Method for forming metal oxide film

Abstract

The present invention relates to a method for forming a metal oxide film, the method comprising the steps of: preparing a substrate; (i) supplying a precursor comprising indium onto the substrate; (ii) supplying a precursor comprising silicon onto the substrate; (iii) supplying a gas comprising oxygen onto the substrate; and (iv) repeating steps (i) and (ii) N times (N is a natural number).

Description

Metal oxide film formation method

[0001] The present invention relates to a method for forming a metal oxide film for forming a metal oxide film on a substrate.

[0002] Oxide semiconductors are semiconductors made of metal oxides. They can be deposited on substrates and implemented as oxide semiconductor thin films during the manufacturing process of electronic devices such as display devices and solar cells.

[0003] For example, an oxide semiconductor thin film composed of indium (In), gallium (Ga), zinc (Zn), and oxygen (O) can be formed as a channel layer of a thin film transistor (TFT) of an electronic device. The channel layer can be formed between a gate insulating film and a source / drain electrode of the thin film transistor. The channel layer can include a metal oxide film containing indium.

[0004] In this metal oxide film, indium and oxygen combine with low dissociation energy. Accordingly, in the process of forming the metal oxide film, the number of oxygen defects in the metal oxide film increases due to surrounding layers such as a gate insulating film, electrode layer, and protective layer arranged around the metal oxide film. Accordingly, the metal oxide film shifts in the direction of lowering the threshold voltage (Vth), and an off-state leakage current is generated. In addition, the metal oxide film deteriorates during subsequent processes such as heat treatment and plasma treatment due to its unstable amorphous structure. In this way, the metal oxide film has a problem of lowering the electrical characteristics and reliability of the thin film transistor because indium and oxygen combine with low dissociation energy.

[0005] The present invention has been devised to solve the above-described needs, and to provide a method for forming a metal oxide film capable of increasing the dissociation energy for bonding between indium and oxygen.

[0006] In order to solve the above-described problem, the present invention may include the following configuration.

[0007] The method for forming a metal oxide film according to the present invention may be a method for forming a metal oxide film containing indium. The method for forming a metal oxide film according to the present invention may include the steps of: preparing a substrate; (i) supplying a precursor containing indium onto the substrate; (ii) supplying a precursor containing silicon onto the substrate; (iii) supplying a gas containing oxygen onto the substrate; and (iv) repeating steps (i) and (ii) N times (N is a natural number).

[0008] The method for forming a metal oxide film according to the present invention may be a method for forming a metal oxide film containing indium, gallium, and zinc. The metal oxide film may include a metal oxide film containing indium. The metal oxide film containing indium may be formed through the steps of: preparing a substrate; (i) supplying a precursor containing indium onto the substrate; (ii) supplying a precursor containing silicon onto the substrate; (iii) supplying a gas containing oxygen onto the substrate; and (iv) repeating steps (i) and (ii) N times (N is a natural number).

[0009] The method for forming a metal oxide film according to the present invention may be a method for forming a metal oxide film containing indium. The method for forming a metal oxide film according to the present invention may include the steps of: preparing a substrate; (i) supplying a precursor containing indium, a precursor containing silicon, and a gas containing oxygen together onto the substrate; and (ii) repeating step (i) N times (N is a natural number).

[0010] The method for forming a metal oxide film according to the present invention may be a method for forming a metal oxide film containing indium, gallium, and zinc. The metal oxide film may include a metal oxide film containing indium. The metal oxide film containing indium may be formed through the steps of: (i) preparing a substrate; (ii) supplying a precursor containing indium, a precursor containing silicon, and a gas containing oxygen together onto the substrate; and (iii) repeating step (i) N times (N is a natural number).

[0011] According to the present invention, the following effects can be achieved.

[0012] The present invention is implemented to increase the low dissociation energy of the bond between indium and oxygen by utilizing the high dissociation energy of the bond between silicon and oxygen. Accordingly, the present invention can suppress an increase in the number of oxygen defects in the metal oxide film, thereby reducing the degree of shift toward lowering the threshold voltage (Vth) of the metal oxide film and reducing the amount of leakage current generated in the off state.

