JPH11186598A - Nitride semiconductor light-emitting device having reflecting p-electrode, its manufacture and semiconductor optical electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the characteristics of a reflecting electrode of a P-type nitride semiconductor. SOLUTION: A silver layer 101 is arranged on a P-type nitride semiconductor layer. The silver layer is set thicker than 20 nm, so as to act as both a reflecting P-electrode and a reflecting layer of a short wavelength light. It is preferable that the silver layer be covered with a stabilizing layer of metal or dielectric, in order to improve mechanical and electrical characteristics of silver. It is possible that the stabilizing layer is provided with a metal layer 103 for circuit connection, and a diffusion preventing layer 102 which is interposed and inserted between the metal layer and the silver layer, the diffusion to silver of which is small and which prevents the diffusion of the metal layer to silver, in order to improve reflectivity. An LED(light-emitting diode) having the P-electrode can obtain more benefit of high reflectivity of the P-electrode, when mounting is performed on a package 110 by using a flip-chip method, so as to generate light from a substrate side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device provided with a nitride semiconductor, and more particularly to an optoelectronic device having a p-type nitride semiconductor provided with a reflective electrode containing silver to improve optical and photoelectric characteristics, and to manufacture the same. And how to.

[0002] In this specification, the term "nitride semiconductor" refers to "group III nitride semiconductor", and the term "light-emitting diode", that is, "LED" refers to a pn junction or a pn junction with an active layer interposed. (Hereinafter, referred to as a "p-n junction" in a broad sense), and is an electronic device that outputs incoherent light. Is a semiconductor multilayer film structure having a pn junction in a broad sense formed by growing one or more semiconductor thin film layers on a single crystal substrate which is not an LED chip. A p-type region and an n-type region are LED members that have respective electrodes, a p-electrode and an n-electrode, and are electrically driven from these electrodes. Bondy from existing electrodes An LED member from which a wire can be pulled out. An “LED product” has an LED chip, which has electric wiring for driving a pn junction in a broad sense. An opto-electronic device die-bonded to the surface (collectively referred to as a die pad) of a ceramic substrate or the like (hereinafter collectively referred to as a package), such as an LED lamp or a seven-element display device.

[0003]

2. Description of the Related Art Short wavelength light emitting devices are being actively developed. In general, if short-wavelength light with a wavelength of 550 nm or less can be efficiently generated, a full-color display or white light source can be realized with a long-wavelength light-emitting device, and it is expected to expand the functions of applied equipment of this device and reduce energy consumption. Have been. Many of these short-wavelength light-emitting devices are assembled based on III-nitride semiconductors, and "III-nitride semiconductors" include GaN, AlN, InN, BN, AlInN, GaInN,
AlGaN, BAlN, BInN, BGaN, BAlGaInN and the like are included. In particular, GaN and other GInN, AlGaN, BGaN, BAlGaInN, etc.
Group III nitride semiconductors with aN as the main component are "GaN-based semiconductors"
Called.

As an example of an LED which is one of the short-wavelength light emitting devices, an LED configured based on a GaN-based semiconductor (hereinafter referred to as a “GaN-based LE”)
D) will be described with reference to FIG. In the following, when not confused, the “thin film layer” is simply referred to as a “layer”.
Each layer is composed of a plurality of sub-layers having different compositions as shown in FIG. 1A disclosed by Yamada et al. In Japanese Patent Application No. 9-30204, for example.
We will choose a concise description for the future.

[0005] In FIG. 1A, a GaN-based LED 21 'includes a sapphire substrate 22', an AlN buffer layer 23 ', an n-type GaN contact layer 24', an n-type AlGaN cladding layer 26 ', and a doped layer.
InGaN layer 28 ', p-type AlGaN cladding layer 30', p-type GaN contact layer 31 ', deposited metal 33', p-electrode 32 ', n
It consists of an electrode 25 '. In FIG. 1A, GaN
The system LED 21 'is one implementation form of the following FIG. 1 (B).

On the other hand, in FIG. 1B, the GaN-based LED 1 has a sapphire substrate 2, an n-layer 3, an active layer 4, which is generally a multiple quantum well layer of a nitride semiconductor, a p-layer 5, a transparent p-electrode 6,
GaN-based LED consisting of p electrode 6a for bonding and n electrode 7
The chip 10 is assembled by die bonding to the die pad 8a of the package 8. The bonding p-electrode 6a and the n-electrode 7 are generally connected to bonding wires 6b and 7
a. A drive voltage is applied between the bonding wires 6b and 7a to cause an input current to flow through the GaN-based LED 1, and output light is generated from the active layer 4 by the input current. At least the surface portion of the bonding p-electrode 6a and the n-electrode 7
Is the metal means for circuit connection.

The following correspondence is established between the light emitting diode 21 'of FIG. 1A and the GaN-based LED 1 of FIG. 1B. Sapphire substrate 2: sapphire substrate 22 ', n-layer 3: AlN buffer layer 23'; n-type GaN contact layer 24 '; n-type AlGaN cladding layer 26', active layer 4: doped InGaN layer 28 ', p-layer 5 : P-type AlGaN cladding layer 30 '; p-type GaN contact layer 31'; p-electrode 6; p-electrode 6a: vapor-deposited metal 33 '; p-electrode 32'; n-electrode 7: vapor-deposited metal 33 '; Although the AlN buffer layer 23 'may be interpreted as one element corresponding to the sapphire substrate 2 in the description of the present invention, there is no particular hindrance for a person skilled in the art to carry out the present invention. The following description is given on a corresponding basis.

In the GaN-based LED 1 having the above structure, therefore, (a) as much light as possible is generated from the active layer 4 with as little drive power (= input current × drive voltage) as possible. It is important to extract as much output light as possible as output light to the outside.

Many efforts have been made to generate as much light from the active layer 4 as possible with as little drive power as possible. The resistivity of the p-type nitride semiconductor layer is considerably larger than the resistivity of the n-type nitride semiconductor layer, and when the p-electrode is formed on the p-type nitride semiconductor layer, when the n-electrode is formed on the n-type nitride semiconductor layer, On the other hand, the metal-semiconductor junction generates a large contact voltage, which is a main cause of increasing the power consumption of the nitride semiconductor device. Therefore, the p-electrode is much wider than the n-electrode to reduce the contact voltage.

In order to reduce the contact voltage, a technique for depositing palladium on a p-type nitride semiconductor layer as a p-electrode (Japanese Patent Application No. 9-30204) or a p-electrode before forming a p-electrode.
Technology for cleaning type nitride semiconductor layer (Japanese Patent Application No. 9-48402)
) Or a technique of inserting a group V substitutional nitride semiconductor layer between a p-type nitride semiconductor layer and a p-electrode metal (Japanese Patent Application No. 9-5339).
No.) was developed. On the other hand, in the LED, since the p-electrode having this large area encounters much of the light generated in the active layer, it is preferable to take out the light generated in the active layer as output light as much as possible as the output light, that is, the transmittance and the transmittance. It is desirable to have both reflectance and reflectance.

