JP2010050168A - Method of fabricating nanodot, and floating gate transistor, and method of fabricating the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of fabricating nanodots at low temperature through a small number of processes, to provide a floating gate transistor having the nanodots, and to provide a method of fabricating the same. <P>SOLUTION: A coaxial type vacuum arc vapor deposition source 1 is used to fabricate the nanodots 33, which are buried in an insulating layer 34 and hold electric charges, from a metal material or semiconductor material. The method includes the processes of forming an oxide film 32 on a substrate 31, fabricating the nanodots 33 on the oxide film 32, burying the nanodots by forming the insulating layer 34 on the nanodots, and forming an electrode film 35 on the insulating layer 34, thereby fabricating the floating gate transistor. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a nanodot manufacturing method, a floating gate transistor, and a manufacturing method thereof, and more particularly to a nanodot manufacturing method using a coaxial vacuum arc evaporation source, a floating gate transistor, and a manufacturing method thereof.

  A semiconductor element such as a flash memory generally has a structure called a floating gate, and the floating gate is formed by forming metal nanodots for holding charges in an insulating layer.

  In a flash memory, for example, a source diffusion layer and a drain diffusion layer are provided on a silicon substrate, and a gate insulating film, a floating gate having metal dots, and a control gate are sequentially provided on the channel region of the silicon substrate. In this configuration, electrons (charges) are written and stored in an electrically insulated floating gate, so that once the information is written, the information is retained even if power is not supplied. Yes. Since this floating gate is not electrically connected anywhere, once stored electrons can be held for a long time.

  As a principle of operation of the floating gate transistor as described above, it is known that an ON / OFF state is created by charging / discharging the metal nanodots formed in the insulating layer constituting the floating gate to function as a memory. Yes.

  As a method for producing metal nanodots, for example, a method of producing silicon nanodots by forming an ultrathin amorphous silicon layer on a silicon substrate and exposing to a silicon-containing gas at a high temperature is known (see, for example, Patent Document 1). ). A technique for producing nanodots at a low temperature using a protein having a supramolecular structure such as ferritin is also known (for example, see Patent Document 2).

JP 2005-129708 A (Claims) Japanese Patent Laying-Open No. 2005-268531 (Claims)

  In order to form the silicon nanodots described above, use of a silicon-containing gas and high-temperature treatment are necessary, and thus there is a problem that a heat source is required and nanodots having impurities such as residual gas are formed. In addition, the nanodot formation method using ferritin can be produced at a low temperature, but it is necessary to remove the protein with UV light, and then reduce the core part encapsulated in ferritin, so the process is complicated. There is a problem that there is.

  Accordingly, an object of the present invention is to solve the above-described problems of the prior art, and to provide a method for producing nanodots at low temperature and with fewer steps, a floating gate transistor having the nanodots, and a method for producing the same. There is.

  The method for producing nanodots of the present invention is characterized by producing nanodots for retaining electric charges embedded in an insulating layer from a metal material or a semiconductor material using a coaxial vacuum arc deposition source.

  By using a coaxial vacuum arc deposition source, nanodots can be fabricated directly on the substrate at low temperature and with few steps, and it is not necessary to use high temperature processing or gas, and it is formed in a vacuum. Therefore, the produced nanodot has high purity.

  The metal material and the semiconductor material used in the method for producing nanodots are not particularly limited as long as they are materials capable of producing nanodots with a coaxial vacuum arc deposition source.

  A floating gate transistor according to the present invention includes an oxide film on a silicon substrate, a nanodot for holding electric charge, which is made of a metal material or a semiconductor material using a coaxial vacuum arc deposition source, and the nanodot. An insulating layer formed to be embedded and an electrode film formed on the insulating layer are arranged in this order.

  By using a coaxial vacuum arc evaporation source, it has nanodots directly produced on a substrate with an oxide film at a low temperature and with few processes, and an insulating film that covers the nanodots so as to embed the nanodots. Since it is not necessary to use a gas and the high-purity nanodots are formed in a vacuum, a useful floating transistor can be provided.

