JPH1045404A - Amorphous optical semiconductor and its production as well as optical semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an amorphous optical semiconductor having excellent photoconductive characteristics, high-speed responsiveness, environmental resistance characteristic and high temp. resistance characteristic and a process for producing the same as well as an optical semiconductor element formed by using this amorphous optical semiconductor. SOLUTION: This amorphous optical semiconductor contains hydrogen and the ratio of the total sum of the atomic number of group III elements and the atomic number of nitrogen atoms is 1:0.5 to 1:2. The amorphous optical semiconductor contg. >=1 to <=50atom.% hydrogen, at least one elements among Al, Ga and I and nitrogen elements and contg. oxygen and carbon respectively at <=15atm.% is more adequate. This amorphous optical semiconductor further contains >=1 elements selected from C, Si, Ge and Sn or >=1 elements selected from Be, Mg, Ca, Zn and Sr. The amorphous optical semiconductor is obtd. by activating a compd. contg. nitrogen to a necessary energy state or excitation species and bringing an org. metal compd. contg. these active species and group 3 elements into reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amorphous optical semiconductor, a method for manufacturing the same, and an optical semiconductor device using the amorphous optical semiconductor.

[0002]

2. Description of the Related Art Conventionally, as an amorphous optical semiconductor, an amorphous chalcogenide compound such as selenium or tellurium has been widely used as a photoelectric conversion member in an image pickup tube, a light receiving element, an electrophotographic photosensitive member, and the like (Ohm Co., Ltd.). Basics of amorphous semiconductors). In recent years, hydrogenated amorphous silicon has been used for solar cells, image sensors, and thin film trams.
nsistor and electrophotographic photoreceptors.

However, amorphous chalcogenide compounds are unstable with respect to heat, are easily crystallized, and have limited conditions under which they can be used. In addition, hydrogenated amorphous silicon can control valence electrons, realize an electric field effect at a pn junction or an interface, and has heat resistance up to about 250 ° C., but the photoconductive property is deteriorated by strong light (Stable).
r, Wronski effect: Applied physics handbook, etc.)
There is a problem that the efficiency of the solar cell decreases during use. Also,
The band gap of hydrogenated amorphous silicon is about 1.7 eV, and it is possible to reduce or widen the band gap by adding Ge or C in order to effectively use sunlight, but even with a change of about 0.3 eV. There is a problem in that the photoconductive characteristics are deteriorated and a wide range of light cannot be used effectively. In addition, semiconductors including these elements are indirect transition types including crystals, and cannot be used for light-emitting elements, and their applications are limited.

Conventionally, an amorphous material of a group III-V compound semiconductor has been prepared by vapor deposition or sputtering of a group III-V crystal.
Alternatively, a film is formed by a reaction between a group III metal atom and a molecule containing a group V element or an active molecule [H. Reuter, H .; Schmitt,
M. Boffgen, Thin Solid Film
s 254, 94 (1995)]. The group III-V compound crystal film is composed of an organic metal compound containing a group III metal and V
It was fabricated on a heated substrate using a compound containing a group III element (organic metal CVD: MOCVD). When the substrate temperature is adjusted by using these methods,
A) by setting the temperature lower than
A group IV compound has been obtained.

However, in this case, no amorphous III-V compound can function as a photoelectric material due to problems such as carbon from an organic metal remaining in the film and a large number of defect levels in the film. On the other hand, it is known that the density of defect states between bands is reduced by hydrogenation of amorphous amorphous silicon, and valence electrons can be controlled.

Many studies have been made on the role of hydrogen on defects in crystalline group III-V compound semiconductors.
Improvement of crystal dislocation defects [Y. Okada, S.M.
Ohta, H .; Shimomura, A .; Kawaba
ta and M.A. Kawabe, J .; J. Appl.
Phys. , 32, L1556 (1993)], (2)
Improvement of interface defects with the surface oxide film [Y. Cha
ng, W.C. Widra, S.M. I. Yi, J .; Mer
z, W.S. E. FIG. Weinberg and E Hu,
J. Vac. Sci. Tech. B12.2605 (1
994)], (3) Improvement of n + -p junction surface [S. Min, W.M. C. Choi, H .; Y. Cho,
M. Yamaguchi, Appl. Phys. Let
t 64,1280 (1994)], (4) Improvement of defects due to lattice mismatch [B. Chatterje
e, S. A. Ringel, R.A. Sieg, R .; Hof
fmanand I. Weinberg, Appl. P
hys. Lett 65, 58 (1994)], (5)
It has been found to passivate bonding defects. Due to the role of hydrogen, the same relationship between crystalline silicon and amorphous silicon can be expected for III-V compound semiconductors due to the problem of changing from crystalline to amorphous.

