JP2007073868A - Method and apparatus for manufacturing spherical semiconductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for manufacturing a spherical semiconductor which can manufacture the spherical semiconductor of a predetermined shape at low cost. <P>SOLUTION: The apparatus has a configuration equipped with a droplet discharging device 10 which discharges a droplet 2 containing a formation material of the spherical semiconductor, a curing device 30 which cures the discharged droplet 2 in the air by heating, a laser irradiation equipment 52 which irradiates an amorphous spherical semiconductor 4 formed by the curing device 30 with a laser beam, and a crystallization equipment 50 to form a crystalline spherical semiconductor 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a spherical semiconductor manufacturing method and a spherical semiconductor manufacturing apparatus.

  In recent years, attention has been drawn to a spherical semiconductor in which elements, circuits, and the like are formed on the surface of a spherical silicon ball having a diameter of about 1 mm. This is because the spherical semiconductor has the largest surface area per unit volume of silicon, and can contribute to downsizing of electronic devices.

Patent Document 1 describes a method for manufacturing a spherical semiconductor. In this manufacturing method, solid silicon grains are introduced from the preheating zone into the ultra-high temperature zone. Silicon grains melt as they pass through the ultra-high temperature zone and become spherical due to surface tension. Thereby, a granular single crystal is generated.
JP-T-2001-501779

  However, the method described in Patent Document 1 requires a high temperature higher than the melting point of silicon. In this case, many costs are required for the introduction and operation of the heating device. In addition, the method described in Patent Document 1 has a problem in that the size of a spherical semiconductor to be manufactured varies because the mass of silicon grains as a raw material varies.

  The present invention has been made to solve the above problems, and provides a spherical semiconductor manufacturing method and a spherical semiconductor manufacturing apparatus capable of manufacturing a spherical semiconductor with excellent dimensional accuracy at low cost. With the goal.

In order to achieve the above object, a method for manufacturing a spherical semiconductor according to the present invention includes a droplet discharging step for discharging a droplet containing a material for forming a spherical semiconductor, and a curing step for curing the discharged droplet in the air. It is characterized by having.
According to the droplet discharge method, a predetermined amount of droplets can be accurately discharged, so that a spherical semiconductor of a predetermined size can be formed. In addition, since it has a step of curing in the air droplets that have become spherical due to surface tension, a spherical semiconductor close to a true sphere can be formed. Therefore, a spherical semiconductor with excellent dimensional accuracy can be manufactured.

The material for forming the spherical semiconductor is a general formula SinXm (where n represents an integer of 5 or more, m represents an integer of n, 2n-2, or 2n, and X represents a hydrogen atom and / or a halogen atom). It is desirable to be a silicon compound having a ring system represented by.
According to this configuration, since the silicon compound having the ring system can be dissolved in a polar solvent or the like, spherical droplets can be formed at room temperature (room temperature). Since the spherical semiconductor can be manufactured by curing the droplet, a high-temperature heating device is not necessary, and the spherical semiconductor can be manufactured at low cost.

The curing step is preferably performed by heating the droplets.
According to this configuration, since the droplets can be easily cured, the spherical semiconductor can be manufactured at low cost.

In the curing step, the droplets may be heated at 400 ° C. or higher.
According to this configuration, since the droplets can be cured at a relatively low temperature, a high-temperature heating device is not necessary, and a spherical semiconductor can be manufactured at a low cost.

In the curing step, it is desirable that the heating temperature of the droplets is raised along the passage route of the droplets.
According to this configuration, it is possible to cure the droplets while preventing the droplets from bumping.

The curing step may be performed by irradiating the droplets with laser light.
In the curing step, it is desirable to increase the energy density of the laser light applied to the droplets along the passage route of the droplets.
Also with this configuration, it is possible to cure the droplet while preventing the droplet from boiling.

Further, it is desirable to have a crystallization step of forming a crystalline spherical semiconductor by irradiating the amorphous spherical semiconductor formed by the curing step with laser light.
According to this configuration, a crystalline spherical semiconductor can be formed continuously from the discharge of the material liquid.

The laser beam is preferably a laser beam having a visible light wavelength.
Since laser light having a visible light wavelength has a deeper penetration depth into the droplet than laser light having an ultraviolet light wavelength, the laser light can be absorbed by the entire droplet.

The laser light irradiation is preferably performed in synchronization with the ejection of the droplets.
According to this configuration, since the laser light can be efficiently absorbed by the droplet, a spherical semiconductor can be manufactured at low cost.

