Method for forming gallium nitride film

Abstract

The present invention relates to a method for forming a gallium nitride (GaN) film on a substrate, the method comprising the steps of: forming a first gallium nitride film by supplying a gallium precursor and a nitrogen-containing gas onto the substrate; and forming a second gallium nitride film by supplying a gallium precursor and subsequently supplying a nitrogen-containing gas onto the substrate.

Description

gallium nitride film formation method

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

[0002] Typically, to manufacture semiconductor devices, display devices, solar cells, etc., a specific thin film layer, thin film circuit pattern, or optical pattern must be formed on a substrate. To this end, substrate processing processes are performed, such as a deposition process that deposits a thin film of a specific material onto the substrate, a photo process that selectively exposes the thin film using a photosensitive material, and an etching process that removes the thin film in the selectively exposed portion to form a pattern.

[0003] Through this process, a gallium nitride (GaN) film is formed on the substrate. Conventionally, a gallium nitride film was formed on the substrate using chemical vapor deposition (CVD) by supplying a gallium precursor and a nitrogen-containing gas together into the processing space. Consequently, the quality of the gallium nitride film was problematic.

[0004] The present invention has been devised to solve the problems described above, and to provide a method for forming a gallium nitride film capable of improving the film quality of the gallium nitride film.

[0005] In order to solve the above-described problem, the present invention may include the following configuration.

[0006] A method for forming a gallium nitride film according to the present invention is a method for forming a gallium nitride (GaN) film on a substrate, the method including: forming a first gallium nitride film by supplying a gallium precursor and a nitrogen-containing gas on the substrate; and forming a second gallium nitride film by supplying a nitrogen-containing gas after supplying the gallium precursor on the substrate. The step of forming the first gallium nitride film may include supplying the gallium precursor on the substrate in a periodic pulse form and continuously supplying the nitrogen-containing gas.

[0007] A method for forming a gallium nitride film according to the present invention is a method for forming a gallium nitride (GaN) film on a substrate, which may include the steps of forming a first gallium nitride film by supplying a gallium precursor onto the substrate and then supplying a nitrogen-containing gas; and the step of forming a second gallium nitride film by supplying a gallium precursor and a nitrogen-containing gas onto the substrate. The step of forming the second gallium nitride film may include supplying the gallium precursor onto the substrate in a periodic pulse form and continuously supplying the nitrogen-containing gas.

[0008] A method for forming a gallium nitride film according to the present invention is a method for forming a gallium nitride (GaN) film on a substrate, the method including: forming a first gallium nitride film by supplying a gallium precursor and a nitrogen-containing gas on the substrate; and forming a second gallium nitride film by supplying a nitrogen-containing gas after supplying the gallium precursor on the substrate. The step of forming the first gallium nitride film may include continuously supplying the gallium precursor on the substrate and supplying the nitrogen-containing gas in a periodic pulse form.

[0009] According to the present invention, the following effects can be achieved.

[0010] The present invention can be implemented to include a section in which deposition is performed by chemical vapor deposition by supplying both a gallium precursor and a nitrogen-containing gas periodically, and a section in which only one of the gallium precursor and the nitrogen-containing gas is supplied periodically. That is, the present invention can be implemented to include a periodic chemical vapor deposition method. Therefore, compared to forming a gallium nitride film on a substrate by chemical vapor deposition alone, the present invention can improve film quality by suppressing vapor phase reactions and more actively inducing adsorption and surface reactions.

[0011] In addition, the present invention can further improve the film quality of a gallium nitride film by forming a gallium nitride film using both a periodic chemical vapor deposition method and an atomic layer deposition method. Furthermore, compared to forming a gallium nitride film using only an atomic layer deposition method, the present invention can increase the deposition speed of depositing a gallium nitride film on a substrate using a periodic chemical vapor deposition method. Therefore, the present invention can increase the productivity of a substrate on which a gallium nitride film is formed.

[0012] Figure 1 is a schematic diagram of an example of a substrate processing device in which a gallium nitride film forming method according to the present invention is performed.

[0013] Figures 2 and 3 are schematic side cross-sectional views of an injection unit in an example of a substrate processing device in which a gallium nitride film forming method according to the present invention is performed.

[0014] Figure 4 is a schematic flowchart of a method for forming a gallium nitride film according to the present invention.

[0015] Figure 5 is a timing diagram showing the point in time at which gas is injected and plasma is generated in the step of forming the first gallium nitride film in the method for forming a gallium nitride film according to the present invention.

[0016] Figure 6 is a schematic flowchart of a method for forming a gallium nitride film according to the present invention.

[0017] Figure 7 is a schematic flowchart of a method for forming a gallium nitride film according to a modified embodiment of the present invention.

[0018] FIG. 8 is a timing diagram of the time at which gas is injected and plasma is generated in the step of forming a second gallium nitride film in a method for forming a gallium nitride film according to a modified embodiment of the present invention.

[0019] Hereinafter, embodiments of a method for forming a gallium nitride 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.

[0020] Referring to Fig. 1, a method for forming a gallium nitride film according to the present invention is for forming a gallium nitride (GaN) film on a substrate (100). The substrate (100) may be a silicon substrate, a glass substrate, a metal substrate, or the like. The gallium nitride film may be provided in a semiconductor element, a display device, a solar cell, or the like.