In FIG. 1B, light generated in the active layer 4 travels in all directions. Among them, light effective as output light of the GaN-based LED 1 is light emitted from the transparent p-electrode 6 to the outside. is there. Therefore, the transparent p-electrode 6 must have a high transmittance. On the package 8 side from the active layer 4, light is reflected and directed toward the transparent p-electrode 6.

As the transparent electrode 6, a multi-layer film of nickel and gold having a thickness of several nm (for example, a two-layer film of 8 nm for 1 nm of nickel) is used, and its transmittance is about 40 to 50%. The transparent electrode 6 is too thin to be suitable for bonding, and a thicker bonding electrode 6a is required at the bonding portion. Equation 1 is used as the bonding electrode 6a.
A multilayer film of nickel and gold having a thickness of 00 nm is often used, and its area is required to be at least a rectangular area of 80 to 100 μm on a side in order to secure the simplicity of the bonding operation.

On the other hand, since there is no active layer 4 immediately below the n-electrode side, it is general that no means for transmitting the optical output is devised. As the n-electrode 7, a multilayer film such as titanium or aluminum is used as the bonding electrode. It is formed as. Since these bonding electrodes cannot transmit light due to their thickness, they are designed to be as small as possible as long as the simplicity of the bonding operation is not impaired.

The light directed toward the package 8 is reflected by the reflection means formed on the surface of the package, that is, the die pad 8a. For example, commonly used reflecting means include a white die pad itself having a high reflectance,
High reflectivity tape provided on the die pad.
In some cases, the package itself is made of metal, and the surface thereof is plated with aluminum or the like to serve as reflection means. In any case, the surface state at the time of mounting and the storage state before mounting are affected, but the reflectance is 50 to 80%.

[0015]

Therefore, the conventional L
In the ED, when light generated from the active layer is output from the transparent p-electrode side and taken out, the light directed to the transparent p-electrode side is not only reflected and absorbed by a bonding electrode or a bonding wire, but also, 50-60 even with transparent p-electrode
% Is reflected and absorbed. On the other hand, the light output to the package side is reflected by the reflection means installed on the die pad.
Although 50 to 80% of the light is reflected, even if the reflected light and the straight light are summed up, only about half of the total amount of light generated in the active layer can be extracted as output light.

If the transmittance of the p-electrode is reduced in order to further increase the intensity of the output light taken out, that is, the emission intensity of the LED, the sheet resistance of the transparent p-electrode increases and the spread of the input current is limited. Is done. for that reason
The voltage between the LED terminals must be increased, and as a result, the luminous efficiency of the LED is reduced. Further, the p-electrode has to have a complicated film structure in order to have two functions of light transmission and bonding. Further, a means for reflecting the light output to the package side is required, which leads to an increase in the number of components, a complicated manufacturing process, and an increase in the cost of the LED. Also,
Reflected by bonding electrodes and bonding wires, etc.
It is desirable that the absorbed light can be effectively used as output light. Further, it is desirable to obtain a p-electrode or device configuration that has excellent mechanical, electrical, optical, opto-electrical properties or improved cooperative properties thereof that can be widely applied to other optoelectronic devices as a p-electrode.

[0017]

SUMMARY OF THE INVENTION The present invention provides a p-electrode having excellent electrical characteristics and optical characteristics by using silver having a low resistivity, that is, Ag, as a first layer metal of at least a portion of the p-electrode. Based on a new technology that can be realized stably. The semiconductor optoelectronic device of the present invention is an electronic device including a p-type nitride semiconductor layer, including a silver layer deposited on the p-type nitride semiconductor layer, and the silver layer functions as an electrode and emits light. Although it is not, it is designed to function as a reflection layer for short wavelength light. By adjusting the thickness, the silver layer or a part thereof is used as a reflective p-electrode having a high reflectance.

In order to improve the mechanical and electrical properties of the silver, it is preferable to cover the silver layer with a metal or dielectric stabilizing layer. Further, in order to increase the reflectance, the silver for the reflective p-electrode may be covered with a diffusion preventing layer, and then the circuit connecting metal may be provided on the diffusion preventing layer. In the case of an LED chip having a transparent substrate, the LED chip may be flip-chip bonded to a package using a p-electrode as a reflective p-electrode so that output light is extracted from the transparent substrate side to the outside.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to understand the present invention relating to the manufacture of a nitride semiconductor LED, an embodiment of the present invention relating to the manufacture of a GaN-based LED will be described below. Those skilled in the art can also gain knowledge when assembling other nitride semiconductor LEDs from the following examples.
In addition, the prospect of applying the transparent p-electrode and the reflective p-electrode to electronic devices other than LEDs can be expected.

FIG. 2 shows a first embodiment of the present invention in which a silver (Ag) layer 21 is deposited as a first layer metal constituting a p-electrode.
FIG. 2 is a sectional view of an N-type LED 20. Parts that exhibit the same functions and performances as those of the LED 1 in FIG. 1 are given the same reference numerals as in FIG. An electrode metal layer 21a for bonding is formed on the silver layer 21 in the same manner as in FIG.
It is composed of gold or the like. Electrode metal layer 21a for bonding
At least the surface portion is made of a metal for circuit connection suitable for circuit connection such as gold. The LED in FIG. 2 includes a substrate 2, an n-type nitride semiconductor layer 3 on the substrate, an active layer 4 made of a nitride semiconductor on the n-type nitride semiconductor layer, and a p-type nitride semiconductor layer on the active layer. 5 in which an LED member having a silver layer 21 on a p-type nitride semiconductor layer is bonded to a package 8
In one embodiment, a GaN-based semiconductor is selected as a nitride semiconductor. As is well known, a main part of each nitride semiconductor layer is formed as a multilayer film including a required number of layers having a required composition.

Hereinafter, the assembling process of the LED 20 will be described with reference to the process chart of FIG. First, an n-layer 3 and an active layer are formed on a sapphire substrate 2 which may be another substrate including an opaque substrate by using a conventional element forming process such as a CVD method (for example, see Japanese Patent Application No. 9-30204). 4 and the p layer 5 were sequentially formed to assemble the LED member (step 31). Next, the LED member is patterned by photolithography using nickel, which may be another metal, as a mask, and the reactive ion etching is used to convert the LED member into a part of the n-layer 3 forming the n-electrode 7 (( A) shows the n-type GaN layer 2
It was dug down to the 4 'deposition metal 33' mounting portion (step 32). Thereafter, nickel used as a mask at room temperature was removed from the LED member with aqua regia (step 33).

