Silicon oxide film formation method

Abstract

The present invention relates to a silicon oxide film formation method and, more specifically, to a silicon oxide film formation method for forming a silicon oxide film on a substrate. The silicon oxide film formation method according to an embodiment of the present invention comprises the steps of: (a) spraying a silicon-containing gas onto a substrate; (b) forming first plasma on the substrate by using a first gas; and (c) spraying an oxygen-containing gas onto the substrate, wherein a process cycle including steps (a) to (c) is repeatedly performed.

Description

Method for forming a silicon oxide film

[0001] The present invention relates to a method for forming a silicon oxide film, and more specifically, to a method for forming a silicon oxide film on a substrate.

[0002] As the integration density of semiconductor devices improves, the line widths and spacing of the elements constituting the semiconductor devices are becoming increasingly fine. For example, the width and spacing of the metal wiring constituting the semiconductor devices are becoming increasingly fine, and the width and spacing of the device isolation layer are also becoming increasingly fine. Accordingly, to form the device isolation layer, Shallow Trench Isolation (STI) technology is mainly used, which involves forming a pattern, such as a narrow and deep trench, on a semiconductor substrate and then gap-filling it with an insulating material, instead of the conventional Local Oxidation Silicon (LOCOS) process.

[0003] In the gap-fill process for forming device isolation layers, such as between trenches or metal wiring, insulating films must be deposited sequentially starting from the bottom surface of the trench to ensure the trench is completely gap-filled. However, due to the overhang phenomenon caused by the simultaneous deposition of insulating films on the entrance and sidewalls as well as the bottom surface of the trench, the top of the trench becomes blocked before it is completely gap-filled, resulting in the formation of voids inside the trench. These voids occur more frequently as the aspect ratio of the trench increases and also cause a degradation of device characteristics. Therefore, suppressing the occurrence of voids is one of the important process goals in the trench gap-fill process.

[0004] (Prior Art Literature)

[0005] Korean Patent Publication No. 10-2009-0001229

[0006] The present invention provides a silicon oxide film forming method and a substrate processing apparatus capable of performing effective gap filling by forming a silicon oxide film on a substrate.

[0007] A method for forming a silicon oxide film according to an embodiment of the present invention is a method for forming a silicon oxide film on a substrate, comprising: (a) a step of spraying a silicon-containing gas onto the substrate; (b) a step of forming a first plasma with a first gas onto the substrate; and (c) a step of spraying an oxygen-containing gas onto the substrate; and repeating a process cycle including steps (a) to (c).

[0008] The first gas may include one or more of nitrogen, nitrous oxide, aluminum, zirconium, hafnium, lanthanum, barium, titanium, argon, helium, germanium, and hydrogen gases.

[0009] After step (c) above, the method may further include step (d) forming a second plasma with a second gas on the substrate.

[0010] The second gas may include one or more of nitrogen, nitrous oxide, aluminum, zirconium, hafnium, lanthanum, barium, titanium, argon, helium, germanium, and hydrogen gas.

[0011] The above oxygen-containing gas may include one or more of oxygen, ozone, and carbon dioxide.

[0012] After step (a) or after step (b), the step of pumping the inside of the chamber where the substrate is provided may be further included.

[0013] It may further include a step of supplying purge gas into the chamber before, after, or both before and after the step of pumping the chamber.

[0014] After step (c) or after step (d), the step of pumping the inside of the chamber where the substrate is provided may be further included.

[0015] It may further include a step of supplying purge gas into the chamber before, after, or both before and after the step of pumping the chamber.

[0016] According to an embodiment of the present invention, by forming a plasma on a substrate between the step of spraying a silicon-containing gas onto a substrate and the step of spraying an oxygen-containing gas, the impurity content can be minimized and a thin film having a desired profile can be formed.

[0017] In addition, by improving the characteristics of the silicon oxide film, the performance of a semiconductor device containing it can be significantly improved.

[0018] FIG. 1 is a schematic diagram showing a substrate processing apparatus according to an embodiment of the present invention.

[0019] FIG. 2 is a drawing showing a substrate support portion of a substrate processing device according to an embodiment of the present invention.

[0020] FIG. 3 is a diagram schematically illustrating a method for forming a silicon insulating film according to an embodiment of the present invention.

[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms, and the embodiments of the present invention are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention.

