Thin film manufacturing method

Abstract

To provide a thin film manufacturing method by an atomic layer deposition method in which incubation time is short and the entire processing time can be shortened, which is hard to depend on the material of a substrate surface, and furthermore can provide a thin film having excellent smoothness.SOLUTION: A thin film manufacturing method in which a plurality of kinds of raw material gas are sequentially supplied into a treatment chamber housing a substrate to form a thin film on the surface of the substrate comprises: a first step of supplying first raw material gas containing hydrazine into the treatment chamber; a second step of supplying second raw material gas containing a metal-containing compound into the treatment chamber; and a third step of supplying third raw material gas containing reactant which reacts with the metal-containing compound into the treatment chamber, where the second step and the third step are alternately performed a plurality of times after performing the first step once.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a thin film manufacturing method, and more particularly to a thin film manufacturing method by atomic layer deposition (ALD). [Background technology]

[0002] Atomic layer deposition (ALD) is a thin film formation method that produces a film by alternately supplying multiple types of source gases to the surface of a substrate. Atomic layer deposition has attracted attention as a film formation process that allows film thickness to be controlled on the order of Å (0.1 nm).

[0003] In atomic layer deposition, in order to form a high-quality film, it is common to insert a nitrogen purge or evacuation process when switching source gases, which can result in a long overall processing time. Therefore, Patent Document 1 proposes that after the first process gas is flowed, the inside of the reaction chamber is purged with a second process gas instead of nitrogen, thereby shortening the overall processing time. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2004-281853 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the atomic layer deposition method, as in the chemical vapor deposition method (CVD), there is a period of time (incubation time) during which no film is formed before film formation begins. In the atomic layer deposition method, even during this incubation time, nitrogen purging or the like is usually performed when switching source gases to ensure sufficient gas replacement, so a long incubation time affects the overall processing time more than in the chemical vapor deposition method. Although Patent Document 1 shortens the time required for each source gas switching, it does not reduce the number of source gas switching times during incubation time, and there is a limit to the effect of shortening the overall processing time.

[0006] Moreover, in recent years, integrated circuits with three-dimensional transistor structures such as Fin-FET and three-dimensional structures such as 3D-NAND have become mainstream. To accommodate these semiconductor manufacturing processes, it is necessary to form uniform thin films even when multiple materials are present on the surface of the substrate to be processed, such as trenches or holes formed in a laminated film made of different types of films.

[0007] However, when multiple materials are present on the surface of the substrate to be treated, the incubation time differs for each material, which results in a problem that the thickness of the thin film formed on the substrate differs for each material. The difference in film thickness impairs the flatness and can also cause voids. Therefore, there is a demand for a film formation method in which the film thickness is less dependent on the surface material of the substrate. Furthermore, as integration density continues to increase and the horizontal and vertical dimensions of integrated circuits continue to shrink, the thin films that are formed also require excellent smoothness.

[0008] In view of the above circumstances, an object of the present invention is to provide a thin film manufacturing method by atomic layer deposition with a short incubation time. Another object of the present invention is to provide a thin film manufacturing method by atomic layer deposition with a film thickness that is less dependent on the surface material of a substrate. Another object of the present invention is to provide a thin film manufacturing method by atomic layer deposition with which a thin film with excellent smoothness can be obtained. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention employs the following configuration. [1] A thin film manufacturing method for forming a thin film on a surface of a substrate by sequentially supplying a plurality of types of source gases into a processing chamber that accommodates the substrate, comprising: a first step of supplying a first source gas containing hydrazine into the processing chamber; a second step of supplying a second source gas containing a metal-containing compound into the processing chamber; and a third step of supplying a third source gas containing a reactant that reacts with the metal-containing compound into the processing chamber, A thin film manufacturing method, comprising: carrying out the first step once; and then alternately carrying out the second step and the third step multiple times. [2] The thin film manufacturing method according to [1], wherein a supply time for supplying the first source gas in the first step is at least twice as long as a supply time for supplying the third source gas in the third step. [3] The thin film manufacturing method according to [1] or [2], wherein the temperature inside the processing chamber in the first step is 600° C. or less. [4] The method for producing a thin film according to any one of [1] to [3], wherein the third source gas contains hydrazine as a reactant. [5] The thin film manufacturing method according to [4], wherein the temperature inside the processing chamber in the third step is 600° C. or lower. [6] A thin film manufacturing method for forming a thin film on a surface of a substrate by sequentially supplying a plurality of types of source gases into a treatment chamber accommodating a substrate, comprising: a first step of supplying a first source gas containing hydrazine into the processing chamber; a second step of supplying a second source gas containing a metal-containing compound into the processing chamber; a third step of supplying into the processing chamber a fourth source gas containing a reactant other than hydrazine that reacts with the metal-containing compound and does not contain hydrazine; and a fourth step of supplying a second source gas containing the metal-containing compound into the processing chamber, A thin film manufacturing method, comprising: alternately repeating the first step and the second step multiple times to form a thin film having a thickness of 0.1 to 1 nm on the surface of the substrate; and then alternately repeating the third step and the fourth step multiple times. [7] The thin film manufacturing method according to [6], wherein the temperature inside the processing chamber in the first step is 600° C. or lower. [8] The method for producing a thin film according to any one of [1] to [7], wherein the substrate has a surface made of a plurality of different materials. Effect of the Invention

[0010] According to the present invention, it is possible to provide a thin film manufacturing method by atomic layer deposition which has a short incubation time and can easily shorten the overall processing time. It is also possible to provide a thin film manufacturing method using atomic layer deposition that has an incubation time that is less dependent on the surface material of the substrate. It is also possible to provide a thin film manufacturing method by atomic layer deposition that can obtain a thin film with excellent smoothness. [Brief description of the drawings]

[0011] [Figure 1] 1 is a first embodiment of a thin-film manufacturing apparatus used in a thin-film manufacturing method of the present invention. [Diagram 2] 2 shows a second embodiment of the thin-film manufacturing apparatus used in the thin-film manufacturing method of the present invention. [Diagram 3] FIG. 1 is an explanatory diagram of the presumed mechanism of action of the present invention. [Figure 4] 4 is a specific example of a time chart of the thin film manufacturing method according to the first embodiment. [Diagram 5] 5 is another specific example of the time chart of the thin film manufacturing method according to the first embodiment. [Figure 6] 5 is another specific example of the time chart of the thin film manufacturing method according to the first embodiment. [Figure 7] 5 is another specific example of the time chart of the thin film manufacturing method according to the first embodiment. [Figure 8] 13 is a specific example of a time chart of the thin film manufacturing method according to the second embodiment. [Figure 9]13 is a specific example of a time chart of the thin film manufacturing method according to the third embodiment. [Figure 10] FIG. 1 is an explanatory diagram of how to determine the incubation time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] <Thin film manufacturing equipment> [First aspect] An embodiment of a thin-film manufacturing apparatus used in the thin-film manufacturing method of the present invention is shown in Fig. 1. The thin-film manufacturing apparatus 100 of Fig. 1 can be used when hydrazine is used as a reactant. The thin-film manufacturing apparatus 100 includes a processing chamber 2 that accommodates a substrate 1. A temperature control device 3 is provided so as to surround the processing chamber 2, and is capable of heating the inside of the processing chamber 2 to a predetermined temperature.