In addition, it is desirable that the laser light irradiation direction be substantially parallel to a passage path of the droplet or the amorphous spherical semiconductor.
According to this configuration, it is possible to irradiate a droplet or an amorphous spherical semiconductor with laser light for a long time with a small number of laser irradiation devices. Therefore, the number of laser irradiation apparatuses can be reduced, and a spherical semiconductor can be manufactured at low cost.

On the other hand, a spherical semiconductor manufacturing apparatus according to the present invention includes a droplet discharge device that discharges droplets containing a spherical semiconductor forming material, and a curing device that cures the discharged droplets in the air. Features.
According to the droplet discharge device, a predetermined amount of droplets can be accurately discharged, so that a spherical semiconductor of a predetermined size can be formed. In addition, since it has a curing device that cures droplets that have become spherical due to surface tension in the air, a spherical semiconductor close to a true sphere can be formed. Therefore, a spherical semiconductor with excellent dimensional accuracy can be manufactured.

In addition, it is desirable to have a crystallization apparatus that forms a crystalline spherical semiconductor by irradiating the amorphous spherical semiconductor cured by the curing apparatus with laser light.
According to this configuration, a crystalline spherical semiconductor can be formed continuously from the discharge of the material liquid.

Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.
FIG. 1 is an overall view of a spherical semiconductor manufacturing apparatus according to this embodiment. A spherical semiconductor manufacturing apparatus 1 according to the present invention includes a droplet discharge device 10 that discharges droplets 2 containing a material for forming a spherical semiconductor, and cures the discharged droplets 2 in the air to form an amorphous spherical semiconductor. (Hereinafter referred to as “amorphous body”) 4. A curing device 30 for forming 4 and a crystalline spherical semiconductor (hereinafter referred to as “crystalline body”) 6 by irradiating the amorphous body 4 with laser light. And a crystallization apparatus 50 to be formed.

(Droplet discharge device)
A droplet discharge device 10 is disposed at the top of the spherical semiconductor manufacturing apparatus 1 according to the present embodiment.
FIG. 2 is an explanatory view of a droplet discharge device, FIG. 2 (a) is a perspective view, and FIG. 2 (b) is a front sectional view. In the droplet discharge device 10 shown in FIG. 2A, the nozzle plate 12 and the vibration plate 13 that are arranged to face each other are joined via a partition member (reservoir plate) 14. By shaping the partition member 14, a plurality of liquid chambers 15 and reservoirs 16 are formed between the nozzle plate 12 and the diaphragm 13. Each liquid chamber 15 is connected to a reservoir 16 via a communication path 17. The reservoir 16 and the liquid chambers 15 are filled with a liquid material containing a spherical semiconductor forming material.

  Corresponding to each liquid chamber 15, nozzles 18 are formed in the nozzle plate 12. Corresponding to each liquid chamber 15, a piezoelectric element (piezo element) 20 is attached to the outside of the diaphragm 13. As shown in FIG. 2B, the piezoelectric element 20 is obtained by sandwiching a piezoelectric material made of lead zirconate titanate (PZT) or the like between a pair of electrodes 21. When an AC voltage is applied to the pair of electrodes 21, the piezoelectric material repeatedly contracts and expands. When the piezoelectric material contracts, the vibration plate 13 is curved to the outside of the liquid chamber 15 and the internal pressure of the liquid chamber 15 is reduced. As a result, the liquid material flows into the liquid chamber 15 from the reservoir. Next, when the piezoelectric material expands, the vibration plate 13 is curved inwardly of the liquid chamber 15 and the internal pressure of the liquid chamber 15 increases. In this way, the droplet 2 is ejected from the nozzle 18.

  The droplet discharge method of the droplet discharge device 10 may be a method other than the piezo jet type using the piezoelectric element 20, for example, a method using an electrothermal transducer as an energy generating element.

(Curing device)
Returning to FIG. 1, a curing device 30 that forms the amorphous body 4 by curing the ejected droplet 2 in the air is disposed below the droplet ejection device 10 described above. The curing device 30 is formed in a cylindrical shape having a height of about 3 to 5 m, and its upper end surface and lower end surface are opened in a rectangular shape, a circular shape, or the like. Thereby, the droplet discharged from the droplet discharge device 10 passes through the inside of the curing device 30 and falls.