[0022] Throughout the specification, when it is mentioned that one component, such as a layer, film, region, or substrate, is located "on" another component, it may be interpreted that the one component is in direct contact "on" the other component, or that other components may exist interposed between them.

[0023] Additionally, relative terms such as "upper" or "lower" may be used herein to describe the relative relationship of certain elements to other elements as illustrated in the drawings. Relative terms may be understood as intended to include other directions of the element in addition to the directions depicted in the drawings. To illustrate the invention in detail, the drawings may be exaggerated, and like reference numerals in the drawings refer to like elements.

[0024]

[0025] FIG. 1 is a schematic diagram showing a substrate processing apparatus according to an embodiment of the present invention, and FIG. 2 is a diagram showing a substrate support portion of a substrate processing apparatus according to an embodiment of the present invention.

[0026] Referring to FIG. 1, a substrate processing device according to an embodiment of the present invention is a device for forming a thin film, for example, a silicon oxide film, on a substrate (S), and comprises a chamber (10), a substrate support member (20) provided within the chamber (10) and for supporting a substrate (S) provided within the chamber (10), a gas injection member (30) provided within the chamber (10) so as to be positioned opposite to the substrate support member (20) and for injecting process gas toward the substrate support member (20), and a gas supply member (40) for providing gas to the gas injection member (30). In addition, the substrate processing device may further include a power supply member (50) for applying power to generate plasma within the chamber (10) and a control member (not shown) for controlling the power supply member (50). Here, a first gas supply path and a second gas supply path are formed separately in the gas injection member (30).

[0027] The chamber (10) provides a predetermined reaction space and maintains it airtight. The chamber (10) may include a body (12) having a predetermined reaction space, comprising a planar portion that is approximately circular or square and a side wall portion that extends upward from the planar portion, and a cover (14) positioned on the body (12) in an approximately circular or square shape to maintain the reaction space airtight. However, the chamber (10) is not limited thereto and may be manufactured in various shapes.

[0028] An exhaust port (not shown) is formed in a predetermined area on the lower surface of the chamber (10), and an exhaust pipe (not shown) connected to the exhaust port may be provided on the outer side of the chamber (10). Additionally, the exhaust pipe may be connected to an exhaust device (not shown). A vacuum pump, such as a turbo molecular pump, may be used as the exhaust device. Accordingly, the inside of the chamber (10) can be vacuum-suctioned to a predetermined reduced pressure atmosphere, for example, to a predetermined pressure of 0.1 mTorr or less, by the exhaust device. The exhaust pipe may be installed not only on the lower surface of the chamber (10) but also on the side of the chamber (10) below the substrate support (20) described later. Furthermore, it is obvious that multiple exhaust pipes and corresponding exhaust devices may be installed to reduce the exhaust time.

[0029] Meanwhile, a substrate (S) provided into the chamber (10) for a substrate processing process can be placed on the substrate support member (20). Here, the substrate (S) may include a silicon wafer, etc., and a pattern, for example, a narrow and deep trench, may be formed on the substrate (S). To allow such a substrate (S) to be placed and supported, the substrate support member (20) may be provided, for example, with an electrostatic chuck, to adsorb and hold the substrate (S) by electrostatic force, or it may support the substrate (S) by vacuum adsorption or mechanical force.

[0030] The substrate support member (20) may be provided in a shape corresponding to the shape of the substrate (S), for example, a circular or square shape. The substrate support member (20) may include a substrate support (22) on which the substrate (S) is placed, and an elevator (24) disposed below the substrate support (22) to move the substrate support (22) up and down. Here, the upper surface of the substrate support (22) forms a support surface on which the substrate (S) is supported. Meanwhile, the elevator (24) is provided to support at least one area of ​​the substrate support (22), for example, the center, and when the substrate (S) is placed on the substrate support (22), the substrate support (22) can be moved to be close to the gas injection unit (30). In addition, a heater (not shown) may be installed inside the substrate support (22). The heater generates heat at a predetermined temperature to heat the substrate support (22) and the substrate (S) placed on the substrate support (22), thereby allowing a thin film to be uniformly deposited on the substrate (S).