[0013] A source gas supply pipe 4 for supplying a source gas to the processing chamber 2 is connected to the upstream side of the processing chamber 2 . To the source gas supply pipe 4, a carrier gas supply pipe 5, a hydrazine gas supply pipe 6, and a metal-containing compound gas supply pipe 7 are connected.

[0014] The upstream end of the carrier gas supply pipe 5 is connected to a carrier gas supply source 15, and on the downstream side of the carrier gas supply source 15, an on-off valve 21, a flow rate control device 22, and an air-operated on-off valve 23 are provided in this order from the upstream side. The flow rate of the carrier gas flowing through the carrier gas supply pipe 5 is adjusted to a predetermined value by the flow rate control device 22. As the flow rate control device 22, for example, a mass flow controller or the like can be used.

[0015] The hydrazine gas supply pipe 6 is connected to the raw material gas supply pipe 4 on the downstream side of the air-driven on-off valve 23. The upstream end of the hydrazine gas supply pipe 6 is connected to a hydrazine gas supply source 16, and an air-driven on-off valve 24 is provided on the downstream side of the hydrazine gas supply source 16. The gas contained in hydrazine gas source 16 may include reactants other than hydrazine in addition to hydrazine.

[0016] The hydrazine gas contained in the hydrazine gas supply source 16 is adapted to be merged with the carrier gas flowing through the raw material gas supply pipe 4 at a predetermined flow rate by a flow rate control device built into the hydrazine gas supply source 16. By closing the air-driven on-off valve 24, the inflow of the hydrazine gas into the processing chamber 2 can be stopped, and the backflow of the carrier gas and the metal-containing compound gas can be prevented.

[0017] The metal-containing compound gas supply pipe 7 is connected to the raw material gas supply pipe 4 downstream of the point where the hydrazine gas supply pipe 6 is connected to the raw material gas supply pipe 4. The upstream end of the metal-containing compound gas supply pipe 7 is connected to a metal-containing compound gas supply source 17, and an air-operated on-off valve 25 is provided downstream of the metal-containing compound gas supply source 17.

[0018] The metal-containing compound gas contained in the metal-containing compound gas supply source 17 is merged with the carrier gas flowing through the raw material gas supply pipe 4 at a predetermined flow rate by a flow rate control device built into the metal-containing compound gas supply source 17. By closing the air-driven on-off valve 25, the inflow of the metal-containing compound gas into the processing chamber 2 can be stopped, and backflow of the carrier gas and hydrazine gas can be prevented.

[0019] A reaction gas exhaust pipe 31 for exhausting the source gas from the processing chamber 2 is connected to the downstream side of the processing chamber 2 . A pressure gauge 32, a pressure control device 33, an on-off valve 34, and a dry vacuum pump 35 are connected to the reaction gas exhaust pipe 31 in this order from the upstream side.

[0020] By operating the dry vacuum pump 35 with the air driven on-off valve 23, the air driven on-off valve 24, and the air driven on-off valve 25 all closed, the inside of the processing chamber 2 can be evacuated to a vacuum. During the supply of the source gas into the processing chamber 2, the pressure (degree of reduction in pressure) within the processing chamber 2 can be adjusted by operating the dry vacuum pump 35 under the control of the pressure control device 33.

[0021] [Second aspect] A second embodiment of the thin-film manufacturing apparatus used in the thin-film manufacturing method of the present invention is shown in Fig. 2. The thin-film manufacturing apparatus 200 of Fig. 2 can be used when a reactant other than hydrazine is used. 2, the same components as those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and detailed description thereof will be omitted.

[0022] The thin-film manufacturing apparatus 200 differs from the thin-film manufacturing apparatus 100 in that a reactant gas supply pipe 8 is connected to a source gas supply pipe 4 . The reactant gas supply pipe 8 is connected to the raw material gas supply pipe 4 downstream of the point where the hydrazine gas supply pipe 6 is connected to the raw material gas supply pipe 4 and upstream of the point where the metal-containing compound gas supply pipe 7 is connected to the raw material gas supply pipe 4.

[0023] The upstream end of the reactant gas supply pipe 8 is connected to a reactant gas supply source 18, and an air-operated on-off valve 27 is provided downstream of the reactant gas supply source 18. The reactant gas contained in the reactant gas supply source 18 is adapted to be merged with the carrier gas flowing through the raw material gas supply pipe 4 at a predetermined flow rate by a flow control device built into the reactant gas supply source 18. By closing the air-driven on-off valve 27, the flow of the reactant gas into the processing chamber 2 can be stopped, and backflow of the carrier gas, hydrazine gas, and metal-containing compound gas can be prevented. The reactant gas source 18 contains a reactant other than hydrazine. The gas contained in the reactant gas source 18 may include hydrazine in addition to reactants other than hydrazine.

[0024] In this embodiment, the processing chamber 2 can be evacuated to a vacuum by operating the dry vacuum pump 35 with the air driven on-off valves 23, 24, 25 and 27 all closed. During the supply of the source gas into the processing chamber 2, the pressure (degree of reduction in pressure) within the processing chamber 2 can be adjusted by operating the dry vacuum pump 35 under the control of the pressure control device 33.

[0025] <Substrate and thin film> In the thin film manufacturing method of the present embodiment, a thin film is formed on the surface of a substrate. The surface of the substrate means the entire surface exposed to the source gas in the processing chamber, and is not limited to the main surface of the substrate, but also includes inner walls of trenches and holes formed in the thickness direction of the substrate perpendicular to the main surface.

[0026] Examples of the material of the surface of the substrate include metals and metal compounds such as metal nitrides, metal oxides, metal carbides, metal carbonitrides, etc. These materials may be present in the form of a film on the surface of the substrate. Examples of the metal or metal constituting the metal compound include silicon, titanium, tantalum, aluminum, gallium, vanadium, iron, zirconium, niobium, tungsten, molybdenum, indium, hafnium, tin, copper, lanthanum, ruthenium, cobalt, yttrium, and zinc. The surface of the substrate may be made of a plurality of different materials. For example, a plurality of different materials may be exposed on the inner wall of a trench formed in the laminated film.

[0027] The thin film formed on the surface of the substrate by the thin film production method of this embodiment may be a metal or a metal compound film such as a metal nitride film, a metal carbide film, or a metal carbonitride film. Examples of the metal or metal constituting the metal compound include silicon, titanium, tantalum, aluminum, gallium, vanadium, iron, zirconium, niobium, tungsten, molybdenum, indium, hafnium, tin, copper, lanthanum, ruthenium, cobalt, yttrium, and zinc.

[0028] <Raw material gas> [First source gas] The first source gas used in the thin film manufacturing method of the present invention contains hydrazine gas. The first source gas is preferably a gas in which hydrazine gas is mixed with a carrier gas. The carrier gas is not particularly limited, but may be one or more of helium (He), nitrogen (N2), argon (Ar), hydrogen (H2), and the like.