It is possible to use phosphoric acid to remove nickel or to use aqua regia at a temperature higher than room temperature. However, the method of removing nickel using aqua regia can also be used to clean the surface of the nitride semiconductor. preferable. Nickel removal can be completed in a few minutes, but the time for immersing the LED member in aqua regia is 30 minutes to 1 hour, which is much longer than 5 minutes (see Japanese Patent Application No. 9-30204) which is usually employed in such a treatment. . 30
When the time is shorter than 30 minutes, it has been found that the cleaning effect of the surface of the p-layer is gradually lost, and the stability of silver deposited on the surface in the subsequent process is lost. Must be avoided.

Thereafter, the sapphire substrate 2 was set at 900 ° C., and the LED members were activated in a nitrogen atmosphere for 5 minutes (step 3).
4). After the activation, the LED member was treated with hydrofluoric acid at room temperature for 10 minutes.
(Step 35), and the surface of the p-layer 5 (the p-type GaN layer 31 'in FIG. 1A) to form the first layer 21 of the p-electrode.
100 nm of Ag was vapor-deposited on most of the surface (step 36). The surface cleaning with hydrofluoric acid is described in Japanese Patent Application No. Hei 9-48.
Reference is made to the disclosure of No. 402.

Next, in order to form an electrode metal layer 21a for bonding a p-electrode, nickel was deposited in a thickness of about 300 nm and gold was deposited in a thickness of about 50 nm, followed by patterning, followed by a first annealing (annealing 1) (step 37). Thereafter, on the n-type GaN portion for forming the n-electrode 7, 10 nm of Ti and 200 nm of Al were sequentially deposited and patterned to form LED members as LED chips, and a second annealing (annealing 2) was performed (annealing 2). Step 38) annealing will be described later. The LED chip thus formed was attached to the die pad 8a of the package 8, a bonding wire was wired, and processing such as resin sealing was performed to complete an LED product (step 39). n
The electrode 7 may have another material configuration, but at least the surface portion is made of a metal for circuit connection such as gold for circuit connection. Note that annealing 1 may be omitted and annealing 2 alone may be used.
Annealing 1 is performed at 200 ° C. or less, and annealing 2 is performed at 200 ° C. or more, preferably 400 ° C. or more.

The characteristics of the formed LED chip are changed by changing the deposition rate when depositing Ag and the temperature of the sapphire substrate 2 during the deposition. In order to examine this characteristic change, a large number of LED members were formed by changing these deposition rates and temperatures. These LED members are obtained before annealing 1 is performed on the LED members at the time when step 36 in FIG. 3 is completed. Each LED chip was operated continuously at room temperature with an input current of 20 mA, and the time change of the light emission intensity was measured. The luminous intensity of the LED chip formed at a temperature of the sapphire substrate 2 at the time of silver vapor deposition at room temperature and a vapor deposition rate of 0.1 nm / sec is less than 5% of the luminous intensity at the beginning of the continuous operation 30 minutes after the start of the continuous operation. Diminished.

On the other hand, the temperature of the sapphire substrate 2 is
It was confirmed that the LED chip formed at 200 ° C. and the deposition rate was 0.03 nm / sec did not reduce the luminous intensity at all even after continuous operation for more than 30 minutes, and that the luminous intensity did not decrease even after continuous operation for a long time. In an LED chip formed with a sapphire substrate 2 at a room temperature and a deposition rate of 0.03 nm / sec.
If you operate continuously for 30 minutes or more, the emission intensity will be 60 to
80%. When the LED chip formed with the sapphire substrate 2 at a temperature of 200 ° C. and a deposition rate of 0.1 nm / sec is operated continuously for 30 minutes or more, the light emission intensity becomes about 90% of that at the start of operation.

At extremely high temperatures, the deposited silver becomes island-shaped and cannot be used as an electrode. When the temperature of the sapphire substrate 2 is further increased, the deposition rate becomes 0.03 nm.
Even at a rate of about 400 ° C./sec, the deposition of silver becomes non-uniform, and when the deposition rate is high, the deposition of silver becomes non-uniform even at lower temperatures. When this non-uniformity occurs, the resistance value of the silver layer increases, the light scattering increases, and the decay of the emission intensity of the LED with time increases, so that the LED cannot be put to practical use. As will be described in detail below, the measurement results of the LED chip of the example were obtained before and after annealing 1 and 2.

As a result of such an experiment, it was found that it is preferable to set the deposition rate of the silver layer to about 0.05 nm / sec or less and the temperature of the sapphire substrate 2 to 200 ° C. or less. Considering the efficiency of LED manufacturing, the higher the deposition rate, the better, but if the rate is too high, the quality of the silver layer decreases. Further, if the temperature of the sapphire substrate 2 is set to a lower temperature such as room temperature for ease of manufacture, it is necessary to lower the deposition rate in order to obtain a good quality of the silver layer. Good. As described above, the temperature of the sapphire substrate 2 was set at around 200 ° C.
It is advisable to choose near 0.03nm / sec.

Further, it is more preferable that the deposition rate of the silver layer and the substrate temperature of the LED member are varied to measure the luminous intensity to determine a more appropriate deposition rate and the substrate temperature of the silver layer for the manufacturing process. In this case, it is preferable that the uniformity of the luminance distribution of the output light in the Ag layer is also good.

In the conventional LED manufacturing process, a method of annealing an LED chip at 400 to 500 ° C. after depositing an electrode has been often used in order to lower the operating voltage of the LED. In forming the LED chip according to the first embodiment of the present invention, immediately after the deposition of Ag, the LED chip is placed in a nitrogen atmosphere at a temperature lower than a generally known temperature (400 to 500 ° C.).
Annealing 1 is performed at ℃, and a metal electrode for bonding and n
After attaching the electrodes, annealing 2 was performed at 500 ° C.
As described above, annealing 1 may be omitted.

FIG. 4 is a graph showing experimental results for confirming the time effect of annealing. FIG. 4 shows a result of measuring a voltage drop between two Ag electrodes deposited on a p-type GaN substrate having the same characteristics as the p-layer 5 by flowing a current of 500 uA between the electrodes. The p-type GaN substrate was annealed at 200 ° C. in a nitrogen atmosphere after Ag deposition, and the voltage drop between the Ag electrodes is plotted by changing the annealing time.
FIG. 4 shows a curve 41 when the temperature Ts of the p-type GaN substrate during Ag deposition is room temperature and a curve 42 when the temperature Ts is 200 ° C.
Even when s was any other value, the voltage drop between the two Ag electrodes was lower than before annealing by annealing for 20 minutes or more. It is advantageous that the effect of annealing can be estimated regardless of the temperature Ts.

The value of the above voltage drop largely depends on the annealing-independent resistance of the p-type GaN substrate. Considering that the voltage between terminals between actually formed LED chips becomes 3 to 4 volts, it can be said that the change in the contact voltage of the Ag electrode with respect to the LED as the final product due to annealing exceeds 50%. Therefore, the efficiency of the LED (output light power / input power) can be improved by annealing. The annealing here corresponds to the above-mentioned annealing 1, and the annealing temperature is 200 ° C.
The above is effective. In particular, when annealing after forming the n-electrode 7 (annealing 2), it is preferable to anneal at 400 to 500 ° C. As described above, the GaN-based LED and the GaN-based LED chip of the first embodiment of the present invention are useful for establishing a manufacturing process of an LED having a p-electrode whose first layer is a silver layer.