[0031] Such a substrate support member (20) can support at least one substrate (S) provided into the chamber (10). That is, the substrate support member (20) may support one substrate (S) or may support multiple substrates (S) as shown in FIG. 2. For example, the substrate support member (20) may support six substrates (S). In this case, the substrate support member (20) may have a central region (20a) and an outer region (20b) positioned outside the central region (20a), and the substrate support member (20) may support multiple substrates (S) in the outer region (20b). At this time, the outer region (20b) may be positioned to surround the central region (20a). Accordingly, the central region (20a) may be positioned inside the outer region (20b). For example, if the central region (20a) is formed in a circular shape, the outer region (20b) may be formed in a circular ring shape surrounding the central region (20a). Here, a plurality of substrates (S) may be arranged spaced apart from each other along the outer region (20b). For example, a plurality of substrates (S) may be supported on a support surface in the outer region (20b) so as to be spaced apart from each other at the same angle with respect to the central axis (C) of the substrate support (22). During the processing process, the substrate support (22) may be rotated around the central axis (C). If the support surface is formed in a circular shape, the central axis (C) may correspond to the center of the support surface. Meanwhile, since a plurality of substrates (S) are supported on the support surface in the outer region (20b), a substrate (S) may not be located in the central region (20a).

[0032] The gas supply unit (40) may be installed, at least partially, outside the chamber (10) and supplies gas to the gas injection unit (30). The gas supply unit (40) may include a first gas supply unit (42) and a second gas supply unit (44). The first gas supply unit (42) and the second gas supply unit (44) may be connected to each type of gas storage unit (not shown) to supply gas required for the process to the reaction space through the gas injection unit (30), and may be configured with piping connecting the gas storage unit and the gas injection unit (30) to deliver the gas provided from the gas storage unit to the gas injection unit (30).

[0033] For example, the source gas may be supplied to the reaction space through the first gas supply unit (42), and the reactant gas may be supplied to the reaction space through the second gas supply unit (44). However, this is not limited thereto, and conversely, the source gas may be supplied to the reaction space through the first gas supply unit (42), and the reactant gas may be supplied to the reaction space through the second gas supply unit (44). Additionally, at least one of the first gas supply unit (42) and the second gas supply unit (44) may supply gas for plasma treating the substrate (S). For example, the plasma treatment gas may be supplied to the reaction space through the second gas supply unit (44), but this is not limited thereto, and the plasma treatment gas may be supplied to the reaction space through the first gas supply unit (42), or supplied to the reaction space through the first gas supply unit (42) and the second gas supply unit (44). Additionally, at least one of the first gas supply unit (42) and the second gas supply unit (44) may supply an inert gas such as argon (Ar) gas or a low-reactivity gas such as nitrogen (N2) gas. In this case, the first gas supply unit (42) and the second gas supply unit (44) do not necessarily provide only one gas, and the first gas supply unit (42) and the second gas supply unit (44) may each be configured to supply multiple gases simultaneously or to supply a selected gas among multiple gases.

[0034] The gas injection unit (30) is installed inside the chamber (10), for example, on the lower surface of the cover (14), and inside the gas injection unit (30), a first gas supply path connected to a first gas supply unit (42) and a second gas supply path connected to a second gas supply unit (44) are formed. The first gas supply path and the second gas supply path are formed to be independent and separated from each other, so that the gas supplied from the first gas supply unit (42) and the gas supplied from the second gas supply unit (44) can be supplied to the substrate (S) separately so that they do not mix within the gas injection unit (30).

[0035] The gas injection unit (30) may include an upper frame (32) and a lower frame (34). Here, the upper frame (32) is detachably attached to the lower surface of the cover (14), and at the same time, a part of its upper surface, for example, the center of the upper surface, is spaced apart from the lower surface of the cover (14) by a predetermined distance. Accordingly, gas provided from the first gas supply unit (42) can be diffused in the space between the upper surface of the upper frame (32) and the lower surface of the cover (14). Additionally, the lower frame (34) is installed at a certain distance from the lower surface of the upper frame (32). Accordingly, gas provided from the second gas supply unit (44) can be diffused in the space between the upper surface of the lower frame (34) and the lower surface of the upper frame (32). The upper frame (32) and the lower frame (34) can be formed integrally by connecting along the outer surface to form a spaced-apart space inside, and it goes without saying that they can also be structured to seal the outer surface by a separate sealing member.

[0036] The first gas supply path may be formed so that gas provided from the first gas supply unit (42) diffuses in the space between the lower surface of the cover (14) and the upper frame (32), penetrates the upper frame (32) and the lower frame (34), and is supplied into the chamber (10). Additionally, the second gas supply path may be formed so that gas provided from the second gas supply unit (44) diffuses in the space between the lower surface of the upper frame (32) and the upper surface of the lower frame (34), penetrates the lower frame (34), and is supplied into the chamber (10). The first gas supply path and the second gas supply path may not be interconnected, and thus the gas supplied from the first gas supply unit (42) and the gas supplied from the second gas supply unit (44) may be supplied separately into the chamber (10) via the gas injection unit (30).