  FIG. 3 is a side sectional view of the curing device. On the inner wall of the curing device 30 in the present embodiment, heating devices 32, 34, and 36 for heating the falling droplets are mounted. As this heating device, various heaters, various lamps, and the like can be employed. Each heating device may be attached to the entire circumference of the curing device 30 or may be arranged on a part of the circumference.

  A plurality of heating devices are arranged in the height direction of the curing device 30. In each heating device, the heating temperature of the droplet 2 is set lower as it is arranged upstream of the passage path of the droplet 2, and the heating temperature is set higher as it is arranged downstream. For example, the first heating device 32 disposed on the upper portion of the curing device 30 is set so that the droplet 2 can be heated to about 300 ° C., and the second heating device 34 disposed in the middle portion of the curing device 30 includes: The third heating device 36, which is set so that the droplet 2 can be heated to about 500 ° C. and disposed below the curing device 30, is set so that the droplet 2 can be heated to about 700 ° C. As described above, by gradually increasing the heating temperature of the droplet 2 from the upstream to the downstream of the passage path of the droplet 2, the droplet 2 can be baked and cured while preventing bumping of the droplet 2. . In addition, the 3rd heating apparatus 36 arrange | positioned at the lowest part is set so that the droplet 2 can be heated to 400 degreeC or more. As a result, the liquid droplet 2 made of a liquid material to be described later can be surely fired to form the amorphous material 4.

  FIG. 4 is a side sectional view of a first modification of the curing device. In the first modification, laser irradiation devices 42, 44, and 46 for irradiating a laser beam onto the falling droplet 2 are mounted instead of the heating device described above. It is desirable to employ a laser irradiation apparatus that can irradiate laser light having a visible light wavelength. An infrared laser having a longer wavelength than the visible light laser is less likely to be absorbed by the droplet 2, while an ultraviolet laser having a shorter wavelength than the visible light laser is absorbed only by the surface of the droplet 2, whereas the visible light laser has a penetration length. This is because it is deeply absorbed by the entire droplet 2. An inexpensive YAG second harmonic wave or the like may be employed as the visible light laser. The laser irradiation device is arranged so that the laser can be irradiated substantially perpendicularly from the inner wall of the curing device 30 toward the central axis.

  In the height direction of the curing device 30, a plurality of laser irradiation devices are arranged. Each laser irradiation device is set so that the energy density of the laser light irradiated to the droplet 2 becomes lower as it is arranged upstream of the passage path of the droplet 2, and the energy density becomes lower as it is arranged downstream. It is set to be. For example, the first laser irradiation device 42 disposed on the upper portion of the curing device 30 is set to have an energy density of about 200 mJ / cm 2, and the second laser irradiation device 44 disposed in the middle portion has an energy density of 300 mJ. The third laser irradiation device 46, which is set to be about / cm 2 and arranged at the lower part, is set to have an energy density of about 400 mJ / cm 2. In this way, by gradually increasing the energy density of the laser light irradiated to the droplet from the upstream to the downstream of the passage path of the droplet 2, the droplet 2 is cured without causing boiling, and thus amorphous. The body 4 can be formed.

  FIG. 5 is a side sectional view of a second modification of the curing device. Since the laser light is emitted from the laser irradiation device 48 within a predetermined angle range, the energy density increases near the laser irradiation device 48 and the energy density decreases as the distance from the laser irradiation device 48 increases. Therefore, in the second modification, the laser irradiation device 48 is arranged so that the laser light can be irradiated from the downstream to the upstream substantially parallel to the passage path of the droplet 2. Thereby, it is possible to realize a state in which the energy density of the laser light irradiated to the droplet increases from the upstream to the downstream of the passage path of the droplet 2. Therefore, the amorphous body 4 can be formed by curing the droplet 2 without bumping. In the second modification, the falling droplet 2 can be irradiated with laser light for a long time with a small number of laser irradiation devices. Therefore, the number of laser irradiation devices can be reduced as compared with the first modification, and the equipment cost can be reduced.

(Crystallizer)
Returning to FIG. 1, a crystallization device 50 for irradiating the amorphous body 4 with laser light to form the crystalline body 6 is disposed below the curing device 30 described above. The crystallization apparatus 50 includes one or a plurality of laser irradiation apparatuses 52. As the laser irradiation device 52, a laser irradiation device similar to the first modification of the curing device 30 can be employed. The laser irradiation device 52 is arranged on the side of the passage path of the amorphous body 4 and can irradiate laser light substantially perpendicularly toward the passage path of the amorphous body 4. The energy density of the laser light irradiated to the amorphous body 4 is set to be about 600 mJ / cm 2. Note that it is desirable to increase the energy density in accordance with the size of the diameter of the amorphous body 4.