  In the floating gate transistor, the nanodot is fixed to a cylindrical trigger electrode and a columnar cathode having an evaporation material member made of a metal material or a semiconductor material, adjacent to each other coaxially through a cylindrical insulator. In a vacuum atmosphere using a vapor deposition apparatus comprising a vacuum chamber having a coaxial vacuum arc vapor deposition source disposed coaxially around the columnar cathode and spaced apart by a cylindrical anode. Without triggering the substrate with a heat source, a voltage is applied between the trigger electrode and the cathode to generate a trigger discharge, and a capacitor and a DC power source are connected between the cathode and the anode to generate a discharge voltage. And intermittently inducing an arc discharge to discharge charged particles generated from the evaporating material member into the vacuum chamber and placing it in the vacuum chamber. Fabricated on the oxide film on the substrate, characterized in that it is a nano-dots are embedded in the insulating layer.

  The metal material and semiconductor material used in the floating gate transistor are not particularly limited as long as they are materials capable of producing nanodots with a coaxial vacuum arc deposition source.

  The method for manufacturing a floating gate transistor according to the present invention includes a step of forming an oxide film on a silicon substrate and a nanodot made of a metal material or a semiconductor material on the oxide film using a coaxial vacuum arc deposition source. A step of embedding the nanodots by forming an insulating layer on the nanodots, and a step of forming an electrode film on the insulating layer.

  By using a coaxial vacuum arc evaporation source, nanodots are produced directly on a substrate with an oxide film at a low temperature and with few steps, and an insulating film covering the nanodots is embedded so as to embed the nanodots. Since it is not necessary to use a gas and the high-purity nanodots are formed in a vacuum, a useful floating gate transistor manufacturing method can be provided.

  In the method for manufacturing a floating gate transistor of the present invention, the nanodot is formed by coaxially connecting a cylindrical trigger electrode and a columnar cathode having an evaporation material member made of a metal material or a semiconductor material via a cylindrical insulator. A vapor deposition apparatus comprising a vacuum chamber having a coaxial vacuum arc vapor deposition source, which is disposed adjacent to each other in a fixed shape, and has a cylindrical anode spaced coaxially around the columnar cathode. In a vacuum atmosphere, without heating the silicon substrate with a heat source, a voltage is applied between the trigger electrode and the cathode to generate a trigger discharge, and a capacitor and a DC power source are connected between the cathode and the anode. And intermittently inducing arc discharge by applying a discharge voltage, discharging charged particles generated from the evaporating material member into the vacuum chamber, Wherein the serial those made on the oxide film on the substrate placed in the vacuum chamber.

  The metal material and the semiconductor material used in the method for manufacturing the floating gate transistor are not particularly limited as long as they are materials capable of forming nanodots with a coaxial vacuum arc deposition source.

  According to the present invention, when nanodots are formed using a coaxial vacuum arc deposition source, it is performed in a vacuum-evacuated nanodot formation chamber (vacuum chamber), so there is no need to use gas, residual gas, etc. It is possible to form and provide nanodots free of impurities.

  Further, according to the present invention, by using a coaxial vacuum arc deposition source as a deposition source, nanodots having a uniform particle size can be formed at a low temperature without heating the substrate to be processed, and after the fabrication Since no treatment is required, the number of steps can be reduced, and as a result, a semiconductor device such as a floating gate transistor can be easily manufactured and provided.

  According to the embodiment of the nanodot manufacturing method according to the present invention, a substrate such as a silicon substrate is heated with a heat source in a vacuum atmosphere using a nanodot forming apparatus (deposition apparatus) provided with a coaxial vacuum arc evaporation source. Without using a coaxial vacuum arc evaporation source, nanodots for holding electric charges embedded in an insulating layer are directly formed on a substrate from a metal material or a semiconductor material, which is a material capable of forming nanodots.

