Film forming apparatus and film forming method

Abstract

The objective is to provide a film formation apparatus that has excellent in-plane film thickness uniformity and film formation speed, and to which the mist CVD method can be applied. [Solution] A film formation apparatus that forms a film on a substrate by heat-treating a mist, the film formation apparatus comprising: a mist-forming unit that turns a raw material solution into mist to generate the mist; a carrier gas supply unit that supplies a carrier gas that transports the mist; a film formation chamber that has inside it a mounting unit on which a substrate is placed; and at least one pair of supply means that are provided on the side of the film formation chamber and that supply the mist in opposing directions.

Description

[Technical field]

[0001] The present invention relates to a film formation apparatus and a film formation method for forming a film on a substrate using a mist of raw material. [Background technology]

[0002] Previously, high vacuum deposition equipment capable of realizing non-equilibrium conditions, such as pulsed laser deposition (PLD), molecular beam epitaxy (MBE), and sputtering, have been developed, making it possible to produce oxide semiconductors that could not be produced by conventional melt methods. In addition, the mist chemical vapor deposition (Mist CVD) method, which uses atomized mist-like raw materials to grow crystals on a substrate, has been developed, making it possible to produce gallium oxide (α-Ga2O3) with a corundum structure. As a semiconductor with a large band gap, α-Ga2O3 is expected to be applied to next-generation switching elements that can achieve high voltage resistance, low loss, and high heat resistance.

[0003] Regarding the mist CVD method, Patent Document 1 describes a tubular furnace type mist CVD apparatus. Patent Document 2 describes a fine channel type mist CVD apparatus. Patent Document 3 describes a linear source type mist CVD apparatus. Patent Document 4 describes a tubular furnace mist CVD apparatus, which differs from the mist CVD apparatus described in Patent Document 1 in that a carrier gas is introduced into the mist generator. Patent Document 5 describes a mist CVD apparatus in which a substrate is placed above a mist generator, and further a susceptor is a rotating stage mounted on a hot plate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 1-257337 [Patent Document 2] JP 2005-307238 A [Patent Document 3] JP 2012-46772 A [Patent Document 4] Patent No. 5397794 [Patent Document 5] JP 2014-63973 A Summary of the Invention [Problem to be solved by the invention]

[0005] Unlike other CVD methods, the mist CVD method can form a film at a relatively low temperature, and can also produce a metastable crystal structure such as the corundum structure of α-gallium oxide. However, the present inventors have found a new problem that when heating is performed in a film formation chamber to form a film by thermal reaction, the supplied mist exponentially decreases, the film formation rate decreases, and it becomes difficult to maintain the in-plane uniformity of the film thickness. This problem is more pronounced as the diameter of the substrate increases. In response to such problems, the inventions described in Patent Documents 3 and 5 attempt to solve the problem by scanning and rotating the substrate. However, even with these methods, the in-plane uniformity of the film thickness has not been completely resolved. In addition, secondary problems have arisen, such as an increase in the initial cost of the device due to the provision of a driving unit for scanning and rotating in the film formation device, and furthermore, maintenance becomes more complicated.

[0006] The present invention has been made to solve the above problems, and aims to provide a film formation apparatus to which the mist CVD method can be applied, which has excellent in-plane film thickness uniformity and film formation speed, and a film formation method which has excellent uniformity and film formation speed. [Means for solving the problem]

[0007] The present invention has been made to achieve the above-mentioned object, and provides a film formation apparatus which forms a film on a substrate by heat-treating a mist, the film formation apparatus having a mist-forming section which turns a raw material solution into a mist to generate the mist, a carrier gas supply section which supplies a carrier gas for transporting the mist, a film formation chamber having an internal mounting section for mounting a substrate, and at least one pair of supply means which are provided on sides of the film formation chamber and supply the mist in opposing directions.

[0008] According to such a film formation apparatus, it is possible to achieve high in-plane uniformity in film thickness and greatly improve the film formation speed with a simple apparatus configuration.

[0009] In this case, the film formation chamber may have an exhaust port above the placement portion.

[0010] This makes it possible to further improve the in-plane uniformity of the film thickness.

[0011] In this case, the at least one pair of supplying means may be disposed opposite to each other so that the supplied mist collides with each other above the placement portion.

[0012] This makes it possible to increase the concentration of the mist above the substrate, thereby enabling a higher growth rate.