[0021] The method for forming a gallium nitride 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 gallium nitride film according to the present invention, an example of the substrate processing device (1) will be specifically examined as follows.

[0022] 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).

[0023] 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 a gallium nitride film 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).

[0024] Referring to Fig. 1, the substrate processing device (1) according to the present invention may include a substrate support unit (3).

[0025] 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).

[0026] Referring to FIGS. 1 to 3, the substrate processing device (1) according to the present invention may include a spraying unit (4).

[0027] 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).

[0028] The above injection unit (4) may include a first gas path (4a) and a second gas path (4b).

[0029] 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).

[0030] 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).

[0031] 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).

[0032] For example, as shown in FIG. 2, the injection unit (4) may include a first plate (41) and a second plate (42).

[0033] 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).

[0034] 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).

[0035] 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).

[0036] 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).

[0037] 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.

[0038] 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.

[0039] 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).

[0040] The method for forming a gallium nitride film according to the present invention can be performed through a substrate processing device (1) like this.

[0041] Referring to FIGS. 1 to 5, the method for forming a gallium nitride film according to the present invention may include a step of forming a first gallium nitride film (S10) and a step of forming a second gallium nitride film (S20).

[0042] The step (S10) of forming the first gallium nitride film may be performed by supplying a gallium precursor and a nitrogen-containing gas onto the substrate (100) to form the first gallium nitride film on the substrate (100). The step (S10) of forming the first gallium nitride film may be performed by supplying the gallium precursor and the nitrogen-containing gas together to the processing space (200). In this case, the gallium precursor and the nitrogen-containing gas may be separately supplied to the processing space (200) and then mixed in the processing space (200). The gallium precursor and the nitrogen-containing gas may be supplied to the processing space (200) after being mixed at least partially. The gallium precursor and the nitrogen-containing gas may be supplied to the processing space (200) by the injection unit (4).

[0043] Meanwhile, the method for forming a gallium nitride film according to the present invention may include a step of forming plasma.

[0044] The step of forming the plasma is to form plasma with a gas including one or more gases selected from the group consisting of hydrogen (H2), nitrogen (N2), oxygen (O2), helium (He), argon (Ar), and germanium (Ge). The step of forming the plasma can be performed by forming plasma using the first plate (41) and the second plate (42).

[0045] The step of forming the plasma may be performed after the step of forming the first gallium nitride film (S10) is performed. Accordingly, the method for forming a gallium nitride film according to the present invention can improve the film quality of the first gallium nitride film by treating with plasma after the first gallium nitride film is formed. In addition, the step of forming the plasma may be performed after the step of forming the second gallium nitride film (S20) is performed. Accordingly, the method for forming a gallium nitride film according to the present invention can improve the film quality of the second gallium nitride film by treating with plasma after the second gallium nitride film is formed.

[0046] The step (S20) of forming the second gallium nitride film may be performed by supplying a nitrogen-containing gas after supplying a gallium precursor onto the substrate (100) to form the second gallium nitride film on the substrate (100). The step (S20) of forming the second gallium nitride film may be performed by first supplying a gallium precursor to the processing space (200), and then supplying a nitrogen-containing gas to the processing space (200) after stopping the supply of the gallium precursor. The gallium precursor and the nitrogen-containing gas may be supplied to the processing space (200) by the injection unit (4).

[0047] The step (S20) of forming the second gallium nitride film can form the second gallium nitride film on the substrate (100) by atomic layer deposition (ALD) by supplying a nitrogen-containing gas after supplying a gallium precursor. Accordingly, compared to the conventional technology of forming a gallium nitride film on the substrate (100) by only chemical vapor deposition, the method of forming a gallium nitride film according to the present invention can further improve the film quality of the gallium nitride film by including the atomic layer deposition method through the step (S20) of forming the second gallium nitride film.

[0048] Here, the step (S20) of forming the first gallium nitride film may be performed by supplying one of the gallium precursor and the nitrogen-containing gas in a periodic pulse form and continuously supplying the other. For example, the step (S20) of forming the first gallium nitride film may be performed by supplying the gallium precursor in a periodic pulse form while continuously supplying the nitrogen-containing gas. In this case, the supply of the gallium precursor and the interruption of the supply of the gallium precursor may be repeatedly performed according to the cycle. For example, the step (S20) of forming the first gallium nitride film may be performed by supplying the nitrogen-containing gas in a periodic pulse form while continuously supplying the gallium precursor. In this case, the supply of the nitrogen-containing gas and the interruption of the supply of the nitrogen-containing gas may be repeatedly performed according to the cycle.