[0037] A first electrode (38) may be installed on the lower surface of the lower frame (34), and a second electrode (36) may be installed at a predetermined distance from the lower side of the lower frame (24) and the outer side of the first electrode (28). At this time, the lower frame (34) and the second electrode (36) may be formed by connecting along the outer surface, and it is obvious that the structure may be formed to seal the outer surface by a separate sealing member.

[0038] In this way, when the first electrode (38) and the second electrode (36) are installed, the gas supplied from the first gas supply unit (42) can be sprayed onto the substrate (S) by penetrating the first electrode (38), and the gas supplied from the second gas supply unit (44) can be sprayed onto the substrate (S) through the space between the first electrode (38) and the second electrode (36).

[0039] RF power from the power supply unit (50) may be supplied to either the lower frame (34) or the second electrode (36). For example, the lower frame (34) and the substrate support (20) may be grounded, and RF power from the power supply unit (50) may be supplied to the second electrode (36). When the lower frame (34) is grounded, the first electrode (38) installed on the lower surface of the lower frame (34) is also grounded. Accordingly, when RF power is supplied to the second electrode (36), a first activation region, i.e., a first plasma region, is formed between the gas injection unit (30) and the substrate support (20), and a second activation region, i.e., a second plasma region, can be formed between the first electrode (38) and the second electrode (36).

[0040]

[0041] Hereinafter, the method for forming a silicon oxide film according to the present invention will be described in detail with reference to FIG. 3. The method for forming a silicon oxide film according to an embodiment of the present invention can be performed by the substrate processing apparatus described above, and thus, descriptions that overlap with the above description regarding the substrate processing apparatus will be omitted.

[0042] FIG. 3 is a diagram schematically illustrating a method for forming a silicon insulating film according to an embodiment of the present invention.

[0043] Referring to FIG. 3, a method for forming a silicon insulating film according to an embodiment of the present invention is a method for forming a silicon oxide film (120) on a substrate (S), comprising: (a) a step of spraying a gas containing silicon (Si) onto the substrate (S); (b) a step of forming a first plasma with a first gas onto the substrate (S); and (c) a step of spraying an oxygen-containing gas onto the substrate (S); and a process cycle including steps (a) to (c) is repeated.

[0044] A method for forming a silicon insulating film according to an embodiment of the present invention may include a step of providing a substrate (S) prior to a step (step (a)) of spraying a gas containing silicon (Si) as illustrated in FIG. 3(a). In the step of providing the substrate (S), the substrate (S) may include a silicon wafer, and although not illustrated, at least one layer among a dielectric layer, a conductive layer, and a semiconductor layer may be formed on the silicon wafer.

[0045] Additionally, a pattern (P), such as a trench, may be formed on the substrate (S). Such a trench may be formed by etching a predetermined area on the substrate (S) to a predetermined depth using a photolithography and etching process with a device isolation mask. Such a trench may have an aspect ratio of 2:1 to 10:1 or greater, where the longitudinal length, i.e., the depth of the trench, and the transverse length, i.e., the width of the trench.

[0046] The step of injecting a gas containing silicon (Si) (step (a)) involves injecting a gas containing silicon (Si) as a source gas onto a substrate (S). For example, the step of injecting a gas containing silicon (Si) (step (a)) may inject the gas containing silicon (Si) through the first gas supply path among a first gas supply path and a second gas supply path formed separately from each other. At this time, the source gas containing silicon (Si) may include silane, disilane, trisilane, and a gas in which any of the silanes is substituted with an amine. For example, the source gas may include TSA (Tris(trimethyil)amine). In the step of injecting a gas containing silicon (Si) (step (a)), the source gas containing silicon (Si) is injected onto the substrate (S) and adsorbed. At this time, the step of spraying a gas containing silicon (Si) (step (a)) can be performed without supplying RF power through the power supply unit (50), and when the step of spraying a gas containing silicon (Si) (step (a)) is performed, a silicon adsorption layer (110) can be formed on the substrate (S) as shown in FIG. 3(b).