[0013] In this case, the area of ​​the substrate is 100 mm 2 or more, or the diameter of the substrate may be 2 inches (50 mm) or more.

[0014] This makes it possible to obtain higher in-plane uniformity even in the case of a large-area substrate, which is prone to uneven film thickness.

[0015] The present invention also provides a film formation method for forming a film on a substrate by heat-treating a mist, the method including a mist generating step of turning a raw material solution into a mist to generate the mist, a transporting step of transporting the mist by a carrier gas, a mist supplying step of supplying the mist in opposing directions from at least a pair of supply means provided on the sides of a film formation chamber, and a film formation step of heat-treating the supplied mist to form a film on the substrate.

[0016] According to such a film formation method, it is possible to improve the in-plane uniformity of the film thickness and the film formation speed significantly by using a simple method.

[0017] At this time, the deposition chamber can be evacuated through an exhaust port provided in an upper portion of the deposition chamber above the substrate.

[0018] This makes it possible to further improve the in-plane uniformity of the film thickness.

[0019] At this time, in the mist supplying step, the mist can be supplied so as to collide with the upper part of the substrate.

[0020] This makes it possible to increase the concentration of the mist above the substrate, resulting in a higher growth rate.

[0021] At this time, the area of ​​the substrate is 100 mm 2 Or, the diameter of the substrate may be 2 inches (50 mm) or more.

[0022] This allows for higher in-plane uniformity even when using a large-area substrate, which is prone to film thickness non-uniformity. Effect of the Invention

[0023] As described above, the film formation apparatus of the present invention has a simple configuration and can achieve high in-plane uniformity in film thickness and a significant improvement in film formation speed. Also, the film formation method of the present invention has a simple configuration and can achieve high in-plane uniformity in film thickness and a significant improvement in film formation speed. [Brief description of the drawings]

[0024] [Figure 1] 1 is a schematic configuration diagram of a film forming apparatus according to the present invention. [Diagram 2] FIG. 2 is a diagram illustrating an example of a mist generating unit of a film forming apparatus according to the present invention. [Diagram 3] FIG. 2 is a schematic diagram (plan view) showing two pairs of mist supply means according to the present invention. [Figure 4] FIG. 2 is a schematic diagram (plan view) showing four pairs of mist supply means according to the present invention. [Diagram 5] FIG. 4 is a schematic diagram (plan view) showing another example of the mist supply means according to the present invention. [Figure 6] FIG. 11 is a schematic view (plan view) showing still another example of the mist supply means according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The present invention will be described in detail below, but the present invention is not limited thereto.

[0026] As described above, in the mist CVD method, there has been a demand for a film formation apparatus that is excellent in in-plane film thickness uniformity and film formation speed, and a film formation method that is excellent in in-plane film thickness uniformity and film formation speed.

[0027] As a result of extensive investigation into the above-mentioned problems, the inventors have discovered that a film formation apparatus for forming a film on a substrate by heat-treating a mist has excellent in-plane film thickness uniformity and film formation speed, the film formation apparatus having a mist-forming section that generates the mist by turning a raw material solution into a mist, a carrier gas supply section that supplies a carrier gas for transporting the mist, a film formation chamber having an internal mounting section for mounting a substrate, and at least one pair of supply means that are provided on sides of the film formation chamber and supply the mist in opposing directions, and have thus completed the present invention.

[0028] The inventors also discovered that a film formation method for forming a film on a substrate by heat-treating a mist includes a mist generating step of turning a raw material solution into a mist to generate the mist, a transporting step of transporting the mist by a carrier gas, a mist supplying step of supplying the mist in opposing directions from at least one pair of supply means provided on the side of a film formation chamber, and a film formation step of heat-treating the supplied mist to form a film on the substrate, thereby improving the in-plane uniformity of the film thickness and increasing the film formation speed, and completed the present invention.

[0029] The following description will be given with reference to the drawings.

[0030] Here, the term "mist" as used in the present invention refers to a general term for fine particles of liquid dispersed in a gas, and includes what are called fog, droplets, and the like.

[0031] 1 shows an example of a film forming apparatus 101 according to the present invention. The film forming apparatus 101 includes a mist generating section 120 that generates mist by misting a raw material solution, a carrier gas supplying section 130 that supplies a carrier gas for transporting the mist, at least a pair of supplying means 111 that are provided on the side of the film forming chamber 107 and supply the mist in opposing directions, and the film forming chamber 107 that heat-treats the supplied mist to form a film on a substrate. An exhaust port 112 may be provided above a mounting section 113 on which a substrate 110 is mounted.