On the other hand, it is known that a dopant for pn control is simultaneously passivated and inactivated in a group III-V crystal semiconductor [S. J. Pearto
n, Material Sci. Forum, 148-
149, (1994) 113-139]. Further, it has been found that the passivation of the dopant due to passivation is activated by annealing. As described above, hydrogen passivates a dangling bond of a defect, but at the same time, inactivates a pn control dopant. Therefore, in the case of an amorphous film, the hydrogen is combined with the constituent elements and composition of the film and the hydrogen content in the film. The site is important.

In a conventional method for producing an amorphous group III-V compound semiconductor, a method is employed in which a crystal is used as a raw material and sputtering is performed. Reuter, H .; S
chmitt, M .; Boffgen, Thin Sol
id Films 254, 94 (1995)].

Further, with respect to amorphous III-V compound semiconductors containing hydrogen, hydrogenation a is carried out by reactive evaporation with H _2.
-GaP has a photoconductivity of [M. Onuki, T .; Fuji
and H. Kubota, J .; non-Crys
t, Solids, 114, 792 (1989)], and the photoconductivity of hydrogenated a-GaAs is described in [V.
Coscia, R .; Murri, N .; Pinto, L .;
Trojani, J .; Non. Cryst. Soli
d, 194 (1996) 103]. However, in these semiconductors, the light-dark resistance ratio is as small as about two digits, and the pn control required for practical use as a semiconductor material cannot be performed.

As a low-temperature film forming method, GaP containing amorphous hydrogen or microcrystalline Ga is formed by a plasma CVD method using an organometallic compound as a group III raw material.
N was obtained but did not show photoconductivity or was insulative [J, Knight, andR. A. Lujan, J,
Appl. Phys. , 42.1291 (197
8)]. The hydrogenated amorphous GaAs produced by the plasma CVD method has only a very small photoconductivity of about 10%, which is far from practical use. In a low temperature region for removing carbon, removal of carbon from the film was a problem [Y. Seg
ui, F .; Carrere and A. Bui, Th
in Solid Films, 92, 303, (19
82).

Japanese Patent Application Laid-Open No. 6-295991 discloses an amorphous III-V film formed by sputtering, CVD, molecular beam epitaxy or plasma CVD.
Compound semiconductor used as antifuse memory material
GaN and A have been proposed as lower melting point materials.
1N is considered unsuitable. No mention is made of the properties as an optical semiconductor.

[0012]

SUMMARY OF THE INVENTION A first object of the present invention is to improve the disadvantages of such amorphous group III-V compound semiconductors and make use of the role of hydrogen in amorphous semiconductors and crystals, and to provide a wide range of optical devices. Amorphous optical semiconductors that can be freely selected, and have high resolution, excellent photoconductive properties, high-speed response, environmental resistance and high temperature resistance, and can be used as a new optically active large-area and inexpensive new optoelectronic material. To provide. A second object of the present invention is to provide a method for manufacturing an amorphous optical semiconductor which can safely manufacture an amorphous optical semiconductor having the above characteristics and can be manufactured at low cost. A third object of the present invention is to provide an optical semiconductor device having the above-mentioned amorphous optical semiconductor.

[0013]

SUMMARY OF THE INVENTION The present invention relates to an amorphous III compound.
The disadvantage of the conventional amorphous III-V compound as an optoelectronic material is that the carbon is removed at a low temperature and the defects in the film are compensated by hydrogen. And an improved material and film forming method to contain the dopant in an activated state.

That is, the present invention activates a compound containing at least nitrogen to an energy state or an excited species, and decomposes and / or activates an organometallic compound containing a group III element by reacting with the active species to form active hydrogen. Are reacted to form a group III-V compound film. In this way, even at a low temperature at which an amorphous film can be grown, the organic group is separated from the organic metal as a stable molecule at a low temperature, is taken into the film, and the dangling hand defects can be removed at the time of film growth, and further generated from the organic group. The present inventors have found that active hydrogen or active hydrogen generated by hydrogen and a hydrogen compound added separately can reduce impurities to a very small amount by removing carbon on the film surface during film growth, and have completed the present invention. In addition, the stoichiometric state can be easily maintained even in the case of an amorphous material in which the composition ratio can be freely determined by selecting nitrogen present as a gas as the V group.

The amorphous optical semiconductor of the present invention contains hydrogen and contains
An amorphous optical semiconductor, wherein the ratio of the total number of atoms of group II elements to the number of nitrogen atoms is 1: 0.5 to 1: 2. Further, the method for producing an amorphous optical semiconductor of the present invention activates a compound containing nitrogen to a required energy state or an excited species, and converts these active species and at least one or more elements of Al, Ga, and In. A method for producing an amorphous optical semiconductor, wherein the method comprises reacting an organic metal compound. The amorphous optical semiconductor of the present invention contains 1 atomic% or more and 50 atomic% or less of hydrogen, at least one element of Al, Ga, and In, and a nitrogen element. %, More preferably, C, Si, Ge, Sn as n-type control elements.
Or at least one element selected from the group consisting of Be, Mg, Ca, Zn,
A material containing at least one element selected from Sr is desirable.