FIG. 5 is a partial sectional view of an LED 50 according to a second embodiment of the present invention. Note that the TiO ₂ layer 52 is much thinner than the bonding electrode metal layer 21a, and the dimensions are not to be trusted in FIG. Portions that exhibit the same function and performance as those of the LED 20 in FIG. 2 are denoted by the same reference numerals as in FIG. Second Embodiment of the Invention and First Embodiment
Is different from the embodiment in that the silver layer 51 deposited as a p-electrode
The thickness was reduced to 10 nm to improve the transmittance for output light, and the TiO ₂ layer 52 was deposited on the p-electrode to protect, stabilize and further improve the transmittance of the silver layer. It is in.

The electrode metal layer 51a for bonding is substantially the same as the electrode metal layer 21a for bonding. Techniques for improving the transmittance by sandwiching a transparent silver electrode with _two TiO ₂ films are well known (see “Thin Film Handbook”, page 496, Ohmsha, Tokyo (1983)).
It has been found that the configuration of the second embodiment in which the TiO ₂ layer 52 is deposited on the silver layer can also improve the transmittance for output light.
The metal layer becomes transparent when the thickness is 20 nm or less, but it is said that the thickness of the transparent conductive film is limited to the range of 3 to 15 nm, and that when the wavelength is 500 nm or less, the absorption of silver is smaller than that of gold. (See “Thin Film Handbook,” p. 495, Ohmsha, Tokyo (1983)). In the second embodiment, the LED
From the viewpoint of improving the efficiency of
nm.

The following experiment was conducted to measure the effect of depositing TiO ₂ on the silver layer deposited as the first layer of the p-electrode and to use it in designing an LED. First is the optical glass commonly used as a transparent substrate for optical components
Silver was deposited on a BK7 substrate ("Science Table", pp. 518-519, Maruzen, Tokyo (1992)). Sample 1 was prepared by depositing a 10-nm-thick Ag layer at a deposition rate of 0.03 nm / sec at a BK7 substrate temperature of room temperature, and sample 2 was further formed by depositing a 25-nm-thick TiO ₂ layer thereon.

FIG. 6 shows the measurement results of the transmittance of Samples 1 and 2 thus prepared. When the wavelength of the measurement light is 450 nm, the transmittance of the sample 1 is 4
In Sample 2, the transmittance increases from curve 62 to 66%, compared to 9%. In the above sample 2, the thickness of the TiO ₂ film was 25
nm was chosen because it is the thickness that maximizes the transmittance of the composite multilayer of Ag and TiO ₂ films at a wavelength of 450 nm. The transmittance of a conventionally used two-layer film of nickel of 1 nm and gold of 8 nm was 47%. It has been found that in the region where the wavelength is shorter than 450 nm, a composite multilayer film of an Ag layer and a TiO ₂ film is more advantageous. (Note that when the thickness of the Ag layer was 7 nm, the transmittances of the Ag layer and the synthetic multilayer film were 52% and 71%, respectively.)

The inventors of the present invention have found that the absorption of the Ag layer is smaller than that of other metal thin film layers, and that the transmittance depends on the reflectance (see also FIG. 8). Was found that the thickness of the TiO ₂ film should be changed in proportion to the wavelength λ in order to maximize the value. One method is to make the film thickness 25 × λ / 450 (nm). In the second embodiment of the present invention, the thickness of the TiO ₂ film is 25 nm, and the transmittance of the Ag layer at a wavelength of 450 nm is maximized. The TiO ₂ film functions as an optical matching layer for increasing the transmittance, and its required thickness is advantageous in that the thickness can be easily controlled regardless of the thickness of the Ag layer. Of course, it is obvious that the effect of increasing the output light can be obtained even if only the portion excluding the lower portion of the bonding metal electrode 51a is formed of a silver layer. Alternatively, the thickness of the silver layer 51 including the vicinity of the lower portion of the bonding metal electrode 51a may be increased to facilitate the connection between the metal electrode 51a and the silver layer.

FIG. 7 shows steps 381 and 382 for manufacturing a GaN-based LED according to the second embodiment of the present invention.
And should be added. In step 38, n
After forming the electrode 7 and subsequently performing the annealing 2, Ti
O ₂ is deposited and patterned to form a TiO ₂ layer 52 (step 381), and a metal electrode 5 for bonding is formed on the TiO ₂ layer 52.
After patterning and forming the hole at the top of 1a, the third annealing (annealing 3) was performed (step 38).
2). Thereafter, the formed LED chip was attached to the die pad 8a of the package 8, a bonding wire was wired, and processing such as resin sealing was performed to complete an LED product (step 39).

When the TiO ₂ layer 52 is used, the conditions at the time of depositing the silver layer 51 are relaxed, and the deposition rate of silver can be increased even if the temperature of the sapphire substrate 2 is the same. That is, it is preferable that the TiO ₂ layer 52 not only functions as an optical matching layer but also functions as a dielectric stabilizing layer for improving mechanical and electrical characteristics of the silver layer 51. As an alternative dielectric transparent thin film, SiO ₂ , Al ₂ O _{3 and the} like are effective, but the TiO ₂ layer 52 is the most effective. As in the first embodiment, annealing may be performed by annealing 1 or 2.
Only annealing 2 or only annealing 3 may be performed.

The LED chip of the second embodiment has almost the same voltage-current characteristics as the curve 151 in FIG.
Good characteristics were obtained. Since the light output was substantially proportional to the transmittance of the transparent electrode, the silver layer 51 was 10 nm and the TiO ₂ layer 52 was 25 nm.
When the nickel layer is a nickel layer, the silver layer 51 and the TiO ₂ layer 52 of FIG. 2 are replaced by a two-layer film of nickel 1 nm and gold 8 nm at least 1.4 times or more as compared with the conventional LED (LED-P). Efficiency (light intensity / input power) could be obtained.

On the other hand, the present inventors have found that the above-mentioned silver layer can constitute a p-electrode functioning as a good reflection film, and constituted a third embodiment of the present invention. The low light absorption of silver is also advantageous here. First, the point that silver is excellent as a metal for realizing a p-electrode having a high reflectance will be described with reference to FIG.

FIG. 8 plots the wavelength dependence of the reflectance of various metal layers having a thickness of 100 nm deposited on glass. 8, a curve 80 is a silver layer, a curve 81 is a palladium layer, a curve 82 is a platinum layer, and a curve 8 respectively.
3 represents a nickel layer, curve 84 represents a gold layer, curve 85 represents an aluminum layer, curve 86 represents a chromium layer, and curve 87 represents a titanium layer. It has been found that the thin film material that can obtain a reflectance of 90% or more at a wavelength near blue to green, which is the output light of the GaN-based LED, is silver or aluminum.