[0032] (Mist generating section) In the mist generating section 120, the raw solution is adjusted and the raw solution is turned into mist to generate mist. The mist generating means is not particularly limited as long as it can turn the raw solution into mist, and any known mist generating means may be used, but it is preferable to use a mist generating means using ultrasonic vibrations, as this allows for more stable mist generation.

[0033] An example of such a mist generating unit 120 will be described with reference to FIG. 2. For example, the mist generating unit 120 may include a mist generating source 104 in which the raw solution 104a is stored, a medium capable of transmitting ultrasonic vibration, for example, a container 105 in which water 105a is stored, and an ultrasonic vibrator 106 attached to the bottom surface of the container 105. In detail, the mist generating source 104, which is a container in which the raw solution 104a is stored, is stored in the container 105 in which the water 105a is stored, using a support (not shown). The bottom of the container 105 is provided with an ultrasonic vibrator 106, which is connected to an oscillator 116. When the oscillator 116 is operated, the ultrasonic vibrator 106 vibrates, and ultrasonic waves are propagated into the mist generating source 104 via the water 105a, turning the raw solution 104a into mist.

[0034] (Carrier gas supply unit) 1, the carrier gas supply unit 130 has a carrier gas source 102a for supplying a carrier gas. In this case, a flow rate control valve 103a for adjusting the flow rate of the carrier gas sent from the carrier gas source 102a may be provided. In addition, a dilution carrier gas source 102b for supplying a dilution carrier gas as required, and a flow rate control valve 103b for adjusting the flow rate of the dilution carrier gas sent from the dilution carrier gas source 102b may also be provided.

[0035] The type of carrier gas is not particularly limited and can be appropriately selected depending on the film to be formed. For example, oxygen, ozone, inert gas such as nitrogen or argon, or reducing gas such as hydrogen gas or forming gas can be used. The type of carrier gas may be one type or two or more types. For example, a dilution gas obtained by diluting the same gas as the first carrier gas with another gas (e.g., diluted 10 times) may be used as the second carrier gas, or air may be used. Furthermore, the number of supply points of the carrier gas is not limited to one, and may be two or more. The flow rate of the carrier gas is not particularly limited. For example, when forming a film on a 30 mm square substrate, the flow rate is preferably 0.01 to 20 L / min, and more preferably 1 to 10 L / min.

[0036] (supply pipe) The film forming apparatus 101 may include a supply pipe 109 that connects the mist generating section 120 and the supply means 111. In this case, the mist is transported by a carrier gas from the mist generating source 104 of the mist generating section 120 to the supply means 111 via the supply pipe 109, and is supplied from the supply means 111 into the film forming chamber 107. The supply pipe 109 may be, for example, a quartz tube or a resin tube.

[0037] (Film forming chamber) In the film formation chamber 107, the mist is heated to cause a thermal reaction, thereby forming a film on the substrate 110. The substrate 110 is placed on a placement portion 113 in the film formation chamber 107. The placement portion 113 may be equipped with a hot plate 108 for heating the substrate 110. The hot plate 108 may be provided outside the film formation chamber 107 as shown in FIG. 1, or may be provided inside the film formation chamber 107. The mist supply means 111 is provided on the side surface of the film forming chamber 107. The supply means 111 will be described in detail later. Moreover, the exhaust port 112 is preferably provided above the placement portion 113 (substrate 110) in the upper portion of the film formation chamber 107. This further improves the uniformity of the film thickness.

[0038] Here, Fig. 3-6 is a view (plan view) of the film formation chamber 107 viewed from above toward the substrate 110. In Fig. 3-6, the film formation chambers 107 are all depicted as rectangular parallelepipeds, but they do not necessarily have to be rectangular parallelepipeds, and may be hexagonal prisms, octagonal prisms, or cylindrical. The substrate 110 may be placed on an upper surface of the film formation chamber 107 in a face-down position, or may be placed on a bottom surface of the film formation chamber 107 in a face-up position.