  FIG. 6 is a side view of a first modification of the crystallization apparatus. In the first modification, the laser irradiation device 52 is arranged so that the laser light can be irradiated from the downstream to the upstream substantially parallel to the passage path of the amorphous body 4. According to this configuration, the single laser irradiation device 52 can irradiate the falling amorphous body 4 with laser light for a long time. Therefore, the number of laser irradiation devices can be reduced, and the equipment cost can be reduced. A guide plate 54 made of a laser beam transmitting material such as quartz is disposed immediately above the laser irradiation device 52. The guide plate 54 includes an inclined surface that descends from the optical axis of the laser light toward the outside of the laser irradiation apparatus. By this inclined surface, it becomes possible to guide the amorphous body 4 falling toward the laser irradiation apparatus 52 to the outside of the laser irradiation apparatus 52 and avoid collision between the laser irradiation apparatus 52 and the amorphous body 4. It can be done.

Returning to FIG. 1, a tray 60 for the crystalline body 6 is disposed below the crystallization apparatus 50. In addition, in order to cool the crystalline body 6, you may fill the inside of the saucer 60 with refrigerant | coolants, such as water.
The spherical semiconductor manufacturing apparatus 1 described in detail above is entirely held in a vacuum or an inert gas atmosphere. In particular, a spherical semiconductor close to a true sphere can be produced by holding it under vacuum.

(Production method of spherical semiconductor)
Next, a spherical semiconductor manufacturing method using the spherical semiconductor manufacturing apparatus according to the present embodiment will be described. As shown in FIG. 1, the spherical semiconductor manufacturing method according to the present embodiment includes a step of discharging a droplet 2 containing a semiconductor forming material, and an amorphous body 4 by curing the discharged droplet 2 in the air. And a step of irradiating the cured amorphous body 4 with a laser to form a crystalline body 6.

  First, a liquid containing a semiconductor forming material is prepared. As a semiconductor forming material made of silicon, a general formula SinXm (where n is an integer of 5 or more, m is an integer of n, 2n-2, or 2n, and X is a hydrogen atom and / or a halogen atom) A silicon compound having a ring system represented by. This silicon compound is dissolved in a polar solvent having a vapor pressure of 0.001 to 200 mmHg at room temperature to prepare a solution having a concentration of about 1 to 80% by weight. The viscosity of the silicon compound solution is usually 1 to 100 mPa · s, but is adjusted to a viscosity that can be discharged by the droplet discharge device 10 as necessary. This liquid material will be described in detail later.

  Next, the adjusted liquid material is filled into the droplet discharge device 10, and the droplet 2 is discharged from the droplet discharge device 10 (droplet discharge step). The discharged droplet 2 becomes spherical due to surface tension. Here, by adjusting the voltage waveform input to the pair of electrodes 21 shown in FIG. 2, the ejection amount of the droplet 2 can be adjusted. This makes it possible to discharge a minute droplet 2 having a diameter of about 10 μm to 100 μm.

  Next, returning to FIG. 1, the discharged droplet 2 is cured in the air (curing process). The discharged liquid droplet 2 falls freely and enters the inside from the upper opening of the curing device 30. In the curing device 30 shown in FIG. 3, the droplet 2 is first heated to about 300 ° C. by the first heating device 32. Next, the droplet 2 is heated to 500 ° C. to 700 ° C. by the second heating device 34 and the third heating device 36. In this way, by gradually heating the droplet 2, the silicon amorphous body 4 can be formed while preventing the droplet 2 from bumping. Since the above-mentioned silicon compound is thermally decomposed by heating at 400 ° C. or higher, the amorphous body 4 can be reliably formed.

  Note that even when the curing device 30 shown in FIGS. 4 and 5 is employed, an amorphous body can be formed in the same manner as described above. In this case, laser light can be efficiently absorbed by oscillating the laser irradiation device in synchronization with the ejection of the droplet 2.