Further, silver, palladium, platinum and nickel are known as metals capable of forming an ohmic junction as a p-electrode. The reflectance of a thin film of these metals other than silver is 65% or less in all wavelengths from blue to near green, and even when these metals are used as p-electrodes, they are clear compared to conventional reflective p-electrodes. We cannot show advantage. On the other hand, it is known that gold, aluminum, chromium, titanium and the like cannot form an ohmic junction as a p-electrode. Therefore, higher reflectance was obtained, and it was found that silver was most suitable as a metal thin film that functions well as a p-electrode.

FIG. 9 shows a plot of the reflectance of the silver thin film with respect to light having a wavelength of 470 nm while changing the film thickness. As the film thickness increases, the reflectance also increases.
Saturates around 50 nm. It can be seen that a film thickness of at least 20 nm is necessary to obtain a remarkable advantage over the conventional p-electrode. If the amount of silver is 50 nm or more, a sufficient effect can be obtained with a small amount of silver. Above 100 nm, there is almost no optical significance for obtaining the reflectance. However, when there is a possibility that the reflectance of silver itself cannot be obtained due to the diffusion of other metal into silver, it is better to further increase the thickness of silver according to the amount of the metal to be diffused and the amount.

Based on the above findings and the technology of the present invention in which a silver layer can be stably formed as a transparent electrode on a p-type nitride semiconductor, the inventors of the present invention have conducted flip bonding of an LED element (chip) to a package. Led to the idea of configuring LEDs.

FIG. 10 shows the third and fourth embodiments of the present invention.
LED chip 100A (FIG. 10A) and LED chip 10
0B (FIG. 10B) is shown. In these third and fourth embodiments, since the sapphire substrate 2 has a high transmittance for light generated from the active layer 4, output light is emitted from the sapphire substrate 2 to the outside. A transparent substrate different from the sapphire substrate 2 may be used. In FIG. 10, parts that exhibit the same functions and performances as those of the LED 20 in FIG. 2 are given the same reference numerals as in FIG. Except for the package 8, the assembly of the LED chip 100 is the same as that of assembling the LED 20, except that the thickness of the deposited silver layer 101 is thicker than the thickness of the silver layer 51.

The LED chip 100A of the third embodiment is an LED chip 20 in which the p-electrode has only the silver layer 101 (thickness 100 nm) and the layer 103A, and has no diffusion blocking layer 102 between the thin films. The layer 103A is a stabilizing layer of the silver layer 101, and is configured to cover the whole or a part of the silver layer with a metal or a dielectric that does not decrease the reflectance of the silver layer 101. First
When the LED chip 100A uses the layer 103A made of a dielectric, a hole is provided in a part of the layer 103A, and a circuit connection metal layer connected to the silver layer is required. Except for the step of forming a reflective layer having a silver layer thickness of 20 nm or more (step 36 in FIG. 3), the manufacturing steps are the same as those in the second embodiment, from step 31 to step 3
8. LED chip 100A through steps 381 to 382
Is formed.

Further, the LED chip 100A moves from the step 382 to a step 391 shown in FIG. 12 to be described later. The bonding electrode such as a gold bump is formed on the metal layer for circuit connection on the silver layer and the n-electrode 7 by a ball bonding method. Then, the LED chip 100A is ready to be mounted (FIG. 11).
(A)). Next, flip chip bonding of the LED chip is performed. First, when a large number of LED chips 100A are formed on a wafer, the back surface of the wafer is wrapped, and the wafer is scribed to each LED.
It was divided into chips 100A (step 392). FIG.
As shown in FIG. 1B, a bump 118b made of an indium-based low melting point metal was formed on the lead wire 118a on the die pad of the package 118 (step 393).
Finally, the LED chip 100A and the package 118 are aligned, heated and pressed to bond the bonding electrode 116 and the bump 118b, and the LED 11 shown in FIG.
0 was obtained (step 394). The LED 110 may be resin-sealed as needed for chip protection or the like. The above LED
Annealing in the process of manufacturing the chip 100A and the LED product is the same as in the second embodiment. Metal layer 10
The case where 3A is used is the same as the case where the second layer 102 is omitted in the LED chip manufacturing process of the fourth embodiment described later, and therefore will not be described here. Further, it is common that the layer 103A functions as a stabilizing layer for the silver layer, whether it is a metal or a dielectric.

LED chip 100 according to a fourth embodiment of the present invention
B is also formed by adding the steps shown in FIG. 12 to the LED member that has passed through step 35 in FIG. Step 3
In step 6A, the silver layer 101 was deposited to a thickness of 20 nm or more, in the fourth embodiment, to a thickness of 100 nm, and in step 371, a nickel diffusion blocking layer 102 was deposited to a thickness of 300 nm. Where L
ED members are not annealed. Diffusion blocking layer 102
Is not essential, but covers the side surface of the silver layer 101 as well.
At the same time, the silver layer 101 was sealed. Next, a metal for circuit connection, here gold was deposited to a thickness of 50 nm (Step 3).
72). The n-electrode 7 was formed by evaporating a titanium layer (thickness 10 nm) on the n-layer 3 and further evaporating an aluminum layer (thickness 200 nm) as a circuit connecting metal thereon (step 38).
The annealing for obtaining a good ohmic junction is shown in FIG.
Substrate temperature 450 ° C., 3
Run for 0 minutes (step 38).

Next, step 373 is omitted, and step 39 described above is omitted.
The bonding electrode 11 such as a gold bump electrode is formed on the gold layer 103 and the n-electrode 7 by a ball bonding method.
6, and the LED chip 100B can be mounted (FIG. 11A). Next, as in the case of the LED chip 100A in the third embodiment, steps 392 to 392 are performed.
Step 394 packages the LED chip 100B into the package 11
8 is flip-chip bonded. The LED 110 may be resin-sealed as needed for chip protection or the like.

In the third embodiment of the present invention, the silver layer 101
When a gold layer or a gold bump electrode is employed as the bonding electrode 116 directly deposited on the silver layer 110, the silver layer 110 is diffused by gold.
Side reflectance may be degraded. Fourth Embodiment of the Present Invention
In the embodiment of the present invention, the above-mentioned disadvantage is solved by forming the p-electrode into a three-layer structure.

That is, the three-layer structure of the p-electrode is the first layer 101
Is a material that provides an ohmic connection with a semiconductor and has a high reflectance, and a material that suppresses a decrease in the reflectance of the first layer by suppressing the metal diffusion to the first layer in a later step. For the third layer 103, it is often preferable to select a material that enables bonding and bump formation. Hereinafter, the case where the material of each layer is selected so as to satisfy these conditions will be described with reference to FIG.