[0039] The thermal reaction is not particularly limited as long as the mist reacts by heating. The reaction conditions can be appropriately set according to the raw material and the film to be formed. For example, the heating temperature can be in the range of 120 to 600°C, preferably in the range of 200°C to 600°C, and more preferably in the range of 300°C to 550°C. The thermal reaction may be carried out under any of the following atmospheres: vacuum, non-oxygen atmosphere, reducing gas atmosphere, air atmosphere, and oxygen atmosphere, and may be appropriately set depending on the film to be formed. The reaction pressure may be under any of atmospheric pressure, pressurized pressure, and reduced pressure, but film formation under atmospheric pressure is preferred because the apparatus configuration can be simplified.

[0040] (supply means) As described above, the mist supply means 111 is provided on the side surface of the film formation chamber 107, and is at least a pair of supply means that supply mist in opposite directions. Fig. 1 shows an example in which a pair of supply means 111 is provided on the left and right sides of a mounting portion 113 (substrate 110) therebetween. Here, "opposite directions" means that, when the substrate 110 is viewed from above the film formation chamber 107, the mist supply direction of one of the pair of supply means is opposite to the mist supply direction of the other of the pair of supply means. In this case, the pair of supply means in the opposite directions is not limited to being completely coaxially opposed to each other. Also, although the supply directions are completely opposite to each other, the axes of the supply directions may be eccentric to each other. Here, when one supply direction is set as the reference 0°, the other supply direction may not only be 180°, but may be within the range of 180°±10°.

[0041] It is also preferable that the mist supply direction when the film formation chamber 107 is viewed from the side is approximately parallel to the substrate surface, and the height of the supply means 111 on the side surface of the film formation chamber 107 is approximately the same height as the substrate surface. In this way, a flow in a direction parallel to the surface of the substrate 110 can be created, which results in improved in-plane film thickness uniformity and higher film formation speed. The supply means 111 may be an opening provided on the side surface of the film formation chamber 107 or a nozzle provided on the side surface of the film formation chamber 107 and inserted into the film formation chamber 107 .

[0042] Fig. 3 shows an example in which two pairs of openings 111a, 111b are provided on either side of a mounting portion 113 (substrate 110) as a mist supply means, and Fig. 4 shows an example in which four pairs of openings 111a, 111b, 111c, 111d are provided. In the figures, the mist supply direction 114 is indicated by a dashed arrow (the same applies to Figs. 5 and 6 described below).

[0043] The upper limit of the number of pairs of supply means 111 is not particularly limited, but may be set appropriately by comparing the size of the substrate, the effect of increasing the number of pairs in improving the in-plane film thickness uniformity and the growth rate, costs, ease of maintenance, etc., and the upper limit can be set to about 8 pairs.

[0044] 3-4, the openings (111a, 111b, 111c, 111d) are arranged such that one of the pair of supply means is located on an extension line of the mist supply direction 114 of the other supply means. In this case, the mist supplied to the film formation chamber 107 collides with the upper part of the substrate 110, and it becomes possible to introduce high-density mist over a wide area on the substrate 110. As a result, the in-plane distribution of the film thickness can be further improved, and the film formation speed can be increased.

[0045] In addition, the "at least one pair of supply means" in the present invention includes, in addition to the examples shown in Fig. 3-4, a positional relationship in which one supply means is provided at a position offset from an extension line of the mist supply direction 114 of the other supply means. For example, as shown in Fig. 5, openings 111a and 111b as supply means may be provided so as to be close to one side of the side surface of the film formation chamber 107. By using such a supply means, the mist concentration on the substrate 110 can be made uniform, improving the in-plane uniformity of the film thickness and increasing the film formation speed.

[0046] Furthermore, the shape of the opening of the supply means may be a large opening supply port 111e, for example, slit-shaped, as shown in FIG.

[0047] As described above in detail, when the supply means is only one opening (nozzle), the inside of the film formation chamber 107 is heated, so the mist exponentially decreases from the side of the film formation chamber 107 toward the inside. On the other hand, when at least one pair of supply means that supply mist in opposing directions provided on the side of the film formation chamber 107 are used, the flow (speed) of the mist is offset on the substrate 110, and as a result, it becomes possible to introduce high-density mist over a wide area on the substrate. This allows a film to be formed on the substrate with a uniform thickness and at a high film formation speed.

