1. An apparatus for growing a single crystalline metal oxide semiconductor outer film, comprising:

a reaction chamber having an inner space;

a substrate mounting unit which is disposed in the internal space and on which a substrate can be mounted;

a metal oxide processing unit that processes a metal oxide and supplies metal ions and oxygen ions generated on the metal oxide onto the substrate;

an arsenic supply unit that is opposite to the substrate and supplies arsenic ions to the substrate;

wherein the metal oxide processing unit includes:

a mount table disposed in the internal space, facing the substrate, and provided with a zinc oxide plate of the metal oxide; and

and an electron beam irradiator for irradiating an electron beam to the zinc oxide plate in a direct manner to move zinc ions and oxygen ions evaporated from the zinc oxide plate to the substrate.

2. The crystalline metal oxide semiconductor outer film growth apparatus of claim 1,

the substrate mounting unit and the electron beam irradiator are disposed at one side of an upper portion of the reaction chamber,

the mounting table is arranged on one side of the lower part of the reaction chamber.

3. The crystalline metal oxide semiconductor outer film growth apparatus of claim 1,

for the zinc oxide plate, the irradiation angle of the electron beam irradiator was decided to be in the range of 20 °.

4. The crystalline metal oxide semiconductor outer film growth apparatus of claim 1,

the electron beam irradiator was operated at a power of 30kW using an acceleration voltage of 30kV and a discharge current of 1A.

5. The crystalline metal oxide semiconductor outer film growth apparatus of claim 3,

the substrate mounting unit and the mounting stage are disposed such that a distance between the zinc oxide plate and the substrate is in a range of 800mm to 1800 mm.

6. The crystalline metal oxide semiconductor outer film growth apparatus of claim 1,

the arsenic supply unit, which is controlled to have a temperature range of 500 ℃ to 1100 ℃ in operation, is used to ionize arsenic and supply the ionized As2 +.

7. The crystalline metal oxide semiconductor outer film growth apparatus of claim 1, further comprising:

and an oxygen supply unit which is opposite to the substrate and supplies oxygen radicals generated by dissociation of oxygen molecules in a gas state to the substrate.

8. The crystalline metal oxide semiconductor outer film growth apparatus of claim 6,

the metal oxide processing unit and the oxygen supply unit are disposed on opposite sides with respect to the substrate mounting unit,

the arsenic supply unit is positioned between the metal oxide treatment unit and the oxygen supply unit.

9. The crystalline metal oxide semiconductor outer film growth apparatus of claim 6,

the reaction chamber further comprises: and a partition wall having a structure in which a protrusion is formed from a bottom portion defining the internal space, and disposed between the oxygen supply unit and the arsenic supply unit, for blocking the oxygen radicals discharged from the oxygen supply unit from moving to the arsenic supply unit and the metal oxide treatment unit side.

10. The crystalline metal oxide semiconductor outer film growth apparatus of claim 6,

the oxygen supply unit includes: a discharge port lower than a bottom horizontal position of the inner space defining the reaction chamber; and a valve opening and closing the discharge port.

11. The crystalline metal oxide semiconductor outer film growth apparatus of claim 1,

the pointing angle of the substrate of the oxygen supply unit is determined to be in the range of 20 ° to 40 °.

12. The crystalline metal oxide semiconductor outer film growth apparatus of claim 1, further comprising:

a driving unit connected to the substrate mounting unit, disposed in the reaction chamber, and driving the substrate mounting unit,

the driving unit moves the substrate mounting unit in a direction away from or toward the arsenic supply unit or rotates the substrate mounting unit.

13. The crystalline metal oxide semiconductor outer film growth apparatus of claim 1, further comprising:

a heating unit for heating the substrate corresponding to the substrate mounting unit;

the heating unit operates in a temperature range of 750 ℃ to 1000 ℃ to maintain the temperature of the substrate at 550 ℃ to 800 ℃ during the film formation process.