[0013] The present invention can stabilize the amorphous structure of a metal oxide film using a metal oxide film containing silicon-doped indium. Accordingly, the present invention can prevent deterioration of the metal oxide film during subsequent processes such as heat treatment and plasma treatment.

[0014] Figure 1 is a schematic diagram showing an example of a substrate processing device in which a metal oxide film forming method according to the present invention is performed.

[0015] Figures 2 and 3 are schematic side cross-sectional views of an injection unit that injects gas in an example of a substrate processing device in which a metal oxide film forming method according to the present invention is performed.

[0016] Figure 4 is a schematic cross-sectional view showing an example of a thin film transistor having a channel layer.

[0017] Figures 5 to 7 are schematic flowcharts of a method for forming a metal oxide film according to the present invention.

[0018] Hereinafter, embodiments of a method for forming a metal oxide film according to the present invention will be described in detail with reference to the attached drawings. When describing embodiments of the present invention, it is described that a structure is formed "on" or "below" another structure, such description should be interpreted to include not only cases where the structures are in contact with each other, but also cases where a third structure is interposed between the structures.

[0019] Referring to FIGS. 1 to 5, a method for forming a metal oxide film according to the present invention is for forming a metal oxide film on a substrate (100). The substrate (100) may be a silicon substrate, a glass substrate, a metal substrate, etc. The method for forming a metal oxide film according to the present invention can form a metal oxide film containing indium (In) on the substrate (100). The method for forming a metal oxide film according to the present invention can also form a metal oxide film containing indium (In), gallium (Ga), and zinc (Zn) on the substrate (100). In this case, the metal oxide film may include a metal oxide film containing indium. The metal oxide film may be provided in a thin film transistor (TFT) of an electronic device such as a display device or a solar cell. The metal oxide film may constitute a channel layer (110) of the thin film transistor. The channel layer (110) may be formed between the gate insulating film (120) and the source / drain electrodes (130, 140). The source electrode (130) and the drain electrode (140) may be formed spaced apart from each other on the channel layer (110). A gate electrode (150) may be formed between the gate insulating film (120) and the substrate (100).

[0020] The method for forming a metal oxide film according to the present invention can be performed by a substrate processing device (1). Before explaining an embodiment of the method for forming a metal oxide film according to the present invention, an example of the substrate processing device (1) will be specifically examined as follows.

[0021] Referring to FIGS. 1 to 3, the substrate processing device (1) may include a chamber (2), a substrate support unit (3), and an injection unit (4).

[0022] Referring to Fig. 1, the chamber (2) provides a processing space (200). In the processing space (200), a processing process for the substrate (100) can be performed. The processing process may be forming the channel layer (110) on the substrate (100). The processing space (200) can be arranged inside the chamber (2). An exhaust port (not shown) for exhausting gas or the like from the processing space (200) can be coupled to the chamber (2). The substrate support unit (3) and the injection unit (4) can be arranged inside the chamber (2).

[0023] Referring to Fig. 1, the substrate processing device (1) according to the present invention may include a substrate support unit (3).

[0024] The substrate support member (3) above supports the substrate (100). The substrate support member (3) may support one substrate (100) or may support multiple substrates (100). When multiple substrates (100) are supported by the substrate support member (3), processing processes for multiple substrates (100) can be performed at once. The substrate support member (3) may be coupled to the chamber (2). The substrate support member (3) may be placed inside the chamber (2).

[0025] Referring to FIGS. 1 to 3, the substrate processing device (1) according to the present invention may include a spraying unit (4).

[0026] The above-described injection unit (4) injects gas toward the substrate support unit (3). The injection unit (4) may be disposed inside the chamber (2). The injection unit (4) may be disposed opposite the substrate support unit (3). The injection unit (4) may be disposed above the substrate support unit (3). The processing space (200) may be disposed between the injection unit (4) and the substrate support unit (3). The injection unit (4) may be coupled to a lid (not shown). The lid may be coupled to the chamber (2) so as to cover the upper portion of the chamber (2).

[0027] The above injection unit (4) may include a first gas path (4a) and a second gas path (4b).

[0028] The first gas path (4a) is for injecting the first gas. The first gas path (4a) may be connected to the processing space (200). Accordingly, the first gas may flow along the first gas path (4a) and then be injected into the processing space (200) through the first gas path (4a). The first gas path (4a) may function as a path for the first gas to flow and may also function as an injection port for injecting the first gas into the processing space (200).