  Nanodots can be formed directly on the substrate at low temperature and with fewer steps using a vacuum-evacuated nanodot forming device equipped with a coaxial vacuum arc deposition source, so there is no need to use gas and floating High-purity nanodots that are free of impurities such as residual gas and hold charges can be formed in a predetermined state in an insulating layer of a semiconductor element having a gate structure (for example, a flash memory).

  Examples of the substrate include a silicon substrate, a glass substrate, and a polymer film.

Examples of the metal material include at least one metal selected from C, Al, Ti, Cr, Fe, Co, Ni, Cu, Zn, Zr, Mo, and W, and a semiconductor. As materials, for example, (1) Group IV semiconductors such as Si and Ge, (2) Mg, Zn, Cd, and Hg are used as Group II elements, and O, S, Se, and Te are used as Group VI elements. For example, a group II-VI semiconductor such as ZnSe, CdS, CdTe, ZnO, (3) Al, Ga, In is used as a group III (group 13) element, N is used as a group V (group 15) element, For example, a compound composed of a III-V group compound semiconductor such as GaAs, InP, GaN, AlN, InN, etc., and (4) a group I-III-VI chalcopyrite semiconductor such as CuInSe ₂ using P, As, Sb Half Examples thereof include III-V group compound semiconductors containing B, Tl, Bi and the like in addition to conductors.

  Further, according to the embodiment of the floating gate transistor according to the present invention, the floating gate transistor is formed on the silicon substrate by using, for example, an oxide film such as silicon oxide and a coaxial vacuum arc evaporation source. A nanodot made of a material or a semiconductor material that retains electric charge, an insulating layer that is formed to embed the nanodot, for example, an oxide film such as silicon oxide, and formed on the insulating layer It is configured to have electrode films such as chromium, aluminum, and silver in this order.

  Furthermore, according to an embodiment of a method for manufacturing a floating gate transistor according to the present invention, the oxide film is formed using a step of forming the oxide film on a substrate such as a silicon substrate and a coaxial vacuum arc evaporation source. Forming nanodots from the metal material or semiconductor material on the film; embedding nanodots by forming the insulating layer on the nanodots; and forming an electrode film on the insulating layer. And have.

  In the floating gate transistor and the manufacturing method thereof, nanodots are formed by using a nanodot forming apparatus that is evacuated and equipped with a coaxial vacuum arc deposition source, so there is no need to use gas, and a floating gate structure is formed. Nanodots free from impurities such as residual gas can be manufactured in an insulating layer of a semiconductor element (eg, a flash memory).

According to the present invention, in the nanodot, a cylindrical trigger electrode and a columnar cathode having an evaporation material member made of a metal material or a semiconductor material are concentrically adjacent to each other via a cylindrical insulator. Using a nanodot forming apparatus comprising a vacuum chamber provided with a coaxial vacuum arc deposition source which is fixedly arranged and coaxially arranged around a columnar cathode with a cylindrical anode spaced apart, 10 ⁻⁶ 10 in -4 ^Pa vacuum atmosphere, without heating the substrate such as a silicon substrate by the heat source, by applying a voltage between the trigger electrode and the cathode to generate a trigger discharge, the capacitor between the cathode and the anode And a DC power source are connected, a discharge voltage is applied to intermittently induce arc discharge, and charged particles generated from the evaporating material member are discharged into the vacuum chamber. It is fabricated on an oxide film on a substrate placed in a chamber.

  A configuration example of a nanodot forming apparatus provided with a coaxial vacuum arc deposition source used in the present invention will be described below with reference to FIG.

  The nanodot forming apparatus has a coaxial vacuum arc deposition source 1 and a nanodot forming chamber 2. The coaxial vacuum arc deposition source 1 includes a cylindrical anode 11, a columnar cathode 12, and a cylindrical trigger electrode 13, and the cathode 12 and the trigger electrode 13 are arranged inside the anode 11 with the anode 11. It is spaced apart from the inner peripheral surface and arranged coaxially. The coaxial vacuum arc vapor deposition source 1 may be arranged so as to fulfill its vapor deposition function, and the whole or a part of the coaxial vacuum arc vapor deposition source 1 only needs to be installed inside the nanodot forming chamber 2.