In the method for manufacturing an amorphous optical semiconductor,
As an activating means for activating a compound containing nitrogen to a required energy state or an excited species, discharge energy, for example, energy of high-frequency discharge and / or microwave discharge can be used. A gaseous raw material containing at least one element of Al, Ga, and In or an element for controlling pn is introduced from the downstream side of each activating means. The optical semiconductor element uses the above-mentioned amorphous optical semiconductor as a photoconductive member, or includes at least one of a p-type amorphous optical semiconductor and an n-type amorphous optical semiconductor.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The amorphous optical semiconductor of the present invention has a ratio of the total number of atoms of group III elements containing hydrogen to the number of nitrogen atoms of 1:
0.5 to 1: 2. Generally, the term “amorphous” refers to a solid state in which a crystal lattice is hardly recognized, but there is often no clear boundary between amorphous and crystalline. The amorphous in the present invention is a so-called amorphous having only a short-range order with adjacent atoms, and a case where the amorphous has microcrystals, or a case where the whole is a collection of microcrystals. Include. However, in this case, the size of the microcrystals is smaller than 50 ° and can be regarded as having no structural order as a whole. In the present invention, the ratio of the sum of the number of group III elements to the number of nitrogen atoms is 1: 0.5 to 1: 2.
It is. When the ratio of the number of atoms is less than 1: 0.5 or more than 1: 2, a portion forming a zinc blende (Zincblend) type due to a bond between a group III element and a nitrogen element is reduced. Therefore, the number of defects increases, and the semiconductor does not function as a good optical semiconductor.

The amorphous optical semiconductor of the present invention contains hydrogen, and its amount is preferably 1 atomic% or more and 50 atomic% or less. In an amorphous optical semiconductor, if the film contains less than 1 atomic% of hydrogen, Al, Ga,
It eliminates dangling bonds generated by amorphization of nitrogen as an In and V element while maintaining a three-dimensional structure by bonding with hydrogen, thereby inactivating a defect level formed in a band. And cannot function as a practical amorphous optical semiconductor.

On the other hand, when the hydrogen content exceeds 50 atomic% in the film, the hydrogen becomes Al, Ga, In as a group III element.
And the probability of two or more bonds to nitrogen as a group V element increases, and as a result, these elements do not maintain a three-dimensional structure,
A chain-like network is formed, a new level is formed in the band, and electrical properties are deteriorated and mechanical properties such as hardness are lowered. Further, the film is easily oxidized, and as a result, a large amount of impurity defects are generated in the film, so that good photoelectric characteristics cannot be obtained.
On the other hand, if the content of hydrogen in the film exceeds 50 atomic%, the dopant to be doped to control the electrical characteristics is activated by hydrogen, so that an electrically active amorphous semiconductor cannot be obtained. .

It is desirable that oxygen and carbon are each 15 atomic% in the amorphous optical semiconductor. When oxygen in the film exceeds 15 atomic% in the film, this oxygen atom becomes II
In order to form a stable bond with Al, Ga, In as a group I element and partially form a three-dimensional structure of Al, Ga, In and a nitrogen atom as a group V element into a two-dimensional flexible structure, This prevents the substitutional dopant for electrical control from taking an electrically active bond configuration in the three-dimensional rigid structure, resulting in pn control being impossible.

Further, when carbon in the film exceeds 15 atomic%, a bond between carbon and hydrogen (81 kcal / mo) is formed.
l) is a bond between Al, Ga, In as a group III atom and hydrogen (Al-H: 68.1 kcal / mol, Ga-
H: 66 kcal / mol, In-H: 59 kcal /
For stable than mol), hydrogen serves to couple many as carbon atoms, and more carbon -CH ₂ -, - the generation of CH ₃ easily take binding will chain structure and voids, the defect level of the film as a whole In addition, pn control cannot be performed due to structural flexibility when a dopant is doped. Also,
Originally, in the case of a transparent film having a wide band gap, the film is colored and changes from yellow to brown, so that the optical characteristics are also deteriorated.
The concentration of oxygen and carbon may increase in the oxygen and carbon near the surface of the film due to surface adsorption or contamination on the film or oxidation of the surface. Refers to the part where there is no.