[0029] The second gas path (4b) is for injecting the second gas. The second gas and the first gas may be different gases. For example, when the first gas is a source gas, the second gas may be a reactant gas. The second gas path (4b) may be connected to the processing space (200). Accordingly, the second gas may flow along the second gas path (4b) and then be injected into the processing space (200) through the second gas path (4b). The second gas path (4b) may function as a path for the second gas to flow and also as an injection port for injecting the second gas into the processing space (200).

[0030] The second gas path (4b) and the first gas path (4a) may be arranged to be spatially separated from each other. Accordingly, the second gas supplied to the second gas path (4b) may be injected into the processing space (200) without passing through the first gas path (4a). The first gas supplied to the first gas path (4a) may be injected into the processing space (200) without passing through the second gas path (4b). The second gas path (4b) and the first gas path (4a) may inject gases toward different parts of the processing space (200).

[0031] For example, as shown in FIG. 2, the injection unit (4) may include a first plate (41) and a second plate (42).

[0032] The first plate (41) is disposed on the upper side of the second plate (42). The first plate (41) and the second plate (42) may be disposed spaced apart from each other. A plurality of first gas holes (411) may be formed in the first plate (41). Each of the first gas holes (411) may function as a passage for the first gas to flow. The first gas holes (411) may belong to the first gas path (4a). A plurality of second gas holes (412) may be formed in the first plate (41). Each of the second gas holes (412) may function as a passage for the second gas to flow. The second gas holes (412) may belong to the second gas path (4b). A plurality of protruding members (413) may be combined with the first plate (41). The protruding members (413) may protrude from the lower surface of the first plate (41) toward the second plate (42). Each of the first gas holes (411) may be formed by penetrating the first plate (41) and the protruding members (413).

[0033] A plurality of openings (421) may be formed in the second plate (42). The openings (421) may be formed by penetrating the second plate (42). The openings (421) may be arranged at positions corresponding to the respective protruding members (413). As illustrated in FIG. 2, the protruding members (413) may be formed to have a length such that they are inserted into each of the openings (421). Although not illustrated, the protruding members (413) may also be formed to have a length such that they are arranged above each of the openings (421). The protruding members (413) may also be formed to have a length that protrudes downward from the second plate (42). The second gas holes (412) may be arranged to inject gas toward the upper surface of the second plate (42). Although not shown, the lower surface of the first plate (41) may be formed flat without the protruding member (413).

[0034] For example, as illustrated in FIG. 3, a plurality of first openings (422) and a plurality of second openings (423) may be formed in the second plate (42).

[0035] The first openings (422) may be formed by penetrating the second plate (42). The second openings (423) may be formed by penetrating the second plate (42). The second plate (42) and the first plate (41) may be arranged to be spaced apart from each other. The lower surface of the first plate (41) facing the second plate (42) may be formed flat without the protruding member (413, illustrated in FIG. 2). The first gas and the second gas may be supplied to the space between the first plate (41) and the second plate (42) through the first gas holes (411) and the second gas holes (412), and then sprayed into the processing space (200) through the first openings (422) and the second openings (423). In this case, when the supply of the first gas through the first gas holes (411) and the supply of the second gas through the second gas holes (412) are performed simultaneously, the first gas and the second gas can be mixed in the space between the first plate (41) and the second plate (42) and then sprayed into the processing space (200) through the first openings (422) and the second openings (423).

[0036] Meanwhile, the first openings (422) may be arranged vertically below each of the first gas holes (411). In this case, the first openings (422) and the first gas holes (411) may be arranged on the same vertical line. Although not shown, the first openings (422) and the first gas holes (411) may be arranged at staggered positions. In this case, the first openings (422) and the first gas holes (411) may be arranged at positions where they do not overlap each other, or may be arranged at positions where they only partially overlap each other.

[0037] Meanwhile, the second openings (423) may be arranged vertically below each of the second gas holes (412). In this case, the second openings (423) and the second gas holes (412) may be arranged on the same vertical line. Although not shown, the second openings (423) and the second gas holes (412) may be arranged at staggered positions. In this case, the second openings (423) and the second gas holes (412) may be arranged at positions where they do not overlap each other, or may be arranged at positions where they only partially overlap each other.