  Next, returning to FIG. 1, the cured amorphous body 4 is irradiated with laser light to form a crystalline body 6 (crystallization step). The amorphous body 4 falls freely and enters the crystallization apparatus 50. In the crystallization apparatus 50, the amorphous body 4 is irradiated with laser light having an energy density of about 600 mJ / cm 2. By irradiating the laser beam, the amorphous body 4 is heated and melted. When this is cooled, crystallization occurs and a crystalline body 6 is formed. Also in this case, laser light can be efficiently absorbed by oscillating the laser irradiation device in synchronization with the ejection of the droplet 2. Even when the crystallization apparatus 50 shown in FIG. 6 is employed, the crystalline body 6 can be formed in the same manner as described above.

Returning to FIG. 1, the crystalline body 6 that has passed through the crystallization apparatus 50 is naturally cooled before reaching the tray 60. It is also possible to fill the inside of the tray 60 with a coolant such as water for forced cooling.
Thus, a spherical semiconductor is formed. It is also possible to continuously form a plurality of spherical semiconductors by discharging droplets continuously from the droplet discharge device 10. It is also possible to simultaneously form a plurality of spherical semiconductors by simultaneously discharging a plurality of droplets 2 from a plurality of nozzles formed in the droplet discharge device 10.

As described in detail above, in the method for manufacturing a spherical semiconductor according to the present embodiment, the step of discharging the droplet 2 containing the semiconductor forming material and the amorphous body by curing the discharged droplet 2 in the air. 4 is formed. According to the droplet discharge method, a predetermined amount of droplets can be accurately discharged, so that a spherical semiconductor of a predetermined size can be formed. For example, while the conventional spherical semiconductor has a diameter of about 1 mm, according to the present embodiment, it becomes possible to form a fine spherical semiconductor having a diameter of about 10 μm to 100 μm, and an electronic device using the spherical semiconductor Can be miniaturized. Further, the discharged droplet 2 becomes spherical due to surface tension, and the droplet 2 is cured in the air, so that a spherical semiconductor close to a true sphere can be formed. Therefore, a spherical semiconductor with excellent dimensional accuracy can be formed.
Further, by adding a step of forming a crystalline spherical semiconductor by irradiating an amorphous spherical semiconductor with a laser, the crystalline spherical semiconductor can be formed continuously from the discharge of the material liquid.

  Further, a silicon compound having a ring system represented by the general formula SinXm is employed as a semiconductor forming material. If the droplets containing the silicon compound are cured, a spherical semiconductor can be manufactured. Therefore, an apparatus for heating silicon to a high temperature not lower than the melting point becomes unnecessary, and the spherical semiconductor can be manufactured at low cost.

(Acceleration sensor)
Next, an electronic device using the spherical semiconductor will be described.
FIG. 7 is a side sectional view of the acceleration sensor. The acceleration sensor 80 includes a crystalline spherical semiconductor 6 at the center. A base insulating film 82 is formed on the entire surface, a lower electrode 84 made of a conductive material is formed on the entire surface, and a dielectric layer 86 is formed on the entire surface. An upper electrode 88 made of a conductive material is formed on the surface of the dielectric layer 86. The upper electrode 88 is arranged in at least ± X direction, ± Y direction, and ± Z direction in a state of being divided into a plurality of parts. A dielectric layer 86 is sandwiched between the upper electrode 88 and the lower electrode 84, and a capacitor is formed in each of the above directions. The upper electrode 88 is mounted on the electrode 94 of the substrate 92 via the bump 96. The entire acceleration sensor 80 is sealed with a resin 98.

When an external force acts on the substrate 92, an inertial force acts on the spherical semiconductor 6, and the spherical semiconductor 6 moves in any direction. Thereby, the capacitance of the capacitor formed in the moving direction of the spherical semiconductor changes. By detecting this change in capacitance, the acceleration of the substrate 92 can be measured.
According to the method for manufacturing a spherical semiconductor according to the present embodiment, a spherical semiconductor close to a true sphere can be formed, so that an acceleration sensor excellent in measurement accuracy can be provided. In addition, according to the method for manufacturing a spherical semiconductor according to the present embodiment, a minute spherical semiconductor can be formed, so that a small acceleration sensor can be provided.

  The electronic device using the spherical semiconductor is not limited to the acceleration sensor described above. For example, an integrated circuit (IC) can be formed by forming elements such as transistors or wirings on the surface of a spherical semiconductor. By mounting the IC, liquid crystal projectors, multimedia-compatible personal computers (PCs) and engineering workstations (EWS), pagers, word processors, televisions, viewfinder type or monitor direct view type video tape recorders, electronic It is also possible to form an electronic device such as a notebook, an electronic desk calculator, a car navigation device, a POS terminal, or a device provided with a touch panel. Any electronic device can be miniaturized by using the minute spherical semiconductor according to this embodiment.