[0049] In this way, the step (S20) of forming the first gallium nitride film can be implemented to include a section in which the gallium precursor and the nitrogen-containing gas are supplied together according to the cycle to perform deposition using the chemical vapor deposition method, and a section in which only one of the gallium precursor and the nitrogen-containing gas is supplied according to the cycle. That is, the step (S20) of forming the first gallium nitride film can form the first gallium nitride film using the cyclic chemical vapor deposition (Cyclic CVD) method. Therefore, compared to the conventional technology of forming a gallium nitride film on the substrate (100) using only the chemical vapor deposition method, the method of forming a gallium nitride film according to the present invention can improve film quality by suppressing the vapor phase reaction and inducing adsorption and surface reactions more actively. In addition, the method for forming a gallium nitride film according to the present invention can further improve the film quality of the gallium nitride film by including the periodic chemical vapor deposition method by the step of forming the first gallium nitride film (S20) and the atomic layer deposition method by the step of forming the second gallium nitride film (S20) to form the gallium nitride film. In addition, compared to a comparative example in which a gallium nitride film is formed only by the atomic layer deposition method, the method for forming a gallium nitride film according to the present invention can increase the deposition speed for depositing the gallium nitride film on the substrate (100) by including the periodic chemical vapor deposition method by the step of forming the first gallium nitride film (S20). Therefore, the method for forming a gallium nitride film according to the present invention can increase the productivity of the substrate (100) on which the gallium nitride film is formed.

[0050] Each of the step of forming the first gallium nitride film (S10) and the step of forming the second gallium nitride film (S20) can be performed by supplying trimethylgallium (TMGa) as a gallium precursor and supplying ammonia (NH3) as a nitrogen-containing gas.

[0051] The step (S10) of forming the first gallium nitride film may be performed by sequentially repeating pulse on (S11) and pulse off (S12) as illustrated in (a) of Fig. 5. Pulse on (S11) may refer to a section in which gas is supplied, and pulse off (S12) may refer to a section in which gas supply is stopped. Meanwhile, the horizontal axis in Fig. 5 may relate to time. The vertical axis in Fig. 5 may relate to supply pressure or supply flow rate in the case of gas, and may relate to whether plasma is formed in the case of plasma.

[0052] In the step (S10) of forming the first gallium nitride film, when the gallium precursor is supplied in a periodic pulse form, the step (S10) of forming the first gallium nitride film can be performed by sequentially repeating pulse-on (S11) for supplying the gallium precursor in a periodic pulse form and pulse-off (S12) for stopping the supply of the gallium precursor, as illustrated in (a) of FIG. 5. In this case, the step (S10) of forming the first gallium nitride film can continuously supply a nitrogen-containing gas, as illustrated in (b) of FIG. Therefore, the step (S10) of forming the first gallium nitride film can form the first gallium nitride film by a cyclic chemical vapor deposition (CVD) method that supplies the gallium precursor in a periodic pulse form.

[0053] In the step (S10) of forming the first gallium nitride film, when the nitrogen-containing gas is supplied in a periodic pulse form, the step (S10) of forming the first gallium nitride film can be performed by sequentially repeating pulse-on (S11) for supplying the nitrogen-containing gas in a periodic pulse form and pulse-off (S12) for stopping the supply of the nitrogen-containing gas, as illustrated in (a) of FIG. 5. In this case, the step (S10) of forming the first gallium nitride film can continuously supply the gallium precursor, as illustrated in (b) of FIG. 5. Therefore, the step (S10) of forming the first gallium nitride film can form the first gallium nitride film by a cyclic chemical vapor deposition (CVD) method that supplies the nitrogen-containing gas in a periodic pulse form.

[0054] The time for which the pulse-off (S12) is performed can be implemented to be longer than the time for which the pulse-on (S11) is performed. Accordingly, the step (S10) for forming the first gallium nitride film can further improve the film quality of the first gallium nitride film by further suppressing the gas phase reaction and more actively inducing adsorption and surface reactions.

[0055] The step (S10) of forming the first gallium nitride film can be performed by continuously forming plasma on the substrate (100). In the step (S10) of forming the first gallium nitride film, the plasma can be formed by the injection unit (4). As shown in (b) of FIG. 5, while continuously supplying one of the gallium precursor and the nitrogen-containing gas and, as shown in (a) of FIG. 5, supplying the other of the gallium precursor and the nitrogen-containing gas in a periodic pulse form, the step (S10) of forming the first gallium nitride film can continuously form plasma as shown in (c) of FIG. 5. Accordingly, the method for forming a gallium nitride film according to the present invention can improve the film quality of the first gallium nitride film by using plasma, and can increase the deposition speed for forming the first gallium nitride film by improving the reactivity.

[0056] The step (S10) of forming the first gallium nitride film may include a step (S13) of forming a first plasma and a step (S14) of forming a second plasma.

[0057] The step (S13) of forming the first plasma may be performed while the pulse-off (S12) is being performed. The step (S13) of forming the first plasma may be performed by forming plasma on the substrate (100). In this case, the plasma may be formed by the injection unit (4).

[0058] The step (S14) of forming the second plasma may be performed by forming plasma on the substrate (100). In this case, the plasma may be formed by the injection unit (4). As illustrated in (d) of Fig. 5, the step (S14) of forming the second plasma may be performed after the step (S13) of forming the first plasma while the pulse-off (S12) is performed. The step (S14) of forming the second plasma may be performed by forming plasma using hydrogen (H2). Accordingly, the step (S10) of forming the first gallium nitride film may further improve the film quality of the first gallium nitride film by removing impurities from the first gallium nitride film through the plasma using hydrogen.