[0038] Meanwhile, the injection unit (4) can form plasma using the second plate (42) and the first plate (41). In this case, plasma power, such as RF power, may be applied to the first plate (41), and the second plate (42) may be grounded. The first plate (41) may be grounded, and plasma power may be applied to the second plate (42).

[0039] The method for forming a metal oxide film according to the present invention can be performed through a substrate processing device (1) like this.

[0040] Referring to FIGS. 1 to 5, the method for forming a metal oxide film according to the present invention may include the following steps.

[0041] First, a substrate (100) is prepared (S10). This substrate preparation step (S10) can be performed by placing the substrate (100) on the substrate support member (3). The substrate (100) may have the gate insulating film (120) or the source / drain electrodes (130, 140) of the thin film transistor exposed. In this case, the gate insulating film (120) may be formed on the substrate (100) without the source / drain electrodes (130, 140). The gate insulating film (120) and the source / drain electrodes (130, 140) may also be formed on the substrate (100). In this case, the source electrode (130) and the drain electrode (140) may be spaced apart from each other. The above substrate (100) can be brought into the chamber (2) by a transport robot (not shown) and placed on the substrate support member (3).

[0042] Next, the metal oxide film is formed on the substrate (100). This metal oxide film formation step may be performed after the substrate preparation step (S10) is performed. The metal oxide film formation step may be performed by having the injection unit (4) inject a precursor, gas, etc. for forming the metal oxide film toward the substrate (100) while the substrate (100) is secured to the substrate support member (3).

[0043] The above metal oxide film formation step may include an indium oxide film formation step (S20).

[0044] The indium oxide film forming step (S20) may be performed by forming a metal oxide film containing indium on the substrate (100). The indium oxide film forming step (S20) may be performed by the spray unit (4) supplying a precursor containing indium, a gas containing oxygen, etc. toward the substrate (100). The spray unit (4) may supply a gas containing oxygen after supplying the precursor containing indium. In this case, the indium oxide film forming step (S20) may form the metal oxide film containing indium on the substrate (100) by an atomic layer deposition (ALD) method. The spray unit (4) may also supply the precursor containing indium and the gas containing oxygen together. In this case, the indium oxide film forming step (S30) may form the metal oxide film containing indium on the substrate (100) by a chemical vapor deposition (CVD) method.

[0045] Referring to FIGS. 1 to 5, the indium oxide film formation step (S20) may include an indium supply step (S21), a silicon supply step (S22), an oxygen supply step (S23), and a N-times repetition step (S24).

[0046] The above indium supply step (S21) can be performed by supplying a precursor containing indium onto the substrate (100). The above indium supply step (S21) can be performed by the injection unit (4) supplying a precursor containing indium toward the substrate (100).

[0047] The above silicon supply step (S22) can be performed by supplying a precursor containing silicon (Si) onto the substrate (100). The above silicon supply step (S22) can be performed by the injection unit (4) supplying a precursor containing silicon toward the substrate (100).

[0048] The oxygen supply step (S23) may be performed by supplying a gas containing oxygen onto the substrate (100). The oxygen supply step (S23) may be performed by supplying the gas containing oxygen toward the substrate (100) through the injection unit (4). Through the oxygen supply step (S23), a thin film layer containing indium, a thin film layer containing silicon, and a gas containing oxygen may react with each other to form a metal oxide film containing indium on the substrate (100). Accordingly, the indium oxide film forming step (S20) may be implemented to form the metal oxide film containing indium on the substrate (100) by an atomic layer deposition method.

[0049] The above N-time repetition step (S24) can be performed by repeating the indium supply step (S21) and the silicon supply step (S22) N times (N is a natural number). After the indium supply step (S21) and the silicon supply step (S22) are performed N times repeatedly, the oxygen supply step (S23) can be performed. Accordingly, the metal oxide film forming method according to the present invention can form a metal oxide film including indium doped with silicon on the substrate (100). Therefore, the metal oxide film forming method according to the present invention can achieve the following operational effects.