(Forming material for spherical semiconductor)
Next, the spherical semiconductor forming material will be described in detail.
In order to form spherical silicon, the liquid material used in the present invention has the general formula SinXm (where n represents an integer of 5 or more, m represents an integer of n, 2n-2, or 2n, and X represents a hydrogen atom) And / or a halogen compound). In particular, as the silicon compound of the general formula SinXm, those in which n is 5 or more and 20 or less are preferable, and those in which n is 5 or 6 are more preferable. When n is less than 5, the silicon compound itself becomes unstable due to distortion due to the ring structure, making it difficult to handle. When n is greater than 20, the solubility in the solution is reduced due to the cohesive force of the silicon compound. And the selectivity of the solvent that can actually be used is narrowed.

  Specific examples of the silicon compound of the above general formula include cyclopentasilane, silylcyclopentasilane, cyclohexasilane, silylcyclohexasilane, and cycloheptasilane, specifically having 2 ring systems. 1, 1′-biscyclobutasilane, 1, 1′-biscyclopentasilane, 1, 1′-biscyclohexasilane, 1, 1′-biscycloheptasilane, 1 1, 1'-cyclobutasilylcyclopentasilane, 1, 1'-cyclobutasilylcyclohexasilane, 1, 1'-cyclobutasilylcycloheptasilane, 1, 1'-cyclopentasilylcyclohexasilane, 1, 1 '-Cyclopentasilylcycloheptasilane, 1,1'-cyclohexasilylcycloheptasilane, spiro [2,2] pentashi Spiro [3,3] heptatasilane, spiro [4,4] nonasilane, spiro [4,5] decasilane, spiro [4,6] undecasilane, spiro [5,5] undecasilane, spiro [5,6] dodecasilane, Spiro [6,6] tridecasilane is mentioned. Examples of polycyclic compounds include silicon hydride compounds 1 to 5 shown in FIG.

  In addition to these silicon hydride compounds, silicon compounds in which hydrogen atoms of these skeletons are partially substituted with SiH 3 groups or halogen atoms can be exemplified. These may be used in combination of two or more. Of these, 1,1′-biscyclopentasilane, 1,1′-biscyclohexasilane, spiro [4,4] nonasilane, spiro [4,5] decasilane, spiro [ 5,5] undecasilane, spiro [5,6] dodecasilane, and silicon compounds having SiH3 groups in their skeletons are particularly preferred.

  In addition, as the silicon compound used in the formation of the spherical silicon in the present invention, a solution containing a silicon compound having a ring system represented by the general formula SinXm as an essential component is used, and n-pentasilane, n -Silicon compounds, such as hexasilane and n-heptasilane, may be contained.

Moreover, the said silicon compound used by this invention can be normally manufactured with the following method, for example, using the monomer which has each structural unit as a raw material.
(A) Dehalogenation condensation polymerization of halosilanes in the presence of an alkali metal (so-called “kipping method”, J. Am. Chem. Soc., 110, 124 (1988), Macromolecules, 23, 3423 (1990)) ;
(B) Dehalogenation condensation polymerization of halosilanes by electrode reduction (J. Chem. Soc., Chem. Commun., 1161 (1990), J. Chem. Soc., Chem. Commun., 897 (1992)) ;
(C) A method of dehydrocondensation of hydrosilanes in the presence of a metal catalyst (JP-A-4-334551):
(D) Method by anionic polymerization of disilene crosslinked with biphenyl or the like (Macromolecules, 23, 4494 (1990)):
(E) After synthesizing a cyclic silicon compound substituted with a phenyl group or an alkyl group by the above-mentioned method, it is obtained by a known method (for example, Z. anorg. Allg. Chem., 459, 123-130 (1979)). It can also be derived into a hydro-substituted product or a halogen-substituted product. These halogenated cyclosilane compounds can be obtained by known methods (for example, see E. Hengge et al., Mh. Chem. 106, 503, 1975), (E. Hengge et al., Z. Anorg. Allg. Chem. 621, 1517 (see 1995)) (P. Boudjouk et al., J. Chem. Soc., Chem. Commun. 777, 1984). By optimizing the synthesis conditions, the chloro compound and hydrogenation can be synthesized. Body and partial chlorinated forms can be used.

