JP2001044499A - ZnO COMPOUND SEMICONDUCTOR LIGHT-EMITTING DEVICE USING SILICON SUBSTRATE AND MANUFACTURING METHOD THEREFOR - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting device and its manufacturing method that use a ZnO-family compound semiconductor, are a vertical type that can take out an electrode from the upper and lower surfaces of a chip, having superior crystallinity of a semiconductor layer and high light emission efficiency, at the same time, which do not use a sapphire substrate, and are convenient in a manufacturing process and use. SOLUTION: A silicon nitride film 2 is provided on the surface of a silicon substrate 1, at least n-type and p-type layers 3 and 4 and 6 and 7 consisting of a ZnO-family compound semiconductor are provided on the silicon nitride film 2, and a semiconductor lamination part 11 is laminated, so that a light emission layer is formed. The silicon nitride film 2 is preferably subjected to heat treatment under atmosphere, where nitrogen as an ammonia gas exists for forming.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical disk memory using a ZnO-based compound semiconductor and having a high storage density,
The present invention relates to a semiconductor light emitting device such as a semiconductor laser or a light emitting diode capable of emitting light in a blue region required for high definition of a laser beam printer, and a method of manufacturing the same. More specifically, the present invention relates to a semiconductor light-emitting element in which a semiconductor layer having excellent light-emitting characteristics is laminated on a substrate using a silicon substrate, electrodes can be taken out from both upper and lower surfaces of the chip and cleaved, and a method for manufacturing the same.

[0002]

2. Description of the Related Art A blue light-emitting diode (hereinafter, referred to as an LED from ultraviolet to yellow wavelength region) used for a light source such as a full-color display and a signal light (hereinafter, referred to as an LED).
) And next-generation high-definition DVDs that oscillate continuously at room temperature
Blue semiconductor lasers for light sources (hereinafter referred to as LD)
Has recently been spotlighted by being obtained by laminating a GaN-based compound semiconductor on a sapphire substrate.

FIG. 6 shows a perspective view of an LD chip.
As shown in the figure, a group III chip is placed on a sapphire substrate 21.
Metal oxide chemical vapor deposition (Metal)
Organic Chemical Vapor Deposition, MOCV
D) and a GaN buffer layer
22, n-type GaN layer 23, Al_0.12Ga_0.88Consisting of N
n-type cladding layer 24, n-type light guide layer 2 made of GaN
5. From the multiple quantum well structure of InGaN-based compound semiconductor
Active layer 26, p-type light guide layer 2 made of p-type GaN
7, p-type Al_0.2Ga_0.8P-type first cladding made of N
Layer 28a, Al _0.12Ga_0.88N-type p-type second crack
Layer 28b and a contact layer 29 made of p-type GaN.
Next, a part of the stacked semiconductor layers is shown in FIG.
Etched by dry etching etc.
The n-type GaN layer 23 is exposed and an n-side electrode 3
1. A p-side electrode 30 is provided on the contact layer 29 described above.
It is constituted by being formed.

On the other hand, ZnO-based compound semiconductors are also wide-gap energy semiconductors, and various studies have begun to be carried out because the band gap energy can be narrowed by mixing crystals of Cd and blue light can be emitted similarly. . This ZnO-based compound semiconductor is also hexagonal (hexagonal) similarly to the GaN-based compound semiconductor and sapphire.
gonal) crystal and the lattice constant is close to these,
Sapphire, which is widely used industrially as a substrate for epitaxial growth of an N-based compound semiconductor, is considered as a substrate. The growth of the ZnO-based compound semiconductor on the sapphire substrate is described, for example, in "Room-temperature ultra violet laser emission from self-assembled ZnO microcrystallite thin films (Room-temperature ultraviol
et laser emission from self-assembled ZnO microcry
stallite thin films) "(Applied Physics Letters, Vol. 72, No. 25, 19)
(June 22, 1998, p. 3270-3272).