  The cathode 12 may have a cylindrical shape, and may be composed entirely of a metal material for forming nanodots or a semiconductor material (hereinafter referred to as “evaporation material”) as described above, and one end is composed of these evaporation materials. The other end may be constituted by a rod-shaped electrode. The cathode 12 is placed so as to face the substrate to be processed so that the evaporation material can be released into the nanodot formation chamber 2. The cathode 12 is inserted in close contact with a cylindrical trigger electrode 13 and a cylindrical insulator (hereinafter referred to as a hat-type insulator) 14.

  Thus, the coaxial vacuum arc vapor deposition source used in the present invention is arranged such that the cylindrical trigger electrode 13 and the columnar cathode 12 are coaxially adjacently fixed via the cylindrical hat-type insulator 14, A cylindrical anode 11 is coaxially arranged around the columnar cathode 12 so as to be spaced apart.

  The hat-type insulator 14 is disposed between the cathode 12 and the trigger electrode 13, and the cathode 12, the hat-type insulator 14, and the trigger electrode 13 are arranged in this order from the center. The three parts of the cathode 12, the hat-type insulator 14, and the trigger electrode 13 are attached in close contact with each other, not shown, but are attached in close contact with screws and the like. The material of the anode 11 and the trigger electrode 13 is, for example, stainless steel, and the material of the hat-type insulator is, for example, alumina.

  The anode 11, the trigger electrode 13, and the cathode 12 are insulated from each other. An arc power source having a DC voltage source 15 a and a capacitor unit 15 b is connected between the cathode 12 and the anode 11, and the trigger electrode 13. Is connected to a trigger power source 16 so that different voltages can be applied to the electrodes 11 and 12. The capacitor unit 15b is a unit formed by connecting a plurality of capacitors in parallel. For example, when five capacitors having a capacity of 360 μF (withstand voltage: 400 V) are arranged in parallel, the capacity becomes 1800 μF.

  Each end of the capacitor unit 15b is connected to the anode 11 and the cathode 12, respectively, and the capacitor unit 15b and the DC voltage source 15a are connected in parallel. The DC voltage source 15a is a power source capable of flowing a current of a capacity of several A at 100V, and is configured to charge the capacitor unit 15b with a constant charging time. Although one capacitor is shown in FIG. 1, the number of capacitors can be increased or decreased as appropriate.

  The trigger power supply 16 is composed of a pulse transformer, and is configured so that a pulse voltage of μs with an input of 200 V is transformed to about 17 times and output with 3.4 kV (several μA) polarity: plus. Is connected to the trigger electrode 13 with a positive polarity with respect to the cathode 12. That is, the positive output terminal of the trigger power supply 16 is connected to the trigger electrode 13, and the negative terminal thereof is connected to the same potential as the negative output side terminal of the arc power supply (DC voltage source 15a) and connected to the cathode 12. ing. The plus terminal of the DC voltage source 15 a is grounded to the ground potential and connected to the anode 11. Further, both terminals of the capacitor unit are connected between the positive and negative terminals of the DC voltage source 15a.

  The coaxial vacuum arc deposition source 1 configured as described above is attached to the wall surface of the nanodot forming chamber 2 having a predetermined evacuation system (for example, a turbo molecular pump and a rotary pump). , Used to form the nanodots of the present invention. One or more coaxial vacuum arc deposition sources 1 can be installed as appropriate.

