimethylindium) gas is set to about 1.5
An In _0.5 GaN compound semiconductor layer is formed under the conditions of μmol / min, and thereafter, the supply amount of the TMA gas is reduced to about 1.1 μm.
ol / min, the supply amount of NH ₃ gas was about 67 mmol / min,
When the supply amount of the TMI gas is about 4.5 μm 0 l / min, the In
_{A 0.15} GaN compound semiconductor layer is formed, and In _0.5 Ga
The formation of the N compound semiconductor layer and the In _0.15 GaN compound semiconductor layer was alternately repeated a plurality of times to obtain the active layer 35. That is, the InGaN compound semiconductor layer in which the molar ratio of In is 0.5
An active layer 35 was obtained by alternately and repeatedly forming an InGaN compound semiconductor layer having an n molar ratio of 0.15 a plurality of times. In FIG. 3, the active layer 35 is schematically shown as one layer.

Next, the heating temperature of the sapphire substrate 20 is set to 1
The temperature was raised to 040 ° C., and the supply amount of TMG gas was increased to about 4.3 μm.
mol / min, the supply amount of NH ₃ gas is about 53.6 mmol.
The n-side light guide layer 36 made of an undoped GaN compound semiconductor layer was formed under the condition of / min. The thickness of the n-side light guide layer 360 is 1000 angstroms.

Next, the heating temperature of the sapphire substrate 20 is set to 1
While maintaining the temperature at 040 ° C., the supply amount of TMG gas was set to about 4.3 μM.
mol / min, the supply amount of NH ₃ gas is about 53.6 mmol.
Per minute, the supply amount of trimethylaluminum gas (TMA gas) is about 2.0 μmol / min, and the supply amount of CP ₂ Mg gas, ie, biscyclopentadienyl magnesium gas, is about 0.48 μmol / min. The clad layer 37 was formed. The carrier concentration of the p-type cladding layer 37 is 3 × 10 ¹⁸ cm ⁻³ , and the thickness is 0.3 μm.
m.

Next, the heating temperature of the sapphire substrate 20 is set to 1
At 040 ° C., the flow rate of TMG gas was about 4.3 μm
ol / min, the flow rate of the NH ₃ gas is about 53.6 mmol / min.
Min, the flow rate of CP ₂ Mg gas is about 0.12 μmol / min.
A p-type contact layer 38 of a GaN compound semiconductor layer was formed at about 1.5 nmol / min. The carrier concentration of the p-type contact layer 38 is 1 × 10 ¹⁸ cm ⁻³ , and the thickness is 1 μm.

Next, the anode 23 was formed on the entire upper surface of the p-type contact layer 38 made of a GaN compound semiconductor. That is, the anode electrode 23 was formed by depositing, for example, nickel and gold on the upper surface of the p-type contact layer 38 by a known vacuum deposition method or the like. This anode electrode 2
3 makes good low-resistance contact with a p-type contact layer 38 made of a GaN compound semiconductor.

Next, the insulating film 39 is removed by a known etching method or the like. Thereby, the cathode electrode 2
The second external connection portion 25 is exposed.

Finally, a chip is cut out from the wafer by a known dicing method, and the cleaved surface is subjected to dry etching or the like to perform an end surface treatment on both ends of the active layer 35.
2 and 3 are completed.

The laser diode of this embodiment has the following effects. (1) The operating voltage can be reduced without impairing various characteristics such as stabilization of the transverse mode and reduction of astigmatic difference of the laser diode. That is, in the laser diode of the present embodiment, the cathode electrode 2 in contact with the buffer layer 31
Since the width of the second narrow portion 24 is sufficiently small, the oscillation region of the active layer 35 is limited to the narrow region corresponding to the narrow portion 24 of the cathode electrode 22. That is, the same effect as in the case where the conventional anode electrode 4 shown in FIG. 1 is formed into a stripe shape can be obtained also with the laser diodes shown in FIGS. When the active region of the active layer 35 is formed in a sufficiently narrow stripe shape, not only the transverse mode can be stabilized, but also the optical output transient response characteristic to a pulse current may cause abnormal relaxation oscillation. In addition, it is possible to prevent the fluctuation phenomenon (noise) of the optical output from occurring during the DC drive, and it is possible to prevent the occurrence of the astigmatic difference satisfactorily. Therefore,
With a single lens, a beam and a small spot with good parallelism can be obtained. Also, the p-type contact layer 38
Also, the anode electrode 23 is not formed narrow, and the area of the upper surface thereof is substantially the same as the area of the upper surface of the p-type flood 37 or the like. That is, p having a relatively large area
The anode electrode 23 is in contact with the entire upper surface of the contact layer 38. p-type contact layer 38 composed of p-type GaN and A
Although the combination of the anode electrode 23 made of u and Ni makes it difficult to obtain an ohmic contact, the contact area between the two is greatly increased as compared with the conventional case.
3, a low-resistance connection is achieved, the voltage drop there is reduced, and the operating voltage of the laser diode can be reduced. Also, as compared with the conventional laser diode of FIG. 1, the laser diode shown in FIGS. 2 and 3 does not include a resistor corresponding to the resistance of the step 6a of the n-type semiconductor layer 6 of FIG.
The operating voltage can be reduced by this amount. (2) Since the cathode electrode 22 is formed of TiN, the cathode electrode 2 is located between the sapphire substrate 20 and the semiconductor 21.
Even if the two narrow portions 24 are arranged, each layer of the semiconductor 21 can be favorably epitaxially grown thereon. (3) Since the external connection portion 25 is formed on the main surface 20a of the substrate 20 as an extension of the narrow portion 24, the external connection portion 25 of the cathode electrode 22 exposed upward as in FIG. 1 can be easily obtained. it can. (4) Since the cathode electrode 22 is directly supported by the sapphire substrate 20, the mechanical stability is high. (5) Since the insulating film 39 is provided on the external connection portion 25 of the cathode electrode 22 and the respective layers 31 to 38 of the semiconductor 21 are epitaxially grown using the insulating film 39 as a mask, the semiconductor 21 is provided on the external connection portion 25 of the cathode electrode 22. Is not formed, and the external connection portion 25 can be easily obtained.