[0059] The step of forming the second plasma (S14) and the step of forming the first plasma (S13) can be performed by forming plasma using different gases on the substrate (100). Accordingly, the step of forming the first gallium nitride film (S10) performs surface treatment using the plasma formed through the step of forming the first plasma (S13) and the plasma formed through the step of forming the second plasma (S14), thereby removing impurities from the first gallium nitride film and improving the density of the first gallium nitride film. For example, the step of forming the first plasma (S13) can form plasma using argon (Ar), and the step of forming the second plasma (S14) can form plasma using hydrogen.

[0060] The method for forming a gallium nitride film according to the present invention may include a step (S30) of continuously supplying an inert gas.

[0061] The step (S30) of continuously supplying the inert gas may be performed by continuously supplying the inert gas onto the substrate (100). The step (S30) of continuously supplying the inert gas may be performed by continuously supplying the inert gas onto the substrate (100) while at least one of the step (S10) of forming the first gallium nitride film and the step (S20) of forming the second gallium nitride film is performed. When the step (S30) of continuously supplying the inert gas is performed while the step (S10) of forming the first gallium nitride film is performed, the step (S30) of continuously supplying the inert gas may be performed by supplying a first flow rate of the inert gas while the pulse-on (S11) is performed and supplying a second flow rate of the inert gas while the pulse-off (S12) is performed. As illustrated in (e) of FIG. 5, the second flow rate may be greater than the first flow rate. Accordingly, the step (S30) of continuously supplying the inert gas can reduce the difference between the pressure of the processing space (200) while the pulse-on (S11) is performed and the pressure of the processing space (200) while the pulse-off (S12) is performed. Therefore, the step (S30) of continuously supplying the inert gas can reduce the pressure change of the processing space (200) while the step (S10) of forming the first gallium nitride film is performed, thereby improving the stability of the process.

[0062] The step (S30) of continuously supplying the above inert gas can be achieved by the injection unit (4) continuously supplying the inert gas to the processing space (200). The inert gas can be argon.

[0063] Here, the method for forming a gallium nitride film according to the present invention can be implemented such that the step (S20) of forming the second gallium nitride film is performed after the step (S10) of forming the first gallium nitride film. Accordingly, the method for forming a gallium nitride film according to the present invention can form the second gallium nitride film by an atomic layer deposition (ALD) method after forming the first gallium nitride film by a cyclic chemical vapor deposition (CVD) method. Therefore, the method for forming a gallium nitride film according to the present invention can form the second gallium nitride film by using only a 100% surface reaction by a self-saturated reaction of an atomic layer deposition (ALD) method after forming the first gallium nitride film by a cyclic chemical vapor deposition (CVD) method, thereby improving the film quality of the gallium nitride film. The method for forming a gallium nitride film according to the present invention can be performed by sequentially repeating the step of forming the first gallium nitride film (S10) and the step of forming the second gallium nitride film (S20).

[0064] In this case, the method for forming a gallium nitride film according to the present invention may include a step (S40) of forming a third gallium nitride film.

[0065] The step (S40) of forming the third gallium nitride film can be performed by supplying a gallium precursor and a nitrogen-containing gas onto the substrate (100) to form the third gallium nitride film on the substrate (100). The step (S40) of forming the third gallium nitride film can be performed by supplying one of the gallium precursor and the nitrogen-containing gas in a periodic pulse form and continuously supplying the other.

[0066] For example, the step (S40) of forming the third gallium nitride film can be performed by supplying the gallium precursor in a periodic pulse form while continuously supplying the nitrogen-containing gas. That is, the supply of the gallium precursor and the interruption of the supply of the gallium precursor can be repeatedly performed according to the cycle. In this case, the step (S10) of forming the first gallium nitride film can be performed by supplying the gallium precursor in a periodic pulse form while continuously supplying the nitrogen-containing gas.

[0067] For example, the step (S40) of forming the third gallium nitride film may be performed by supplying nitrogen-containing gas in a periodic pulse form while continuously supplying the gallium precursor. That is, the supply of nitrogen-containing gas and the interruption of the supply of nitrogen-containing gas may be repeatedly performed according to the cycle.

[0068] In this way, the step (S40) of forming the third gallium nitride film can form the third gallium nitride film using a cyclic chemical vapor deposition (CVD) method. A gallium precursor and a nitrogen-containing gas can be supplied to the processing space (200) by the injection unit (4). The step (S40) of forming the third gallium nitride film can be performed by supplying trimethylgallium (TMGa) as the gallium precursor and supplying ammonia as the nitrogen-containing gas.

[0069] The step (S40) of forming the third gallium nitride film may be performed after the step (S20) of forming the second gallium nitride film. Accordingly, the method for forming a gallium nitride film according to the present invention may form the first gallium nitride film by a cyclic chemical vapor deposition (CVD) method, form the second gallium nitride film by an atomic layer deposition (ALD) method, and form the third gallium nitride film by a cyclic chemical vapor deposition (CVD) method. The method for forming a gallium nitride film according to the present invention may sequentially repeat the step (S10) of forming the first gallium nitride film, the step (S20) of forming the second gallium nitride film, and the step (S40) of forming the third gallium nitride film.