In order to realize an amorphous structure while maintaining the three-dimensional structure, dangling bonds are generated in both the group III element and the group V element. For this reason, it is desirable that hydrogen be bonded to the group III element and the group V element equally. In addition, when hydrogen is bonded to the dopant, substitutional impurity doping cannot be performed. Therefore, it is preferable that hydrogen is not bonded to the dopant. These hydrogen bonding states can be easily measured by an infrared absorption spectrum. Each composition in the film was determined by X-ray photoelectron spectroscopy (XPS), electron microprobe, Hydrogenford.
It can be measured by a method such as back scattering (HFS). The absolute amount of hydrogen can be measured by Rutherford back scattering (RBS). The amount of hydrogen can also be estimated by measuring the amount of hydrogen released by heating or measuring the IR spectrum.

Next, the amorphous optical semiconductor of the present invention can be manufactured as follows. Hereinafter, description will be made with reference to the drawings.
The method shown in FIG. 1 is a method using plasma as an activating means.
1 is a container which can be evacuated to a vacuum, 2 is an exhaust port, 3 is a substrate holder, 4 is a heater for heating the substrate, and 5 and 6 are quartz tubes connected to the container 1. Communicating. The quartz tube 5 is connected to a gas introduction tube 11, and the quartz tube 6 is connected to a gas introduction tube 12.

In this apparatus, for example, N ₂ is used as a nitrogen source and introduced into the quartz tube 5 from the gas introduction tube 9. A microwave of 2.45 GHz is supplied to a microwave waveguide 8 connected to a microwave oscillator (not shown) using a magnetron to generate a discharge in the quartz tube 5.
For example, H ₂ is introduced into the quartz tube 6 from another gas inlet 10. A high frequency of 13.56 MHz is supplied from a high frequency oscillator (not shown) to the high frequency coil 7 to generate a discharge in the quartz tube 6. Amorphous gallium nitride can be obtained on the substrate by introducing trimethyl gallium from the gas introduction pipe 12 from the downstream side of the discharge space. The amorphous state can be changed by the substrate temperature and the gas flow pressure. When the substrate temperature is high or the flow rate of the group III source gas is small, the material tends to be amorphous having microcrystal nuclei of less than 50 °. Instead of trimethylgallium, an organometallic compound containing indium and aluminum can be used, or can be mixed. Further, these organometallic compounds may be introduced from the gas introduction pipe 11.

A gas containing at least one element selected from the group consisting of C, Si, Ge, and Sn;
A gas containing at least one element selected from the group consisting of Mg, Ca, Zn, and Sr is supplied to the downstream side of the discharge space (gas introduction pipe 1).
1 or by introducing gas through a gas introduction pipe 12).
It is possible to obtain an amorphous nitride semiconductor of any conductivity type such as a p-type and a p-type. In the case of C, carbon may be used as the organometallic compound depending on conditions.

The substrate temperature is between 20 ° C. and 600 ° C. In the above-described apparatus, active nitrogen or active hydrogen formed by discharge energy may be controlled independently, or a gas such as NH ₃ containing both nitrogen and hydrogen atoms may be used. Further, H ₂ may be added. Further, a condition under which active hydrogen is liberated from the organometallic compound may be used. By doing so, activated group III atoms and nitrogen atoms are present on the substrate in a controlled state, and hydrogen atoms convert methyl and ethyl groups into inert molecules such as methane and ethane. Therefore, despite the low temperature, it is possible to generate an amorphous film in which almost no carbon enters and film defects are suppressed.

In the above-described apparatus, the activating means may be a high-frequency oscillator, a micro-oscillator, an electrocyclotron resonance system or a helicon plasma system,
One of these may be used, or two or more of them may be used. Also, both may be microwave oscillators,
Both may be high-frequency oscillators. In the case of high-frequency discharge, an inductive type or a capacitive type may be used. Further, an electron cyclotron resonance method may be used. When different activating means (exciting means) are used, it is necessary to allow discharge to occur simultaneously at the same pressure, and a pressure difference may be provided between the inside of the discharge and the film forming unit (inside the container 1). When the same pressure is used, different activating means (exciting means), for example, microwave and high-frequency discharge can be used to greatly change the excitation energy of the excited species, which is effective for controlling the film quality.
The amorphous optical semiconductor of the present invention can be formed in an atmosphere in which at least hydrogen is activated, such as a reactive vapor deposition method, ion plating, and reactive sputtering.