Background

Generally, Oxide thin films including Indium Tin Oxide (ITO), zinc Oxide (ZnO), and zinc compounds such as AZO, GZO, and IGZO are widely used in the fields of both electrodes of display patterns of Liquid Crystal Displays (LCDs), Organic Light Emitting Semiconductors (OLEDs), etc., communication layers for transmitting alert charges of thin films used for transparent electrodes, pixel driving, etc., and cathode and anode electrodes of solar cells, etc., and are widely used in commercial developments as core electrode materials and active layer materials of next-generation transparent electronic devices, and related researchers are developing them. Further, many research and development efforts have been continuously made and published as a light emitting layer of a light emitting diode.

In the above application fields, similarly to a film formation method using a polycrystalline oxide semiconductor thin film, even when an oxide semiconductor thin film having an n-type characteristic which is significantly superior in terms of a signal processing speed to a degree of electron mobility in a hole movement is used, there is no problem in most cases. Accordingly, a process for forming a doped (dopant) Acceptor (Acceptor) or the like having a p-type oxide film with characteristics opposite to those described above, and a device technology for performing the process have not been widely disclosed.

Among the additives for forming p-type zinc oxide thin films, nitrogen is most studied, but it is very difficult to form p-n junction having a remarkable reproducibility effect, and the field of application is still in the stage of manufacturing transistors. Therefore, the countermeasure to the above problem has been studied for materials such As Na, Li, Ag, Sb, B, As, and the like. Among them, arsenic is the most likely substance, and it is easier to adjust the concentration of arsenic ions as a receptor, and it is easier to adjust this property than other substances, and thus it is considered to be the most suitable substance in the prior art.

However, in the MOCVD technique, the content of hydrocarbon element in metal organic source (metal organic source) As a raw material is high, and the probability of occurrence of O — H bonding is higher than that of bonding between arsenic (As) and zinc oxide (Zn — O) used As an additive (done) when a p-type zinc oxide film is grown. Thus, the probability that arsenic ions participate As an additive to form Zn-O-As in combination with Zn-O is relatively significantly reduced.

Disclosure of Invention

(problem to be solved)

One of the objects of the present invention is to provide an apparatus for growing a single-crystal metal oxide semiconductor outer film, which can inject arsenic into a receptor substance and can efficiently form a high-purity p-type zinc oxide thin film.

Another object of the present invention is to provide an apparatus for growing a single crystalline metal oxide semiconductor outer film, which can improve the yield by disclosing a process technology for forming a high purity single crystalline zinc oxide substrate.

(means for solving the problems)

In order to achieve the above object, the present invention provides an apparatus for growing a single-crystal metal oxide semiconductor outer film, comprising: a reaction chamber having an inner space; a substrate mounting unit which is disposed in the internal space and on which a substrate can be mounted; a metal oxide processing unit that processes a metal oxide and supplies metal ions and oxygen ions generated on the metal oxide onto the substrate; an arsenic supply unit that is opposite to the substrate and supplies arsenic ions to the substrate; wherein the metal oxide processing unit includes: a mount table disposed in the internal space, facing the substrate, and provided with a zinc oxide plate of the metal oxide; and an electron beam irradiator for irradiating an electron beam to the zinc oxide plate in a direct manner to move zinc ions and oxygen ions evaporated from the zinc oxide plate to the substrate.

Here, the substrate mounting unit and the electron beam irradiator may be disposed at an upper side of the reaction chamber, and the mounting stage may be disposed at a lower side of the reaction chamber.

Here, the irradiation angle of the electron beam irradiator was determined to be within 40 ° for the zinc oxide plate.

Here, the electron beam irradiator was operated at a power of 30kW using an acceleration voltage of 30kV and a discharge current of 1A.

Here, the substrate mounting unit and the mounting stage are disposed such that a distance between the zinc oxide plate and the substrate is in a range of 800mm to 1800 mm.

Here, the arsenic supply unit, which has a temperature range of 500 ℃ to 1100 ℃ in operation, is used to ionize arsenic and supply the ionized As2 +.

Here, the apparatus of the present invention may further include an oxygen supply unit that supplies oxygen radicals generated by dissociation of oxygen molecules in a gas state to the substrate, opposite to the substrate.