[0048] (Raw material solution) The raw material solution is not particularly limited as long as it contains a material that can be turned into mist, and may be an inorganic material or an organic material. A metal or a metal compound is preferably used, and one or more metals selected from gallium, iron, indium, aluminum, vanadium, titanium, chromium, rhodium, nickel, and cobalt can be used. The raw material solution is not particularly limited as long as it can turn the metal into mist, but the raw material solution can be suitably used in which the metal is dissolved or dispersed in an organic solvent or water in the form of a complex or salt. Examples of the complex include acetylacetonate complexes, carbonyl complexes, ammine complexes, and hydride complexes. Examples of the salt include metal chlorides, metal bromides, and metal iodides. In addition, the metals can be dissolved in hydrobromic acid, hydrochloric acid, hydroiodic acid, or the like to be used as an aqueous salt solution.

[0049] The raw material solution may be mixed with additives such as hydrohalic acid and oxidizing agents. Examples of the hydrohalic acid include hydrobromic acid, hydrochloric acid, and hydroiodic acid, with hydrobromic acid and hydroiodic acid being preferred. Examples of the oxidizing agent include peroxides such as hydrogen peroxide (H2O2), sodium peroxide (Na2O2), barium peroxide (BaO2), and benzoyl peroxide (C6H5CO)2O2, hypochlorous acid (HClO), perchloric acid, nitric acid, ozone water, and organic peroxides such as peracetic acid and nitrobenzene.

[0050] Furthermore, the raw material solution may contain a dopant. The dopant is not particularly limited. For example, n-type dopants such as tin, germanium, silicon, titanium, zirconium, vanadium, or niobium, or p-type dopants such as copper, silver, tin, iridium, or rhodium, may be used. The concentration of the dopant may be, for example, about 1×10 16 / cm 3 ~1×10 22 / cm 3 may be about 1 x 10 17 / cm 3 Even at low concentrations below 1×10 20 / cm 3 A concentration higher than this may be used.

[0051] (substrate) The substrate 110 is not particularly limited as long as it can form a film and can support the film. The material of the substrate 110 is also not particularly limited, and a known substrate can be used, and may be an organic compound or an inorganic compound. Examples of the substrate include polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyimide, polyetherimide, fluororesin, metals such as iron, aluminum, stainless steel, and gold, silicon, sapphire, quartz, glass, and gallium oxide, but are not limited thereto. The thickness of the substrate is not particularly limited, but is preferably 10 to 2000 μm, and more preferably 50 to 800 μm. The size of the substrate 110 is not particularly limited, but the larger the area, the more likely the film thickness is to become non-uniform, and therefore the effect of the present invention becomes more pronounced. 2 The above are preferably used, and substrates having a diameter of 2 to 8 inches (50 to 200 mm) or more can also be used.

[0052] Next, an example of the production method according to the present invention will be described below with reference to FIG. First, the raw solution 104a is accommodated in the mist generating source 104, and the substrate 110 is placed on the hot plate 108 directly or through the wall of the film forming chamber 107, and the hot plate 108 is operated. Next, the flow rate control valves 103a and 103b are opened to supply carrier gas from the carrier gas sources 102a and 102b into the film forming chamber 107, and the atmosphere in the film forming chamber 107 is sufficiently replaced with the carrier gas, and then the flow rate of the carrier gas and the flow rate of the dilution carrier gas are adjusted. Next, as a mist generating step, the ultrasonic vibrator 106 is vibrated, and the vibration is propagated to the raw solution 104a through the water 105a, thereby misting the raw solution 104a to generate mist. Next, as a transport step, the mist is transported by the carrier gas through the supply pipe 109 to at least one pair of supply means 111 that are provided on the side of the film forming chamber 107 and supply the mist in opposite directions. Next, in a mist supplying step, the mist is introduced into the film forming chamber 107 from the at least one pair of supply means 111. Furthermore, in a film forming step, the mist is thermally reacted with the heat of the hot plate 108 in the film forming chamber 107 to form a film on the substrate 110. Here, the gas in the film forming chamber 107 may be exhausted to the outside from an exhaust port 112 provided above the substrate 110. By supplying the mist in this manner, the mist introduced into the film forming chamber 107 becomes dense over a wide area on the substrate 110, so that the in-plane distribution of the film thickness can be improved and the film forming speed can be increased. EXAMPLES

[0053] The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

[0054] Example 1 First, a film forming apparatus 101 used in this embodiment will be described with reference to Fig. 1. The film forming apparatus 101 includes a carrier gas source 102a for supplying a carrier gas, a flow rate control valve 103a for controlling the flow rate of the carrier gas sent from the carrier gas source 102a, a dilution carrier gas source 102b for supplying a dilution carrier gas, a flow rate control valve 103b for controlling the flow rate of the dilution carrier gas sent from the dilution carrier gas source 102b, a mist generating source 104 containing a raw material solution 104a, a container 105 containing water 105a, an ultrasonic vibrator 106 attached to the bottom surface of the container 105, a film forming chamber 107, a supply pipe 109 of a quartz pipe connecting the mist generating source 104 to the film forming chamber 107, and a hot plate 108 provided outside the film forming chamber 107. A substrate 110 is placed on a placement portion 113 in the film forming chamber 107 and heated by the hot plate 108.