[0047] The step of forming the first plasma (step (b)) forms the first plasma with the first gas on the substrate (S) as illustrated in FIG. 3(c). For example, the step of forming the first plasma (step (b)) may include the step of supplying the first gas on the substrate (S) through at least one of a first gas supply path and a second gas supply path formed separately from each other, and the step of applying RF power through a power supply unit (50) to form the plasma of the first gas. Here, the first gas may include one or more gases selected from nitrogen (N2), nitrous oxide (N2O), aluminum (Al), zirconium (Zr), hafnium (Hf), lanthanum (La), barium (Ba), titanium (Ti), argon (Ar), helium (He), germanium (Ge), and hydrogen (H2).

[0048] When the step of forming a first plasma (step (b)) is performed after the step of injecting a silicon (Si)-containing gas (step (a)), the substrate (S) into which the silicon (Si)-containing gas, i.e., the source gas, has been injected can be pre-treated using plasma. Accordingly, by removing impurities within the silicon adsorption layer (110) adsorbed on the substrate (S), the quality of the thin film deposited on the substrate (S) can be improved, and by removing the impurities, the thickness of the silicon adsorption layer (110) above the pattern (P) can be reduced, thereby preventing the pattern (P), for example, the top of the trench, from becoming clogged. Furthermore, when the step of forming a first plasma (step (b)) is performed after the step of injecting a silicon (Si)-containing gas (step (a)), not only is the thin film densified, but the pattern (P), for example, the top of the trench, can also be prevented from becoming clogged due to ion bombardment.

[0049] The step of injecting an oxygen-containing gas (step (c)) injects an oxygen-containing gas as a reactant gas onto the substrate (S). For example, the step of injecting an oxygen-containing gas (step (c)) may inject the oxygen-containing gas through the second gas supply path among the first gas supply path and the second gas supply path formed separately from each other. Here, the oxygen-containing gas may include one or more gases among oxygen (O2), ozone (O3), and carbon dioxide (CO2). When such an oxygen-containing gas is used as a reactant gas, a uniform thin film having enhanced stack coverage can be formed on the substrate (S). At this time, the step of injecting oxygen-containing gas (step (c)) may be performed without supplying RF power through the power supply unit (50) or while supplying RF power through the power supply unit (50), and when the step of injecting oxygen-containing gas (step (c)) is performed, a silicon oxide film (120) may be formed on the substrate (S) as shown in FIG. 3(d).

[0050] Meanwhile, the method for forming a silicon oxide film according to an embodiment of the present invention may further include a step of forming a second plasma (step (d)) after the step of injecting an oxygen-containing gas (step (c)). The step of forming the second plasma (step (d)) forms a second plasma with a second gas on a substrate (S) as shown in FIG. 3(e). For example, the step of forming the second plasma (step (b)) may include a step of supplying a second gas on a substrate (S) through at least one of a first gas supply path and a second gas supply path formed separately from each other, and a step of applying RF power through a power supply unit (50) so that the plasma of the second gas is formed. Here, the second gas may include one or more of the following gases: nitrogen (N2), nitrous oxide (N2O), aluminum (Al), zirconium (Zr), hafnium (Hf), lanthanum (La), barium (Ba), titanium (Ti), argon (Ar), helium (He), germanium (Ge), and hydrogen (H2).

[0051] If a step of forming a second plasma (step (d)) is performed after the step of injecting an oxygen-containing gas (step (c)), the silicon oxide film (120) can be post-treated using plasma. Accordingly, by removing impurities within the silicon oxide film deposited on the substrate (S), densification of the thin film can be achieved, and the quality of the thin film can be further improved.

[0052] Meanwhile, a method for forming a silicon oxide film according to an embodiment of the present invention may include a step of supplying a first purge gas to a reaction space, i.e., inside a chamber (10) where a substrate is provided, between a step of injecting a gas containing silicon (Si) as a source gas (step (a)) and a step of injecting an oxygen-containing gas as a reactant gas (step (c)). For example, a method for forming a silicon oxide film according to an embodiment of the present invention may include a step of supplying a first purge gas after the step of injecting the gas containing silicon (Si) (step (a)) or after the step of forming the first plasma (step (b)). Additionally, a method for forming a silicon oxide film according to an embodiment of the present invention may include a step of supplying a second purge gas to a reaction space after the step of injecting the oxygen-containing gas as a reactant gas (step (c)). For example, a method for forming a silicon oxide film according to an embodiment of the present invention may include a step of supplying a second purge gas after the step of injecting the oxygen-containing gas (step (c)) or after the step of forming the second plasma (step (d)).