  In the method of the present invention, a solution in which the silicon compound of the above general formula SinXm is dissolved in a solvent is used. In the present invention, the solvent used in the above solution is usually one having a vapor pressure at room temperature of 0.001 to 200 mmHg. When the vapor pressure is higher than 200 mmHg, the solvent may evaporate first and it may be difficult to form a good semiconductor. On the other hand, in the case of a solvent having a vapor pressure lower than 0.001 mmHg, drying is slow and the solvent tends to remain in the silicon compound, and it is difficult to obtain good quality spherical silicon even after heat and / or light treatment in the post-process. is there.

  The solvent used in the present invention is not particularly limited as long as it dissolves a silicon compound and does not react with the solvent. Specific examples include n-hexane, n-heptane, n-octane, n-decane, and dicyclopentane. In addition to hydrocarbon solvents such as benzene, toluene, xylene, durene, indene, tetrahydronaphthalene, decahydronaphthalene, squalane, dipropyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, Diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, tetrahydrofuran, tetrahydropyran, 1,2-dimethoxyethane, bis (2-methoxyethyl) ether Ether solvent such as p- dioxane, propylene carbonate, .gamma.-butyrolactone, N- methyl-2-pyrrolidone, dimethyl formamide, acetonitrile, dimethyl sulfoxide, it can be mentioned polar solvents such as chloroform. Of these, hydrocarbon solvents and ether solvents are preferable in view of solubility in silicon compounds and modified silicon compounds and stability of the solution, and more preferable solvents include hydrocarbon solvents. These solvents can be used singly or as a mixture of two or more. Hydrocarbon solvents are particularly preferred from the viewpoint of improving the solubility of the silicon compound and suppressing the residual silicon compound during heat treatment or light treatment.

  In the present invention, the spherical silicon is formed by discharging a solution in which a silicon compound is dissolved from a droplet discharge device, drying the solvent of the droplet to form a sphere of the silicon compound, and thermally decomposing the sphere of the silicon compound. Alternatively, it is photolyzed and converted into spherical metallic silicon. In general, droplets are discharged at a temperature of room temperature or higher. If the temperature is lower than room temperature, the solubility of the silicon compound may be reduced and partly precipitated. Further, it is preferable that the discharge atmosphere is performed in an inert gas such as nitrogen, helium, or argon, and in which a reducing gas such as hydrogen is mixed as necessary, or in a vacuum.

  In the present invention, the silicon compound is converted into spherical silicon by heat and / or light treatment. The spherical silicon obtained in the present invention is amorphous or polycrystalline. However, in the case of heat treatment, amorphous silicon is generally obtained when the ultimate temperature is about 550 ° C. or lower, and polycrystalline spherical silicon is obtained at higher temperatures. It is done. When it is desired to obtain amorphous spherical silicon, the heat treatment is preferably performed at 300 ° C. to 550 ° C., more preferably at 350 ° C. to 500 ° C. When the ultimate temperature is less than 300 ° C., the thermal decomposition of the silicon compound does not proceed sufficiently, and spherical silicon may not be formed. The atmosphere for performing the heat treatment is preferably an inert gas such as nitrogen, helium, or argon, a mixture of an inert gas and a reducing gas such as hydrogen, or a vacuum. When it is desired to obtain polycrystalline spherical silicon, the amorphous spherical silicon obtained above can be converted into polycrystalline spherical silicon by irradiating a laser. The atmosphere for irradiating the laser should be an inert gas such as nitrogen, helium, or argon, or a mixture of these inert gases with a reducing gas such as hydrogen, or an atmosphere that does not contain oxygen, such as a vacuum. Is preferred.

  On the other hand, the light treatment can be performed on the droplets of the silicon compound solution in an inert gas atmosphere before and / or after removing the solvent. The silicon compound that is soluble in the solvent is not only changed into a solvent-insoluble tough substance by the reaction by the light treatment, but also converted into spherical silicon with excellent optical and electrical properties by heat treatment after or simultaneously with the light treatment. Is done.