Here, the metal oxide processing unit and the oxygen supply unit are disposed on opposite sides with respect to the substrate mounting unit, and the arsenic supply unit is located between the metal oxide processing unit and the oxygen supply unit.

Here, the reaction chamber further includes a partition wall forming a convex structure from a bottom defining the internal space, disposed between the oxygen supply unit and the arsenic supply unit, for blocking the oxygen radicals discharged from the oxygen supply unit from moving to a side of the arsenic supply unit and the metal oxide treatment unit.

Here, the oxygen supply unit includes: a discharge port lower than a bottom horizontal position of the inner space defining the reaction chamber; and a valve opening and closing the discharge port.

Here, the pointing angle of the substrate of the oxygen supply unit is determined to be in the range of 20 ° to 40 °.

Here, the apparatus of the present invention further includes: and a driving unit connected to the substrate mounting unit, disposed in the reaction chamber, and configured to drive the substrate mounting unit, wherein the driving unit moves the substrate mounting unit from the arsenic supply unit in a direction away from or close to the arsenic supply unit, or rotates the substrate mounting unit.

Here, the apparatus of the present invention further includes: and a heating unit for heating the substrate, wherein the heating unit operates in a temperature range of 750 ℃ to 1000 ℃ to maintain the temperature of the substrate at 550 ℃ to 800 ℃ during the film forming process, corresponding to the substrate mounting unit.

(Effect of the invention)

The apparatus for growing a single-crystal metal oxide outer film according to the present invention having the above-described structure is different from the conventional MOCVD technique in which it is difficult to form a p-type zinc oxide thin film, in which arsenic is supplied as a material to be extracted during the growth of the zinc oxide outer film layer, thereby smoothly forming the p-type zinc oxide single-crystal thin film.

Moreover, the conventional electron beam irradiator is located at the lower part of the reaction chamber, and in order to irradiate an electron beam onto the zinc oxide plate from a close distance, it is feasible to provide power in the range of 6-15kW by a deflection (diffraction) method of diffraction of 180-.

Drawings

FIG. 1 is a schematic diagram illustrating an apparatus 100 for growing an outer film of a single-crystal MOS according to an embodiment of the present invention.

Fig. 2 is a flowchart illustrating a process of forming a single crystalline metal oxide semiconductor layer using the single crystalline metal oxide semiconductor outer film growth apparatus 100 of fig. 1.

(brief description of the drawing)

100: single crystal MOS extension forming device

110: the reaction chamber 130: substrate mounting unit

150: the metal oxide processing unit 170: oxygen supply unit

180: the arsenic supply unit 190: drive unit

210: heating unit

Detailed Description

Hereinafter, an apparatus for growing an outer film of a single crystalline metal oxide semiconductor according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the present specification, the same or similar reference numerals will be used for the same or similar structures even in embodiments different from each other, and the description thereof only needs to refer to the initial description.

FIG. 1 is a schematic diagram illustrating an apparatus 100 for growing an outer film of a single-crystal MOS according to an embodiment of the present invention.

Referring to the drawings, a single crystalline metal oxide semiconductor outer film growth apparatus 100 includes: a reaction chamber 110; a substrate mounting unit 130, a metal oxide treating unit 150, an oxygen supplying unit 170, a driving unit 190, and a heating unit 210.

The reaction chamber 110 has an inner space 111, and a process for forming a high purity zinc oxide thin film is performed in the inner space 111. The inner space 111 is substantially at 10-8to 10-9torr, and a vacuum of 10-5to 10-6torr is formed when the thin film is formed. For this purpose, a vacuum pump 113 is connected to the inner space 111. The reaction chamber 110 may be additionally connected to a Load lock chamber. The pre-vacuumizing chamber is divided into two spaces, one is a substrate storage field for maintaining the horizontal vacuum degree of 10 < -3 > torr and the other is a substrate transfer field for maintaining the horizontal vacuum degree of 10 < -8 > to 10 < -9 > torr. The pre-evacuation chamber may include: an automatic transfer device of the substrate mounting unit 130 for transferring the mounting substrate, a preheating unit for shortening an exhaust (exhausting) time of the metal oxide, and a slit capable of storing at least 5 substrate clamping portions. As for the degree of vacuum of the pre-vacuuming chamber, the vacuum level of the reaction chamber 110 can be maintained at 10-8to 10-9torr during the process. The transfer of the substrate W between the pre-vacuum chamber and the reaction chamber 110 is performed by a robot. Further, a convex partition wall 115 is formed on the bottom of the inner space 111.