[0050] The method for forming a metal oxide film according to the present invention is implemented so that, since silicon and oxygen combine with relatively high dissociation energy, the high dissociation energy for the bond between silicon and oxygen increases the low dissociation energy for the bond between indium and oxygen. Accordingly, the method for forming a metal oxide film according to the present invention can suppress an increase in the number of oxygen defects in the metal oxide film due to the oxygen scavenging effect at the interface between the metal oxide film and the surrounding layer. Therefore, the method for forming a metal oxide film according to the present invention can reduce the degree to which the threshold voltage (Vth) of the metal oxide film shifts toward lowering, and can reduce the amount of off-state leakage current. For example, when the metal oxide film forming method according to the present invention forms the channel layer (110), the metal oxide film forming method according to the present invention can suppress an increase in the number of oxygen defects in the channel layer (110) due to oxygen reduction power at the boundary between the channel layer (110) and a surrounding layer, such as a gate insulating film, an electrode layer, a protective layer, etc., arranged around the channel layer (110). Therefore, the metal oxide film forming method according to the present invention can reduce the degree to which the threshold voltage of the channel layer (110) shifts in the direction of lowering, and can reduce the amount of leakage current generated in the off state.

[0051] The method for forming a metal oxide film according to the present invention can stabilize the amorphous structure of the metal oxide film by using a metal oxide film including indium doped with silicon. Accordingly, the method for forming a metal oxide film according to the present invention can prevent the occurrence of a deterioration phenomenon in the metal oxide film, etc. during a subsequent process such as heat treatment, plasma treatment, etc. For example, when the method for forming a metal oxide film according to the present invention forms the channel layer (110), the method for forming a metal oxide film according to the present invention is implemented to form the channel layer (110) by using a metal oxide film including indium doped with silicon, thereby stabilizing the amorphous structure of the channel layer (110). Accordingly, the method for forming a metal oxide film according to the present invention can prevent the occurrence of a deterioration phenomenon in the channel layer (110), etc. during a subsequent process such as heat treatment, plasma treatment, etc.

[0052] In this way, the method for forming a metal oxide film according to the present invention can suppress an increase in oxygen defects in the metal oxide film and a deterioration phenomenon in the subsequent process, and thus can contribute to improving the electrical characteristics and reliability of a thin film transistor.

[0053] Meanwhile, in the indium oxide film forming step (S20), the precursor containing indium and the precursor containing silicon can be individually supplied toward the substrate (100) without being mixed with each other. Accordingly, the indium oxide film forming step (S20) is implemented so as to form a metal oxide film containing indium doped with silicon using a nano lamination method. Therefore, the metal oxide film forming method according to the present invention can improve the film quality of the metal oxide film containing indium doped with silicon, and thus can contribute to further improving the electrical characteristics and reliability of the thin film transistor.

[0054] Referring to FIGS. 1 to 6, the indium oxide film formation step (S20) may include a coflow supply step (S25) and the N-times repetition step (S24).

[0055] The co-flow supply step (S25) may be performed by supplying a precursor containing indium, a precursor containing silicon, and a gas containing oxygen together onto the substrate (100). In this case, the co-flow supply step (S25) may be performed by the injection unit (4) supplying a mixed fluid containing a precursor containing indium, a precursor containing silicon, and a gas containing oxygen toward the substrate (100). Accordingly, the indium oxide film forming step (S20) may be implemented to form a metal oxide film containing indium doped with silicon on the substrate (100) by a chemical vapor deposition method.

[0056] Accordingly, the method for forming a metal oxide film according to the present invention is implemented to increase the low dissociation energy for the bond between indium and oxygen by utilizing the high dissociation energy for the bond between silicon and oxygen. Accordingly, the method for forming a metal oxide film according to the present invention can reduce the degree of shift toward lowering the threshold voltage (Vth) of the metal oxide film by suppressing an increase in the number of oxygen defects in the metal oxide film, and can reduce the amount of leakage current generated in the off state. In addition, the method for forming a metal oxide film according to the present invention can stabilize the amorphous structure of the metal oxide film by using the metal oxide film including indium doped with silicon, and thus can prevent the occurrence of a deterioration phenomenon during the course of a subsequent process. Therefore, the method for forming a metal oxide film according to the present invention can suppress an increase in oxygen defects in the metal oxide film and the occurrence of a deterioration phenomenon during the subsequent process, and thus can contribute to improving the electrical characteristics and reliability of a thin film transistor.