  In the present invention, as a light source used for light treatment when converting a silicon compound into spherical silicon, low pressure or high pressure mercury lamp, deuterium lamp, discharge light of rare gas such as argon, krypton, xenon, YAG, etc. An excimer laser such as a laser, an argon laser, a carbon dioxide laser, XeF, XeCl, XeBr, KrF, KrCl, ArF, ArCl, or the like can be used as a light source. These light sources generally have an output of 10 to 5000 W, but 100 to 1000 W is usually sufficient. The wavelength of these light sources is not particularly limited as long as the silicon compound absorbs even a little, but 400 nm to 700 nm is particularly preferable from the viewpoint of absorption efficiency and penetration depth. The use of laser light is particularly preferred from the viewpoint of conversion efficiency to polycrystalline spherical silicon. The temperature during these light treatments is usually from room temperature to 500 ° C., and can be appropriately selected according to the semiconductor characteristics of the obtained spherical silicon.

The concentration of the silicon compound solution of the present invention is about 1 to 80% by weight and can be prepared according to the desired spherical silicon diameter. If it exceeds 80%, it tends to precipitate and uniform spherical silicon cannot be obtained.
The viscosity of the silicon compound solution thus prepared is usually in the range of 1 to 100 mPa · s, and can be appropriately selected according to the droplet discharge device and the diameter of the target spherical silicon. When it exceeds 100 mPa · s, it becomes difficult to obtain uniform spherical silicon.

  It should be noted that the technical scope of the present invention is not limited to the above-described embodiments, and includes those in which various modifications are made to the above-described embodiments without departing from the spirit of the present invention. In other words, the specific materials and layer configurations described in the embodiments are merely examples, and can be changed as appropriate.

1 is an overall view of a spherical semiconductor manufacturing apparatus according to an embodiment. It is explanatory drawing of a droplet discharge apparatus. It is side surface sectional drawing of a hardening apparatus. It is side surface sectional drawing of the 1st modification of a hardening device. It is side surface sectional drawing of the 2nd modification of a hardening apparatus. It is a side view of the 1st modification of a crystallization apparatus. It is side surface sectional drawing of an acceleration sensor. It is a structural diagram of a polycyclic silicon hydroxide compound.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Spherical semiconductor manufacturing apparatus 2 ... Droplet 4 ... Amorphous spherical semiconductor 6 ... Crystalline spherical semiconductor 10 ... Droplet discharge device 30 ... Curing device 50 ... Crystallization device 52 ... Laser irradiation device

Claims (13)

A droplet discharge step of discharging a droplet containing a spherical semiconductor forming material;
A curing step of curing the discharged droplets in the air;
A method for producing a spherical semiconductor, comprising:   The material for forming the spherical semiconductor has a general formula SinXm (where n represents an integer of 5 or more, m represents n, 2n-2 or 2n, and X represents a hydrogen atom and / or a halogen atom). The method for producing a spherical semiconductor according to claim 1, wherein the compound is a silicon compound having a ring system represented by:   The method for producing a spherical semiconductor according to claim 1, wherein the curing step is performed by heating the droplet.   The method for producing a spherical semiconductor according to claim 1, wherein the curing step is performed by heating the droplets at 400 ° C. or higher.   3. The method for manufacturing a spherical semiconductor according to claim 1, wherein the curing step is performed by increasing a heating temperature of the droplets from upstream to downstream of a passage path of the droplets.   The method for producing a spherical semiconductor according to claim 1, wherein the curing step is performed by irradiating the droplets with laser light.   3. The spherical shape according to claim 1, wherein the curing step is performed by increasing an energy density of laser light applied to the droplet from upstream to downstream of a passage path of the droplet. Semiconductor manufacturing method.   8. The method according to claim 1, further comprising a crystallization step of forming a crystalline spherical semiconductor by irradiating the amorphous spherical semiconductor formed by the curing step with laser light. A method for producing a spherical semiconductor according to 1.   9. The method for manufacturing a spherical semiconductor according to claim 6, wherein the laser beam is a laser beam having a visible light wavelength.   10. The method for producing a spherical semiconductor according to claim 6, wherein the laser light irradiation is performed in synchronization with the ejection of the droplet.   The method for producing a spherical semiconductor according to claim 6, wherein an irradiation direction of the laser light is substantially parallel to a passage path of the droplet or the amorphous spherical semiconductor. . A droplet discharge device for discharging droplets containing a spherical semiconductor forming material;
A curing device for curing the discharged droplets in the air;
An apparatus for producing a spherical semiconductor, comprising:   13. The spherical semiconductor manufacturing method according to claim 12, further comprising a crystallization device that forms a crystalline spherical semiconductor by irradiating the amorphous spherical semiconductor cured by the curing device with a laser beam. apparatus.

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