The substrate mounting unit 130 is provided in the internal space 111 and is configured to mount the substrate W. The substrate mounting unit 130 may be sized to load up to 108 sapphire substrates of 4 feet. The substrate mounting unit 130 is transferred from the pre-vacuum chamber and attached to a hanger (cradle) provided in the reaction chamber 110. Therefore, 4 electromagnets are provided at the connection portion between the hanger and the substrate mounting unit 130, and when the outer film growth layer is formed after the electromagnets are attached, the substrate mounting unit 130 can move upward, close to the heating unit 210 located at the upper portion, to a position where the temperature of the substrate W is maintained at 550-. In order to transfer the substrate mounting unit 130 to the pre-vacuum chamber, after the outer film layer growth process is completed, the hanger is lowered by 80mm, and then the magnetic field of the electromagnet is released, so that the substrate mounting unit 130 can be mounted to the transfer system. Meanwhile, when the above-mentioned structure is transferred, it can be stored in a slit provided in the pre-vacuum chamber. In order to control the position of the substrate mounting unit 130, and also in order to control the position of the substrate mounting unit 130 attached to the hanger and the epitaxial growth process, a position sensor may be installed at a position that should be moved upward, so that the position of the substrate mounting unit 130 can be accurately controlled.

The metal oxide processing unit 150 processes the metal oxide such that metal ions and oxygen ions generated on the metal oxide are supplied to the structure of the substrate W. In this embodiment, the treatment of the metal oxide means that the metal oxide is irradiated with an electron beam to evaporate metal ions and oxygen ions and move the metal oxide toward the substrate W.

The metal oxide may be zinc oxide as a specific example, and this may be accomplished by sintering zinc oxide powder. The metallic zinc ion may be Zn2+ and the oxygen ion is O2-. The zinc oxide sheet was 8 feet in diameter and was assumed to have a thickness that could be changed to a state having a capacity of 900cm3 under 100% vaporization in a 2 inch state. When the epitaxial growth process is performed 5 times a day, a capacity of 4 months at most can be used, and the amount is also suitable for mass production. On the zinc oxide plate, the solid state is changed into gas state by irradiating electron beam, the temperature of zinc oxide in the sublimation area is between 1000-1500 ℃, and the melting point is 1950 ℃.

A zinc oxide plate may be disposed on the mount table 151. The mounting table is provided at a lower portion of the internal space 111 and is disposed to face the substrate mounting unit 130.

Zinc oxide, which is a ceramic material, has a thermal conductivity of less than 14% of that of metal, i.e., 5W/mK, and is relatively low in thermal conductivity. The evaporation region in which the local temperature is raised by irradiation of the electron beam and the other regions generate a temperature difference, and therefore it is necessary to prevent deformation due to hot pressing generated on the zinc oxide plate. For this purpose, a heating unit (not shown) may be provided around the zinc oxide plate to minimize the temperature gradient. Such a heating unit is provided on the mounting table 151, and wraps the zinc oxide plate, preferably by means of differential heating, so that the temperature field of the zinc oxide plate is divided into at least 5 or more regions, and the temperature difference between the respective regions does not exceed 300 ℃.

It is also possible to additionally provide a device (fig. 2) for rotating the zinc oxide plate on the mounting table 151, which is a method for forming a uniform erosion profile (erosion profile) on the zinc oxide plate, thereby increasing the efficiency of use of the zinc oxide plate. The use is carried out according to a certain use cycle interval. The rotation angle of the zinc oxide plate is 45 deg., and the zinc oxide plate can be rotated for 8 times in total until the zinc oxide plate is replaced.

In order to prevent the blocking (clogging) phenomenon of the zinc oxide vapor which may occur at the initial stage of evaporation, a louver (shutter) having a diameter of 9 inches or more may be provided at a position of 70mm, for example, on the upper layer of the zinc oxide plate. The louver material can be stainless steel compound, tantalum or aluminum.

When the electron beam with high energy is emitted to the zinc oxide plate, backscattered electrons (backscattered electrons) are generated due to the scattering phenomenon of the electrons. It is generally accepted that the energy of the backscattered electrons is almost comparable to the energy of the electron beam incident on the zinc oxide plate. In order to minimize the problem of heat caused by backscattered electrons, a metal trap for trapping backscattered electrons may be provided around the zinc oxide plate.

An electron beam irradiator 155 for irradiating an electron beam to the zinc oxide plate is provided on the upper side of the internal space 111. The electron beam irradiator 155 is substantially at the same height as the substrate mounting unit 130. The electron beam irradiator 155 fixes the position of the electron beam source at an angle (θ 1) of 90 ° or within 40 ° directly above the reaction chamber 110, and irradiates the electron beam onto the zinc oxide plate in a direct manner. The irradiation angle θ 1 is preferably set to an angle within 20 °. When the acceleration voltage of the electron beam is high, secondary electrons (secondary electrons) are generated after the electron beam is irradiated to the zinc oxide plate. It is important to minimize the generation of secondary electrons; if the irradiation angle of the electron beam exceeds 40 °, the ratio of the generated secondary electrons is concentrated and increased to a level of 50%, thereby negatively affecting the evaporation efficiency of zinc oxide, the use efficiency of the zinc oxide plate, contamination of the chamber wall of the reaction chamber 110, and the like, and thus it is preferable to adjust the irradiation angle to within 20 °.

The electron beam irradiated from the electron irradiator 155 can reach a power of 60kW at maximum under the conditions of using an acceleration voltage in the range of 5to 30kV and a discharge current of 2A at maximum. Preferably, an acceleration voltage of 30kv and a discharge current of 1A are used, up to a power of 30 kW.

The distance between the zinc oxide plate and the electron beam irradiator 155 may be set to 600 to 1800mm, and the maximum should not exceed 1800 mm. Further, if a plurality of substrates (for example, 4 inches by 108 sheets) are mounted on the substrate mounting unit 130, it is preferable that the distance between the zinc oxide plate and the substrate W is maintained between 800 and 1800 mm. If the distance is 800mm or less, it is impossible to maintain a uniform coating layer over the entire substrate W, and if the distance is 1800mm or more, although a uniform coating layer can be maintained, the disadvantage that the adhesion speed is too slow occurs.

The oxygen supply unit 170 is a structure for additionally supplying oxygen radicals (O) to the substrate W after dissociation of oxygen molecules in a gaseous state. The oxygen supply unit 170 is disposed in the reaction chamber 110 and opposite to the substrate.

When growing a single crystal of zinc oxide, the ratio of zinc to oxygen atoms should theoretically be 1: 1, but if the actual composition of the characteristics of the actual zinc oxide thin film is analyzed, the oxygen atom ratio is low compared to the zinc atom, which is a naturally occurring phenomenon. Therefore, in order to adjust the ratio of zinc oxide to 1: 1, oxygen radicals are supplied to the substrate W by the oxygen supply unit 170. The supplied oxygen should not be in the state of molecular oxygen O2, but should be oxygen radicals supplied in a dissociated state by heat or plasma.

The oxygen supply unit 170 may utilize an RF Atom source, which is a structure installed at a lower portion of the reaction chamber 110. The mounting angle θ 2 is an angle of 20 to 40 °, preferably 30 ° or less, from the position where the substrate W is viewed. In the case of the RF Atom source, a louver may be further provided at the end thereof in order to prevent a splashing (splashing) phenomenon or a clogging (clogging) phenomenon at the initial stage of supplying oxygen radicals. Further, the oxygen-free plasma generator may further include a nozzle for injecting oxygen radicals into the internal space 111, and may further include an RF plasma source for dissociating oxygen, a power supply device, and an impedance matching system. In the present embodiment, a remote plasma is selected to minimize the influence of the plasma.

In order to efficiently dissociate O2, the RF Plasma Power can be in the range of 300-750W, but preferably 500W is suitable. The distance between the RF Atom Source for oxygen radical supply and the substrate W is 800-1400mm, preferably 800 mm.

If the amount of oxygen radicals supplied is too large, oxygen radicals can fill the empty space in the zinc oxide extension layer more, but too much oxygen radicals can oxidize the components present in the reaction chamber 110 and the internal space 111, and thus cause deterioration of the performance thereof. If the oxygen radicals are too small, sufficient oxygen radicals are not available on the zinc oxide extension layer, and the oxygen radicals cannot fill the empty space, which may deteriorate the performance of the zinc oxide extension layer. It is therefore important to select an appropriate supply amount of oxygen radicals. In this example, the oxygen radical supply amount was selected so as to maintain the vacuum at 10-5 torr.

Further, in order to prevent oxygen radicals supplied from the oxygen supply unit 170 from causing oxidation of peripheral parts, the oxygen supply unit 170 and the metal oxide processing unit 150 are disposed on opposite sides with respect to the substrate mounting unit 130. Further, an arsenic element supply unit 180 described later is disposed therebetween. The partition wall 115 blocks oxygen radicals discharged from the oxygen supply unit 170 from entering the arsenic supply unit 180 and the metal oxide treatment unit 150.

As another method, the discharge port 171 of the oxygen supply unit 170 may be located at a position lower than the bottom of the inner space 111. In the above configuration, the discharge port 171 is provided with a valve 175 that is opened and closed by a controller. The valve 175 is opened and closed only during the formation of the zinc oxide thin film on the substrate W, and oxygen radicals are allowed to flow into the internal space 111.

The arsenic supply unit 180 is configured to supply arsenic ions to the substrate W. Which is disposed at the bottom of the reaction chamber 110 and is disposed opposite to the substrate W.

The arsenic supply unit 180 may be, for example, a Knudsen cell (K-cell) which decomposes solid arsenic at a temperature of 500 to 1100 ℃, preferably 600 to 1100 ℃, and supplies the arsenic to the substrate W in an ion state of As2+, at normal temperature. If As4+ is supplied to the substrate W among arsenic ions, the Zn-O-As bonding does not proceed properly, and a high-quality p-type zinc oxide thin film does not grow properly. Therefore, in the above temperature range, it is important to manufacture As2+ for supply. And, the installation angle (θ 3) of the arsenic supply unit 180 facing the substrate W is preferably between 20 and 40 °. The arsenic supply unit 180 may further include a control valve for controlling the amount of arsenic ions (basically, As2+, doping concentration) within a range of 1017 to 1021/cm 3, so that the arsenic ions can conform to the characteristics of the epitaxial thin film.

In the initial stage of supplying arsenic to the substrate after decomposition, the concentration of impurities increases due to the sputtering (sputtering) phenomenon of As2+ acceptor, and in order to control this, the arsenic supply unit 180 itself further includes a louver and a heating unit for model-based heating for decomposition of arsenic. Also, the arsenic supply unit 180 may further be provided with a storage for storing arsenic.

The driving unit 190 is a structure for driving the substrate mounting unit 130. The driving unit 190 is connected to the substrate mounting unit 130 and is disposed in the reaction chamber 110. Specifically, the driving unit 190 moves the substrate mounting unit 130 in the vertical direction V in a direction gradually away from or gradually toward the bottom of the reaction chamber 110. Further, the driving unit 190 may rotate the substrate mounting unit 130 in the rotation direction R.

Specifically, the driving unit 190 may move the substrate mounting unit 130 up and down by 50-100mm, preferably 80mm, in the vertical direction V. In order to attach a uniform thin film to the substrate W, the driving unit 190 may rotate the substrate mounting unit 130 at a speed of 5to 50rpm, preferably at a speed of 10 rpm. In this case, the driving unit 190 may rotate only the holder, and may actually rotate the entire substrate mounting unit 130.

The heating unit 210 is provided to heat the substrate W, and corresponds to the substrate mounting unit 130. The heating unit 210 may be disposed on the reaction chamber 110 or the driving unit 190, on the inner space 111. The heating unit 210 may be operated at 750 ℃ to 1000 ℃ so that the temperature of the substrate W during film formation may be maintained at 550 ℃ to 800 ℃. In order to uniformly maintain the overall temperature of the substrate W, 1 to 4 heating units 210 may be provided. The heating unit 210 transfers heat to the substrate W by radiation in a vacuum state.

The formation of the single crystalline metal oxide semiconductor layer using the above-mentioned single crystalline metal oxide semiconductor outer film growth apparatus will be described with reference to fig. 2, which is an additional drawing. Fig. 2 is a flowchart illustrating a process of forming a single crystalline metal oxide semiconductor layer using the single crystalline metal oxide semiconductor outer film growth apparatus 100 of fig. 1.

Referring to the drawings (fig. 2 and 1), first, the transfer to the substrate W and the heat treatment are completed (S1). Specifically, the substrate mounting unit 130 on which the substrate W is mounted is put into the pre-vacuum chamber. Here, the exhausting process is performed by the heat treatment process at a temperature of 300 ℃. The heat treatment time is preferably 5to 30 minutes, and the pressure of the pre-vacuum chamber is maintained at 10 to 3 torr. The heat-treated substrate W is transferred to the field of the transfer chamber in an ultra-high vacuum state of 10-8torr and then subjected to an exhaust process for 5-30 minutes.

Thereafter, the substrate W is transferred to the reaction chamber 110 to be thermally processed (S3). Specifically, after the valve connected between the transfer chamber and the reaction chamber 110 is opened, the substrate W is transferred to the reaction chamber 110. The transfer chamber is then separated from the reaction chamber 110 as the valve is closed. The vacuum of the reaction chamber 110 is maintained at 10-8torr, which is the same as that of the transfer chamber. After the heating unit 210 is supplied with power in the reaction chamber 110, the temperature of the substrate W is raised to 600 to 700 c, and then the third evacuation is performed.

The surface treatment of the substrate W is now performed (S5). The surface of the substrate is treated with oxygen plasma, and a very thin oxide film is naturally formed without affecting the deposition of the single-crystal metal oxide on the surface of the substrate W. The substrate processing time using oxygen plasma may be between 10-60 seconds more. In order to remove the organic impurities present on the surface of the substrate W, a process of treating the substrate surface with hydrogen plasma is performed. The time for treating the substrate with the hydrogen plasma is preferably within 30 seconds.

The thin film on the substrate W is grown (S7). The evaporation process of the metal oxide may be performed while the substrate W is rotated at a speed of 5to 50 rpm. In order to prevent a large amount of metal oxide from being evaporated in the initial stage and transferred onto the substrate during evaporation of the metal oxide, the shutter provided on the evaporation source (zinc oxide plate) side blocks the metal oxide gas, and when the biochemical ratio reaches a certain level, the shutter is moved to move the metal oxide gas to the substrate W. At the same time, oxygen radicals generated by plasma dissociation are simultaneously supplied to the substrate W, and a metal oxide layer is formed on the substrate W. To form the p-type metal oxide layer, As2+ was supplied to the substrate, and at this time, after the supply of the metal oxide gas and oxygen radicals was started, the supply of 2-valent arsenic was started.

The film growth end stage (S9). After the formation of the p-type metal oxide thin film having a desired thickness is confirmed by a thickness measuring instrument, the supply of the metal oxide gas, the oxygen radical, and the 2-valent arsenic gas is stopped, and the rotation of the substrate W is stopped.

Thereafter, the surface of the film is treated (S11). In order to grow the single crystalline metal oxide thin film, a heat treatment process at a temperature of 700 ℃ is performed, and the time of the heat treatment is controlled within 10 minutes to 30 minutes, preferably within 30 minutes.

Finally, the substrate is transferred (S13). After the temperature of the substrate W is cooled, the substrate W is moved in the order of the transfer chamber and the pre-vacuum chamber.

The above-described single crystal MOS outer film growth apparatus is not limited to the above-described embodiments. In the embodiments, various modifications can be made by selectively combining some or all of the structures of the above-described embodiments.