[0030]

[Modifications] The present invention is not limited to the above-described embodiment, and for example, the following modifications are possible. (1) The number of layers in the stacked semiconductor 21 can be increased or decreased. For example, the n-side light guide layer 34 and the p-side light guide layer 36
Etc. can be omitted. In addition, the semiconductor 21
Can have the same configuration as the semiconductor 2 of FIG. (2) A configuration in which the substrate 20 is omitted can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a conventional laser diode.

FIG. 2 is a perspective view schematically showing a laser diode according to an embodiment of the present invention.

FIG. 3 is an enlarged sectional view taken along line AA of FIG. 2;

FIG. 4 is a perspective view showing a substrate of the laser diode of FIG. 2;

FIG. 5 is a perspective view showing a structure in which a TiN film is formed on the substrate of FIG. 2;

FIG. 6 is a perspective view showing a cathode electrode formed of the TiN film of FIG. 5;

FIG. 7 is a perspective view showing a state where an insulating film is formed on the external connection portion of FIG. 6;

[Explanation of symbols]

 REFERENCE SIGNS LIST 20 sapphire substrate 21 laminated semiconductor for laser diode 22 cathode electrode 22 a TiN film 23 anode electrode 24 strip portion 25 external connection portion 39 insulating film

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masataka Yanagihara 3-6-1 Kitano, Niiza-shi, Saitama Prefecture Within Sanken Electric Co., Ltd. (72) Inventor Masaaki Kikuchi 3-63 Kitano 3-chome, Niiza-shi, Saitama Prefecture 4M104 AA04 AA10 BB05 BB30 BB37 CC01 DD37 DD40 DD42 DD86 GG04 HH15 5F073 AA74 CA07 CB05 CB22 DA05 EA29

Claims (4)

[Claims] 1. A first electrode having an insulating substrate, a strip disposed on one main surface of the substrate, and an external connection connected to the strip, and at least a first electrode. A conductive type clad layer, an active layer, and a second conductive type clad layer, wherein the conductive layer is disposed on the substrate having the first electrode so as to cover the strip portion but not the external connection portion. And a second electrode disposed on the surface of the semiconductor and having a wider width than the narrow portion. 2. The semiconductor device according to claim 1, wherein the first electrode is a cathode electrode made of titanium nitride, and the semiconductor is a GaN electrode provided on the substrate so as to cover the narrow portion of the first electrode.
A buffer layer made of n-type GaN provided on the buffer layer; an n-type clad layer made of n-type AlGaN provided on the n-type semiconductor layer; An active layer provided on the shaped cladding layer with or without an n-side light guide layer made of GaN, and an active layer provided on the active layer with or without a p-side light guide layer made of GaN A p-type cladding layer made of p-type AlGaN and a p-type contact layer made of p-type GaN provided on the p-type cladding layer, wherein the second electrode is formed on the p-type contact layer. 2. The semiconductor light emitting device according to claim 1, wherein the semiconductor light emitting device is a connected anode electrode. 3. A strip cathode electrode made of titanium nitride; a buffer layer made of GaN disposed adjacent to the cathode electrode and having a wider width than the cathode electrode; An n-type cladding layer formed on the layer with or without an n-type semiconductor layer made of n-type GaN; and provided on the cladding layer with or without an n-side light guide layer. An active layer; a p-type cladding layer provided on or without the p-side light guide layer on the active layer; and a p-type contact comprising p-type GaN provided on the p-type cladding layer. A semiconductor light emitting device comprising: a layer; and an anode electrode provided on the p-type contact layer. 4. forming a first electrode having a strip portion and an external connection portion connected to the strip portion on one main surface of the insulating substrate; Forming a layer of a substance that inhibits the growth of semiconductors on the surface of the substrate including the strip portion;
Forming a semiconductor having a conductive type clad layer, an active layer, and a second conductive type clad layer; and forming a second electrode having a wider width than the strip on the surface of the semiconductor. A method for manufacturing a semiconductor light emitting device comprising: