JP2007043016A - Crystal silicon element, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crystal silicon element capable of extracting desired visible light efficiently by improving the crystallinity of nano Si greatly, and to provide a method for manufacturing the crystal silicon element. <P>SOLUTION: The crystal silicon element comprises a silicon substrate 10 of an n-type single crystal; nano Si (p-type crystal silicon) 12 that is provided at one surface side of the silicon substrate 10 separately from the silicon substrate 10, and has the same crystal axis as that of the silicon substrate 10; transparent electrode 15 that is formed at one surface side where the nano Si (p-type crystal silicon) 12 is provided on the silicon substrate 10; and a metal electrode 16 formed at the other surface side of the silicon substrate 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

    The present invention relates to a crystalline silicon device and a method for manufacturing the same, and more particularly to a crystalline silicon device such as a light emitting device made of nanocrystalline silicon and a method for manufacturing the same.

  In recent years, as the current control element has been replaced by a solid semiconductor from a vacuum tube, the illumination element has also been rapidly replaced by a solid light emitting element such as a III-V compound semiconductor from a fluorescent tube. There is no doubt about the progress of solidification of light emitting elements. However, Ga-based compound semiconductors, which are currently mainstream, require low-defect epitaxial growth on expensive sapphire substrates, and it is necessary to form pn junctions and quantum well structures. For this reason, it is difficult to provide an inexpensive element in that a complicated multilayer film structure including Al, P, In, N and the like must be formed.

  In response to such problems, attempts have been made to obtain an inexpensive light-emitting element using silicon (Si), which is the most abundant material on the earth. Since Si is an indirect transition type, has low luminous efficiency, and has a band gap in the near infrared region, it has been considered unsuitable as a visible light emitting material. However, for example, Non-Patent Document 1 reports that visible luminescence can be obtained from porous Si formed by anodic oxidation, and nano-sized crystalline Si (hereinafter abbreviated as nano-Si) is used as a visible light-emitting element. Attracted attention as a strong candidate. The light emission phenomenon caused by nano-Si is considered to be a quantum confinement effect (expansion of band gap) that occurs by reducing Si crystal to nano-size. In order to realize the nano-Si light emitting device, it is essential to increase the light emission efficiency to a practical level, and improvement of crystallinity including the surface state is the biggest issue. Further, in order to bring out the desired emission color, wavelength control is necessary, and the crystal size of nano-Si must be controlled with high accuracy.

Porous Si using the anodic oxidation method as described above erodes the Si surface in a porous manner by a unique oxidation action. Therefore, although the quality of the crystal itself is relatively good, it has been pointed out that the surface area is very large and the emission characteristics are unstable. Furthermore, since the shape can hardly be controlled, there is a problem that the emission wavelength cannot be controlled. As a means for solving these problems, several methods have been proposed so far. For example, a device for forming a granular Si crystal on a substrate by using an ion implantation method, a sputtering method, a CVD (Chemical Vapor Deposition) method, etc., and additionally embedding it in a stable material such as silicon oxide (SiO ₂ ). (For example, see Patent Documents 1, 2, and 3).

L.T.Canham, Appl.Phys. Lett.Vol.57, p.1046, 1990 Japanese Patent Laid-Open No. 8-17577 Japanese Patent Laid-Open No. 2004-296781 JP-A-8-307011

  However, any of the conventional methods described above is formed by implanting or depositing Si or a Si compound, and thus there is a problem in crystal uniformity. For this reason, it has been difficult to emit visible light with high efficiency in the conventional light emitting device.

  The present invention has been made to solve the technical problems as described above. The object of the present invention is to improve the crystallinity of nano-Si, for example, to increase desired visible light. An object of the present invention is to provide a crystalline silicon device that can be pulled out efficiently and to provide a method for manufacturing the same.

  Under such a purpose, the present inventors have found that it is important to improve the crystallinity of nano-Si and to control the crystal axis in order to increase the luminous efficiency. That is, rather than having random crystal axes as in the prior art, the luminous efficiency is remarkably improved by aligning the crystal axes of a plurality of nano-Si provided on the substrate in the same direction. Although the mechanism is not clear, the maximum luminous efficiency is obtained when the plane orientation of the plane perpendicular to the streamline direction of the carriers flowing into nano-Si is set to (100), and then good at (110) and (111) Luminous efficiency was obtained. Since the dangling bond density on the Si surface is smaller in the order of (100), (110), and (111), the presence of non-radiative recombination centers due to the dangling bond density is one factor that affects the luminous efficiency. it is conceivable that. Therefore, in order to obtain high-efficiency light emission, it is desirable to control the nano-Si crystal axis in the same direction as well as controlling to (100).

  That is, a crystalline silicon device to which the present invention is applied includes an n-type single crystal silicon substrate having one surface and another surface, and a nano-crystal provided on one surface side of the silicon substrate and having the same crystal axis as the silicon substrate. Size p-type crystalline silicon (nano-Si), a metal electrode, and a transparent electrode that forms a pair of electrodes together with the metal electrode and sandwiches the p-type crystalline silicon and the silicon substrate. Here, the metal electrode is ohmic-bonded to the silicon substrate on the other surface side of the silicon substrate, and the transparent electrode is provided on the p-type crystalline silicon. According to these structures, carriers (electrons / holes) injected from the electrode into the p-type crystalline silicon (nano-Si) are efficiently recombined (increased quantum efficiency) to the emission center, so that the emission efficiency is remarkably improved. It is preferable in that it can be improved. Moreover, according to these structures, since nano-Si of a light emitting layer is comprised with the same member as a silicon substrate, it is excellent also from the point which can aim at stabilization of light emission which is hard to receive to the influence of distortion by thermal expansion etc.

In addition, this transparent electrode is bonded to p-type crystalline silicon (nano-Si) through a thin insulating film in which carrier tunnel injection is performed, so that the nano-Si surface is protected by a stable insulating film. Therefore, for example, the surface recombination current that does not contribute to light emission is reduced, and the light emission efficiency can be improved and stabilized.
Further, it is preferable that the transparent electrode is in direct contact with p-type crystalline silicon, since the pn junction surface functions as a hole barrier, so that the luminous efficiency can be improved. Also, if nano-Si and the transparent electrode are in direct contact with each other to form an ohmic junction with holes, carrier injection can be performed at a lower voltage (improving injection efficiency) compared to the case of an insulating film. Therefore, the power consumption of the light emitting element can be reduced.
Furthermore, this p-type crystalline silicon is characterized by having a crystal structure with a (100) crystal orientation of a plane substantially perpendicular to the streamline direction of injected carriers. Since non-radiative recombination can be reduced, it is excellent in that the luminous efficiency can be improved.

Furthermore, if the resistivity of this silicon substrate is 10 mΩ or less, the efficiency of injection of electrons into nanocrystalline silicon can be increased and the resistance loss in the silicon substrate during energization can be reduced, resulting in higher efficiency. Is preferable in that it can be achieved.
Furthermore, if this p-type crystalline silicon is characterized by being doped with aluminum, it produces a deeper acceptor level than boron, which is a general p-type dopant, so that the thermal stability of the emission characteristics. Can be achieved.

  From another point of view, the crystalline silicon device to which the present invention is applied is divided into an n-type single crystal silicon substrate having one surface and another surface, and one surface side of the silicon substrate separated from the silicon substrate. A nano-sized p-type crystal silicon having the same crystal axis as the silicon substrate, a transparent electrode formed on one surface side of the silicon substrate provided with the p-type crystal silicon, and the other surface of the silicon substrate And a metal electrode formed on the side.

Further, in this crystalline silicon element, the p-type crystalline silicon and the transparent electrode are connected via an insulating film, and a carrier is applied by applying a voltage between two electrodes with the transparent electrode serving as an anode and the metal electrode serving as a cathode. It can be characterized in that the current path at the time of implantation is transparent electrode-insulating film-p-type crystal silicon-silicon substrate-metal electrode.
In addition, the p-type crystal silicon and the transparent electrode are directly joined, and a current path when a carrier is injected by applying a voltage between two electrodes using the transparent electrode as an anode and a metal electrode as a cathode, It can be characterized by being transparent electrode-p-type crystalline silicon-silicon substrate-metal electrode.

  On the other hand, the present invention is a method for manufacturing a crystalline silicon device using silicon microcrystals, and includes a plurality of nano-sized nanocrystals having the same crystal axis as a silicon substrate on one surface side of an n-type single crystal silicon substrate. A step of providing the p-type crystalline silicon by solid phase growth, a step of providing a transparent electrode on one surface side where the p-type crystalline silicon is formed, and a step of providing a metal electrode on the other surface side of the silicon substrate. . Since nanocrystalline silicon having the same crystal axis as the silicon substrate can be formed at low temperature by solid phase epitaxial growth, there is no redistribution of p-type and n-type dopants. For this reason, since a nano-sized pn junction can be easily formed with high reproducibility, a highly efficient light-emitting element can be provided at low cost.

  Here, the step of providing the p-type crystal silicon by solid-phase growth includes a step of forming a thin film made of aluminum silicon (AlSi) on a silicon substrate and a temperature not exceeding the melting point of aluminum silicon (AlSi). The heat treatment can include a step of solid-phase epitaxially growing p-type crystalline silicon on a silicon substrate and a step of removing a thin film made of aluminum / silicon (AlSi).

From another viewpoint, a method for manufacturing a crystalline silicon element to which the present invention is applied includes a step of forming a thin film made of aluminum / silicon (AlSi) on one surface side of a silicon substrate made of a single crystal, and an aluminum Performing a solid phase epitaxial growth of p-type crystalline silicon on a silicon substrate by performing a heat treatment within a predetermined temperature range where solid phase epitaxial growth can occur at a temperature not exceeding the melting point of silicon (AlSi); And a step of removing a thin film made of silicon (AlSi).
Here, the predetermined temperature range in which solid phase epitaxial growth can occur is preferably set such that the lower limit is about 350 ° C. and the upper limit is about 550 ° C. not exceeding the melting point 570 ° C. Also, by using Al.Si as a Si supply source for solid phase growth, p-type nano-Si with auto-doped Al can be easily formed with good reproducibility. Therefore, a highly efficient light-emitting element can be provided at low cost.

  According to the present invention, it is possible to obtain a nano-Si light emitting device having a small number of non-radiative recombination centers and excellent crystallinity.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a partial cross-sectional view of a nano-Si light emitting device according to this embodiment.
As shown in FIG. 1, a nano-Si light emitting device as a crystalline silicon device includes an n-type silicon substrate 10 made of a single crystal having a pair of main surfaces and one main surface (one surface side) of the silicon substrate 10. ) And a plurality of nano-Si (p-type crystalline silicon) provided on the openings of the silicon oxide film 13 and having the same crystal axis as that of the silicon substrate 10. 12. Further, a silicon oxide film 14 provided so as to cover the upper surface and side surfaces of the nano Si 12 and a transparent electrode (for example, ITO) 15 provided so as to cover at least the upper surface of the nano Si 12 are provided. Furthermore, a metal electrode (for example, aluminum) 16 is provided on the other main surface (other surface side) of the silicon substrate 10 so as to be in ohmic contact therewith.

  The nano-Si light emitting device configured as described above operates as a visible light emitting device by applying voltage with the transparent electrode 15 as an anode and the metal electrode 16 as a cathode. A current path when a carrier is injected by applying a voltage between two electrodes using the transparent electrode 15 as an anode and the metal electrode 16 as a cathode is transparent electrode 15-insulating film (silicon oxide film 14) -p-type crystalline silicon. (Nano-Si12) -silicon substrate 10-metal electrode 16.

  FIG. 2 is an explanatory diagram showing a band structure and a carrier flow for explaining the operation principle of FIG. As shown in FIG. 2, the holes tunneled through the silicon oxide film 14 from the transparent electrode 15 and the electrons injected through the pn junction from the metal electrode 16 through the single crystal silicon substrate 10 are: Light is emitted by being trapped in the recombination center in the nano-Si 12. The reason why silicon having a near-infrared band gap emits visible light is due to the quantum confinement effect (expansion of the band gap) due to the reduction in crystal size. Since the pn junction between the nano-Si 12 and the silicon substrate 10 functions as a hole barrier, the quantum confinement effect is not impaired. That is, it is not necessary to cover the nano-Si 12 with a silicon oxide film as in the prior art, and the light emission efficiency can be improved.

  The nano-Si light emitting device configured as described above is also characterized in that various wavelength components can be extracted by controlling the size of the nano-Si 12. In the examination results in the present embodiment, when expressed in terms of the diameter when nano-Si 12 is converted into a sphere, it is blue at about 2 nm, green at about 2.5 nm, and red at about 3.3 nm. Therefore, in order to eliminate the useless infrared light and realize a highly efficient visible light emitting element, the diameter of the nano-Si 12 (equivalent to a sphere) needs to be 4 nm or less, and in particular, it can be controlled to 2 to 4 nm. desirable.

  On the other hand, as a result of investigating the relationship between the luminous efficiency and the crystal axis of nano-Si12 in detail, the nano-Si12 in the present embodiment in which the crystal orientation is aligned on the same axis is markedly higher than the prior art having random crystal axes It was found that the luminous efficiency can be improved. Further, in relation to the plane orientation of the top surface of nano-Si 12 (a plane substantially orthogonal to the carrier stream direction), the crystal structure (100) had the highest efficiency, and then (110) and (111) in this order. . This is considered to be because the dangling bond on the surface of the nano-Si 12 acts as a non-radiative recombination center because it has an inverse relationship with the dangling bond density. Therefore, it is desirable to control the upper surface of the nano-Si 12 to the (100) plane orientation.

FIG. 3 is a partial cross-sectional view showing a modification of the nano-Si light emitting device shown in FIG. Here, in order to avoid duplication of description, a different part from the example shown in FIG. 1 is demonstrated. In the modification shown in FIG. 3, at least the thin silicon oxide film 14 on the upper surface of the nano-Si 12 is omitted, so that the nano-Si 12 and the transparent electrode 15 are brought into direct contact to form an ohmic junction. That is, the electron injection from the transparent electrode 15 into the nano-Si 12 is the same as the example shown in FIG. 1 except that the tunnel injection through the insulating film barrier is replaced with the tunnel injection (ohmic junction) through the Schottky barrier. .
As described above, in the example shown in FIG. 3, the nano-Si 12 that is p-type crystalline silicon and the transparent electrode 15 are directly joined, and the gap between the two electrodes using the transparent electrode 15 as an anode and the metal electrode 16 as a cathode. A current path for injecting carriers by applying a voltage to transparent electrode 15 is transparent electrode 15 -p-type crystalline silicon (nano-Si 12) -silicon substrate 10 -metal electrode 16.

  FIG. 4 is a diagram showing a band structure and a carrier flow for explaining the operation principle of the modification shown in FIG. The advantage of the ohmic junction is that the barrier height is low and stable as compared with the case where the silicon oxide film 14 is provided as in the example of FIG. That is, the barrier height can be kept constant regardless of the film thickness. As a result, the operating voltage can be reduced by improving the hole injection efficiency, that is, the power consumption of the nano-Si light emitting device can be reduced.

Next, a method for manufacturing a nano-Si light emitting device to which this embodiment is applied will be described.
FIGS. 5A and 5B are partial cross-sectional views illustrating the method for manufacturing the nano-Si light emitting device according to the present embodiment, and the manufacturing method is illustrated in the order of the manufacturing steps. Here, first, an n-type single crystal silicon substrate 10 containing a high concentration of phosphorus (P) on a pair of main surfaces consisting of (100) planes is prepared. Then, an Al.Si alloy film 11 having a Si content of 1 wt% is formed on one main surface (one surface side) by sputtering (FIG. 5-1 (a)). Next, by performing heat treatment at about 450 ° C. in a hydrogen atmosphere, nano-Si 12 having the same crystal axis as that is grown on the single-crystal silicon substrate 10 by solid-phase epitaxial growth (FIG. 5-1 (b)). Since the melting point of aluminum silicon (AlSi) is about 570 ° C., about 450 ° C. was selected as a predetermined temperature not exceeding this melting point. In the current research by the inventors, the lower limit of the predetermined temperature at which solid phase epitaxial growth can occur is preferably about 350 ° C., and the upper limit of the predetermined temperature is preferably about 550 ° C. At this time, the degree of growth can be adjusted by controlling the annealing temperature and time. Thereafter, an unnecessary Al / Si alloy film 11 is removed by etching with heated phosphoric acid (FIG. 5-1 (c)).

  Next, by performing heat treatment in an oxidizing atmosphere containing water vapor, a thick silicon oxide film 13 is formed on the single crystal silicon substrate 10, and a thin silicon oxide film 14 is formed on the nano-Si 12 (FIG. 5). 1 (d)). This utilizes the accelerated oxidation phenomenon of silicon containing a high concentration of P. Next, a transparent electrode (ITO) 15 made of an indium oxide compound is formed on the main surface (one surface side) provided with nano-Si 12, and a metal electrode 16 made of aluminum is formed on the opposite surface side (other surface side). (FIG. 5-1 (e)).

  The nano-Si light emitting device produced by such a series of steps functioned as an EL device using the transparent electrode 15 as an anode and the metal electrode 16 as a cathode, and confirmed highly efficient visible light emission. This nano-Si light emitting device has been able to dramatically improve the light emission efficiency for the following reason. First, since the nano-Si 12 has the same crystal orientation as that of the single-crystal silicon substrate 10 and the crystal plane orientation is aligned to (100), the non-light-emitting recombination center due to dangling bonds on the nano-Si 12 surface. Can be minimized. Further, since nano-Si 12 is obtained by epitaxially growing excess Si of the Al · Si alloy film 11, nano-Si 12 becomes a p-type crystal in which Al atoms are auto-doped. As a result, a pn junction having a nano-sized contact surface can be formed with the n-type single crystal silicon substrate 10. Since this pn junction surface functions as a hole barrier, the light emission efficiency in the nano-Si light emitting device can be improved.

  As described above, according to the manufacturing method shown in FIGS. 5A and 5B, the ratio of Si contained in the Al · Si alloy and the annealing temperature and time during solid phase growth are controlled, thereby increasing the size of the nano-Si 12. You can change it freely. That is, elements having different emission wavelengths can be easily manufactured by the same manufacturing process. Therefore, it becomes possible to provide a nano-Si light emitting device having a desired wavelength at a high yield and at a low cost.

  Although the completed form of the crystalline silicon element manufactured by the manufacturing method shown in FIGS. 5-1 and 5-2 is exemplified as the same as that in FIG. 1, various modifications are possible. For example, after the silicon oxide film 14 on the upper surface of the nano-Si 12 is removed by performing an etching process by RIE (Reactive Ion Etching) after FIG. 5D, the modification shown in FIG. 3 can be developed. The transparent electrode 15 is exemplified by ITO (Indium Tin Oxide), but is not particularly limited as long as it is transparent to visible light and has electrical conductivity. The metal electrode 16 is exemplified by aluminum, but there is no limitation as long as the material has excellent electrical conductivity and can be ohmic-bonded to the silicon substrate 10. Further, phosphorus (P) is exemplified as the dopant of the n-type single crystal silicon substrate 10, but arsenic (As), antimony (Sb), or the like may be used. In addition, the n-type single crystal silicon substrate 10 needs to be as thin and low in resistivity as possible from the viewpoint of reducing resistance loss during current application, and is practically preferably 10 mΩcm or less.

6A and 6B are partial cross-sectional views illustrating another method for manufacturing the nano-Si light emitting device according to the present embodiment in the order of steps. First, an n-type single crystal silicon substrate 10 containing a high concentration of As having a pair of main surfaces consisting of (100) planes is prepared, and a silicon nitride film 20 is formed on one main surface by a CVD (Chemical Vapor Deposition) method. It forms (FIG. 6-1 (a)). For example, magnetite (Fe ₃ O ₄ ) fine particles 21a having a diameter of 5 nm and nanoparticles 21 having organic protective groups 21b around the fine particles are applied on the silicon nitride film 20 and dispersedly arranged (FIG. 6-1 (b)). ). Then, using the nanoparticles 21 as a mask, the silicon nitride film 20 is etched by the RIE method to form a patterned silicon nitride film 20a (FIG. 6-1 (c)). Thereafter, wet treatment with an organic solvent is performed to remove the nanoparticles 21, and then heat treatment is performed in an oxidizing atmosphere using the silicon nitride film 20a as an oxidation protection mask, thereby forming a thick silicon oxide film 13, and further having a diameter of about 4 nm or less. The opening 22 is formed (FIG. 6-1 (d)).

  Next, an Al.Si alloy film 11 having a Si content of 1.5 wt% is formed by sputtering (FIG. 6-2 (e)). Then, by performing heat treatment at about 480 ° C. in a hydrogen atmosphere, nano Si 12 having the same crystal axis as that of the silicon substrate 10 is selectively solid-phased in the opening 22 of the silicon oxide film 13 on the single crystal silicon substrate 10. Epitaxial growth is performed (FIG. 6-2 (f)). Then, unnecessary Al.Si alloy film 11 is removed by etching with heated phosphoric acid (FIG. 6-2 (g)). Finally, a transparent electrode (ITO) 15 made of an indium oxide compound is formed on the main surface (one surface side) provided with nano-Si 12, and a metal electrode 16 made of aluminum is formed on the opposite surface side (other surface side). Thus, a nano-Si light emitting device was fabricated (FIG. 6-2 (h)).

  The nano-Si light emitting device thus fabricated has columnar nano-Si 12 having a diameter of about 2.5 nm, and a peak wavelength is about 550 nm by applying voltage with the transparent electrode 15 as an anode and the metal electrode 16 as a cathode. Green emission was confirmed. In the present embodiment, since the size of the opening 22 of the silicon oxide film 13 can be controlled with high accuracy by the size of the nanoparticle 21, the uniformity of the particle size of the nano-Si 12 selectively grown on the opening 22 is remarkably improved. To do. Furthermore, the diameter of the nano-Si 12 can be controlled by controlling the size of the nanoparticles 21 and the oxidation conditions of the silicon oxide film 13, and the three primary colors of red, green, and blue can be created separately in the same process procedure. . Therefore, there is an effect that a highly efficient light-emitting element excellent in controllability of emission wavelength can be provided at low cost.

The nanoparticles are exemplified by magnetite (Fe ₃ O ₄ ), but other ferrite particles or metal particles such as Au, Pt, Pd, and Co may be used and function as an etching mask for the silicon nitride film. There is no limit as long as the material. Moreover, although the coating method of the nanoparticle with an organic protective group was illustrated as dispersion | distribution arrangement | positioning of a nanoparticle, the method of sputtering a metal particle directly etc. may be sufficient. Further, a method using an LB (Langmuir Blodgett) film or the like, or a method using phase separation of a block copolymer or the like may be used.

  As described above in detail, according to the present embodiment, by providing p-type conductive nano-sized crystalline silicon having the same crystal axis on an n-type conductive silicon substrate, non-light emission A nano-Si light emitting device with few recombination centers and excellent crystallinity can be realized. This makes it possible to provide a long-lived and highly efficient nano-Si light emitting device at low cost.

In the present embodiment, a light emitting element using nano-Si is illustrated, but it can also be applied to a power generation element (photovoltaic element) with the same configuration. That is, when nano-Si is irradiated with light from the transparent electrode side, carriers (electron / hole pairs) are generated, and electric power can be taken out from the pair of electrodes. In particular, it is possible to realize a power generating element that is highly sensitive to visible to ultraviolet light.
In addition, the nano-Si element to which the present embodiment is applied can be easily formed in an arbitrary shape simply by adding several manufacturing steps to normal IC manufacturing. Therefore, a single chip may be combined with a control circuit, an amplifier circuit, a memory circuit, a protection circuit, and the like. In other words, by making various circuits and nano-Si elements into an IC on the same substrate, various functions can be added, functions can be improved, or costs can be reduced. The application is not limited to light emitting elements and power generation elements, but includes communication, memory, sensors, or displays.

It is the figure which showed the partial cross section of the nano Si light emitting element which concerns on this Embodiment. It is explanatory drawing which shows the band structure for demonstrating the operation | movement principle of FIG. 1, and the flow of a carrier. It is a fragmentary sectional view which shows the modification of the nano Si light emitting element shown in FIG. It is a figure which shows the band structure and the flow of a carrier for demonstrating the principle of operation of the modification shown in FIG. It is a fragmentary sectional view showing a manufacturing method of a nano Si light emitting element concerning this embodiment. It is a fragmentary sectional view showing a manufacturing method of a nano Si light emitting element concerning this embodiment. It is a fragmentary sectional view showing other manufacturing methods of nano Si light emitting element concerning this embodiment in process order. It is a fragmentary sectional view showing other manufacturing methods of nano Si light emitting element concerning this embodiment in process order.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Silicon substrate, 11 ... Al * Si alloy film, 12 ... Nano Si (p-type crystalline silicon), 13 ... Silicon oxide film, 14 ... Silicon oxide film, 15 ... Transparent electrode (for example, ITO), 16 ... Metal electrode ( For example, aluminum), 20 ... silicon nitride film, 21 ... nanoparticles

Claims (15)

An n-type single crystal silicon substrate having one surface and another surface;
A crystalline silicon element comprising nano-sized p-type crystalline silicon provided on the one surface side of the silicon substrate and having the same crystal axis as the silicon substrate. The crystalline silicon device according to claim 1, further comprising:
A metal electrode;
A crystalline silicon device comprising: a pair of electrodes formed with the metal electrode, and a transparent electrode sandwiching the p-type crystalline silicon and the silicon substrate. The crystalline silicon device according to claim 2,
The metal electrode is in ohmic contact with the silicon substrate on the other surface side of the silicon substrate,
The crystal silicon element, wherein the transparent electrode is provided on the p-type crystal silicon. The crystalline silicon device according to claim 3, wherein
The crystal silicon element, wherein the transparent electrode is joined to the p-type crystal silicon through a thin insulating film in which carrier tunnel injection is performed. The crystalline silicon device according to claim 3, wherein
The transparent electrode is formed of an ohmic junction by being in direct contact with the p-type crystalline silicon. The crystalline silicon device according to claim 1,
The p-type crystalline silicon has a crystalline structure in which the plane orientation of a plane substantially orthogonal to the streamline direction of injected carriers is (100). The crystalline silicon device according to claim 1,
A crystalline silicon device, wherein the silicon substrate has a resistivity of 10 mΩ or less. The crystalline silicon device according to claim 1,
The crystalline silicon device, wherein the p-type crystalline silicon is doped with aluminum. An n-type single crystal silicon substrate having one surface and another surface;
Nano-sized p-type crystalline silicon provided on the one surface side of the silicon substrate, separated from the silicon substrate and having the same crystal axis as the silicon substrate;
A transparent electrode formed on the one surface side provided with the p-type crystalline silicon of the silicon substrate;
A crystalline silicon element comprising: a metal electrode formed on the other surface side of the silicon substrate. In the crystalline silicon device according to claim 9,
The p-type crystalline silicon and the transparent electrode are connected via an insulating film,
The current path when a carrier is injected by applying a voltage between two electrodes using the transparent electrode as an anode and the metal electrode as a cathode is the transparent electrode, the insulating film, the p-type crystalline silicon, the silicon substrate, and the like. A crystalline silicon element characterized by being a metal electrode. In the crystalline silicon device according to claim 9,
The p-type crystalline silicon and the transparent electrode are directly joined,
The current path when a carrier is injected by applying a voltage between two electrodes using the transparent electrode as an anode and the metal electrode as a cathode is the transparent electrode, the p-type crystal silicon, the silicon substrate, and the metal electrode. A crystalline silicon device characterized by that. A method for producing a crystalline silicon element using silicon microcrystals,
a step of providing, on one surface side of an n-type single crystal silicon substrate, solid-phase growth of a plurality of nano-sized p-type crystal silicon having the same crystal axis as the silicon substrate;
Providing a transparent electrode on the one surface side where the p-type crystalline silicon is formed;
Providing a metal electrode on the other surface side of the silicon substrate. In the manufacturing method of the crystalline silicon device according to claim 12,
The step of providing the p-type crystalline silicon by solid-phase growth includes:
Forming a thin film made of aluminum silicon (AlSi) on the silicon substrate;
Subjecting the p-type crystalline silicon to solid phase epitaxial growth on the silicon substrate by heat treatment at a temperature not exceeding the melting point of aluminum silicon (AlSi);
And a step of removing the thin film made of aluminum / silicon (AlSi). A method for producing a crystalline silicon element using silicon microcrystals,
Forming a thin film made of aluminum / silicon (AlSi) on one surface side of a single-crystal silicon substrate;
Performing a solid phase epitaxial growth of p-type crystalline silicon on the silicon substrate by performing a heat treatment within a predetermined temperature range in which solid phase epitaxial growth can occur at a temperature not exceeding the melting point of aluminum silicon (AlSi);
And a step of removing the thin film made of aluminum / silicon (AlSi). The method of manufacturing a crystalline silicon device according to claim 14, further comprising:
Providing a transparent electrode on the one surface side of the silicon substrate;
Providing a metal electrode on the other surface side of the silicon substrate.

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