[0029] The first source gas may be supplied after activating hydrazine with plasma or a catalyst in advance. Hydrazine activated with plasma or a catalyst has high reactivity, so that the incubation time can be further shortened. However, as semiconductors become smaller, there is a demand for technology to form uniform films on deep trench structures with high aspect ratios, and there is concern that the activated hydrazine may be deactivated within the deep trench structure, resulting in variations in the incubation time along the depth direction. Therefore, particularly when treating a substrate having a deep trench structure on its surface, it is preferable not to activate it with plasma or a catalyst.

[0030] The concentration of hydrazine gas in the first raw material gas can be 1 to 100% by volume. A higher concentration of hydrazine gas in the first raw material gas is preferable because the higher the concentration, the higher the partial pressure in the processing chamber 2 is and the easier it is to generate reaction sites.

[0031] The first raw material gas may contain, in addition to hydrazine, a component other than hydrazine among the reactants described below. In addition, other components may be contained within a range that does not impair the effects of the present invention. Examples of other components include gases that can be used as carrier gases, as well as ammonia, amine compounds, organic hydrazine compounds, silane, disilane, diborane, and the like.

[0032] [Second source gas] The second source gas used in the thin film manufacturing method of the present invention contains a metal-containing compound. The second source gas is preferably a gas in which a gaseous metal-containing compound is mixed with a carrier gas. The carrier gas may be the same as the carrier gas in the first source gas.

[0033] The metal-containing compound is not particularly limited, but examples thereof include: Silicon compounds such as Si2Cl6 (HCDS: hexachlorodisilane), 3DMAS (trisdimethylaminosilane), BDEAS (bisdiethylaminosilane), BTBAS (bistertiarybutylaminosilane), SiCl4, SiHCl3, SiH2Cl2, SiH3Cl, SiI4, SiHI3, SiH2I2, and SiH3I; ·Titanium compounds such as TiCl4, TDMAT (tetrakisdimethylaminotitanium); ·Tantalum compounds such as TaCl5, PDMAT (pentakisdimethylaminotantalum); Aluminum compounds such as AlCl3, TMA (trimethylaluminum); Gallium compounds such as GaCl3 and TMG (trimethylgallium); ·Zirconium compounds such as ZrCl4; Hafnium compounds such as HfCl4; ·Molybdenum compounds such as MoCl5, MoO2Cl2; Tungsten compounds such as WF6, WCl6, WCl5; Platinum compounds, ruthenium compounds, cobalt compounds, etc. are listed, and are selected according to the type of thin film to be formed.

[0034] The concentration of the metal-containing compound gas in the second source gas can be 1 to 100% by volume. The higher the concentration, the higher the partial pressure in the processing chamber 2 and the easier the thin film formation reaction will proceed, which is preferable from the viewpoint of forming a high-quality film. The second source gas may contain other components within the scope of the present invention, such as gases that can be used as carrier gases, as well as silane, disilane, diborane, ethylene, acetylene, propane, methane, etc.

[0035] [Third source gas] The third source gas used in the thin film manufacturing method of the present invention contains a reactant. The third source gas is preferably a gas in which a gaseous reactant is mixed with a carrier gas. The carrier gas may be the same as the carrier gas in the first source gas.

[0036] The reactant is a component that reacts with the metal-containing compound to form a thin film of a desired material. The reactant is not particularly limited, but examples thereof include hydrazine, hydrazine compounds such as organic hydrazines, amine compounds, ammonia, acetylene, ethylene, and hydrogen.

[0037] From the viewpoint of reactivity, it is preferable to use hydrazine compound, amine compound, and ammonia as the reactant, and among them, it is preferable to use hydrazine compound with higher reactivity, and hydrazine is more preferable. It is particularly preferable that the reactant is only hydrazine. This is because it is known that when organic hydrazine compound or amine compound is used, the carbon component contained in these compounds is contained in the film, and thus the electrical properties such as electrical conductivity are deteriorated.

[0038] The concentration of the reactant gas in the third source gas can be 1 to 100% by volume. A higher concentration is preferable from the viewpoint of forming a high-quality film, since the higher the concentration, the higher the partial pressure in the processing chamber 2 becomes and the easier the thin film formation reaction proceeds. The third source gas may contain other components within the scope of the present invention, such as gases that can be used as carrier gases, ammonia, amine compounds, organic hydrazine compounds, silane, disilane, diborane, etc.

[0039] [Fourth source gas] The fourth source gas used in the thin film manufacturing method of the present invention contains a reactant other than hydrazine, but does not contain hydrazine. The fourth source gas is preferably a gas in which a gaseous reactant other than hydrazine is mixed with a carrier gas. The carrier gas may be the same as the carrier gas in the first source gas.

[0040] The reactant may be the same as the reactant in the third embodiment, except that hydrazine is excluded. The preferred concentration of the reactant gas in the fourth source gas is the same as the preferred concentration of the reactant gas in the third source gas. The fourth source gas may contain components other than hydrazine as long as the effects of the present invention are not impaired. Examples of the other components include gases that can be used as carrier gases, as well as amine compounds, ammonia, acetylene, and ethylene.

[0041] [Gasification] When the metal-containing compound or reactant has a low vapor pressure and is in the form of a solid or liquid, it can be gasified and supplied, for example, by the following method. A mixed gas supply method in which a carrier gas or the like is introduced into a raw material container filled with a compound to be gasified, and a gas containing the compound to be gasified is supplied from the raw material container. The carrier gas may be supplied by bubbling by making the container a dip tube structure, or it may be supplied to the gas phase of the container without bubbling. Note that by keeping the temperature and pressure in the raw material container, and the flow rate of the carrier gas supplied to the raw material container constant, the raw material gas can be supplied with a stable concentration of the compound to be gasified.

[0042] A pressure-controlled supply method in which the compound to be gasified is gasified to the vapor pressure and then supplied. At this time, the gas can be supplied while controlling the flow rate with a mass flow controller, etc. When the compound to be gasified is a liquid, the liquid is pumped through a dip tube built into the container to a vaporizer installed downstream of the container, and the liquid is gasified using the vaporizer before being supplied.

[0043] First Embodiment The thin film manufacturing method according to the first embodiment of the present invention can be carried out, for example, by sequentially supplying a plurality of types of raw material gases using the thin film manufacturing apparatus 100. The first embodiment has the following steps, and is a method in which the following first step is carried out once, and then the following second step and the following third step are carried out alternately a plurality of times.

[0044] First step: a step of supplying a first source gas containing hydrazine into the processing chamber 2. Second step: a step of supplying a second source gas containing a metal-containing compound into the processing chamber 2. Third step: A step of supplying into the processing chamber 2 a third source gas containing hydrazine as a reactant that reacts with the metal-containing compound.

[0045] The first step of supplying a first raw material gas into the processing chamber 2 can be carried out by flowing a carrier gas from a carrier gas supply source 15 into the raw material gas supply pipe 4 at a constant flow rate while merging hydrazine gas from a hydrazine gas supply source 16 into the raw material gas supply pipe 4 at a constant flow rate. In the first step, a first raw material gas containing highly reactive hydrazine is supplied into the treatment chamber 2, so that the substrate surface can be substituted with bonds derived from hydrazine, thereby increasing the number of reaction points, as shown in FIG. 3.