FIG. 13 is a diagram in which the reflectance of the p-electrode is plotted with respect to the wavelength of the measurement light in order to explain the necessity of the second layer of the p-electrode. The change in the reflectance of the p-electrode with respect to light can be seen by the above-described annealing for obtaining an ohmic junction. Curve 131 is the reflectance as viewed from the sapphire substrate 2 side immediately after the silver layer 101 was deposited as a p-electrode, and curve 13
Reference numeral 2 denotes a second nickel layer serving as a diffusion blocking layer 102 as a first nickel layer.
The reflectance after annealing in the three-layer structure provided between the silver layer as the third layer and the gold layer 103 as the third layer, and the curve 133 shows the two-layer structure of the silver layer 101 and the gold layer 103 without the second layer. Is the reflectance after annealing.

In the above two-layer structure, gold diffuses to the silver layer 101 side by annealing, and there is a remarkable color change even by visual observation with a microscope, resulting in a decrease in reflectance.
On the other hand, when nickel is provided as the second layer (curve 1
Regarding (32), even after annealing, the decrease in reflectance was about 5%, and no remarkable color change was observed by visual observation with a microscope. Nickel of the second layer 102 functions as a diffusion preventing layer, and gold of the third layer 103 prevents diffusion to the silver layer as the first layer 101. In the fourth embodiment, the gold thickness is selected while emphasizing gold diffusion and slightly sacrificing the bonding property.

Next, the fourth embodiment of the present invention will be described with reference to FIGS.
Example will be further described. FIG. 14 is a plot obtained by comparing the change in the luminous intensity 141 of the output light of the LED according to the fourth embodiment of the present invention with the luminous intensity 142 of the output light of the conventional LED with respect to the input current in arbitrary units (au). .
The LED chip of this conventional LED (the LED-P) is the same as the LED chip 10 of FIG. 1 and has a different electrode configuration from the chip of the fourth embodiment, but the other configurations are equivalent. And have the same p-layer area. About 15% of the area of the p-layer is the metal p-electrode for bonding, and it is expected that the output light will increase by this degree by flip-chip mounting. FIG.
Is the LED driving voltage 151 according to the fourth embodiment of the present invention.
7 is a plot in which the change of the drive voltage 152 of the conventional LED with respect to the input current is plotted for comparison.

As is clear from FIGS. 14 and 15, the LED according to the fourth embodiment of the present invention is about twice as bright as the conventional LED, and the driving voltage is equal or slightly lower. The same effect can be obtained even if the third layer 103 is changed from a gold layer to an aluminum layer. In addition, since the second layer 102 and the like are provided on the silver layer 101, the stability of the silver layer is increased. Is advantageous.
That is, the second layer 101 preferably functions not only as a diffusion blocking layer but also as a metal stabilizing layer for improving the mechanical and electrical characteristics of the silver layer 101.

The second layer 102 and the third layer 103 may themselves be multilayer thin films, and the configurations of the multilayer films need not be uniform over their area.
When the second layer 102 functions as only a stabilizing layer and is used as a stabilizing layer, it is particularly required that the second layer does not diffuse into the silver layer 100. When the second layer 102 functions as a diffusion blocking layer, it is necessary that the second layer does not diffuse into the silver layer 100 and has a high ability to prevent the third layer from diffusing into the silver layer. In the third embodiment, if the second layer 102 is omitted, the third layer 103 is suitable for circuit connection and the silver layer 100
It is particularly required that they do not spread to

The second layer 102 on the silver layer 101 as the first layer
Since the diffusion of the metal of the third layer 103 is remarkable during the high-temperature annealing, the following steps were changed in the fourth embodiment to obtain the fifth embodiment. (1) The step 372 is omitted, and in the fourth embodiment, the step 373 is omitted, and the metal electrode for circuit connection is deposited. In this case, the third layer could be deposited thicker than in step 372 to improve bonding. In this way, the diffusion of the third layer 103 is extremely reduced, and the silver layer 1
01, the decrease in the reflectance is reduced, and the light amount of the LED, that is, the light emission intensity can be further increased. However, care must be taken so that the surface of the second layer 102 does not undergo a change such as oxidation during the annealing 2 in the step 38, which deteriorates the adhesion to the third layer. If such a change occurs, a process for removing the changed surface may be added. (2) Step 371 and step 373 are performed to reduce the deterioration of the adhesion due to the change in the surface.
At 72, the third layer 103 may be deposited thinner than in step 371 of the fourth embodiment, and at step 373, an additional third layer may be deposited.

In the third to fifth embodiments, the annealing 11 in the step 371 is not performed. However, the annealing 11 is performed for the purpose of process control or the like, and various measurements of the LED member after the steps up to the step 371 are performed. You may. In the third to fifth embodiments, a flip-chip structure is used.
In the conventional method, the transparent electrode, the bonding electrode, the bonding wire, etc., which caused the output light to be reflected and absorbed, do not exist in the output light emitting direction, and a large amount of light is output.
Can be taken out of the LED chip. Also, the silver layer 1 of the p-electrode
01 has high reflectivity, which further enhances the light extraction efficiency, and at the same time simplifies the LED chip thin film structure and simplifies the structure of LED products because there is no need to increase the reflectivity of die pads. And reduce costs.

Further, in the LED chip of the second embodiment, the thickness of the silver layer 51 is made larger than 20 nm, and the LED chip is flip-chip bonded to be similar to the LEDs of the third and fourth embodiments. LED product of the sixth embodiment of the present invention
Obtained as an LED. Further, the bonding electrode for flip chip bonding and the bump made of indium-based low melting point metal can be exchanged between the LED chip and the package, or can be made of another suitable metal.

The embodiments of the present invention have been described above.
The present invention is not limited to the embodiments, but can be applied to more electronic devices by making various modifications and additions. The following is a listing of some of the embodiments of the present invention for reference to various implementations of the invention.

(Embodiment 1): A substrate, an n-type nitride semiconductor layer on the substrate, an active layer made of a nitride semiconductor on the n-type nitride semiconductor layer, and a p-type nitride semiconductor layer on the active layer When,
An LED member comprising: a silver layer having a thickness of more than 20 nm for reflecting light generated by the active layer on a p-type nitride semiconductor layer.

(Embodiment 2): The LED member according to Embodiment 1, wherein a dielectric is provided on the surface of the silver layer for stabilizing a part of the surface of the silver layer. (Embodiment 3): The method according to embodiment 1 or 2, wherein a metal layer which does not easily diffuse into silver and prevents diffusion of at least one other metal into silver is provided on the silver layer.
LED components. (Embodiment 4): The LED member according to embodiment 3, wherein a portion of the metal layer that contacts the silver layer is any one of nickel, palladium, and platinum.