[0057] Meanwhile, the indium oxide film forming step (S20) can be performed by supplying a precursor containing indium, a precursor containing silicon, and a gas containing oxygen in a mixed state toward the substrate (100). Accordingly, the indium oxide film forming step (S20) is implemented so as to form a metal oxide film containing indium doped with silicon in a co-flow manner. Therefore, the metal oxide film forming method according to the present invention can shorten the time required to form a metal oxide film containing indium doped with silicon, and thus can contribute to increasing the productivity of a thin film transistor having a metal oxide film.

[0058] The above N-time repetition step (S24) can be performed by repeating the above coflow supply step (S25) N times. Accordingly, the metal oxide film formation method according to the present invention can form a metal oxide film containing indium doped with silicon on the substrate (100) to a thickness desired by the user.

[0059] Referring to FIGS. 1 to 7, the metal oxide film forming step may further include a gallium oxide film forming step (S30) and a zinc oxide film forming step (S40).

[0060] The gallium oxide film forming step (S30) may be performed by forming an oxide film containing gallium on the substrate (100). The gallium oxide film forming step (S30) may be performed by the spray unit (4) supplying a precursor containing gallium, a gas containing oxygen, etc. toward the substrate (100). The spray unit (4) may supply a gas containing oxygen after supplying a precursor containing gallium. In this case, the gallium oxide film forming step (S30) may form the oxide film containing gallium on the substrate (100) by an atomic layer deposition (ALD) method. The spray unit (4) may also supply the precursor containing gallium and the gas containing oxygen together. In this case, the gallium oxide film forming step (S30) may form the oxide film containing gallium on the substrate (100) by a chemical vapor deposition (CVD) method.

[0061] The zinc oxide film forming step (S40) may be performed by forming an oxide film containing zinc on the substrate (100). The zinc oxide film forming step (S40) may be performed by the spray unit (4) supplying a precursor containing zinc, a gas containing oxygen, etc. toward the substrate (100). The spray unit (4) may supply a gas containing oxygen after supplying a precursor containing zinc. In this case, the zinc oxide film forming step (S40) may form the oxide film containing zinc on the substrate (100) by an atomic layer deposition (ALD) method. The spray unit (4) may also supply the precursor containing zinc and the gas containing oxygen together. In this case, the zinc oxide film forming step (S40) may form the oxide film containing zinc on the substrate (100) by a chemical vapor deposition (CVD) method.

[0062] The method for forming a metal oxide film according to the present invention may further include a repeating step M times (S50).

[0063] The above M repetition step (S50) can be performed by repeating the indium oxide film forming step (S20), the gallium oxide film forming step (S30), and the zinc oxide film forming step (S40) M times (M is a natural number).

[0064] Accordingly, the method for forming a metal oxide film according to the present invention is implemented to form the metal oxide film by individually and repeatedly forming the metal oxide film including the indium, the oxide film including the gallium, and the oxide film including the zinc on the substrate (S), thereby improving the overall film quality of the metal oxide film. Therefore, the method for forming a metal oxide film according to the present invention can improve the performance of the metal oxide film through the improvement of the film quality, thereby contributing to improving the performance of the thin film transistor. In addition, the method for forming a metal oxide film according to the present invention is implemented to individually and repeatedly form the metal oxide film including the indium, the oxide film including the gallium, and the oxide film including the zinc on the substrate (S), thereby improving the accuracy and ease of the task of adjusting the composition ratio between indium, gallium, and zinc to correspond to the type, specifications, etc. of the thin film transistor. Therefore, the method for forming a metal oxide film according to the present invention can improve the responsiveness to changes in the type and specifications of thin film transistors, and can improve the versatility of forming a metal oxide film applicable to various thin film transistors.

[0065] The metal oxide film forming step may be performed after the indium oxide film forming step (S20), and the gallium oxide film forming step (S30) may be performed after the gallium oxide film forming step (S30), and the zinc oxide film forming step (S40) may be performed after the gallium oxide film forming step (S30). In this case, the M repetition step (S50) may be performed by repeating the indium oxide film forming step (S20), the gallium oxide film forming step (S30), and the zinc oxide film forming step (S40) in that order M times.