[0046] The supply time for supplying the first raw material gas in the first step is preferably at least twice as long as the supply time for supplying the third raw material gas in the third step, more preferably 2.5 to 100 times, and even more preferably 3 to 30 times. By setting the supply time of the first source gas to a preferable lower limit or more with respect to the supply time of the third source gas, the number of reaction sites can be sufficiently increased, and by setting the supply time of the third source gas to a preferable upper limit or less, the total processing time can be shortened.

[0047] For the same reason, the supply time for supplying the first raw material gas in the first step is preferably from 1 to 600 seconds, more preferably from 10 to 450 seconds, and further preferably from 30 to 300 seconds. The first source gas may contain a reactant other than hydrazine as long as the effect of the present invention is not impaired.

[0048] The temperature inside the treatment chamber 2 in the first step is preferably 600°C or lower, more preferably 30 to 500°C, and further preferably 100 to 400°C. By keeping the temperature in the treatment chamber 2 at 600° C. or lower in the first step, it is easy to prevent the pyrolysis of hydrazine and the generation of ammonia, which has low reactivity. In addition, by keeping the temperature at or above the preferable lower limit, it is easy to promote an increase in the number of reaction sites on the surface of the substrate. The temperature inside the treatment chamber 2 is preferably set to a predetermined temperature for the first step before the start of the first step.

[0049] The flow velocity of the first raw material gas in the first step is preferably 60 cm / s or more, more preferably 60 to 20,000 cm / s, and even more preferably 1,000 to 5,000 cm / s. By setting the flow rate of the first raw material gas to 60 cm / s or more, hydrazine can easily reach the substrate surface, particularly the surface in the case of a deep trench structure, before it is thermally decomposed. Also, by setting the flow rate to the preferred upper limit or less, the supply flow rate can be suppressed and the reaction sites can be efficiently increased. In the first step, the higher the temperature in the treatment chamber 2, the faster the flow rate of the first raw material gas is. The higher the temperature in the treatment chamber 2, the more reaction sites there are, but hydrazine is more likely to be thermally decomposed. A high flow rate can suppress decomposition.

[0050] The pressure inside the processing chamber 2 in the first step is preferably 0.01 to 100 Torr, more preferably 0.1 to 50 Torr, and further preferably 0.1 to 10 Torr. By keeping the pressure in the treatment chamber 2 in the first step below the upper limit of the preferred range, the flow rate is increased, making it easier to suppress thermal decomposition of hydrazine. By keeping the pressure above the lower limit of the preferred range, the number of collisions of hydrazine with the substrate surface increases, making it easier to increase the number of reaction sites. The pressure inside the processing chamber 2 is preferably set to a predetermined pressure for the first step before the start of the first step.

[0051] The second step of supplying the second raw material gas into the processing chamber 2 can be carried out by flowing a carrier gas from the carrier gas supply source 15 into the raw material gas supply pipe 4 at a constant flow rate while merging the metal-containing compound gas from the metal-containing compound gas supply source 17 into the raw material gas supply pipe 4 at a constant flow rate. In the second step, a metal-containing compound is chemisorbed onto the reaction sites on the substrate surface.

[0052] The supply time for supplying the second raw material gas in the second step is preferably from 1 to 600 seconds, more preferably from 1 to 450 seconds, and further preferably from 1 to 300 seconds. By setting the supply time for the second source gas to a preferable lower limit or more, the source gas can be sufficiently adsorbed and saturated at the generated reaction points, and by setting the supply time to a preferable upper limit or less, a thin film can be formed with good productivity. There are no particular limitations on the temperature, flow rate, and pressure inside the treatment chamber 2 in the second step, but it is preferable to set the temperature, flow rate, and pressure to the same as those in the first step, as these are easier to control.

[0053] The third step of supplying the third raw material gas into the processing chamber 2 can be carried out by flowing a carrier gas from the carrier gas supply source 15 into the raw material gas supply pipe 4 at a constant flow rate while merging hydrazine gas from the hydrazine gas supply source 16 into the raw material gas supply pipe 4 at a constant flow rate. In the third step, the metal-containing compound that has been chemisorbed onto the reaction points on the substrate surface in the second step reacts with hydrazine to produce a nitride.

[0054] The supply time for supplying the third raw material gas in the third step is preferably from 1 to 600 seconds, more preferably from 1 to 450 seconds, and further preferably from 1 to 300 seconds. By setting the supply time of the third source gas to a preferable lower limit or more, the reaction with the substrate surface to which the second source gas is adsorbed proceeds sufficiently until the reaction is saturated. By setting the supply time to a preferable upper limit or less, a thin film can be formed with good productivity. The third source gas may contain a reactant other than hydrazine as long as the effect of the present invention is not impaired.

[0055] The preferred ranges of the temperature, flow rate, and pressure in the processing chamber 2 in the third step are the same as those in the first step for the same reason as in the first step, since the third source gas contains hydrazine as a reactant. For ease of control, it is preferable to set the temperature, flow rate, and pressure to the same as those in the first step.

[0056] By repeating the second and third steps multiple times (multiple cycles, for example 500 cycles), a thin film of a metal nitride having a desired thickness can be produced. In this embodiment, since the third source gas in the third step contains hydrazine, which has high reactivity, as a reactant, a metal nitride thin film having a desired thickness can be manufactured in fewer steps.

[0057] In this embodiment, the following four methods are given as main methods for switching between different source gases for each process. In particular, when a deep trench structure is present, gas is likely to remain in the deep trench structure, so that a method using vacuum evacuation is preferable as described in (iii) and (iv) below.

[0058] (i) A method in which, after the supply of raw material gas in one process is stopped, the supply of raw material gas in the next process is immediately started. (ii) A method in which after the supply of the raw material gas in a certain process is stopped, only the carrier gas is allowed to flow, and then the supply of the raw material gas in the next process is started. (iii) A method in which after the supply of source gas in a certain step is stopped, the processing chamber 2 is evacuated to a vacuum, and then the supply of source gas in the next step is started. (iv) A method in which after the supply of source gas in a certain process is stopped, the processing chamber 2 is evacuated to a vacuum, and then only the carrier gas is allowed to flow before starting the supply of source gas in the next process.

[0059] FIG. 4 shows, as a specific example of (i), an example in which the supply time for supplying the first raw material gas in the first step is 600 seconds, the supply time for supplying the second raw material gas in the second step, and the supply time for supplying the third raw material gas in the third step are each 10 seconds.

[0060] FIG. 5 shows, as a specific example of (ii), an example in which the supply time for supplying the first raw material gas in the first step is 600 seconds, the supply time for supplying the second raw material gas in the second step and the supply time for supplying the third raw material gas in the third step are each 10 seconds, and the time for flowing the carrier gas when switching raw material gases is 10 seconds.

[0061] FIG. 6 shows, as a specific example of (iii), an example in which the supply time for supplying the first raw material gas in the first step is 600 seconds, the supply time for supplying the second raw material gas in the second step and the supply time for supplying the third raw material gas in the third step are each 10 seconds, and the time for evacuation when switching raw material gases is 10 seconds.