[0005]

As described above, in a conventional blue semiconductor light emitting device, since a sapphire substrate is used as a substrate, the substrate has no conductivity and electrodes are provided on the upper and lower surfaces of the laminate. (Which means a structure in which electrodes are formed on the front and back surfaces of a chip, the same applies hereinafter) cannot be formed. Therefore, both electrodes must be provided on the surface of the laminated semiconductor layer and the lower semiconductor layer in which a part of the surface is etched and exposed, which complicates the manufacturing process and the chip bonding. There is a problem. Moreover, since the sapphire substrate is very hard, it is difficult to cleave the sapphire substrate, and there is a problem that a flat end face required as a mirror surface of an optical resonator of a semiconductor laser cannot be formed. In other words, the sapphire substrate is forced to have difficulties in workability and electrode formation when manufacturing an element in a manufacturing process in exchange for obtaining a good single crystal semiconductor layer.

The present invention has been made to solve such a problem, and it is a vertical type using a ZnO-based compound semiconductor, from which electrodes can be taken out from both front and back surfaces of a chip, and having a semiconductor layer having good crystallinity. With excellent luminous efficiency,
It is an object of the present invention to provide a semiconductor light emitting device having a convenient structure in terms of a manufacturing process and use without using a sapphire substrate as a substrate, and a method for manufacturing the same.

Another object of the present invention is to provide a Z
An object of the present invention is to provide a method for manufacturing a semiconductor light emitting device including a surface treatment of a silicon substrate which is particularly suitable for growing an nO-based compound semiconductor with good crystallinity.

[0008]

In order to eliminate the inconvenience of growing a ZnO-based compound semiconductor on a sapphire substrate as described above, the present inventors used a large-diameter silicon substrate which is easy to handle. Intensive investigations were made to grow a compound semiconductor. As a result, even if a ZnO-based compound semiconductor is to be grown directly on a silicon
The reason that the system compound becomes amorphous and a semiconductor layer with good crystallinity cannot be obtained is that radical oxygen introduced for growing the ZnO compound causes the silicon substrate to grow first before the ZnO compound semiconductor grows. The surface is intensely oxidized and becomes amorphous. By applying a silicon nitride treatment to the surface of the silicon substrate to form a thin nitride film, the oxidation of the silicon substrate surface is prevented and the crystallinity is reduced. It has been found that an excellent ZnO-based compound semiconductor layer can be grown, and a semiconductor light-emitting element having excellent light-emitting characteristics can be obtained.

A semiconductor light emitting device according to the present invention comprises a silicon substrate, a silicon nitride film provided on a surface of the silicon substrate, an n-type layer made of a ZnO-based compound semiconductor, and a p-type layer provided on the silicon nitride film. A semiconductor laminated portion having at least a shape layer and laminated to form a light emitting layer.

[0010] Here, the ZnO-based compound semiconductor is an oxide containing Zn, specifically, a group IIA element in addition to ZnO and ZZ.
Group n or IIB element and Zn or Group IIA element and IIB
It means that it is an oxide of each of a group III element and Zn.

According to this structure, since a silicon nitride film is formed on the surface of the silicon substrate, Zn
Even if radical oxygen for growing the O-based compound semiconductor layer is introduced, the surface of the silicon substrate is not oxidized and roughened, and the ZnO-based compound semiconductor layer grown on the surface also grows with good crystallinity. As a result, a semiconductor laminated portion having good crystallinity is obtained, and a semiconductor light emitting device having excellent light emitting characteristics is obtained.

It is preferable that the surface of the silicon nitride film is formed on a flat surface without being made amorphous, since the crystallinity of the ZnO-based compound semiconductor layer grown thereon is further improved.

Here, "the surface of the silicon nitride film is formed as a flat surface" refers to a surface state in which the lattice arrangement can be recognized without the surface becoming amorphous and unevenness becoming severe. Diffraction method (RHEE
Method D: An electron beam accelerated at 10 to 50 kV is incident on the substrate surface at a shallow angle (1 to 2 ° or less), and the electron beam reflected and diffracted by the surface atoms is projected on a fluorescent screen to change the surface state of the crystal. (Investigation method) means a state in which a spotty image appears from the streak state.