In the nanodot forming chamber 2, a substrate stage 21 for placing a substrate to be processed is installed facing the coaxial vacuum arc deposition source 1. A substrate stage is placed at the center of the lower surface of the substrate stage 21. A rotation mechanism 22 is connected to be rotatable. In addition, a vacuum exhaust system including a valve 23a, a turbo molecular pump 23b, a valve 23c, and a rotary pump 23d is connected to the wall surface of the nanodot forming chamber 2 in this order by a metal pipe. With this evacuation system, the inside of the nanodot forming chamber 2 is evacuated, and the inside of the chamber can be maintained at 10 ⁻⁴ Pa or less.

  Examples of the coaxial vacuum arc deposition source 1 described above include ARL-300 manufactured by ULVAC. In the following examples, nanodots are produced using this ULVAC coaxial vacuum arc deposition source. The coaxial vacuum arc deposition source is known to have higher energy of particles than the sputtering method, and has a feature that there are few impurities because it is a film formation in a gas phase.

According to the present invention, evacuated and discharged charged particles such as metal material or semiconductor material generated by the operation of the coaxial vacuum arc deposition source 1 into the nanodot forming chamber 2 in which a predetermined vacuum atmosphere is formed. Then, the substrate is supplied onto the substrate to be processed placed in the nanodot forming chamber 2 to form nanodots on the substrate to be processed. The anode 11 and the nanodot forming chamber 2 are connected to the ground potential.
Hereinafter, an operation example of the coaxial vacuum arc deposition source 1 used in the present invention will be described.

  First, the capacitance of the capacitor unit 15 b is set to 1800 μF, a variable voltage is output from the DC voltage source 15 a to 0 to 400 V, the capacitor unit 15 b is charged with the voltage, and the capacitor unit 15 is connected between the anode 11 and the cathode 12. A charging voltage of 15b is applied. A negative voltage output from the capacitor unit 15b is applied to the evaporation material member.

  When a pulsed trigger voltage of 3.4 kV is output from the trigger power supply 16 with the voltage applied as described above and applied between the cathode 12 and the trigger electrode 13, trigger discharge (at the surface of the hat-type insulator 14 ( Creeping discharge) occurs. Electrons are emitted from the joint between the cathode 12 and the hat insulator 14.

  With this trigger discharge, the withstand voltage between the anode 11 and the cathode 12 decreases, and arc discharge is induced between the inner peripheral surface of the anode 11 and the outer peripheral surface (side surface) of the cathode 12.

  Due to the discharge of the electric charge charged in the capacitor unit 15b, an arc current having a peak current of 1800 A or more flows for about 200 μs, and metal vapor is released from the side surface of the cathode 12 (that is, the evaporation material member). Plasma is formed. At this time, nanoparticles of several nanometers are formed by metal atomic ions or clustered metals.

  As described above, the cathode 12 is arranged on the central axis of the anode 11, and the arc power source (DC voltage source 15 a) is connected to the end of the cathode 12. A magnetic field is formed in the anode 11 through the axis. The electrons emitted into the anode 11 are subjected to a Lorentz force in the direction opposite to the direction in which the current flows by the magnetic field formed by the arc current, and are emitted into the nanodot formation chamber 2.

  The metal vapor discharged from the side surface of the cathode 12 includes ions (charged particles) and neutral particles, but giant charged particles such as droplets having a small charge-mass ratio (charge is smaller than mass). The neutral particles travel straight and collide with the wall surface of the anode 11, but charged particles having a large charge-mass ratio are attracted to electrons by the Coulomb force, and the nanodot formation chamber from the discharge port 11 a of the anode 11 facing the substrate stage 21. 2 is released.

  A substrate to be processed is placed at a predetermined distance from the surface of the anode 11, and when the metal vapor ions released into the nanodot formation chamber 2 reach the surface of the substrate to be processed, a metal of nanometer order is obtained. Particles are formed on the substrate to be processed. The use of a coaxial vacuum arc deposition source has the advantage that nanodots can be formed at low temperatures and with fewer steps.