[0062] FIG. 7 shows, as a specific example of (iv), an example in which the supply time for supplying the first raw material gas in the first step is 600 seconds, the supply time for supplying the second raw material gas in the second step and the supply time for supplying the third raw material gas in the third step are each 10 seconds, and the time for evacuation when switching raw material gases and the time for flowing carrier gas are each 10 seconds.

[0063] According to this embodiment, since the first source gas in the first step and the third source gas in the third step contain highly reactive hydrazine, the number of cycles of the incubation time (the number of cycles until the formation of the film begins) can be reduced. In this embodiment, the number of cycles is counted as one cycle, starting from the second process immediately after the end of the first process, with the second process and the third process as a set.

[0064] By reducing the number of incubation cycles, the processing time until film formation can be shortened. In particular, when switching between source gases, time is required to flow a carrier gas or evacuate, so the effect of shortening the processing time until film formation begins is significant.

[0065] <Second embodiment> The thin film manufacturing method according to the second embodiment of the present invention can be carried out, for example, by sequentially supplying a plurality of types of raw material gases using the thin film manufacturing apparatus 200. The second embodiment has the following steps, and is a method in which the following first step is carried out once, and then the following second step and the following third step are carried out alternately a plurality of times.

[0066] First step: a step of supplying a first source gas containing hydrazine into the processing chamber 2. Second step: a step of supplying a second source gas containing a metal-containing compound into the processing chamber 2. Third step: A step of supplying into the processing chamber 2 a third source gas containing a reactant other than hydrazine as a reactant that reacts with the metal-containing compound.

[0067] The first and second steps in this embodiment are the same as the first and second steps in the first embodiment, and the preferred aspects of the temperature, flow rate, and pressure within the processing chamber 2 are also the same, so detailed explanations thereof will be omitted. The preferable relationship between the supply time for supplying the source gas in the first and second steps and the supply time for supplying the first source gas with respect to the supply time for supplying the third source gas in the third step is also similar to that in the first embodiment.

[0068] The third step of supplying the third raw material gas into the processing chamber 2 can be carried out by flowing a carrier gas from the carrier gas supply source 15 into the raw material gas supply pipe 4 at a constant flow rate while merging the reactant gas from the reactant gas supply source 18 into the raw material gas supply pipe 4 at a constant flow rate. In the third step, the metal-containing compound chemically adsorbed to the reaction points on the substrate surface in the second step reacts with a reactant to produce a metal film, or a metal compound film such as a metal nitride film, a metal oxide film, a metal carbide film, or a metal carbonitride film, depending on the type of reactant.

[0069] The third raw material gas may contain hydrazine as a reactant in addition to a reactant other than hydrazine. In this case, hydrazine may be contained in the gas contained in the reactant gas supply source 18, or the reactant gas from the reactant gas supply source 18 and the hydrazine gas from the hydrazine gas supply source 16 may be merged into the raw material gas supply pipe 4 at constant flow rates while a carrier gas is flowed from the carrier gas supply source 15 to the raw material gas supply pipe 4 at a constant flow rate.

[0070] The supply time for supplying the third raw material gas in the third step is preferably from 1 to 600 seconds, more preferably from 1 to 450 seconds, and further preferably from 1 to 300 seconds. By setting the supply time of the third source gas to a preferable lower limit or more, the reaction with the substrate surface to which the second source gas is adsorbed proceeds sufficiently until the reaction is saturated. By setting the supply time to a preferable upper limit or less, a thin film can be formed with good productivity.

[0071] The temperature and flow rate in the treatment chamber 2 in the third step may be set appropriately depending on the reactivity of the reactants, but it is preferable to set the same temperature, flow rate, and pressure as in the first step because they are easier to control. By repeating the second and third steps multiple times (multiple cycles, for example, 500 cycles), a metal film having a desired thickness, or a metal compound film such as a metal nitride film, a metal oxide film, a metal carbide film, or a metal carbonitride film, can be produced.

[0072] In this embodiment, the main methods for switching between different source gases for each process include the above four methods (i) to (iv), as in the first embodiment. FIG. 8 shows, as a specific example of (ii), an example in which the supply time for supplying the first raw material gas in the first step is 600 seconds, the supply time for supplying the second raw material gas in the second step and the supply time for supplying the third raw material gas in the third step are each 10 seconds, and the time for flowing the carrier gas when switching raw material gases is 10 seconds.

[0073] According to this embodiment, since the first source gas in the first step contains highly reactive hydrazine, the number of cycles of the incubation time (the number of cycles until the start of film formation) can be reduced. In this embodiment as well, the number of cycles is counted as one cycle starting from the second process immediately after the end of the first process, with the second process and the third process as a set.

[0074] By reducing the number of incubation cycles, the processing time until film formation can be shortened. In particular, when switching between source gases, time is required to flow a carrier gas or evacuate, so the effect of shortening the processing time until film formation begins is significant.

[0075] <Third embodiment> The thin film manufacturing method according to the first embodiment of the present invention can be carried out, for example, by sequentially supplying a plurality of types of raw material gases using the thin film manufacturing apparatus 200. The second embodiment has the following steps, and is a method for carrying out a pretreatment step in which the following first step and second step are alternately carried out a plurality of times, and then carrying out a film formation step in which the following third step and fourth step are alternately carried out a plurality of times.

[0076] First step: a step of supplying a first source gas containing hydrazine into the processing chamber 2. Second step: a step of supplying a second source gas containing a metal-containing compound into the processing chamber 2. A third step: a step of supplying into the processing chamber 2 a fourth source gas that contains a reactant other than hydrazine that reacts with the metal-containing compound and does not contain hydrazine. Fourth step: A step of supplying a second source gas containing a metal-containing compound into the processing chamber 2.

[0077] The first step of supplying a first raw material gas into the processing chamber 2 can be carried out by flowing a carrier gas from a carrier gas supply source 15 into the raw material gas supply pipe 4 at a constant flow rate while merging hydrazine gas from a hydrazine gas supply source 16 into the raw material gas supply pipe 4 at a constant flow rate. In the first step, a first raw material gas containing highly reactive hydrazine is supplied into the treatment chamber 2, so that the substrate surface can be substituted with bonds derived from hydrazine, thereby increasing the number of reaction points, as shown in FIG. 3.

[0078] The supply time for supplying the first raw material gas in the first step is preferably from 1 to 600 seconds, more preferably from 1 to 450 seconds, and further preferably from 1 to 300 seconds. By setting the supply time of the first raw material gas to a preferable lower limit or more, the number of reaction sites can be sufficiently increased, while by setting the supply time to a preferable upper limit or less, the total processing time can be shortened. The first source gas may contain a reactant other than hydrazine as long as the effect of the present invention is not impaired.

[0079] The preferred temperature, flow rate and pressure in the treatment chamber 2 in the first step are similar to the preferred temperature, flow rate and pressure in the treatment chamber 2 in the first embodiment. The temperature and pressure inside the processing chamber 2 are preferably set to predetermined temperature and pressure for the first step before the start of the first step.

[0080] The second step of supplying the second raw material gas into the processing chamber 2 can be carried out by flowing a carrier gas from the carrier gas supply source 15 into the raw material gas supply pipe 4 at a constant flow rate while merging the metal-containing compound gas from the metal-containing compound gas supply source 17 into the raw material gas supply pipe 4 at a constant flow rate. In the second step, a metal-containing compound is chemisorbed onto the reaction sites on the substrate surface.