It is preferable that the silicon nitride film is formed to a thickness of 100 ° or less because the surface of the silicon nitride film tends to be flat without being polycrystallized.

[0015] The semiconductor lamination portion is made of Cd _x Zn _1-x O
The active layer composed of (0 ≦ x <1) is formed of Mg _y Zn _1-y O
(0 ≦ y <1), which has a double hetero structure sandwiched by cladding layers having a bandgap energy larger than that of the active layer, so that an LED or LD using a ZnO-based compound semiconductor and having excellent emission characteristics can be obtained. preferable.

According to a method of manufacturing a semiconductor light emitting device of the present invention, a silicon nitride film is formed on a surface of a silicon substrate by heat-treating the silicon substrate in an atmosphere in which nitrogen is present.
A semiconductor laminated portion made of a ZnO-based compound semiconductor and forming a light emitting layer is grown on the silicon nitride film.

By using this method, a nitrided film for preventing oxidation is formed on the surface of the silicon substrate.
The crystal plane of the silicon substrate can be maintained without polycrystallizing the surface, a ZnO-based compound semiconductor having excellent crystallinity can be grown on the surface, and the silicon nitride film can be formed very thin. In addition, the conductivity between the silicon substrate and the semiconductor laminated portion is not divided.

The process for forming the silicon nitride film is as follows:
It is preferable to perform the treatment while controlling the temperature or time so that the surface of the formed silicon nitride film can maintain the flat surface of the silicon substrate because polycrystallization can be prevented. That is, for example, in the case of performing the nitriding treatment at 650 ° C., when performing the nitriding treatment in about 5 to 10 minutes, and more preferably in about 7 minutes, a ZnO-based compound semiconductor layer having excellent crystallinity can be obtained. Then, the surface is polycrystallized, and the ZnO-based compound semiconductor grown thereon is also polycrystallized, so that a ZnO-based compound semiconductor layer having good crystallinity cannot be obtained. In addition, in the case of performing the nitriding treatment at 800 ° C., even with a treatment time of about 3 minutes, a ZnO-based compound semiconductor layer having excellent crystallinity can be obtained. Conversely, when the temperature of the nitriding treatment is lowered, the treatment time is lengthened. More preferred. These conditions can be set so that the surface of the silicon nitride film becomes flat by inspecting the surface state of the silicon nitride film by, for example, the above-mentioned RHEED method.

[0019]

Next, a semiconductor light emitting device of the present invention and a method of manufacturing the same will be described with reference to the drawings.

FIG. 1 is a perspective view of an LED chip according to an embodiment of the present invention. As shown in FIG. 1, a silicon nitride film 2 is provided on the surface of a silicon substrate 1. On the silicon nitride film 2, at least n-type layers 3, 4 and p-type layers 6, 7 made of a ZnO-based compound semiconductor are provided, and a semiconductor laminated portion 11 is laminated so as to form a light emitting layer.

As described above, the present inventors have made intensive studies to grow a ZnO-based compound semiconductor on a silicon substrate with good crystallinity, and as a result, have found that
When an attempt is made to grow a compound semiconductor, radical oxygen, which is a material of the ZnO compound semiconductor, first reacts violently with silicon, and the surface becomes amorphous and irregularities are formed. It has been found that a base compound semiconductor layer cannot be obtained. Then, the surface of the silicon substrate is first subjected to a nitriding treatment, Si and N of dangling bonds on the surface of the substrate are combined, and a thin silicon nitride film is formed on the surface.
It has been found that a compound semiconductor can be grown thereon. This silicon nitride film was heat-treated in an atmosphere in which nitrogen such as nitrogen gas or ammonia gas is present, and a preferable result was obtained by forming a nitride film on the surface of the silicon substrate. If the treatment is excessively performed, the ZnO-based compound semiconductor thereon is rather polycrystallized, and a ZnO-based compound semiconductor having excellent crystallinity cannot be obtained.