[0070] Referring to FIGS. 1 to 6, the method for forming a gallium nitride film according to the present invention may be implemented such that the step (S10) of forming the first gallium nitride film is performed after the step (S20) of forming the second gallium nitride film. That is, the step (S20) of forming the second gallium nitride film may be performed before the step (S10) of forming the first gallium nitride film. Accordingly, the method for forming a gallium nitride film according to the present invention may form the first gallium nitride film by a cyclic chemical vapor deposition (CVD) method after forming the second gallium nitride film by an atomic layer deposition (ALD) method. Therefore, the method for forming a gallium nitride film according to the present invention forms the first gallium nitride film by forming a seed in atomic layers without being limited to the type or material of the lower film (not shown) formed on the substrate (100) by atomic layer deposition, and then forms the second gallium nitride film at a higher deposition rate than the atomic layer deposition (ALD) method by cyclic chemical vapor deposition (CVD), thereby shortening the process time required to form the gallium nitride film. The method for forming a gallium nitride film according to the present invention can be performed by sequentially repeating the step (S20) of forming the second gallium nitride film and the step (S10) of forming the first gallium nitride film.

[0071] In this case, in the method for forming a gallium nitride film according to the present invention, the step (S40) of forming the third gallium nitride film can be implemented as follows.

[0072] The step (S40) of forming the third gallium nitride film may be performed by supplying a nitrogen-containing gas after supplying a gallium precursor onto the substrate (100) to form the third gallium nitride film on the substrate (100). The step (S40) of forming the third gallium nitride film may be performed by first supplying the gallium precursor to the processing space (200), stopping the supply of the gallium precursor, and then supplying the nitrogen-containing gas to the processing space (200). The gallium precursor and the nitrogen-containing gas may be supplied to the processing space (200) by the injection unit (4). The step (S40) of forming the third gallium nitride film may be performed by supplying trimethylgallium (TMGa) as the gallium precursor and supplying ammonia as the nitrogen-containing gas.

[0073] The step (S40) of forming the third gallium nitride film can form the third gallium nitride film on the substrate (100) by atomic layer deposition (ALD) by supplying a nitrogen-containing gas after supplying a gallium precursor. The step (S40) of forming the third gallium nitride film can be performed after the step (S10) of forming the first gallium nitride film. Accordingly, the method for forming a gallium nitride film according to the present invention can form the third gallium nitride film by atomic layer deposition (ALD) after forming the first gallium nitride film by cyclic chemical vapor deposition (CVD). Therefore, the method for forming a gallium nitride film according to the present invention can improve the film quality of the gallium nitride film by forming the third gallium nitride film using only 100% surface reaction through a self-saturated reaction of the atomic layer deposition (ALD) method after forming the first gallium nitride film by a cyclic chemical vapor deposition (CVD) method. The method for forming a gallium nitride film according to the present invention can be performed by sequentially repeating the step of forming the second gallium nitride film (S20), the step of forming the first gallium nitride film (S10), and the step of forming the third gallium nitride film (S40).

[0074] Hereinafter, an embodiment of a method for forming a gallium nitride film according to a modified embodiment of the present invention will be described in detail with reference to the attached drawings.

[0075] Referring to FIGS. 1 to 3, 7, and 8, a method for forming a gallium nitride film according to a modified embodiment of the present invention may include a step of forming a first gallium nitride film (S50), and a step of forming a second gallium nitride film (S60).

[0076] The step (S50) of forming the first gallium nitride film may be performed by supplying a gallium precursor onto the substrate (100) and then supplying a nitrogen-containing gas to form the first gallium nitride film on the substrate (100). The step (S50) of forming the first gallium nitride film may be performed by first supplying a gallium precursor to the processing space (200), and then supplying a nitrogen-containing gas to the processing space (200) after stopping the supply of the gallium precursor. The gallium precursor and the nitrogen-containing gas may be supplied to the processing space (200) by the injection unit (4).

[0077] The step (S50) of forming the first gallium nitride film can form the first gallium nitride film on the substrate (100) by atomic layer deposition (ALD) by supplying a nitrogen-containing gas after supplying a gallium precursor. Accordingly, compared to the conventional technology of forming a gallium nitride film on the substrate (100) by only chemical vapor deposition, the method of forming a gallium nitride film according to a modified embodiment of the present invention can further improve the film quality of the gallium nitride film by including the atomic layer deposition method through the step (S50) of forming the first gallium nitride film.

[0078] The step (S60) of forming the second gallium nitride film may be performed by supplying a gallium precursor and a nitrogen-containing gas onto the substrate (100) to form the second gallium nitride film on the substrate (100). The step (S60) of forming the second gallium nitride film may be performed by supplying the gallium precursor and the nitrogen-containing gas together to the processing space (200). In this case, the gallium precursor and the nitrogen-containing gas may be separately supplied to the processing space (200) and then mixed in the processing space (200). The gallium precursor and the nitrogen-containing gas may be supplied to the processing space (200) after being mixed at least partially. The gallium precursor and the nitrogen-containing gas may be supplied to the processing space (200) by the injection unit (4).

[0079] The step (S60) of forming the second gallium nitride film may be performed by supplying the gallium precursor in a periodic pulse form and continuously supplying the nitrogen-containing gas. In this case, the step (S60) of forming the second gallium nitride film may be performed by supplying the gallium precursor in a periodic pulse form while continuously supplying the nitrogen-containing gas. In other words, the supply of the gallium precursor and the interruption of the supply of the gallium precursor may be repeatedly performed according to the cycle.

[0080] In this way, the step (S60) of forming the second gallium nitride film can be implemented to include a section in which deposition is performed by chemical vapor deposition by supplying the gallium precursor and the nitrogen-containing gas together according to the cycle, and a section in which only one of the gallium precursor and the nitrogen-containing gas is supplied according to the cycle. That is, the step (S60) of forming the second gallium nitride film can form the second gallium nitride film by cyclic chemical vapor deposition (Cyclic CVD). Therefore, compared to the conventional technology of forming a gallium nitride film on the substrate (100) by only chemical vapor deposition, the method of forming a gallium nitride film according to a modified embodiment of the present invention can improve film quality by suppressing a vapor phase reaction and inducing adsorption and surface reactions more actively. In addition, the method for forming a gallium nitride film according to a modified embodiment of the present invention can further improve the film quality of the gallium nitride film by including the atomic layer deposition method by the step of forming the first gallium nitride film (S50) and the periodic chemical vapor deposition method by the step of forming the second gallium nitride film (S60) to form the gallium nitride film. In addition, compared to a comparative example in which a gallium nitride film is formed only by the atomic layer deposition method, the method for forming a gallium nitride film according to a modified embodiment of the present invention can increase the deposition speed for depositing the gallium nitride film on the substrate (100) by including the periodic chemical vapor deposition method by the step of forming the second gallium nitride film (S60). Therefore, the method for forming a gallium nitride film according to a modified embodiment of the present invention can increase the productivity for the substrate (100) on which the gallium nitride film is formed.

[0081] The step of forming the second gallium nitride film (S60) and the step of forming the first gallium nitride film (S50) can each be performed by supplying trimethylgallium (TMGa) as a gallium precursor and supplying ammonia (NH3) as a nitrogen-containing gas.

[0082] The step (S60) of forming the second gallium nitride film may be performed by sequentially repeating pulse on (S61) and pulse off (S62) as illustrated in (a) of Fig. 8. Pulse on (S61) may refer to a section in which gas is supplied, and pulse off (S62) may refer to a section in which gas supply is stopped. Meanwhile, the horizontal axis in Fig. 8 may relate to time. The vertical axis in Fig. 8 may relate to supply pressure or supply flow rate in the case of gas, and may relate to whether plasma is formed in the case of plasma.

[0083] In the step (S60) of forming the second gallium nitride film, when the gallium precursor is supplied in a periodic pulse form, the step (S60) of forming the second gallium nitride film can be performed by sequentially repeating pulse-on (S61) for supplying the gallium precursor in a periodic pulse form and pulse-off (S62) for stopping the supply of the gallium precursor, as illustrated in (a) of FIG. 8. In this case, the step (S60) of forming the second gallium nitride film can continuously supply a nitrogen-containing gas, as illustrated in (b) of FIG. Therefore, the step (S60) of forming the second gallium nitride film can form the second gallium nitride film by a cyclic chemical vapor deposition (CVD) method that supplies the gallium precursor in a periodic pulse form.

[0084] The time for which the pulse-off (S62) is performed can be implemented to be longer than the time for which the pulse-on (S61) is performed. Accordingly, the step (S60) of forming the second gallium nitride film can further improve the film quality of the second gallium nitride film by further suppressing the gas phase reaction and more actively inducing adsorption and surface reactions.

[0085] The step (S60) of forming the second gallium nitride film can be performed by continuously forming plasma on the substrate (100). In the step (S60) of forming the second gallium nitride film, the plasma can be formed by the injection unit (4). As shown in (b) of FIG. 8, while continuously supplying a nitrogen-containing gas and supplying a gallium precursor in a periodic pulse form as shown in (a) of FIG. 8, the step (S60) of forming the second gallium nitride film can continuously form plasma as shown in (c) of FIG. 8. Accordingly, the method for forming a gallium nitride film according to a modified embodiment of the present invention can improve the film quality of the second gallium nitride film by using plasma, and can increase the deposition speed for forming the second gallium nitride film by improving the reactivity.

[0086] The step of forming the second gallium nitride film (S60) may include a step of forming a first plasma (S63) and a step of forming a second plasma (S64).

[0087] The step (S63) of forming the first plasma may be performed while the pulse-off (S62) is being performed. The step (S63) of forming the first plasma may be performed by forming plasma on the substrate (100). In this case, the plasma may be formed by the injection unit (4).

[0088] The step (S64) of forming the second plasma may be performed by forming plasma on the substrate (100). In this case, the plasma may be formed by the injection unit (4). As illustrated in (d) of Fig. 8, the step (S64) of forming the second plasma may be performed after the step (S63) of forming the first plasma while the pulse-off (S62) is performed. The step (S64) of forming the second plasma may be performed by forming plasma using hydrogen (H2). Accordingly, the step (S60) of forming the second gallium nitride film may further improve the film quality of the second gallium nitride film by removing impurities from the second gallium nitride film through the plasma using hydrogen.

[0089] The step of forming the second plasma (S64) and the step of forming the first plasma (S63) can be performed by forming plasma using different gases on the substrate (100). Accordingly, the step of forming the second gallium nitride film (S60) performs surface treatment using the plasma formed through the step of forming the first plasma (S63) and the plasma formed through the step of forming the second plasma (S64), thereby removing impurities from the second gallium nitride film and improving the density of the second gallium nitride film. For example, the step of forming the first plasma (S63) can form plasma using argon, and the step of forming the second plasma (S64) can form plasma using hydrogen.

[0090] A method for forming a gallium nitride film according to a modified embodiment of the present invention may include a step (S70) of continuously supplying an inert gas.

[0091] The step (S70) of continuously supplying the inert gas may be performed by continuously supplying the inert gas onto the substrate (100). The step (S70) of continuously supplying the inert gas may be performed by continuously supplying the inert gas onto the substrate (100) while at least one of the step (S60) of forming the second gallium nitride film and the step (S50) of forming the first gallium nitride film is performed. When the step (S70) of continuously supplying the inert gas is performed while the step (S60) of forming the second gallium nitride film is performed, the step (S70) of continuously supplying the inert gas may be performed by supplying a first flow rate of the inert gas while the pulse-on (S61) is performed and supplying a second flow rate of the inert gas while the pulse-off (S62) is performed. As illustrated in (e) of FIG. 8, the second flow rate may be greater than the first flow rate. Accordingly, the step (S70) of continuously supplying the inert gas can reduce the difference between the pressure of the processing space (200) while the pulse-on (S61) is performed and the pressure of the processing space (200) while the pulse-off (S62) is performed. Therefore, the step (S70) of continuously supplying the inert gas can reduce the pressure change of the processing space (200) while the step (S60) of forming the second gallium nitride film is performed, thereby improving the stability of the process.

[0092] The step (S70) of continuously supplying the above inert gas can be achieved by the injection unit (4) continuously supplying the inert gas to the processing space (200). The inert gas can be argon.

[0093] The method for forming a gallium nitride film according to a modified embodiment of the present invention may be implemented such that the step of forming the second gallium nitride film (S60) is performed after the step of forming the first gallium nitride film (S50). That is, the step of forming the first gallium nitride film (S50) may be performed before the step of forming the second gallium nitride film (S60). Accordingly, the method for forming a gallium nitride film according to a modified embodiment of the present invention may form the second gallium nitride film by a cyclic chemical vapor deposition (CVD) method after forming the first gallium nitride film by an atomic layer deposition (ALD) method. Therefore, the method for forming a gallium nitride film according to a modified embodiment of the present invention forms a seed in atomic layers without being limited to the type or material of the lower film (not shown) formed on the substrate (100) by atomic layer deposition, forms the second gallium nitride film, and then forms the first gallium nitride film at a higher deposition rate than the atomic layer deposition (ALD) method by cyclic chemical vapor deposition (CVD), thereby shortening the process time required to form the gallium nitride film. The method for forming a gallium nitride film according to a modified embodiment of the present invention can be performed by sequentially repeating the step (S50) of forming the first gallium nitride film and the step (S60) of forming the second gallium nitride film.

[0094] In this case, the method for forming a gallium nitride film according to a modified embodiment of the present invention may be implemented as follows in the step (S80) of forming a third gallium nitride film.

[0095] The step (S80) of forming the third gallium nitride film may be performed by supplying a nitrogen-containing gas after supplying a gallium precursor onto the substrate (100) to form the third gallium nitride film on the substrate (100). The step (S80) of forming the third gallium nitride film may be performed by first supplying the gallium precursor to the processing space (200), stopping the supply of the gallium precursor, and then supplying the nitrogen-containing gas to the processing space (200). The gallium precursor and the nitrogen-containing gas may be supplied to the processing space (200) by the injection unit (4). The step (S80) of forming the third gallium nitride film may be performed by supplying trimethylgallium (TMGa) as the gallium precursor and supplying ammonia as the nitrogen-containing gas.

[0096] The step (S80) of forming the third gallium nitride film can form the third gallium nitride film on the substrate (100) by atomic layer deposition (ALD) by supplying a nitrogen-containing gas after supplying a gallium precursor. The step (S80) of forming the third gallium nitride film can be performed after the step (S60) of forming the second gallium nitride film. Accordingly, the method for forming a gallium nitride film according to the present invention can form the third gallium nitride film by atomic layer deposition (ALD) after forming the second gallium nitride film by cyclic chemical vapor deposition (CVD). Therefore, the method for forming a gallium nitride film according to the present invention can improve the film quality of the gallium nitride film by forming the third gallium nitride film using only 100% surface reaction through a self-saturated reaction of the atomic layer deposition (ALD) method after forming the second gallium nitride film by a cyclic chemical vapor deposition (CVD) method. The method for forming a gallium nitride film according to the present invention can be performed by sequentially repeating the step of forming the first gallium nitride film (S50), the step of forming the second gallium nitride film (S60), and the step of forming the third gallium nitride film (S80).

[0097] 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 gallium nitride (GaN) film on a substrate, A step of forming a first gallium nitride film by supplying a gallium precursor and a nitrogen-containing gas on the substrate; and A step of forming a second gallium nitride film by supplying a nitrogen-containing gas after supplying a gallium precursor on the substrate is included. A method for forming a gallium nitride film, characterized in that the step of forming the first gallium nitride film comprises supplying a gallium precursor onto the substrate in a periodic pulse form and continuously supplying a nitrogen-containing gas.

2. In paragraph 1, After the step of forming the second gallium nitride film, a step of forming a third gallium nitride film is included by supplying a gallium precursor and a nitrogen-containing gas onto the substrate. A method for forming a gallium nitride film, characterized in that the step of forming the third gallium nitride film comprises supplying a gallium precursor onto the substrate in a periodic pulse form and continuously supplying a nitrogen-containing gas.

3. A method for forming a gallium nitride (GaN) film on a substrate, A step of forming a first gallium nitride film by supplying a nitrogen-containing gas after supplying a gallium precursor on the substrate; and A step of forming a second gallium nitride film by supplying a gallium precursor and a nitrogen-containing gas on the substrate, A method for forming a gallium nitride film, characterized in that the step of forming the second gallium nitride film comprises supplying a gallium precursor onto the substrate in a periodic pulse form and continuously supplying a nitrogen-containing gas.

4. In paragraph 3, A method for forming a gallium nitride film, characterized in that the step of forming the second gallium nitride film comprises continuously forming plasma on the substrate.

5. In paragraph 3, A method for forming a gallium nitride film, characterized in that the step of forming the second gallium nitride film sequentially repeats pulse on for supplying a gallium precursor according to a periodic pulse shape and pulse off for stopping the supply of the gallium precursor.

6. In paragraph 5, A method for forming a gallium nitride film, characterized in that the time for which the pulse-off is performed is longer than the time for which the pulse-on is performed.

7. In paragraph 5, The step of forming the second gallium nitride film includes the step of forming a first plasma on the substrate while the pulse-off is performed, and the step of forming a second plasma on the substrate. A method for forming a gallium nitride film, characterized in that the step of forming the second plasma forms plasma using hydrogen.

8. In paragraph 5, Comprising a step of continuously supplying an inert gas onto the above substrate, The step of continuously supplying the above inert gas supplies a first amount of inert gas while the pulse-on is performed, and supplies a second amount of inert gas while the pulse-off is performed. A method for forming a gallium nitride film, characterized in that the second flow rate is greater than the first flow rate.

9. A method for forming a gallium nitride (GaN) film on a substrate, A step of forming a first gallium nitride film by supplying a gallium precursor and a nitrogen-containing gas on the substrate; and A step of forming a second gallium nitride film by supplying a nitrogen-containing gas after supplying a gallium precursor on the substrate is included. A method for forming a gallium nitride film, characterized in that the step of forming the first gallium nitride film comprises continuously supplying a gallium precursor onto the substrate and supplying a nitrogen-containing gas in a periodic pulse form.

10. In paragraph 1 or paragraph 9, A method for forming a gallium nitride film, characterized in that the step of forming the first gallium nitride film sequentially repeats pulse on for supplying nitrogen-containing gas according to a periodic pulse pattern and pulse off for stopping the supply of nitrogen-containing gas.

11. In paragraph 9, A method for forming a gallium nitride film, characterized in that the step of forming the second gallium nitride film is performed before the step of forming the first gallium nitride film.

12. In paragraph 11, A step of forming a third gallium nitride film by supplying a nitrogen-containing gas after supplying a gallium precursor on the substrate is included. A method for forming a gallium nitride film, characterized in that the step of forming the third gallium nitride film is performed after the step of forming the first gallium nitride film.

13. In paragraph 9, A method for forming a gallium nitride film, characterized in that the step of forming the second gallium nitride film is performed after the step of forming the first gallium nitride film.

14. In paragraph 13, After the step of forming the second gallium nitride film, a step of forming a third gallium nitride film is included by supplying a gallium precursor and a nitrogen-containing gas onto the substrate. A method for forming a gallium nitride film, characterized in that the step of forming the third gallium nitride film comprises continuously supplying a gallium precursor onto the substrate and supplying a nitrogen-containing gas in a periodic pulse form.

15. In either paragraph 1 or paragraph 9, A method for forming a gallium nitride film, characterized in that the step of forming the first gallium nitride film comprises continuously forming plasma on the substrate.

16. In paragraph 10, A method for forming a gallium nitride film, characterized in that the time for which the pulse-off is performed is longer than the time for which the pulse-on is performed.

17. In paragraph 10, The step of forming the first gallium nitride film includes the step of forming a first plasma on the substrate while the pulse-off is performed, and the step of forming a second plasma on the substrate. A method for forming a gallium nitride film, characterized in that the step of forming the second plasma forms plasma using hydrogen.

18. In paragraph 10, Comprising a step of continuously supplying an inert gas onto the above substrate, The step of continuously supplying the above inert gas supplies a first amount of inert gas while the pulse-on is performed, and supplies a second amount of inert gas while the pulse-off is performed. A method for forming a gallium nitride film, characterized in that the second flow rate is greater than the first flow rate.

19. In paragraph 1, Comprising a step of forming a plasma with a gas comprising one or more gases selected from the group consisting of hydrogen, nitrogen, oxygen, helium, argon, and germanium; A method for forming a gallium nitride film, characterized in that the step of forming the plasma is performed after the step of forming the first gallium nitride film is performed.

20. In paragraph 3, Comprising a step of forming a plasma with a gas comprising one or more gases selected from the group consisting of hydrogen, nitrogen, oxygen, helium, argon, and germanium; A method for forming a gallium nitride film, characterized in that the step of forming the plasma is performed after the step of forming the second gallium nitride film is performed.

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