[0053] That is, the silicon oxide film can be formed by sequentially supplying a source gas, a first purge gas, a reactant gas, and a second purge gas onto a substrate (S). At this time, the step of forming the first plasma (step (b)) can be performed after the source gas is supplied and before the first purge gas is supplied, or after the first purge gas is supplied and before the reactant gas is supplied. This can be performed by supplying the first gas after the source gas is supplied or after the first purge gas is supplied, and by supplying RF power through a power supply unit (50) to activate the first gas. Additionally, the step of forming the second plasma (step (d)) may be performed after the reactant gas is supplied and before the second purge gas is supplied, or after the second purge gas is supplied and before the source gas of the next process cycle is supplied. This may be performed by supplying the second gas after the reactant gas is supplied or after the second purge gas is supplied, and by supplying RF power through the power supply unit (50) to activate the second gas.

[0054] Alternatively, the silicon oxide film may be formed by continuously supplying the first purge gas and the second purge gas. That is, the step of supplying the first purge gas is performed continuously from the step of injecting a gas containing silicon (Si) (step (a)) until a silicon oxide film of the desired thickness is formed, and the step of supplying the second purge gas can also be performed continuously from the step of injecting a gas containing silicon (Si) (step (a)) until a silicon oxide film of the desired thickness is formed. In this case, the first purge gas and the second purge gas can be continuously supplied even during the step of forming the first plasma (step (b)) and the step of forming the second plasma (step (d)). Meanwhile, the first purge gas and the second purge gas may include an inert gas such as argon (Ar) gas or a gas with low reactivity such as nitrogen (N2) gas.

[0055] Meanwhile, the method for forming a silicon oxide film according to an embodiment of the present invention may include a pumping step of pumping the inside of a chamber (10). Such a pumping step may be a step of performing a process of vacuum suctioning and exhausting the inside of the chamber (10) without supplying process gas into the chamber (10).

[0056] A method for forming a silicon oxide film according to an embodiment of the present invention may include a first pumping step of pumping the inside of a chamber (10) after a step of injecting a gas containing silicon (Si) (step (a)) or after a step of forming a first plasma (step (b)). That is, the first pumping step may be performed between the step of injecting the gas containing silicon (Si) as a source gas (step (a)) and the step of injecting an oxygen-containing gas as a reactant gas (step (c)). Such a first pumping step may be performed in place of the step of supplying a first purge gas, or separately from the step of supplying a first purge gas.

[0057] For example, the first pumping step can be performed between the step of injecting a gas containing silicon (Si) as a source gas (step (a)) and the step of supplying the first purge gas. In this way, if the first pumping step is performed after supplying the source gas, the pressure on the substrate can be instantaneously lowered, and raw materials that are not adsorbed on the substrate or are unevenly adsorbed can be removed. Additionally, the base pressure inside the chamber (10) can be reduced before supplying the first purge gas to purge the source gas, thereby enhancing the purging effect of the first purge gas supply step performed after the first pumping step. Furthermore, the first pumping step can be performed after the step of supplying the first purge gas. In this way, if the first pumping step is performed after the step of supplying the first purge gas, raw materials that were not removed in the step of supplying the first purge gas can be effectively removed, and the base pressure inside the chamber (10) can be reduced to enhance the supply effect of the process gas supplied thereafter. By performing a first pumping step after supplying source gas, or by performing a first pumping step after supplying a first purge gas, a silicon oxide film of uniform thickness can be formed in a pattern having a high aspect ratio, i.e., a high aspect ratio, such as a trench. Meanwhile, the first pumping step may be performed before and after the step of supplying the first purge gas, respectively. In this case, it goes without saying that all of the aforementioned effects can be obtained.

[0058] In addition, the method for forming a silicon oxide film according to an embodiment of the present invention may include a second pumping step of pumping the inside of the chamber (10) after the step of injecting an oxygen-containing gas (step (c)) or after the step of forming a second plasma (step (d)). Such a second pumping step may also be performed in place of the step of supplying a second purge gas, or separately from the step of supplying a second purge gas.

[0059] For example, the second pumping step can be performed between the step of injecting the oxygen-containing gas as a reactant gas (step (c)) and the step of supplying the second purge gas. In this way, if the second pumping step is performed after the supply of the reactant gas, the pressure on the substrate can be instantaneously lowered, and the reactive material remaining without reacting with the raw material can be removed. Additionally, the base pressure inside the chamber (10) can be reduced before the supply of the second purge gas to purge the reaction gas, thereby enhancing the purging effect of the second purge gas supply step performed after the second pumping step. Additionally, the second pumping step can be performed after the step of supplying the second purge gas. In this way, if the second pumping step is performed after the step of supplying the second purge gas, the reactive material that was not removed in the step of supplying the second purge gas can be effectively removed, and the base pressure inside the chamber (10) can be reduced to enhance the supply effect of the process gas supplied thereafter. By performing a second pumping step after supplying the reactant gas, or by performing a second pumping step after supplying the second purge gas, a silicon oxide film of uniform thickness can be formed in a pattern having a high aspect ratio, that is, a high aspect ratio, such as a trench, where the ratio of depth to width is high. Meanwhile, the second pumping step may be performed before and after the step of supplying the second purge gas, respectively. In this case, it goes without saying that all of the aforementioned effects can be obtained.

[0060] Meanwhile, in the thin film formation method according to an embodiment of the present invention, the step of injecting a gas containing silicon (Si) (step (a), the step of forming a first plasma (step (b), and the step of injecting an oxygen-containing gas (step (c))) may constitute a process cycle of an atomic layer deposition (ALD) process. Additionally, if the thin film formation method according to an embodiment of the present invention further includes the step of forming a second plasma (step (d), the step of injecting a gas containing silicon (Si) (step (a), the step of forming a first plasma (step (b), the step of injecting an oxygen-containing gas (step (c), and the step of forming a second plasma (step (d)))) may constitute a process cycle of an atomic layer deposition process. Such a process cycle may be repeated multiple times until a thin film of a desired thickness is formed.

[0061] Thus, according to an embodiment of the present invention, by forming a plasma on a substrate between the step of spraying a silicon-containing gas onto a substrate and the step of spraying an oxygen-containing gas, the impurity content can be minimized and a thin film having a desired profile can be formed.

[0062] In addition, by improving the characteristics of the silicon oxide film, the performance of a semiconductor device containing it can be significantly improved.

[0063]

[0064] In the foregoing, preferred embodiments of the present invention have been described and illustrated using specific terms, but such terms are intended solely to clarify the present invention, and it is obvious that various modifications and changes may be made to the embodiments and described terms of the present invention without departing from the technical spirit and scope of the following claims. Such modified embodiments should not be understood separately from the spirit and scope of the present invention, but should be considered to fall within the scope of the claims of the present invention.

Claims

1. A method for forming a silicon oxide film by forming a silicon oxide film on a substrate, wherein (a) a step of spraying a silicon-containing gas onto the substrate; (b) forming a first plasma with a first gas on the substrate; and (c) a step of spraying an oxygen-containing gas onto the substrate; comprising, A method for forming a silicon oxide film by repeating the process cycle including the steps (a) to (c) above.

2. In Claim 1, A method for forming a silicon oxide film in which the first gas comprises one or more of nitrogen, nitrous oxide, aluminum, zirconium, hafnium, lanthanum, barium, titanium, argon, helium, germanium, and hydrogen gases.

3. In Claim 1, After step (c) above, (d) a step of forming a second plasma with a second gas on the substrate; further comprising a method for forming a silicon oxide film.

4. In Claim 3, A method for forming a silicon oxide film in which the second gas comprises one or more of nitrogen, nitrous oxide, aluminum, zirconium, hafnium, lanthanum, barium, titanium, argon, helium, germanium, and hydrogen gases.

5. In Claim 1, A method for forming a silicon oxide film in which the above oxygen-containing gas comprises one or more of oxygen, ozone, and carbon dioxide gases.

6. In Claim 1, A method for forming a silicon oxide film, further comprising the step of pumping the inside of the chamber where the substrate is provided after step (a) or after step (b).

7. In Claim 6, A method for forming a silicon oxide film, further comprising the step of supplying purge gas into the chamber before, after, or both before and after the step of pumping into the chamber.

8. In Claim 3, A method for forming a silicon oxide film, further comprising the step of pumping the inside of the chamber where the substrate is provided after step (c) or after step (d).

9. In Claim 8, A method for forming a silicon oxide film, further comprising the step of supplying purge gas into the chamber before, after, or both before and after the step of pumping into the chamber.

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