That is, the silicon substrate 1 is subjected to a cleaning treatment and put into an MBE (Molecular Beam Epitaxy) crystal growth apparatus. For example, NH ₃ gas is introduced into the MBE crystal growth apparatus in a state of being plasma-excited by an RF power supply. Then, when the processing temperature and the processing time for forming the silicon nitride film 2 are variously changed, the Zn grown thereon is changed.
The state of the film quality of the O-based compound semiconductor layer was examined. As shown in Table 1, the heat treatment at 650 ° C. for 7 minutes gives a very good film quality (double circle), and the heat treatment at 650 ° C. for 5 to 10 minutes gives a good film quality of the ZnO-based compound semiconductor layer. Was obtained (white circles), but heat treatment at the same temperature for 15 minutes was not preferable because the ZnO-based compound semiconductor layer became amorphous (x mark). In addition, as a result of performing the nitriding treatment at 800 ° C. for 3 minutes, similarly, good film quality of the ZnO-based compound semiconductor layer was obtained. FIG. 2 shows this relationship. As a range in which good film quality can be obtained, the processing speed is naturally low at a low temperature, and thus the same film quality can be obtained over a long processing time.
It is assumed that by performing the treatment under the condition of the range A surrounded by the solid line, a silicon nitride film having good film quality can be obtained, and also a ZnO-based compound semiconductor layer grown thereon can have good film quality. You.

[0023]

[Table 1] As shown in FIG. 3A, the inspection of the film quality is accelerated at 10 to 50 kV by an electron gun 51, that is, a method generally called a reflection high energy electron diffraction method (RHEED method) provided in the MBE apparatus. Electron beam 52
Is incident on the surface of the substrate 53 at a shallow angle (1 to 2 ° or less) θ, and the electron beam 54 reflected and diffracted by the surface atoms is projected on the fluorescent screen 55 to examine the surface state of the crystal. The voltage was set at 20V. By performing this method, the incidence, reflection, and diffraction beam measurement of the electron beam are performed at a shallow angle.
The measurement can be performed while the film is formed without affecting the supply of the molecular beam performed from the direction perpendicular to the direction of 3.

As the diffraction image, if the substrate surface has a crystal structure, a straight or band-like light and dark (streak-like image) appears, but if the substrate surface has irregularities and islands are formed, these islands are formed. The contribution of the transmitted and diffracted electron beam increases, so that the streak-like image disappears and a spotty image appears. Further, when the surface becomes polycrystalline, the spot disappears and a ring-shaped diffraction image is obtained.
This is caused by the random distribution of crystallite orientations. Further, when the surface becomes amorphous, the periodicity of the atomic arrangement is lost, so that the diffraction condition is not satisfied, and the RHEED line becomes a band (halo) of uniform intensity. Therefore, by observing the surface state of the silicon nitride film 2 by this measurement and similarly examining the film quality of the ZnO-based compound semiconductor grown thereon, a correlation between the two can be obtained.

When the surface of the silicon substrate 1 is first subjected to a nitrification treatment while measuring the surface state, an oxide film is first formed on the surface of the silicon substrate. A ring-shaped diffraction image as shown in FIG. 3 (c) is obtained. In this state, the aforementioned NH ₃ gas is
When the holder (substrate) is heated to about 650 ° C. while being introduced into the chamber of the MBE apparatus under plasma excitation with the F power supply, oxidized oxygen on the surface of the silicon substrate 1 is reduced and removed, and the surface state becomes As shown in FIG. 3B, a point image appears. When held in this state, the surface oxygen is removed to form dangling bonds between Si and N.
Are combined to form silicon nitride, and the nitriding process continues, but with a thickness of the nitrided film 2 of about 100 ° or less,
The above-mentioned point-like image is maintained as the diffraction image. However, if the nitriding process is continued for more than 10 minutes, the dot image becomes blurred.
After about 5 minutes, a ring-shaped image is again formed as shown in FIG.