[0055] In this embodiment, a film formation apparatus was used as the supply means 111, which has a pair of openings at a position approximately at the same height as the surface of the substrate 110 on the side of the film formation chamber 107 so as to form a flow approximately parallel to the surface of the substrate 110, and an exhaust port 112 at the top of the film formation chamber 107, above the mounting portion 113.

[0056] The film formation was carried out as follows. First, a raw material solution was prepared by preparing an aqueous solution of 0.1 mol / L gallium bromide, and adding 48% hydrobromic acid solution to the aqueous solution so that the volume ratio of the aqueous solution was 10%. This was used as raw material solution 104a.

[0057] The raw material solution 104a obtained as described above was contained in the mist generating source 104. Next, a c-plane sapphire substrate having a diameter of 8 inches (200 mm) was placed as the substrate 110 on a placement portion 113 adjacent to the hot plate 108 in the film formation chamber 107, and the hot plate 108 was operated to raise the temperature to 500°C. Next, the flow rate control valves 103a and 103b were opened to supply carrier gas from the carrier gas sources 102a and 102b into the film formation chamber 107, and the atmosphere in the film formation chamber 107 was sufficiently replaced with the carrier gas, after which the flow rate of the carrier gas was adjusted to 20 L / min and the flow rate of the dilution carrier gas was adjusted to 60 L / min. Note that oxygen was used as the carrier gas.

[0058] Next, the ultrasonic vibrator 106 was vibrated at 2.4 MHz, and the vibration was propagated to the raw material solution 104a through the water 105a, thereby misting the raw material solution 104a to generate mist. This mist was introduced into the film formation chamber 107 through the supply pipe 109 by the carrier gas. Then, the mist was thermally reacted in the film formation chamber 107 under atmospheric pressure and at 500°C to form a thin film of gallium oxide (α-Ga2O3) having a corundum structure on the substrate 110. The film formation time was 30 minutes.

[0059] The film thickness of the thin film formed on the substrate 110 was measured at 17 points on the surface of the substrate 110 using a step gauge, and the average film thickness, film formation rate, and standard deviation were calculated. As a result, the average film thickness was 5.2 μm, the film formation rate was 10.4 μm / hr, and the standard deviation was 0.4 μm.

[0060] Example 2 Film formation was carried out under the same conditions as in Example 1, except that, as the supply means 111, two pairs of openings 111a, 111b were provided on the side surface of the film formation chamber 107 as shown in FIG. As a result, the average film thickness was 5.4 μm, the film formation rate was 10.8 μm / hr, and the standard deviation was 0.2 μm.

[0061] (Comparative Example) Film formation was carried out under the same conditions as in Example 1, except that the supply means used was a supply port provided at only one location on the side surface of the film formation chamber. As a result, the average film thickness was 3.5 μm, the film formation rate was 7.0 μm / hr, and the standard deviation was 0.9 μm.

[0062] The results of Examples 1 and 2 and the Comparative Example are summarized in Table 1.

[0063] [Table 1]

[0064] Comparing Examples 1 and 2 with the Comparative Example, it was found that by providing one or two pairs of supply means for supplying mist in opposing directions on the side of the film-forming chamber, the standard deviation of the film thickness was greatly improved, and the in-plane distribution of the film thickness was dramatically improved. In addition, the average film thickness was also larger in Examples 1 and 2, which showed that the film-forming speed could be increased and the utilization efficiency of the raw materials was improved.