(Embodiment 5): The LED according to any one of Embodiments 2 to 4, wherein a circuit connecting metal means is provided on the n-type nitride semiconductor layer and on the metal layer or the silver layer. Element. (Embodiment 6): The LED member according to embodiment 5, wherein a surface of the metal means for circuit connection distal from the metal layer has a portion of gold or aluminum. (Embodiment 7): The LED member according to embodiment 6, wherein the gold or aluminum portion is a thin film layer thinner than the metal layer.

(Embodiment 8): The LED member according to any one of Embodiments 6 and 7, wherein a bonding electrode is provided on the circuit connecting metal means. (Embodiment 9): The LED member according to embodiment 8, wherein the bonding electrode is a gold bump. (Embodiment 10): A wafer on which a plurality of the LED members according to any one of Embodiments 3 to 9 are integrated.

(Embodiment 11): An LED product formed by flip-chip bonding the LED member according to Embodiment 8 or 9 to a package. (Embodiment 12): The LED product according to embodiment 11, wherein the bonding electrode is connected to a bump bump made of an indium-based low melting point metal on a lead wire of the package by a gold bump.

(Embodiment 13) A method for forming an LED member, comprising the steps of: preparing a substrate;
Growing a nitride semiconductor layer, growing an active layer of a nitride semiconductor on the n-type nitride semiconductor layer, growing a p-type nitride semiconductor layer on the active layer, Heating the p-type nitride semiconductor layer to activate the p-type nitride semiconductor layer; providing a silver layer having a predetermined thickness of 20 nm or more on the p-type nitride semiconductor layer; And a method of manufacturing an LED member.

(Embodiment 14): The LED according to embodiment 13, wherein the stabilizing layer is a dielectric.
Manufacturing method of the member. Embodiment 15: The method of manufacturing an LED member according to embodiment 13, wherein the stabilizing layer is a metal layer that does not easily diffuse into silver and can prevent diffusion of at least one other metal into silver. (Embodiment 16) The method of manufacturing an LED member according to embodiment 15, wherein a portion of the metal layer that contacts the silver layer is one of nickel, palladium, and platinum.

(Embodiment 17): Either of Embodiment 15 or Embodiment 16 further comprising a step of providing a circuit connecting metal means on the n-type nitride semiconductor layer and on the metal layer or the silver layer. 3. The method for manufacturing an LED member according to 1. (Embodiment 18): The method of manufacturing an LED member according to embodiment 17, wherein a surface of the metal means for circuit connection distal from the metal layer has a portion of gold or aluminum. (Embodiment 19) The method of manufacturing an LED member according to embodiment 18, wherein the metal means for circuit connection is a thin layer of gold or aluminum having a thinner metal layer.

(Embodiment 20): The method for manufacturing an LED member according to any one of Embodiments 17 to 19, wherein a step of providing a bonding electrode on the circuit connecting metal means is added. (Embodiment 21): An LED comprising a step of integrating a plurality of the LED members according to any one of Embodiments 3 to 9 on a wafer, lapping the wafer, and dicing to separate LED chips. Product manufacturing method. (Embodiment 22): The method of manufacturing an LED product according to embodiment 21, further comprising a step of flip-chip bonding the separated LED chips.

(Embodiment 23): A step of providing a first circuit connecting metal means on the n-type nitride semiconductor layer to form a first LED member, and a step of forming the first LED member in a nitrogen atmosphere. The method for manufacturing an LED member according to any one of Embodiments 15 to 16, further comprising a step of annealing at 200 ° C. or higher. (Embodiment 24): An embodiment characterized by adding a step of providing a second circuit connection metal means on the metal layer and a step of providing a bonding electrode on the first and second circuit connection metal means. 24. The method for manufacturing an LED member according to 23.

(Embodiment 25): A third circuit connecting metal means is provided on the metal layer, and a first circuit connecting metal means is provided on the n-type nitride semiconductor layer to form a second LED member. Forming the second LED member in a nitrogen atmosphere.
The method for manufacturing an LED member according to any one of Embodiments 15 to 16, further comprising a step of annealing at 0 ° C. or higher. (Embodiment 26): The method for manufacturing an LED member according to embodiment 24, further comprising a step of providing a bonding electrode on the third circuit connection metal means.

(Embodiment 27): An electronic device including a p-type nitride semiconductor layer, including a silver layer having a thickness of more than 20 nm deposited on the p-type nitride semiconductor layer, and the silver layer functions as an electrode. A semiconductor optoelectronic device characterized by functioning as a reflection layer for short-wavelength light. (Embodiment 28) The semiconductor optoelectronic device according to embodiment 27, wherein the silver layer has a stabilizing layer. (Embodiment 29): A metal layer in which the stabilizing layer is in contact with the silver layer and is not easily diffused into silver, and a metal layer having excellent bonding properties in contact with the metal layer are sequentially deposited on the silver layer to form a vapor deposition optical system. 29. The semiconductor optoelectronic device according to embodiment 28, functioning as a matching layer.

[0074]

According to the present invention, a brighter diode can be obtained as compared with the conventional one. Further, the following effects can be obtained. 1) LE with low operating voltage and stable operation for continuous operation
D can be realized efficiently. 2) The light extraction efficiency can be increased while maintaining a low operating voltage in the LED. Can be 3) Since the silver layer is used as the reflective p-electrode, the structure of the LED is simplified, the manufacturing process is simplified, and the reliability and the cost can be reduced. 4) Further, with these, for example, in a light emitting device in which two LEDs are conventionally used, the same performance can be obtained with one LED, and the number of LEDs can be reduced. And cost reduction can be realized. 5) In addition, any optoelectronic device including a p-type nitride semiconductor layer such as a light receiving device includes the silver layer of the present invention, and the silver layer functions as an electrode and emits light, particularly, but not limited to, short-wavelength light. This is useful because it can be widely applied to semiconductor optoelectronic devices that function well as a transmission layer or a reflection layer.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a GaN-based LED configured based on a GaN-based semiconductor according to a conventional technique.

FIG. 2 is a cross-sectional view of a GaN-based LED 20 according to a first embodiment of the present invention in which a silver (Ag) layer 21 is deposited as a first layer metal forming a p-electrode.

FIG. 3 is a process chart for explaining an assembly process of the LED 20;

FIG. 4 is a graph showing experimental results for confirming the effect of annealing.

FIG. 5 is a partial sectional view of an LED 50 according to a second embodiment of the present invention.

FIG. 6 is a graph showing the transmittance of Samples 1 and 2 when the wavelength of the measurement light is 450 nm showing the measurement results of the transmittance.

FIG. 7 is a partial affirmative diagram showing that steps 381 and 382 should be added to the step diagram of FIG. 3 to manufacture the GaN-based LED of the second embodiment of the present invention.

FIG. 8 is a graph plotting the wavelength dependence of the reflectance of various metal layers having a thickness of 100 nm deposited on glass.

FIG. 9 is a graph in which the reflectance of a silver layer with respect to light having a wavelength of 470 nm is plotted while changing the film thickness.