That is, the above-mentioned good film quality is obtained only when the spot-like diffraction image as shown in FIG. 3B is obtained and the dot-like image is slightly blurred. In the case where a ZnO-based compound semiconductor is grown in the state of a film, when a ring-like diffraction image as shown in FIG. 3C is obtained, the surface state becomes significantly uneven due to excessive nitriding treatment. In this state, the crystallinity of the ZnO-based compound semiconductor grown thereon decreases. Therefore, good film quality of the ZnO-based compound semiconductor can be obtained by performing a nitriding treatment for maintaining flatness so that the surface is not amorphous and unevenness is not increased.

As the silicon substrate 1, for example, an n-type phosphorus (P) -doped silicon substrate (111) used for an ordinary IC or the like can be used. However, a p-type substrate doped with boron (B) or the like or having a plane orientation of (100)
It may be. The silicon substrate 1 is previously subjected to organic cleaning such as ultrasonic cleaning with acetone, methanol and pure, and substrate cleaning including light etching of a surface oxide film with diluted hydrofluoric acid.

As described above, the silicon nitride film 2 can be formed by performing heat treatment in an atmosphere in which nitrogen is present, so that the surface of the silicon substrate 1 does not become polycrystalline or amorphous. It is preferable because it is easy.
This nitriding treatment does not need to be performed by the MBE apparatus as described above. However, when the processing is performed while observing the surface state, if the MBE apparatus is used, the processing is performed while observing by the RHEED method as described above. This is preferred because In addition, in the above-described example, the ammonia gas is used with plasma excitation to use an atmosphere in which nitrogen is present. However, N ₂ gas can be plasma-excited, and NO gas can be used.
₂ can also be used. This silicon nitride film 2
Is processed so as not to be in a polycrystalline state as described above, but to be in a state where a flat surface can be obtained. That is, 10
It is formed so as to have a thickness of 0 ° or less, more preferably 50 ° or less. The conditions for this are adjusted by the processing temperature and the processing time. The higher the temperature, the shorter the time, and the lower the temperature, the longer the processing.

In the example shown in FIG. 1, the semiconductor lamination portion 11 has a contact layer 3 made of Ga-doped n-type ZnO of about 1 μm, and a Mg _y Zn
_The n-type cladding layer 4 made of _1-y O (0 ≦ y <1, for example, y = 0.15) is about 0.2 μm, and Cd _x Zn _1-x O
(0 ≦ x <1, and a composition in which the band gap energy is smaller than that of the cladding layer, for example, x = 0.08) is about 0.1 μm, and Mg _y Zn _1-y doped with Ga and N simultaneously. O (0 ≦ y <1, for example, y =
0.15) is about 0.2 μm,
A p-type contact layer 7 made of ZnO doped with Ga and N at the same time is laminated to a thickness of about 1 μm to form a semiconductor laminated portion 11 having a light emitting layer forming portion having a double hetero structure. These semiconductor layers correspond to the aforementioned M
It is grown in the BE apparatus following the nitriding treatment. The active layer 5 is preferably non-doped in order to avoid formation of non-radiative recombination centers. The n-type and p-type cladding layers 4 and 6 are formed so as to have a band gap larger than that of the active layer 5 and have an effect of effectively confining carriers in the active layer 5.

On the semiconductor laminated portion 11, a transparent electrode 8 made of, for example, an ITO film for diffusing a current is set to 0.1 mm.
A film of about 2 μm is formed, and Ni / A
1 or a p-side electrode 10 made of a laminate such as Ni / Au
An n-side electrode 9 made of a laminate of Ti / Al or Ti / Au is formed on the entire back surface of the silicon substrate 1 by a vacuum deposition method or the like.

Next, a method of manufacturing the LED will be described. For example, the silicon substrate 1 is set in the MBE apparatus, the temperature of the substrate 1 is set to about 650 ° C., NH ₃ gas is introduced at a flow rate of 0.6 sccm, and the plasma is excited by a high frequency power supply of about 300 W into the chamber. Introduce. It is preferable to set the flow rate to this level because the plasma excitation light can be strongly obtained. Then, a nitrification process is performed for about 7 minutes.