The substrate used in the present invention may be conductive or insulating, and may be crystalline or non-quality. Examples of the conductive substrate include metals such as aluminum, stainless steel, nickel, and chromium, and alloy crystals of Si and GaAs.
semiconductors such as s and SiC. Also,
An insulative substrate having a substrate surface subjected to a conductive treatment may be used. Examples of the insulating substrate include a polymer film, glass, and ceramic. The conductive treatment is performed by forming a film of the above metal, gold, silver, copper, or the like by an evaporation method, a sputtering method, an ion plating method, or the like.
In addition, as a light-transmitting support of a transparent conductive substrate for light input / output, a transparent inorganic material such as glass, quartz, sapphire, or a fluororesin, polyester, polycarbonate, polyethylene, polyethylene terephthalate, epoxy, etc. A transparent organic resin film or plate, an optical fiber, a selfoc optical plate, or the like can be used.

As the light-transmitting electrode provided on the light-transmitting support, a transparent conductive material such as ITO, zinc oxide, tin oxide, lead oxide, indium oxide, and copper iodide is used. , A metal such as Al, Ni, Au or the like formed by vapor deposition or sputtering so as to be translucent.

The raw materials for the amorphous optical semiconductor of the present invention include:
Selected from Al, Ga, and In as group III elements
Use of organometallic compounds containing one or more elements
it can. These organometallic compounds include trimethyl alcohol.
Luminium, triethyl aluminum, tertiary
Chill aluminum, trimethyl gallium, triethyl gall
Lium, tertiary butyl gallium, trimethyl in
Indium, triethylindium, tertiary butyl
Liquid or solid such as indium
Use in a mixed state by bubbling with carrier gas.
Can be used. Hydrogen as carrier gas,
N_Two, Methane, ethane and other hydrocarbons, CF _Four, C_TwoF
₆And the like can be used.

N ₂ , NH ₃ , N
Gases and liquids such as F ₃ , N ₂ H ₄ and methyl hydrazine can be used by vaporizing or bubbling with a carrier gas. Further, in the amorphous optical semiconductor of the present invention, an element can be doped into the film for controlling p and n. Examples of n-type elements include Li and Ib of the Ia group.
Group Cu, Ag, Au, group IIa Mg, group IIb Z
n, IVa group Si, Ge, Sn, Pb and VIa group S, Se, Te can be used. Examples of elements for the p-type include Li, Na, K of the Ia group, Cu, Ag of the Ib group,
Au, IIa Be, Mg, Ca, Sr, Ba, R
a, IIb group Zn, Cd, Hg, IVa group C, S
i, Ge, Sn, Pb, VIa group S, Se, Te, V
Cr, Mo, W of group Ib, Fe, Co of group VIIIa,
Ni or the like can be used.

It is known that hydrogen in a film binds to a dopant and inactivates it in the case of a crystal. In order for a doping element to function as a dopant in an amorphous network, a defect level is required. It is necessary that hydrogen for passivating the bond is selectively bonded to the group III element and the group V element rather than the dopant, and the bond energy is [group 3 element] -H, [group 5 element] -H> dopant atom- H is desirable. From this point, Si, Ge, and Sn are particularly preferable as the n-type element, and Be, Mg, Ca, Zn, and Sr are particularly preferable as the p-type element.

As a doping method, for n-type, SiH ₄ , Si ₂ H ₆ , GeH ₄ , GeF ₄ , SnH ₄
And BeH ₂ , BeCl ₂ , BeC for p-type
It can be used in the gaseous state of l ₄ , cyclopentadienyl magnesium, dimethyl calcium, dimethyl strontium, dimethyl zinc, diethyl zinc, and the like. In addition, a known method such as a thermal diffusion method or an ion implantation method can be used to dope the element into the film.

In order to obtain an optical semiconductor device using the amorphous optical semiconductor of the present invention, only an undoped film, p-type or i-type film may be provided on the substrate, or p-type and n-type films may be formed. The pn junction may be formed and a i-type film may be provided between the p-type and n-type films. Also, a film p + or n + layer doped with a higher concentration than p-type and n-type may be inserted between the electrodes for contact with the electrodes. Further, a multilayer structure having a pn or pin structure unit can be formed. Furthermore, these p-type, i-type, and n-type layers are made of different Al,
It may have a composition of Ga, In, N, p-type, i
Each of the n-type and n-type films may have a plurality of compositions.

Such an amorphous optical semiconductor containing at least one element of Al, Ga, and In and nitrogen has a variable band gap in the entire region from red to ultraviolet, and has high light transmittance and low darkness. In addition to the single case of conductivity and high light sensitivity, a tandem type in which layers having different absorption regions are sequentially combined makes it possible to effectively use a wide range of light from the visible region to the ultraviolet region. Furthermore, this optical semiconductor element is excellent in light resistance, heat resistance, and oxidation resistance, can respond at high speed, and has a light emitting function that is not available in conventional amorphous semiconductors in the entire wavelength range. It can also be used for hybrid devices that combine light emitting devices. Specific examples include a high-efficiency solar cell, a high-speed TFT, an electrophotographic photosensitive member, a high-sensitivity sensor, a high-sensitivity avalanche light sensor, a large-area LED, a full-color display, a light modulator, and an element for an optical interconnect.