FIG. 10 is a sectional view of an LED chip 100 according to a fourth embodiment of the present invention.

FIG. 11 is a diagram illustrating a procedure for bonding the LED chip 100 to a package.

FIG. 12 shows an LED chip 100B according to a fourth embodiment of the present invention.
FIG. 4 is a process diagram showing a process of manufacturing and mounting the device.

FIG. 13 is a graph in which the reflectance of the p-electrode is plotted against the wavelength of the measurement light to explain the necessity of the second layer of the p-electrode.

FIG. 14 is a graph in which the change in the light emission intensity 141 of the LED according to the fourth embodiment of the present invention and the light emission intensity 142 of the conventional LED with respect to the input current is plotted in arbitrary units (au).

FIG. 15 is a graph showing comparison plots of a change in an input current between an LED driving voltage 151 according to a fourth embodiment of the present invention and a conventional LED driving voltage 152.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 GaN-based LED 2 sapphire substrate 3 n-layer 4 active layer 4, 5 p-layer 5, 6 transparent p-electrode 6 6 a bonding p-electrode 7 n-electrode 8 package 8 a die pad 10 conventional GaN-based LED chip 20 present invention GaN-based LED 21 of the first embodiment 21 Silver (Ag) layer 21a Electrode metal layer for bonding 100A, 100B LED chip 101 Silver layer (first layer) 102 Diffusion blocking layer (second layer) 103 Metal for circuit connection Layer (third layer) 103A Metal layer for circuit connection 110 LED 116 Bonding electrode 118 Package 118a Lead wire 118b Bump made of low melting point metal

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Watanabe 3-2-2, Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa Prefecture Hewlett-Packard Laboratories Japan Inc. Chome No.2-2 Hewlett-Packard Laboratories Japan Inc.

Claims (29)

[Claims] A substrate, an n-type nitride semiconductor layer on the substrate, an active layer made of a nitride semiconductor on the n-type nitride semiconductor layer, a p-type nitride semiconductor layer on the active layer, And a silver layer having a thickness of more than 20 nm for reflecting light generated by the active layer on the nitride semiconductor layer. 2. The LED according to claim 1, wherein a dielectric is provided on the surface of the silver layer for stabilizing a part of the surface of the silver layer.
Element. 3. The LED member according to claim 1, further comprising a metal layer provided on the silver layer, the metal layer not easily diffusing into silver but preventing diffusion of at least one other metal into silver. . 4. The LED member according to claim 3, wherein a portion of the metal layer that contacts the silver layer is one of nickel, palladium, and platinum. 5. The LED member according to claim 2, wherein a metal means for circuit connection is provided on the n-type nitride semiconductor layer and on the metal layer or the silver layer. 6. The LED member according to claim 5, wherein a surface of the metal means for connecting a circuit, which is distal from the metal layer, has a portion of gold or aluminum. 7. The method according to claim 6, wherein said gold or aluminum portion is a thin film layer thinner than said metal layer.
LED member according to the above. 8. The LED member according to claim 6, wherein a bonding electrode is provided on the circuit connecting metal means. 9. The LED member according to claim 8, wherein said bonding electrode is a gold bump. 10. A wafer on which a plurality of the LED members according to claim 3 are integrated. 11. An LED according to claim 8 or claim 9.
An LED product formed by flip chip bonding components to a package. 12. The LED product according to claim 11, wherein said bonding electrode is connected to a bump bump made of an indium-based low melting point metal on a lead wire of said package by a gold bump. 13. A method for forming an LED member, comprising: providing a substrate; growing an n-type nitride semiconductor layer on the substrate; and forming a nitride semiconductor on the n-type nitride semiconductor layer. A step of growing an active layer consisting of: a step of growing a p-type nitride semiconductor layer on the active layer; a step of heating the substrate to activate the p-type nitride semiconductor layer; A method for manufacturing an LED member, comprising: providing a silver layer having a predetermined thickness of 20 nm or more on a nitride semiconductor layer; and depositing a stabilizing layer on the silver layer. 14. The method according to claim 13, wherein the stabilizing layer is a dielectric. 15. The method for manufacturing an LED member according to claim 13, wherein the stabilizing layer is a metal layer which does not easily diffuse into silver and can prevent diffusion of at least one other metal into silver. 16. The method according to claim 15, wherein a portion of the metal layer that contacts the silver layer is one of nickel, palladium, and platinum. 17. The LED according to claim 15, further comprising a step of providing a circuit connecting metal means on the n-type nitride semiconductor layer and on the metal layer or the silver layer. Manufacturing method of the member. 18. The method according to claim 17, wherein a surface of the metal means for connecting a circuit, which is distal to the metal layer, has a portion of gold or aluminum. 19. The method for manufacturing an LED member according to claim 18, wherein said metal means for circuit connection is a thin layer of gold or aluminum thinner than said metal layer. 20. The method according to claim 1, further comprising the step of providing a bonding electrode on said metal means for circuit connection.
The method for manufacturing an LED member according to any one of claims 7 to 19. 21. An LED product comprising a step of integrating a plurality of the LED members according to claim 3 on a wafer, lapping the wafer, and dicing to separate LED chips. Manufacturing method. 22. The method according to claim 21, further comprising a step of flip-chip bonding the separated LED chips.
Manufacturing method of LED product described in. 23. A step of providing a first circuit connecting metal means on the n-type nitride semiconductor layer to form a first LED member, and forming the first LED member at 200 ° C. or more in a nitrogen atmosphere. 2. The method according to claim 1, further comprising an annealing step.
7. The method for manufacturing an LED member according to any one of 6. 24. The method according to claim 23, further comprising the step of providing a second circuit connecting metal means on the metal layer and the step of providing a bonding electrode on the first and second circuit connecting metal means. 3. The method for manufacturing an LED member according to 1. 25. A step of providing a third circuit connecting metal means on the metal layer and providing a first circuit connecting metal means on the n-type nitride semiconductor layer to form a second LED member. 17. The method of manufacturing an LED member according to claim 15, further comprising a step of annealing the second LED member at 200 ° C. or more in a nitrogen atmosphere. 26. The method of manufacturing an LED member according to claim 24, further comprising a step of providing a bonding electrode on said third circuit connection metal means. 27. An electronic device comprising a p-type nitride semiconductor layer, comprising a silver layer having a thickness of more than 20 nm deposited on the p-type nitride semiconductor layer, wherein the silver layer functions as an electrode and has a short wavelength light. A semiconductor optoelectronic device characterized by functioning as a reflective layer. 28. The semiconductor optoelectronic device according to claim 27, wherein said silver layer has a stabilizing layer. 29. A metal layer in which the stabilizing layer is in contact with the silver layer and is not easily diffused into silver, and a metal layer having good bonding properties in contact with the metal layer are sequentially deposited on the silver layer, and vapor deposition optical matching is performed. 29. The semiconductor optoelectronic device according to claim 28, which functions as a layer.