  As described above, it has been explained that nanodots can be formed by using a coaxial vacuum arc evaporation source without heating the substrate to be processed with a heat source that is a heating means such as a heater, but the heat source is heated to a predetermined temperature. Even when a substrate to be processed is used, nanodots can be formed as in the case where the substrate is used without heating.

  An arc discharge is induced once by one trigger discharge, and an arc current flows for 300 μs. When the charging time of the capacitor unit 15b is about 1 second, arc discharge can be induced with a period of 1 Hz. Arc discharge is induced a predetermined number of times to form nanodots with a predetermined number of shots (number of shots).

  In FIG. 1, a valve 24a, a mass flow meter 24b, and a gas cylinder 24c are provided for cases where it is necessary to introduce gas into the nanodot forming apparatus.

Next, an example of a method for manufacturing a floating gate transistor is described with reference to FIGS. First, an oxide film 32 such as a thermal oxide film made of SiO ₂ or the like is formed on a substrate 31 such as a Si substrate by a known method, and then a coaxial vacuum arc provided in the nanodot forming apparatus shown in FIG. The metal material or semiconductor material nanodots 33 are formed on the oxide film 32 by using a vapor deposition source. Thereafter, an insulating layer 34 such as a silicon oxide film is formed by using a sputtering method, a CVD method, or the like, and nanodots 33 are embedded in the insulating layer 34 to form a capacitor structure. Finally, the floating gate device can be manufactured by forming the electrode film 35 on the insulating layer 34 by using a sputtering method, a CVD method, or the like.

  Hereinafter, an example is given and the present invention is explained in detail. In the following examples, Co, Fe, and Si were selected as metal materials, and nanodots were vapor-deposited on a Si substrate. Nanodots can be formed in the same manner by using a coaxial vacuum arc deposition source with the above-described other metal materials and substrates. Moreover, a useful nanodot can be similarly produced even if it uses the above-mentioned semiconductor material instead of a metal material. It is not limited to what was mentioned in the Example, Moreover, discharge conditions should just be the conditions range which can form a nanodot similarly using a coaxial type vacuum arc vapor deposition source, and are not limited to the conditions as described in the following Examples.

Co nanodots were formed on a Si substrate with a SiO ₂ thermal oxide film using a coaxial vacuum arc evaporation source (manufactured by ULVAC, Inc .: ARL-300). The discharge conditions in this case were set to 200 V, 1800 μF, and 10 shots. In this case, the Si substrate was not heated with a heat source.

  FIG. 3 shows a TEM image of the substrate after nanodot formation thus obtained. As apparent from FIG. 3, it was confirmed that Co nanodots having a particle size of about 5 nm were formed.

  When Fe nanodots were formed according to the same method as in Example 1 using Fe as the metal material, it was confirmed that Fe nanodots having the same particle diameter as in Example 1 were formed.

  When Si nanodots were formed according to the same method as in Example 1 using Si as the metal material, it was confirmed that Si nanodots having the same particle size as in Example 1 were formed.

After forming Co nanodots on the Si substrate with the SiO ₂ thermal oxide film by the method described in Example 1, the SiO ₂ oxide was formed as an insulating layer under the known conditions (300 W, 0.5 Pa in Ar) by sputtering. A film was formed and Co nanodots were embedded in this insulating layer to form a capacitor structure. Finally, an electrode film made of chromium was formed on the insulating layer by a sputtering method under a known condition (300 W, 0.5 Pa in Ar), and a floating gate device could be manufactured.

  By applying a gate voltage in the positive direction to the obtained floating gate transistor, the drain current increased. When voltage was next applied in the negative direction from that state, the current decreased faster than when voltage was applied positively, and the IV curve formed hysteresis. From this, it was confirmed that the manufactured transistor had a memory effect and a floating gate transistor was formed.

  According to the present invention, compared to the conventional method, nanodots can be produced at a low temperature and no post-processing is required, so that the number of steps can be greatly reduced, and a semiconductor element such as a floating gate transistor can be easily produced. Is possible. In addition, since high-purity nanodots with uniform particle diameters can be formed, high-performance semiconductor elements can be produced. Therefore, the present invention can be applied in the field of semiconductor devices.