[0036]

EXAMPLE 1 A cleaned Al substrate, a quartz substrate, and a Si wafer were placed on a substrate holder 3, the inside of the container 1 was evacuated through an exhaust port 2, and the substrate was heated to 250 ° C. by a heater 4. N ₂
The gas is introduced into the quartz tube 5 having a diameter of 25 mm from the gas introduction tube 9.
1. Introduce 00 sccm, and via microwave waveguide 8
A microwave of 45 GHz was set at an output of 200 W, and matching was performed with a tuner to perform discharge. The reflected wave at this time was 0W. H ₂ gas has a diameter of 3
200 sccm was introduced into a 0 mm quartz tube 6. The microwave output was set to 200W. The reflected wave was 0W. In this state, 2 sccm of trimethylgallium (TMGa) vapor held at room temperature was directly introduced from the gas introduction tube 12 through a mass flow controller. At this time, the reaction pressure measured with a Baratron vacuum gauge was 0.2 Torr.
Met.

The film was formed for 1 hour, and the film thickness was measured by a step measurement to be 3 μm. XPS and RBS film composition
(Rutherford backscattering) showed that the Ga / N ratio was 1.1, which was almost equivalent to stoichiometry. At this time, carbon (C) was 8 atomic%, and oxygen (O) could not be detected. Optical gap is 3.
It was 5 eV. Hydrogen is Ga as a result of IR spectrum measurement.
-H and NH were included in this GaN film. The amount of hydrogen measured from the hydrogen heated and released in vacuum was 20 atomic%. The X-ray diffraction spectrum did not show a clear peak, indicating that it was amorphous. When the resistance of this amorphous GaN film was measured, it was 2.0 × 10 ⁺¹⁴ Ωcm.
When irradiated with Xe lamp light, 1.5 × 10 ¹⁰ Ωcm
It was found that photoconductivity of 4 digits or more in light-dark ratio was exhibited.

Example 2 A film was formed under the same conditions as in Example 1 except that H ₂ gas was discharged at a high frequency of 13.56 MHz and an output of 100 W through a high frequency coil 7. The film composition was almost stoichiometric with a Ga / N ratio of 0.99 and carbon was 3 atomic%. No oxygen was detected. The amount of hydrogen was 30 atomic%. The dark resistance was 1 × 10 ⁺¹⁴ Ωcm, and the light-dark resistance ratio was four digits or more. The infrared absorption spectrum of the film composition was as shown in FIG. In FIG. 2, 2
900 cm ^-1 is the stretching vibration of C-H, and 3200 cm
^-1 is the stretching vibration of NH, and 2100 cm ^-1 is G
aH stretching vibration. The absorption intensity ratio of NH / GaH was 0.23.

COMPARATIVE EXAMPLE 5 g of GaN powder having a purity of 5N was placed in a crucible using a commercially available electron beam evaporation apparatus, and the same substrate as that of Example 1 was placed in a 15 cm-size space.
Installed on top. The evaporator was carefully evacuated to 10 ^-4 Pa. The substrate was heated to 200 ° C. by an infrared lamp heater.
The electron beam current was gradually increased, kept constant at 100 mA, and the shutter was opened to perform vapor deposition on the substrate for 5 minutes. The substrate temperature was increased by 50 ° C. during the deposition. After cooling, the film was cooled immediately, taken out into the air after cooling, and the characteristics were evaluated. This film was amorphous and its composition was almost stoichiometric. This film did not contain hydrogen. The same light irradiation as in Example 1 was performed on this amorphous GaN film, but the conductivity did not change.

[0040]Example 3 Using the same apparatus and the same substrate as in Example 1, N_TwoGas
500 sccm introduced from the inlet pipe 9 and 2.45 GHz
At a microwave output of 200 W. This time,
The reflected wave was 0W. H_Two200 sccm of gas
Introduced through introduction tube 10 and exited at 13.56 MHz high frequency
The discharge was performed at a power of 100 W. At this time, the reflected wave is 0W.
Was. The temperature of the substrate holder is set to 250 ° C. by the heater 4
And In this state, trimethyl gall
Trimethyl ether kept at 2 sccm and 50 ° C.
N for N_Two1 sccm was mixed with the gas and introduced.
In addition, N_TwoSiH diluted to 1% with_Four
And n-type a-Ga _XIn_YN_ZWas formed. Pressure
The force was 0.2 Torr. After forming the film for 10 minutes,
The valves of the inlet pipe 12 and the gas inlet pipe 11 were closed. This
At this time, the discharge was continued. In this state
Again, trimethylgallium 2sccm, trimethylin
Introducing a mixed gas of 1 sccm from the gas inlet pipe 12
And feed bispentadienyl magnesium into the gas inlet tube 1
N from 1 as carrier gas_Two10 sccm using
And p-type a-Ga_XIn_YN_ZWas formed for 5 minutes.