[0065] The present invention is not limited to the above-described embodiment. The above-described embodiment is merely an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included in the technical scope of the present invention. [Explanation of symbols]

[0066] 101...film forming apparatus, 102a...carrier gas source, 102b...dilution carrier gas source; 103a...flow rate control valve; 103b...flow rate control valve, 104...mist source, 104a...raw material solution, 105...container, 105a...water, 106...ultrasonic transducer, 107...film formation chamber, 108...hot plate; 109...supply pipe; 110...substrate; 111...supply means, 111a, 111b, 111c, 111d, 111e...opening, 112 ... exhaust port, 113 ... placement portion, 114 ... mist supply direction, 116 ... oscillator, 120... mist generating section, 130... carrier gas supply section.

Claims

1. A film forming apparatus for forming a film on a substrate by heat-treating a mist, a mist generating unit that generates mist by misting the raw material solution; A carrier gas supply unit that supplies a carrier gas that carries the mist; a deposition chamber having a mounting portion for mounting a substrate thereon; the deposition chamber has an exhaust port having an area smaller than a deposition surface of the substrate above the placement portion, a supply means for supplying the mist from the side of the substrate placement part so as to form a flow substantially parallel to the film formation surface of the substrate, collide with the substrate above the substrate placement part, and then head toward the exhaust port, the supply means being provided on a side surface of the film formation chamber; The film forming apparatus is characterized in that the supplying means comprises at least a pair of means arranged opposite to each other so that the supplied mist collides with each other above the placement part.

2. 2. The film forming apparatus according to claim 1, wherein the exhaust port is provided approximately above the center of the film forming surface of the substrate.

3. A film forming apparatus for forming a gallium oxide film on a substrate by heat-treating a mist, a mist generating unit that generates mist by misting the raw material solution; A carrier gas supply unit that supplies a carrier gas that carries the mist; a film formation chamber having a mounting portion for mounting a substrate thereon; The mist supply device includes at least one pair of supply means that are provided on a side surface of the film formation chamber and supply the mist in opposite directions, A film forming apparatus characterized in that the mist supply direction of the at least one pair of supply means is a direction approximately parallel to the substrate surface, and / or the at least one pair of supply means is provided at approximately the same height as the substrate surface.

4. 4. The film forming apparatus according to claim 3, wherein the film forming chamber has an exhaust port above the placement portion.

5. 5. The film forming apparatus according to claim 3, wherein the at least one pair of supplying means are disposed opposite each other so that the supplied mist collides with each other above the placement portion.

6. The area of ​​the substrate is 100 mm ２ 6. The film forming apparatus according to claim 1, wherein the diameter of the substrate is 2 inches (50 mm) or more.

7. A film forming method for forming a film on a substrate by heat-treating a mist, comprising the steps of: a mist generating step of misting the raw material solution to generate mist; a transport step of transporting the mist by a carrier gas; a mist supplying step of supplying the mist from a supplying means provided on a side surface of the film formation chamber from a side of the substrate so as to form a flow substantially parallel to the film formation surface of the substrate and collide with the substrate above the substrate; a film forming process for forming a film on the substrate by heat-treating the supplied mist, The mist after the heat treatment is exhausted from an exhaust port provided above the substrate, the exhaust port having an area smaller than the film formation surface of the substrate; The film forming method, wherein the supplying means is at least a pair of supplying means that supply the mist in opposite directions.

8. A film forming method for forming a film on a substrate by heat-treating a mist, comprising the steps of: a mist generating step of misting the raw material solution to generate mist; a transport step of transporting the mist by a carrier gas; a mist supplying step of supplying the mist in opposite directions from at least one pair of supply means provided on a side surface of the film forming chamber; and a film formation process for forming a gallium oxide film on the substrate by heat-treating the supplied mist, A film forming method, characterized in that the mist supply direction of the at least one pair of supply means is a direction approximately parallel to the substrate surface, and / or the height of the at least one pair of supply means is approximately the same as the height of the substrate surface.

9. 9. The film forming method according to claim 8, wherein the film forming chamber is evacuated through an exhaust port provided in an upper portion of the film forming chamber above the substrate.

10. 10. The film forming method according to claim 8, wherein in the mist supplying step, the mist is supplied so as to collide with an upper portion of the substrate.

11. 11. The method according to claim 7, wherein the mist undergoes a thermal reaction during the heat treatment in the film-forming step, and a film is formed by the thermal reaction.

12. 8. The method according to claim 7, wherein a gallium oxide film is formed in the film forming step.

13. The area of ​​the substrate is 100 mm ２ 13. The film forming method according to claim 8, wherein the diameter of the substrate is 2 inches (50 mm) or more.

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