The block diagram which shows typically one structural example of the nanodot formation apparatus provided with the coaxial type vacuum arc vapor deposition source used by this invention. The block diagram which shows typically the example of 1 structure of a floating gate transistor. The photograph which shows the TEM image of the substrate surface after nanodot formation formed according to Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coaxial type vacuum arc evaporation source 2 Nanodot formation chamber 11 Anode 11a Emission port 12 Cathode 13 Trigger electrode 14 Hat type insulator 15a DC voltage source 15b Capacitor unit 16 Trigger power supply 21 Substrate stage 22 Rotating mechanism 23a, 23c Valve 23b Turbo molecular pump 23d Rotary pump 31 Substrate 32 Oxide film 33 Nanodot 34 Insulating layer 35 Electrode film

Claims (8)

A method for producing nanodots, characterized in that a nanodot for retaining electric charges embedded in an insulating layer is produced from a metal material or a semiconductor material using a coaxial vacuum arc deposition source. The method for producing nanodots according to claim 1, wherein the metal material and the semiconductor material are materials capable of producing nanodots with a coaxial vacuum arc deposition source. On a silicon substrate, using an oxide film, a coaxial vacuum arc evaporation source, a nanodot for holding electric charge, which is made of a metal material or a semiconductor material, and an insulating layer formed so as to embed the nanodot And an electrode film formed on the insulating layer in this order. The nanodots are arranged in a cylindrical trigger electrode and a columnar cathode having an evaporation material member made of a metal material or a semiconductor material, fixed coaxially adjacent to each other via a cylindrical insulator, A deposition apparatus comprising a vacuum chamber provided with a coaxial vacuum arc deposition source in which a cylindrical anode is coaxially disposed around the columnar cathode, and the substrate is used as a heat source in a vacuum atmosphere. Without heating, a voltage is applied between the trigger electrode and the cathode to generate a trigger discharge, a capacitor and a DC power source are connected between the cathode and the anode, and a discharge voltage is applied to intermittently An arc discharge is induced, charged particles generated from the evaporating material member are discharged into the vacuum chamber, and are produced on an oxide film on a substrate placed in the vacuum chamber. Floating gate transistor according to claim 3, characterized in that the nanodots embedded in the insulating layer. 5. The floating gate transistor according to claim 3, wherein the metal material and the semiconductor material are materials capable of producing nanodots with a coaxial vacuum arc deposition source. A step of forming an oxide film on a silicon substrate; a step of forming nanodots made of a metal material or a semiconductor material on the oxide film using a coaxial vacuum arc deposition source; and an insulating layer on the nanodots. A method for manufacturing a floating gate transistor, comprising: a step of embedding the nanodots by forming; and a step of forming an electrode film on the insulating layer. 7. The method for manufacturing a floating gate transistor according to claim 6, wherein the metal material and the semiconductor material are materials capable of forming nanodots with a coaxial vacuum arc deposition source. The nanodots are arranged in a cylindrical trigger electrode and a columnar cathode having an evaporation material member made of a metal material or a semiconductor material, fixed coaxially adjacent to each other via a cylindrical insulator, A deposition apparatus comprising a vacuum chamber provided with a coaxial vacuum arc deposition source in which a cylindrical anode is coaxially disposed around the columnar cathode, and the substrate is used as a heat source in a vacuum atmosphere. Without heating, a voltage is applied between the trigger electrode and the cathode to generate a trigger discharge, a capacitor and a DC power source are connected between the cathode and the anode, and a discharge voltage is applied to intermittently An arc discharge is induced, charged particles generated from the evaporating material member are discharged into the vacuum chamber, and are produced on an oxide film on a substrate placed in the vacuum chamber. The method for manufacturing a floating gate transistor according to claim 6 or 7, wherein the of the a.