[0066] The metal oxide film forming step may be performed after the zinc oxide film forming step (S40), and the indium oxide film forming step (S20) may be performed after the indium oxide film forming step (S20), and the gallium oxide film forming step (S30) may be performed after the indium oxide film forming step (S20). In this case, the M repetition step (S50) may be performed by repeating the zinc oxide film forming step (S40), the indium oxide film forming step (S20), and the gallium oxide film forming step (S30) in that order M times.

[0067] The metal oxide film forming step may be performed after the gallium oxide film forming step (S30), and the zinc oxide film forming step (S40) may be performed after the zinc oxide film forming step (S40). In this case, the M repetition step (S50) may be performed by repeating the gallium oxide film forming step (S30), the zinc oxide film forming step (S40), and the indium oxide film forming step (S20) in that order M times.

[0068] The present invention described above is not limited to the above-described embodiments and the attached drawings, and it will be apparent to a person skilled in the art to which the present invention pertains that various substitutions, modifications, and changes are possible within a scope that does not depart from the technical spirit of the present invention.

Claims

1. A method for forming a metal oxide film containing indium, Steps to prepare the substrate; (i) a step of supplying a precursor containing indium onto the substrate; (ii) a step of supplying a precursor containing silicon onto the substrate; (iii) a step of supplying a gas containing oxygen onto the substrate; and (iv) a step of repeating steps (i) and (ii) N times (N is a natural number); A method for forming a metal oxide film, characterized by including:

2. A method for forming a metal oxide film containing indium, gallium, and zinc, The above metal oxide film includes a metal oxide film containing indium, The metal oxide film containing the above indium is Steps to prepare the substrate; (i) a step of supplying a precursor containing indium onto the substrate; (ii) a step of supplying a precursor containing silicon onto the substrate; (iii) a step of supplying a gas containing oxygen onto the substrate; and (iv) a step of repeating steps (i) and (ii) N times (N is a natural number); A method for forming a metal oxide film, characterized in that it is formed through .

3. In paragraph 1 or 2, A method for forming a metal oxide film, characterized in that the metal oxide film constitutes a channel layer of a thin film transistor.

4. In paragraph 1 or 2, A method for forming a metal oxide film, characterized in that the above substrate exposes the gate insulating film or source / drain electrode of the thin film transistor.

5. In paragraph 2, It includes a step of forming an oxide film containing gallium on the substrate, and a step of forming an oxide film containing zinc on the substrate, A method for forming a metal oxide film, characterized in that the above steps (i), (ii), (iii), and (iv) constitute steps for forming a metal oxide film containing indium on the substrate.

6. In paragraph 5, A method for forming a metal oxide film, characterized in that it comprises a step of repeating the step of forming a metal oxide film containing indium, the step of forming an oxide film containing gallium, and the step of forming an oxide film containing zinc M times (M is a natural number).

7. A method for forming a metal oxide film containing indium, Steps to prepare the substrate; (i) a step of supplying a precursor containing indium, a precursor containing silicon, and a gas containing oxygen together onto the substrate; and (ii) a step of repeating the above step (i) N times (N is a natural number); A method for forming a metal oxide film, characterized by including:

8. A method for forming a metal oxide film containing indium, gallium, and zinc, The above metal oxide film includes a metal oxide film containing indium, The metal oxide film containing the above indium is Steps to prepare the substrate; (i) a step of supplying a precursor containing indium, a precursor containing silicon, and a gas containing oxygen together onto the substrate; and (ii) a step of repeating the above step (i) N times (N is a natural number); A method for forming a metal oxide film, characterized in that it is formed through .

9. In paragraph 8, It includes a step of forming an oxide film containing gallium on the substrate, and a step of forming an oxide film containing zinc on the substrate, A method for forming a metal oxide film, characterized in that the above steps (i), (ii), (iii), and (iv) constitute steps for forming a metal oxide film containing indium on the substrate.

10. In paragraph 8, A method for forming a metal oxide film, characterized in that it comprises a step of repeating the step of forming a metal oxide film containing indium, the step of forming an oxide film containing gallium, and the step of forming an oxide film containing zinc M times (M is a natural number).

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