The obtained film thickness was 1 μm. When the composition of this film was measured by RBS, Ga / In / N was 0.7
/0.3/1, oxygen 5 atomic%, carbon 7 atomic%
Met. The amount of hydrogen measured by HFS is 18 atomic%.
Met. The overall optical gap of this film is 2.9 e.
V. A 100A Au electrode capable of transmitting light to a film on an Al substrate and an Au electrode above and below a Si wafer are deposited.
Irradiation with an e-lamp yielded a photovoltaic voltage of 0.9 V at open voltage.

Embodiment 4 Using the same apparatus and the same substrate as in Embodiment 2, 500 sccm of N ₂ gas was introduced from the gas introduction pipe 9 to 2.45 GHz.
Was discharged at a microwave output of 250 W. At this time,
The reflected wave was 0W. 100 sccm of H ₂ gas was introduced from the gas introduction tube 10, and discharge was performed at a high frequency of 13.56 MHz and an output of 100 W. At this time, the reflected wave was 0W. The temperature of the substrate holder is set to 100 ° C. by the heater 4
And In this state, 1 sccm of trimethylgallium was introduced from the gas introduction tube 12. The film composition has a Ga / N ratio of 1.0
5 was found to be approximately equal to stoichiometric. At this time, carbon (C) and oxygen (O) were 0 atomic%. Further, the hydrogen content by HFS measurement was 35 atomic%. However, the surface was oxidized, and the hydrogen concentration was low while the oxygen concentration exceeded 20 atomic%. Optical gap is 3.5
eV. An electron diffraction spectrum and an X-ray diffraction spectrum did not show a clear peak, indicating that they were amorphous. Further, the infrared absorption spectrum of the obtained film composition was as shown in FIG. In FIG. 3, NH and G
The absorption intensity ratio of aH was 0.4, and there was almost no absorption of CH. The amorphous GaN film was irradiated with Xe lamp light, and the light-dark resistance ratio was measured. As a result, it was found that the amorphous GaN film exhibited photoconductivity of three digits or more.

Example 5 A film was produced under the same conditions as in Example 4 except that the temperature of the substrate was set at 200 ° C. It was found that the film composition was almost equal to stoichiometric at a Ga / N ratio of 0.95. At this time, no carbon (C) was detected, but oxygen (O) was 10 atomic%. The cause of this oxygen was unknown. In addition, hydrogen by RBS measurement was 27 atomic%. No oxidation of the surface was observed. An electron diffraction spectrum and an X-ray diffraction spectrum did not show a clear peak, indicating that they were amorphous. Further, the infrared absorption spectrum of the obtained film composition was as shown in FIG. In FIG. 4, NH and G
The absorption intensity ratio of aH was 0.25, and there was no absorption of CH. When the amorphous GaN film was irradiated with Xe lamp light and the light-dark resistance ratio was measured, it was found that the amorphous GaN film exhibited photoconductivity of four digits or more.

Example 6 A film was produced under the same conditions as in Example 4 except that the temperature of the substrate was set at 300 ° C. It was found that the film composition was almost equal to stoichiometric at a Ga / N ratio of 0.98. At this time, carbon (C) and oxygen (O) were not detected. In addition, hydrogen by RBS measurement was 18 atomic%. No oxidation of the surface was observed. In the electron beam diffraction spectrum, bright spots were observed in a blurred pattern, and it was found that the film was amorphous with microcrystals of less than about 50 °. Further, the infrared absorption spectrum of the obtained film composition was as shown in FIG. In FIG. 5, the absorption intensity ratio between NH and GaH was 0.46, and there was no absorption of CH. 570
It was found that the peak absorption intensity of GaN near cm ^-1 increased, and the line width became narrower, including a microcrystalline state. When the amorphous GaN film was irradiated with Xe lamp light and the light-dark resistance ratio was measured, it was found that the amorphous GaN film exhibited photoconductivity of four digits or more. The dark resistance was lower than in Example 5.