Next, the temperature of the substrate 1 is set to 300 to 450 ° C.
Under the conditions of plasma oxygen irradiation, the Zn source source (cell) shutter is opened to irradiate Zn, and the n-type dopant Ga shutter is also opened to n.
An n-type contact layer 3 made of ZnO is grown to about 1 μm. Then, the shutter of the source (cell) of Mg is opened, and the n-type cladding layer 4 made of Mg _0.15 Zn _0.85 O is grown to about 0.2 μm.

Next, in order to grow the active layer 5, the cell of Mg and the cell of Ga as a dopant are closed, the shutter of the cell of the source metal of Cd is opened, and Cd is irradiated.
the d _{0. 08} Zn _0.92 O to growth of about 0.1μm. Then
The shutter of the Cd cell is closed, the Mg cell and the Ga cell are opened again, and plasma-excited N ₂ as a p-type dopant is introduced. Although Ga is an n-type dopant, it can be effectively p-type by co-doping with plasma-excited N ₂ , so that it is doped at the same time. Then, a p-type cladding layer 6 made of Mg _0.15 Zn _0.85 O is grown to a thickness of about 0.2 μm, and simultaneously doped to form a p-type contact layer 7 made of p-type ZnO of 1 μm.
The semiconductor laminated portion 11 is grown by growing the semiconductor layer 11 to a certain degree.

After that, the epitaxially grown wafer is taken out from the MBE apparatus and put into, for example, a sputtering apparatus to form an ITO film, and the transparent electrode 8 is provided to a thickness of about 0.2 μm. Thereafter, the back surface of the substrate 1 is polished,
A thickness of about 0 μm, an n-side electrode 9 made of Ti / Al or the like is
P-side electrode 10 made of Ti / Al or the like on a part of O film 8
Are each 0.2 μm by a lift-off method or the like.
m. Thereafter, by chipping from the wafer, the LED chip shown in FIG. 1 is obtained.

According to the semiconductor light emitting device of the present invention, the silicon nitride film is provided on the surface of the silicon substrate, and the ZnO-based compound semiconductor layer is laminated thereon.
Since the system compound semiconductor layer is grown with good crystallinity, a blue semiconductor light emitting device using a silicon substrate can be obtained with the same high luminous efficiency as when growing on a sapphire substrate.
That is, conventionally, even when a ZnO-based compound semiconductor was grown on a silicon substrate, the film quality was poor and the number of non-radiative recombination centers was large, so the luminous efficiency was very poor. As a result, a semiconductor light emitting device was obtained. On the other hand, a silicon nitride film is a very thin layer having a thickness of 100 ° or less, and has conductivity with almost no voltage drop by being sandwiched between upper and lower conductive semiconductor layers. As a result, a vertical light emitting element can be obtained in which the p-side electrode and the n-side electrode can be respectively taken out from the upper and lower sides of the chip, and it is not necessary to etch a part of the laminated semiconductor layer for forming the electrode. The process is simplified, and when mounting the light-emitting element, both electrodes are not wire-bonded, and one of them can be directly connected to the electrode by die bonding, which reduces wire bonding, making it very convenient in terms of use. become.

Further, when forming an LD as described later, it is preferable to make the end face of the optical resonator a mirror surface.
By stacking the cubic semiconductor layer on the silicon substrate, the semiconductor stacked portion is aligned by the cubic crystal from the substrate, so that it is easier to cleave than the sapphire substrate, and the end face of the optical resonator is It can be formed on a cleavage plane. As a result, a blue semiconductor laser having excellent oscillation characteristics can be obtained.

Although the above-described example is an example of an LED, an LD
The same applies to In this case, the semiconductor laminated portion 11 is slightly different. For example, as shown in a sectional view of FIG. 4, the active layer 15 is made of non-doped Cd _0.03 Zn _0.97 O / C.
It is preferable to form the barrier layer and the well layer made of d _0.2 Zn _0.8 O by a multiple quantum well structure in which 2 to 5 layers are alternately stacked by 50 ° and 40 °, respectively. When the active layer 15 is too thin to sufficiently confine light in the active layer 15, light guide layers 14 and 16 made of, for example, ZnO are provided on both sides of the active layer 15.

In the example shown in FIG. 4, an LD chip having a SAS structure in which the current confinement layer 17 is buried is formed, for example, on the p-type first cladding layer 6a made of p-type Mg _0.15 Zn _0.85 O. A current confinement layer 17 made of n-type Mg _0.2 Zn _0.8 O is provided in a thickness of about 0.4 μm. Once the wafer is taken out of the crystal growth apparatus, a resist film is provided on the surface and patterned in a stripe shape, and the resultant is exposed to an alkaline solution such as NaOH. The current confinement layer 17 is etched in a stripe shape to form a stripe groove 18, and the wafer is returned to the MBE apparatus again, and the p-type second cladding layer 6b made of p-type Mg _0.15 Zn _0.85 O and the p-type ZnO The contact layer 7 is formed by growing in the same manner as in the above-described example. In this case, a transparent electrode made of ITO is unnecessary, and the p-side electrode 1 is almost entirely formed on the p-type contact layer 7.
0 is formed. Although not shown, a p-type Ga layer is provided between the p-type first cladding layer 6a and the current confinement layer 17.
It is preferable to provide an etching stop layer made of N.

Since ZnO-based compound semiconductors can be etched by wet etching, G
S to bury current constriction layer, which is difficult with aN-based compound semiconductor
An LD chip having an AS type structure can be formed, a current confinement layer can be formed near an active layer, and a semiconductor laser with high characteristics can be obtained. However, the structure of the LD chip is
Not limited to the SAS type structure, an electrode stripe structure in which the p-side electrode is simply formed in a stripe shape, a mesa stripe structure in which the semiconductor layers on both sides of the stripe-shaped electrode are etched into a mesa shape up to the top of the p-type cladding layer, A proton implantation type in which protons or the like are implanted can also be used. FIG. 5 shows an example of an LD chip having an electrode stripe structure. This structure is different from the structure in FIG. 4 only in that the p-side electrode 10 is patterned in a stripe shape and the current constriction layer is not provided, and other structures are almost the same as those in FIG. Are denoted by the same reference numerals, and description thereof is omitted. Reference numeral 6 denotes a p-type cladding layer.

Even in such a structure, since silicon is used for the substrate, both electrodes can be taken out from both the upper and lower surfaces, which is very convenient from both the manufacturing and use sides, and has an optical resonator. Can be formed as cleavage planes by cleavage, so that a semiconductor laser with high characteristics can be obtained.

In the above example, the LED has a double hetero structure, but other structures such as a simple pn junction or a MIS (metal-insulating-semiconductor layer) structure may be used. In addition, the structure of the LD chip is not limited to the above-described laminated structure without the light guide layer provided with another layer. Furthermore, although the silicon substrate and the subsequent growth of the ZnO-based compound semiconductor were performed using the MBE apparatus, even if the nitrogen processing and the subsequent growth of the semiconductor layer were performed using the MOCVD apparatus, etc. As long as it is set, it is not necessary to perform the observation while observing the surface state, and the same surface state can be formed, and it can be manufactured by another method.

[0042]

According to the present invention, Zn is deposited on a silicon substrate.
An O-based compound semiconductor can be grown, and a vertical blue semiconductor light-emitting device having electrodes on both upper and lower surfaces can be obtained. Therefore, the manufacturing process is simple, cost can be reduced, and wire bonding can be reduced even at the stage of use, so that an easy-to-use semiconductor light emitting device can be obtained at low cost.

Further, since the laser cavity can be cleaved, a laser resonator having an excellent end face can be obtained, and an optical disk having a high storage density and a high-performance semiconductor laser with a short wavelength which can be used for high definition of a laser beam printer. Is obtained.

[Brief description of the drawings]

FIG. 1 shows an LED according to an embodiment of the semiconductor light emitting device of the present invention.
It is a perspective explanatory view of a chip.

FIG. 2 is a diagram showing a relationship between preferable conditions depending on temperature and time of a nitrification treatment of a silicon substrate surface.

FIG. 3 is an explanatory view of a method of inspecting a substrate surface by the RHEED method and an explanatory view of an observed diffraction image of the substrate surface.

FIG. 4 is an explanatory sectional view of another embodiment of the semiconductor light emitting device of the present invention.

FIG. 5 is an explanatory sectional view of another embodiment of the semiconductor light emitting device of the present invention.

FIG. 6 is a perspective explanatory view of an example of a conventional LD chip using a GaN-based compound semiconductor.

[Explanation of symbols]

 Reference Signs List 1 silicon substrate 2 silicon nitride film 4 n-type clad layer 5 active layer 6 p-type clad layer 11 semiconductor laminated portion

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[Procedure amendment]

[Submission date] August 2, 1999 (1999.8.2)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 4

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

[0006] The present invention has been made to solve the Do you Yo this problem, using the ZnO based compound semiconductor, a vertical type that can be taken out electrodes from both sides of the chip,
It is another object of the present invention to provide a semiconductor light emitting device having excellent crystallinity of a semiconductor layer and high luminous efficiency, and having a structure convenient in terms of a manufacturing process and use without using a sapphire substrate, and a method for manufacturing the same.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Change

[Correction contents]

[0023]

[Table 1] As shown in FIG. 3A, the inspection of the film quality is accelerated at 10 to 50 kV by an electron gun 51, that is, a method generally called a reflection high energy electron diffraction method (RHEED method) provided in the MBE apparatus. Electron beam 52
Is incident on the surface of the substrate 53 at a shallow angle (1 to 2 ° or less) θ, and the electron beam 54 reflected and diffracted by the surface atoms is projected on the fluorescent screen 55 to examine the surface state of the crystal. voltage was carried out in the 20 k V. By performing this method, the incidence, reflection,
Since the measurement of the diffracted beam is performed at a shallow angle, the measurement can be performed while forming the film without affecting the supply of the molecular beam performed from a direction substantially perpendicular to the substrate 53.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroya Iwata 1-1-4 Umezono, Tsukuba, Ibaraki Pref. Ministry of International Trade and Industry (METI) (72) Inventor Paul Fons 1 Umezono, Tsukuba, Ibaraki -1-4 Ministry of International Trade and Industry, National Institute of Advanced Industrial Science and Technology (72) Inventor Tetsuhiro Tanabe 21 Ryoin Mizozakicho, Ukyo-ku, Kyoto City Inside Rohm Co., Ltd. Address ROHM F-term (reference) FA27

Claims (6)

[Claims] 1. A semiconductor device comprising: a silicon substrate; a silicon nitride film provided on a surface of the silicon substrate; and at least an n-type layer and a p-type layer provided on the silicon nitride film and made of a ZnO-based compound semiconductor Using a silicon substrate including a semiconductor laminated portion laminated to form a light emitting layer
O-based compound semiconductor light emitting device. 2. The semiconductor light emitting device according to claim 1, wherein a surface of said silicon nitride film is formed on a flat surface without being made amorphous. 3. The semiconductor light emitting device according to claim 1, wherein said silicon nitride film is formed to a thickness of 100 ° or less. 4. The method according to claim 1, wherein the semiconductor lamination portion is Cd _x Zn _1-x O
The active layer composed of (0 ≦ x <1) is formed of Mg _y Zn _1-y O
4. The semiconductor light emitting device according to claim 1, wherein the semiconductor light emitting device has a double hetero structure which is sandwiched by a cladding layer made of (0 ≦ y <1) and having a band gap energy larger than that of the active layer. 5. A silicon nitride film is formed on a surface of the silicon substrate by heat-treating the silicon substrate in an atmosphere in which nitrogen is present, and a light emitting layer is formed on the silicon nitride film by using a ZnO-based compound semiconductor. A method for manufacturing a semiconductor light emitting device, comprising: growing a semiconductor laminated portion to be formed. 6. A process for forming the silicon nitride film while controlling the temperature or time of the process so that the surface of the formed silicon nitride film can maintain the flat surface of the silicon substrate. A method for producing the semiconductor light-emitting device according to the above.