[0081] The supply time for supplying the second raw material gas in the second step is preferably from 1 to 600 seconds, more preferably from 1 to 450 seconds, and further preferably from 1 to 300 seconds. By setting the supply time for the second source gas to a preferable lower limit or more, the source gas can be sufficiently adsorbed and saturated at the generated reaction points, and by setting the supply time to a preferable upper limit or less, a thin film can be formed with good productivity. There are no particular limitations on the temperature, flow rate, and pressure inside the treatment chamber 2 in the second step, but it is preferable to set the temperature, flow rate, and pressure to the same as those in the first step, as these are easier to control.

[0082] By performing a pretreatment process in which the first and second steps are repeated multiple times, a large number of reaction sites are formed on the surface of the substrate. The first and second steps are repeated until a thin film having a thickness of 0.1 to 1 nm is formed on the surface of the substrate.

[0083] By repeating the first and second steps until a thin film with a thickness of 0.1 nm or more is formed on the substrate surface, reaction sites are formed with sufficient density on the substrate surface. Also, when a thin film with a thickness of 1 nm or less is formed, a film formation process is started in which the third and fourth steps are repeated, whereby a thin film according to the type of reactant can be rapidly formed.

[0084] The third step of supplying the fourth raw material gas into the processing chamber 2 can be performed by flowing a carrier gas from the carrier gas supply source 15 into the raw material gas supply pipe 4 at a constant flow rate, while merging the hydrazine-free reactant gas from the reactant gas supply source 18 into the raw material gas supply pipe 4 at a constant flow rate. In the third step, the metal-containing compound chemically adsorbed to the reaction points on the substrate surface in the second or fourth step reacts with a reactant to produce a metal film or a metal compound film depending on the type of reactant.

[0085] The supply time for supplying the fourth raw material gas in the third step is preferably from 1 to 600 seconds, more preferably from 1 to 450 seconds, and further preferably from 1 to 300 seconds. By setting the supply time for the fourth raw material gas to a preferable lower limit or more, the reaction with the fourth raw material gas can be sufficiently progressed until it becomes saturated on the substrate surface on which reaction points have been formed by repeating the first and second steps. In addition, by setting the supply time to a preferable upper limit or less, a thin film can be formed with good productivity.

[0086] The temperature and flow rate in the treatment chamber 2 in the third step may be set appropriately depending on the reactivity of the reactants, but it is preferable to set the same temperature, flow rate, and pressure as in the first step because they are easier to control.

[0087] The fourth step of supplying the second raw material gas into the processing chamber 2 can be carried out by flowing a carrier gas from the carrier gas supply source 15 into the raw material gas supply pipe 4 at a constant flow rate while merging the metal-containing compound gas from the metal-containing compound gas supply source 17 into the raw material gas supply pipe 4 at a constant flow rate. In the fourth step, the metal-containing compound is chemisorbed onto the substrate surface reacted in the third step.

[0088] The supply time for supplying the second raw material gas in the fourth step is preferably from 1 to 600 seconds, more preferably from 1 to 450 seconds, and further preferably from 1 to 300 seconds. By setting the supply time for supplying the second source gas to a preferable lower limit or more, the source gas is adsorbed and saturated on the substrate surface where the reaction has sufficiently progressed to saturation in the third step. By setting the supply time to a preferable upper limit or less, a thin film can be formed with good productivity. There are no particular limitations on the temperature, flow rate, and pressure inside the treatment chamber 2 in the fourth step, but it is preferable to set the temperature, flow rate, and pressure to the same as those in the first step because these are easier to control.

[0089] By repeating the third and fourth steps multiple times (multiple cycles, for example, 500 cycles), a thin film of a metal or a metal compound such as a metal nitride, metal oxide, metal carbide, or metal carbonitride having a desired thickness can be produced.

[0090] In this embodiment, the main methods for switching between different source gases for each process include the above four methods (i) to (iv), as in the first embodiment. FIG. 9 shows, as a specific example of (ii), an example in which the supply time for each raw material gas in the first to fourth steps is 10 seconds, and the time for flowing the carrier gas when switching the raw material gas is 10 seconds.

[0091] According to this embodiment, the pretreatment process consisting of the first and second steps using highly reactive hydrazine is repeated, so that the number of cycles of the incubation time (the number of cycles until the formation of the film begins) can be reduced. In this embodiment, the number of cycles (Y cycle in FIG. 9) is counted as one cycle, starting from the third step immediately after the end of the pretreatment step (immediately after the end of the second step of the Xth cycle in FIG. 9).

[0092] By reducing the number of incubation cycles, the processing time until film formation can be shortened. In particular, when switching between source gases, time is required to flow a carrier gas or evacuate, so the effect of shortening the processing time until film formation begins is significant.

[0093] [Effects] As already explained, each of the above embodiments has the effect of reducing the number of incubation cycles, and therefore the processing time until the start of film formation, which is believed to be because the substrate surface is exposed to highly reactive hydrazine at least in the first step, thereby increasing the number of reaction sites.

[0094] In addition, according to each of the above embodiments, the film thickness is less dependent on the surface material of the substrate. Although the number of cycles of the incubation time is somewhat dependent on the surface material of the substrate in each of the above embodiments, the absolute value of the number of cycles of the incubation time is reduced, so that the final film thickness difference due to the difference in the surface material is easily reduced.

[0095] In particular, in the first embodiment, if the supply time for the first source gas in the first step is made sufficiently long, the number of cycles of the incubation time can be made extremely small regardless of the surface material. As a result, regardless of the surface material, film formation starts simultaneously substantially immediately after the end of the first step, and the film thickness difference can be almost completely eliminated.

[0096] Furthermore, in the above embodiment, it is easy to form a thin film with excellent smoothness. This is believed to be because highly reactive hydrazine forms reaction points at a high density on the substrate surface. If the density of reaction points formed on the substrate surface is low, a difference in film thickness occurs between the areas where reaction points are present and those where they are not, and the smoothness is believed to be impaired. EXAMPLES

[0097] <Base material> In the following experimental examples, substrates with various surface materials were used. The following materials were used for the outermost surface and the substrates whose outermost surfaces were made of these materials.

[0098] [The outermost surface is SiO] Base material: silicon wafer. Film type: thermal oxide film 100nm. [The top surface is Si] Base material: silicon wafer. [Top surface is Cu] Base material: silicon wafer. Film type: Cu (sputtering method) 100 nm. [The top surface is AlO] Base material: silicon wafer. Film type: AlO (CVD method) 100nm.

[0099] <Gas> The following raw material gases were used in the following experimental examples. N2: Nitrogen gas. N2H4: Hydrazine gas. NH3: Ammonia gas. Al(CH3)3: Al(CH3)3 gas. TiCl4: TiCl4 gas. Al(CH3)3: Al(CH3)3 gas.

[0100] <Measurement method etc.> [Temperature inside the treatment chamber] The measured temperature was that of a temperature controller. [Flow rate] The flow rate of the source gas in the processing chamber was calculated based on the cross-sectional area and flow rate of the processing chamber. [pressure] The pressure inside the treatment chamber was measured using a pressure gauge manufactured by MKS. [Flow rate] The flow rate of each source gas was set to the flow rate value by a mass flow controller.

[0101] [Incubation time cycles] For the film thickness at three or more cycles, a graph was created with the cycle number on the x-axis and the film thickness on the y-axis as shown in Figure 10, and the x-intercept calculated by the least squares method was taken as the number of cycles of the incubation time. When the x-intercept was a negative value, the number of cycles was taken as zero.

[0102] In the later-described Examples 1 to 19 and Comparative Examples 1 to 9, the number of cycles is counted as one cycle starting from the second step immediately after the end of the first step, and including the second and third steps as a set. In the later-described Examples 20 and 21 and Comparative Examples 10 and 11, the number of cycles is counted as one cycle starting from the third step immediately after the end of the pretreatment step, and including the third and fourth steps as a set. The film thickness was measured using a spectroscopic ellipsometer manufactured by SOPRA.

[0103] [Time until film formation begins] In Examples 1 to 19 and Comparative Examples 1 to 9 described below, the time (including the nitrogen purging time) from the start of the first step to the completion of a set of the second and third steps of the number of cycles determined above was calculated. In Examples 20 and 21 and Comparative Examples 10 and 11 described below, the time (including the nitrogen purging time) from the start of the initial first step to the completion of the set of the third and fourth steps for the number of cycles determined above was calculated.

[0104] [RMS] For Examples 10 to 13 and Comparative Examples 7 and 8 described below, the "root mean square roughness Rq (RMS)" defined in JIS B 0601 was evaluated using an atomic force microscope (AFM, NanoScope scanning probe microscope manufactured by Digital Instruments).

[0105] <Production and evaluation of thin films> [Examples 1 to 15 and Comparative Examples 1 to 8] After the first step of supplying the first source gas to the surface of the substrate was performed once, the second step of supplying the second source gas and the third step of supplying the third source gas were alternately repeated. However, in Comparative Example 2, the first step was not performed.

[0106] Tables 1 and 2 show the material of the outermost surface of the substrate used in each example, the type of film to be formed, and the temperature inside the processing chamber throughout all steps, as well as the components in the first to third raw material gases used in each example and the supply time of each raw material gas. However, as a component in the first source gas in Example 15, hydrazine that had been plasma-treated in advance was used.

[0107] In the first step, nitrogen gas was used as a carrier gas, the component in the first raw material gas (hydrazine or ammonia) was 50 sccm, and the total flow rate including the carrier gas was 2,000 sccm. In the second step, nitrogen gas was used as a carrier gas, the metal-containing compound in the second source gas was 5 sccm, and the total flow rate including the carrier gas was 2,000 sccm. In the third step, nitrogen gas was used as a carrier gas, the reactant (hydrazine or ammonia) in the third source gas was 50 sccm, and the total flow rate including the carrier gas was 2,000 sccm. In this specification, sccm is ccm normalized at 0°C.

[0108] When switching between the source gases, only the carrier gas was allowed to flow at a flow rate of 2,000 sccm for 10 seconds each. Throughout all steps, the pressure in the process chamber was set to 1 Torr when the film type was AlN or TiN, and 10 Torr when the film type was SiN. Throughout all steps, the flow rate in the processing chamber was set to 10,000 cm / s when the pressure was 1 Torr, and 1,000 cm / s when the pressure was 1 Torr. The number of incubation cycles and the time until the start of membrane formation obtained in each example are shown in Tables 1 and 2.

[0109] [Table 1]

[0110] [Table 2]

[0111] As shown in Table 1, Comparative Example 1, in which ammonia was used as a component in the first raw material gas in the first step, and Comparative Example 2, in which the first step was not performed, had a longer incubation time than Example 1, in which hydrazine was used as a component in the first raw material gas. The incubation time in Comparative Example 2 was shorter than that in Comparative Example 1, probably because highly reactive hydrazine was used in the third step.

[0112] In addition, comparing Examples 1 to 3, the longer the supply time of the first raw material gas, the shorter the incubation time. This is considered to be because the longer the supply time of the first raw material gas, the more reaction points can be generated on the substrate surface.

[0113] In Comparative Examples 1 and 2 and Examples 1 to 3, an AIN film was formed on a substrate whose outermost surface was made of SIO, whereas in Comparative Example 3 and Examples 4 and 5, an AIN film was formed on a substrate whose outermost surface was made of Si, and in Comparative Example 4 and Examples 6 and 7, an AIN film was formed on a substrate whose outermost surface was made of Cu. As shown in Table 1, when comparing Example 3 with Examples 5 and 7, the incubation times did not differ significantly despite the difference in the materials of the outermost surfaces of the substrates. In contrast, the incubation times of Comparative Examples 1, 3, and 4 differed significantly.

[0114] As shown in Table 1, in the case of using a substrate whose outermost surface is made of Si or Cu, as in the case of using a substrate whose outermost surface is made of SIO, in the examples in which hydrazine was used as a component in the first raw material gas, the incubation time was shorter than in the comparative example in which ammonia was used. Also, in the examples, the longer the supply time of the first raw material gas, the shorter the incubation time.

[0115] As shown in Table 2, in Comparative Examples 5 and 6 and Examples 8 and 9, a TiN film was formed on a substrate whose outermost surface was made of AlO. In these cases as well, the incubation time was shorter in the Examples in which hydrazine was used as a component in the first source gas than in the Comparative Examples in which ammonia was used. In addition, in the examples, Example 9 in which the supply time of the first raw material gas was longer had a shorter incubation time than Example 8. On the other hand, in the comparative examples, Comparative Example 6 in which the supply time of the first raw material gas was longer had a smaller number of cycles than Comparative Example 5, but the time until the start of film formation was almost the same.

[0116] As shown in Table 2, in Comparative Examples 7 and 8 and Examples 10 to 15, a SiN film was formed on a substrate whose outermost surface was made of SlO. In these cases as well, the incubation time was shorter in the Examples in which hydrazine was used as a component in the first source gas than in the Comparative Examples in which ammonia was used.

[0117] Furthermore, as shown in Comparative Examples 7 and 8 and Examples 10 to 13, the Examples had smaller RMS (Å) and were more excellent in smoothness. In the comparative example in which ammonia was used as a component in the first source gas, reaction sites were formed sparsely on the substrate surface. In contrast, in the example in which hydrazine was used as a component in the first source gas, reaction sites were formed uniformly and evenly on the substrate surface, which is thought to be why the film surface was formed smoothly.

[0118] Furthermore, the effect of shortening the incubation time was greater in Examples 12 to 15, in which hydrazine was used as the reactant for the third raw material gas in the third step, than in Examples 10 and 11, in which ammonia was used as the reactant for the third raw material gas in the third step. However, in Example 14, where the temperature inside the treatment chamber was set high, the effect of shortening the incubation time was somewhat small. This is thought to be because when the temperature inside the treatment chamber was high, hydrazine was thermally decomposed into ammonia, reducing the effect of using hydrazine.

[0119] [Examples 16 to 19 and Comparative Example 9] After the first step of supplying the first source gas to the surface of the substrate was performed once, the second step of supplying the second source gas and the third step of supplying the third source gas were alternately repeated. The material of the outermost surface of the substrate used in each example was SiO. The film-forming species in each example, the total flow rate including the carrier gas throughout the entire process, the flow rate in the processing chamber, and the temperature in the processing chamber, as well as the components in the first to third source gases used in each example, and the flow rate and supply time of each source gas are shown in Table 3.

[0120] In the first step, nitrogen gas was used as a carrier gas, and the flow rate of the components in the first source gas (hydrazine or ammonia) was controlled so that the partial pressure of the components in the first source gas in the processing chamber was 0.025 Torr. In the second step, nitrogen gas was used as a carrier gas, and the flow rate of the metal-containing compound in the second source gas was controlled so that the partial pressure of the metal-containing compound in the second source gas in the processing chamber was 0.025 Torr. In the third step, nitrogen gas was used as a carrier gas, and the flow rate of the reactant gas in the third source gas was controlled so that the partial pressure of the reactant (hydrazine or ammonia) in the third source gas inside the processing chamber was 0.025 Torr.

[0121] When switching between the source gases, only the carrier gas was allowed to flow at a flow rate of 2,000 sccm for 10 seconds each. Throughout all steps, the pressure in the processing chamber was kept at 1 Torr. Throughout all steps, the flow rate in the treatment chamber was set to the values ​​shown in Table 3. The number of incubation cycles and the time until the start of membrane formation obtained in each example are shown in Table 3.

[0122] [Table 3]

[0123] As shown in Table 3, in Comparative Example 9 and Examples 16 and 17, an AiN film was formed on a substrate whose outermost surface was made of SlO. In these cases as well, the incubation time was shorter in the examples in which hydrazine was used as a component in the first source gas than in the comparative examples in which ammonia was used. However, in Example 17, in which the flow rate in the first step was reduced, the effect of shortening the incubation time was small. This is thought to be because the slower flow rate caused the hydrazine gas to stay in the treatment chamber for a longer time, which led to the hydrazine being thermally decomposed into ammonia, reducing the effect of using hydrazine.

[0124] As shown in Table 3, in Examples 18 and 19, a SiN film was formed on a substrate whose outermost surface was made of SlO. In this case as well, Example 19, which had a high flow rate in the first step, had a greater effect of shortening the incubation time than Example 18. This is believed to be because the increased flow rate shortened the residence time of the hydrazine gas in the treatment chamber, thereby suppressing the thermal decomposition of hydrazine into ammonia.

[0125] [Examples 20 to 21 and Comparative Examples 10 and 11] A pretreatment process in which a first step of supplying a first raw material gas and a second step of supplying a second raw material gas to the surface of the substrate were alternately repeated 20 times, and then a third step of supplying a fourth raw material gas and a fourth step of supplying the second raw material gas were alternately repeated. Table 4 shows the material of the outermost surface of the base material used in each example, the type of film to be formed, and the temperature inside the processing chamber throughout all steps, as well as the components in the first to fourth source gases used in each example and the supply time of each source gas.

[0126] In the first step, nitrogen gas was used as a carrier gas, the component in the first raw material gas (hydrazine or ammonia) was 50 sccm, and the total flow rate including the carrier gas was 2,000 sccm. In the second step, nitrogen gas was used as a carrier gas, the metal-containing compound in the second source gas was 5 sccm, and the total flow rate including the carrier gas was 2,000 sccm. In the third step, nitrogen gas was used as a carrier gas, the reactant (ammonia) in the fourth source gas was 50 sccm, and the total flow rate including the carrier gas was 2,000 sccm. In the fourth step, nitrogen gas was used as a carrier gas, the metal-containing compound in the second source gas was 5 sccm, and the total flow rate including the carrier gas was 2,000 sccm.

[0127] When switching between the source gases, only the carrier gas was allowed to flow at a flow rate of 2,000 sccm for 10 seconds each. Throughout all steps, the pressure in the processing chamber was kept at 10 Torr. Throughout the entire process, the flow rate in the treatment chamber was set to 1,000 cm / s. The number of incubation cycles and the time until the start of membrane formation obtained in each example are shown in Table 4.

[0128] [Table 4]

[0129] As shown in Table 4, in the first step, Comparative Example 10 and Comparative Example 11, in which ammonia was used as a component in the first raw material gas, had a longer incubation time than Example 20 and Example 21, in which hydrazine was used as a component in the first raw material gas, respectively. It is believed that if highly reactive hydrazine is used in the pretreatment process, which involves repeating steps 1 and 2, many reactive sites are formed on the substrate surface, thereby shortening the incubation time. [Explanation of symbols]

[0130] 1 Base material 2. Processing Room 3 Temperature control device 4. Raw gas supply pipe 5 Carrier gas supply pipe 6 Hydrazine gas supply pipe 7 Metal-containing compound gas supply pipe 8 Reactant gas supply pipe 15 Carrier gas supply source 16 Hydrazine gas supply source 17 Metal-containing compound gas supply source 18 Reactant gas supply source 31 Reaction gas exhaust pipe 32 Pressure gauge 33 Pressure control device 100 Thin film manufacturing equipment 200 Thin film manufacturing equipment

Claims

1. A thin film manufacturing method for forming a thin film on a surface of a substrate by sequentially supplying a plurality of types of source gases into a processing chamber that accommodates the substrate, comprising: a first step of supplying a first source gas containing hydrazine into the processing chamber; a second step of supplying a second source gas containing a metal-containing compound into the processing chamber; and a third step of supplying a third source gas containing a reactant that reacts with the metal-containing compound into the processing chamber, A thin film manufacturing method, comprising the steps of: performing the first step once; and then performing the second step and the third step alternately a plurality of times.

2. 2. The thin film manufacturing method according to claim 1, wherein a supply time for supplying the first source gas in the first step is at least twice as long as a supply time for supplying the third source gas in the third step.

3. 2. The thin film manufacturing method according to claim 1, wherein the temperature inside the processing chamber in the first step is 600° C. or less.

4. 2. The method for producing a thin film according to claim 1, wherein the third source gas contains hydrazine as a reactant.

5. 5. The thin film manufacturing method according to claim 4, wherein the temperature inside the processing chamber in the third step is 600[deg.] C. or less.

6. A thin film manufacturing method for forming a thin film on a surface of a substrate by sequentially supplying a plurality of types of source gases into a processing chamber that accommodates the substrate, comprising: a first step of supplying a first source gas containing hydrazine into the processing chamber; a second step of supplying a second source gas containing a metal-containing compound into the processing chamber; a third step of supplying into the processing chamber a fourth source gas containing a reactant other than hydrazine that reacts with the metal-containing compound and does not contain hydrazine; and a fourth step of supplying a second source gas containing the metal-containing compound into the processing chamber, a thin film manufacturing method comprising: alternately repeating the first step and the second step a plurality of times to form a thin film having a thickness of 0.1 to 1 nm on the surface of the substrate; and then alternately repeating the third step and the fourth step a plurality of times.

7. 7. The thin film manufacturing method according to claim 6, wherein the temperature inside the processing chamber in the first step is 600[deg.] C. or less.

8. The thin film manufacturing method according to any one of claims 1 to 7, wherein the substrate has a surface made of a plurality of different materials.

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