Example 7 Using the same apparatus and the same substrate as in Example 2, 900 sccm of N ₂ gas was introduced from the gas introduction pipe 9 to 2.45 GHz.
Was discharged at a microwave output of 250 W. At this time,
The reflected wave was 0W. 300 sccm of H ₂ gas was introduced from the gas introduction tube 10 and no discharge was performed. Heater 4
To set the temperature of the substrate holder to 250 ° C. In this state, 3 methyltrimethyl gallium was introduced through the gas inlet tube 12. It was found that the film composition was almost equal to stoichiometric at a Ga / N ratio of 0.97. At this time, carbon (C)
Was 12 atomic%. Oxygen (O) was 0 atomic%. In addition, hydrogen was 22 atomic% by RBS measurement.
The optical gap was 3.4 eV. An electron diffraction spectrum and an X-ray diffraction spectrum did not show a clear peak, indicating that they were amorphous. Further, the infrared absorption spectrum of the obtained film composition was as shown in FIG. In FIG. 6, the absorption intensity ratio between NH and GaH was 0.2.
When the amorphous GaN film was irradiated with Xe lamp light and the light-dark resistance ratio was measured, it was found that the amorphous GaN film exhibited photoconductivity of four digits or more.

[0046]

As described above, according to the amorphous optical semiconductor of the present invention, a wide range of light from visible to ultraviolet light can be effectively used due to high light transmittance, low dark conductivity and high light sensitivity.
Further, it has excellent light resistance, heat resistance, and oxidation resistance, and has high-speed response, and can be used for various optical semiconductor devices by utilizing these properties.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a preferred embodiment of an apparatus for producing an amorphous optical semiconductor of the present invention.

FIG. 2 is a graph showing an infrared absorption spectrum of a film composition obtained in Example 2.

FIG. 3 is a graph showing an infrared absorption spectrum of the film composition obtained in Example 4.

FIG. 4 is a graph showing an infrared absorption spectrum of the film composition obtained in Example 5.

FIG. 5 is a graph showing an infrared absorption spectrum of the film composition obtained in Example 6.

FIG. 6 is a graph showing an infrared absorption spectrum of the film composition obtained in Example 7.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Exhaust port 3 Substrate holder 4 Heater 5, 6 Quartz tube 7 High frequency coil 8 Micro waveguide 9-12 Gas introduction tube

Claims (16)

[Claims] 1. An amorphous optical semiconductor comprising hydrogen and having a ratio of the total number of atoms of Group III elements to the number of nitrogen atoms of 1: 0.5 to 1: 2. 2. The amorphous optical semiconductor according to claim 1, wherein the amorphous optical semiconductor contains 1 atomic% to 50 atomic% of hydrogen. 3. The amorphous material according to claim 1, which is formed using an organometallic compound containing at least a group III element as a raw material, and is composed of a group III element and a nitrogen element containing hydrogen. Quality optical semiconductor. 4. The method according to claim 1, wherein the group III element is at least Al, Ga,
3. The amorphous optical semiconductor according to claim 1, comprising one or more elements selected from In. 5. An atomic mass of 1 to 50 atomic% of hydrogen,
An amorphous optical semiconductor comprising at least one element of Al, Ga, and In and a nitrogen element, wherein oxygen and carbon are each 15 atomic% or less. 6. The amorphous optical semiconductor according to claim 1, further comprising at least one element selected from the group consisting of C, Si, Ge, and Sn. 7. The amorphous optical semiconductor according to claim 1, further comprising at least one element selected from the group consisting of Be, Mg, Ca, Zn, and Sr. 8. A nitrogen-containing compound is activated to a required energy state or an excited species, and these active species and Al, G
a. A method for producing an amorphous optical semiconductor, comprising reacting an organometallic compound containing at least one element of In and In. 9. A method for manufacturing an amorphous optical semiconductor, comprising activating an organometallic compound containing at least one element of Al, Ga, and In to a required energy state and excited species. 10. A compound containing nitrogen and Al, Ga, I
n or more activation means for activating an organometallic compound containing at least one element of n to a required energy state or excited species, wherein the activation means is discharge energy. The method for manufacturing an amorphous optical semiconductor according to claim 8, wherein: 11. The high-frequency discharge and / or the activating means.
11. The method of manufacturing an amorphous optical semiconductor according to claim 8, wherein a microwave discharge is used. 12. The method of manufacturing an amorphous optical semiconductor according to claim 8, wherein at least one or more compounds containing Al, Ga, and In are introduced downstream of said activating means. Method. 13. The method for manufacturing an amorphous optical semiconductor according to claim 8, wherein hydrogen, nitrogen, ammonia, and an inert gas are used for high-frequency discharge and / or microwave discharge. 14. A gaseous raw material containing at least one element selected from Be, Mg, Ca, Zn and Sr is introduced from the downstream side of the activating means. Item 14. The method for producing an amorphous optical semiconductor according to Item 13. 15. A gaseous raw material containing at least one element selected from C, Si, Ge, and Sn is introduced from a downstream side of the activating means. 3. The method for producing an amorphous optical semiconductor according to item 1. 16. An optical semiconductor device comprising the amorphous optical semiconductor according to claim 1. Description: