CN118266061A

CN118266061A - Method for forming deposited film

Info

Publication number: CN118266061A
Application number: CN202280076694.XA
Authority: CN
Inventors: 佐藤大辅; 冈优希; 谷胁萌
Original assignee: Lishennoco Co ltd
Current assignee: Lishennoco Co ltd
Priority date: 2021-12-02
Filing date: 2022-10-07
Publication date: 2024-06-28

Abstract

The invention provides a method for forming a deposited film, which can form a deposited film with improved uniformity of film thickness. A method for forming a deposited film on a substrate (21) on which a pattern (22) is formed, comprising a deposition step of forming a deposited film (40) on the substrate (21) by using a plasma obtained by plasmatizing a deposition gas in a state in which the substrate (21) is placed on an electrode and bias power is applied or not applied to the electrode, wherein the material constituting the pattern (22) is at least one of a carbonaceous material, a siliceous material and a metal-containing material, the deposition gas contains an unsaturated halogenated hydrocarbon as an unsaturated compound having fluorine atoms, bromine atoms and carbon atoms in the molecule, and the number of carbon atoms is 2 or 3. Further, the power density when bias power is applied to the electrode is greater than 0W/cm ² and not more than 0.5W/cm ².

Description

Method for forming deposited film

Technical Field

The present invention relates to a method for forming a deposited film.

Background

In the process of manufacturing a semiconductor device, there are cases where a semiconductor substrate is etched and deposited by generating plasma by plasmatizing a gas using an etching apparatus. The active species (radicals) of the plasma contributing to the reaction of etching and deposition have a property of being pulled in the direction of the electric field formed between the counter electrodes by a potential difference generated between the counter electrodes to which the bias power is applied. This property is called anisotropy.

When deposition is performed using an etching apparatus, deposition is deposited on the top and side wall surfaces of the pattern formed on the semiconductor substrate and the portion of the surface of the semiconductor substrate where the pattern is not formed, thereby forming a deposited film covering the surface of the pattern and the surface of the semiconductor substrate. For example, patent documents 1 to 3 disclose methods for forming a deposited film on a patterned semiconductor substrate.

Patent literature

[ Prior Art literature ]

[ Patent literature ]

Patent document 1 japanese patent laid-open publication 2009 No. 290079

[ Patent document 2] Japanese patent laid-open publication No. 153702 in 2010

[ Patent document 3] Japanese patent laid-open publication 2012 No. 231162

Disclosure of Invention

[ Problem to be solved by the invention ]

However, since it is difficult to deposit a sufficient amount of the film on the side wall surface of the pattern parallel to the direction of the electric field, the film thickness of the deposited film covering the side wall surface of the pattern tends to be smaller than that of the deposited film covering the top surface of the pattern perpendicular to the direction of the electric field and the surface of the semiconductor substrate. Therefore, it is difficult to make the film thickness of the deposited film uniform by the techniques disclosed in patent documents 1 to 3.

In general, it is preferable that the deposited film has a uniform film thickness. If the deposited film is formed by a method capable of forming a deposited film having a uniform film thickness, the variation in film thickness of the deposited film can be suppressed in addition to the improvement of the controllability of the film thickness of the deposited film.

The invention provides a method for forming a deposited film, which can form a deposited film with improved uniformity of film thickness.

[ Means for solving the problems ]

In order to solve the above problems, the embodiments of the present invention are as follows [1] to [10].

[1] A method for forming a deposited film on a substrate having a pattern formed thereon,

Comprises a deposition step of forming a deposition film on the substrate by using a plasma obtained by plasmatizing a deposition gas in a state where the substrate is placed on an electrode and a bias power is applied or not applied to the electrode,

The material constituting the pattern is at least one of a carbonaceous material, a siliceous material and a metalliferous material,

The deposition gas contains an unsaturated halogenated hydrocarbon (Halon) as an unsaturated compound having fluorine atoms, bromine atoms and carbon atoms in the molecule and the number of carbon atoms is 2 or 3,

The bias power applied to the electrode has a power density of greater than 0W/cm ² and less than 0.5W/cm ² when the bias power is applied.

[2] The method for forming a deposited film according to [1], wherein the number of carbon atoms of the unsaturated halogenated hydrocarbon is 2.

[3] The method for forming a deposited film as described in [1] or [2], wherein the unsaturated halogenated hydrocarbon is an unsaturated compound represented by the chemical formula C ₂H_xBrF_(3-x), wherein x is 0, 1 or 2.

[4] The method for forming a deposited film according to any one of [1] to [3], wherein the deposition gas further contains an inert gas.

[5] The method for forming a deposited film according to [4], wherein the inert gas is at least one of nitrogen, helium, neon, argon, krypton, and xenon.

[6] The method for forming a deposited film according to any one of [1] to [5], wherein the deposition gas further contains at least one selected from the group consisting of fluorocarbons, hydrofluorocarbons, and hydrogen.

[7] The method for forming a deposited film according to [6], wherein the fluorocarbon is at least one of carbon tetrafluoride, hexafluoro-1, 3-butadiene, octafluorocyclobutane and octafluorocyclopentene.

[8] The method for forming a deposited film according to [6], wherein the hydrofluorocarbon is at least one of trifluoromethane, difluoromethane and fluoromethane.

[9] The method for forming a deposited film according to any one of [1] to [8], wherein the deposited film has a crown portion, a side wall portion and a bottom portion, the crown portion is a portion formed on a crown surface of the pattern, the side wall portion is a portion formed on a side wall surface of the pattern, the bottom portion is a portion formed on a portion of the surface of the substrate where the pattern is not formed, and a ratio of a film thickness of the crown portion to a film thickness of the side wall portion and a ratio of a film thickness of the bottom portion to a film thickness of the side wall portion are each 0.7 to 1.6.

[10] The method for forming a deposited film according to any one of [1] to [9], the deposited film having a sidewall portion which is a portion formed on a sidewall surface of the pattern, at least a portion of the sidewall portion being formed so as to bury a gap between adjacent and opposing sidewall surfaces of the pattern.

[ Effect of the invention ]

The invention can form a deposited film with improved uniformity of film thickness.

Drawings

FIG. 1 is a schematic view illustrating an example of a plasma etching apparatus according to an embodiment of a method for forming a deposited film according to the present invention.

FIG. 2 is a schematic cross-sectional view illustrating an example of a substrate on which a deposited film is formed.

Fig. 3 is a schematic cross-sectional view illustrating an example of a substrate on which a deposited film is formed such that a sidewall portion buries a gap between sidewall surfaces of adjacent and opposing patterns.

Fig. 4 is a schematic cross-sectional view illustrating an example in which a recess exists above a buried portion of a deposited film.

Fig. 5 is a schematic cross-sectional view illustrating a state after etching treatment is performed on the substrate of fig. 4.

Fig. 6 is a schematic cross-sectional view illustrating a state in which the substrate of fig. 4 is etched in double patterning using the original pattern and the buried portion as an etching mask.

Fig. 7 is a schematic cross-sectional view illustrating the depth of a recess formed in the upper surface of the buried portion.

FIG. 8 is a schematic cross-sectional view illustrating an example of a substrate subjected to deep trench etching.

Fig. 9 is a schematic cross-sectional view of a substrate to which the 1 st etching step is applied.

Fig. 10 is a schematic cross-sectional view of a substrate to which the 1 st deposition process is applied.

Fig. 11 is a schematic cross-sectional view of a substrate to which the 2 nd etching step is applied.

Fig. 12 is a schematic cross-sectional view of a substrate to which the deposition process 2 is applied.

Fig. 13 is a schematic cross-sectional view of a substrate illustrating the concave portion and the concave amount of the concave portion formed by the deep etching.

Fig. 14 is a schematic cross-sectional view of a substrate illustrating a state in which a gap is generated in a wiring material loaded into the inside of a recess.

Fig. 15 is a schematic cross-sectional view of a substrate illustrating a state in which a wiring material is polished by a polishing step.

Detailed Description

The following description is made of an embodiment of the present invention. The present embodiment is merely an example of the present invention, and the present invention is not limited to the present embodiment. The present embodiment is capable of various modifications and improvements, and such modifications and improvements are also included in the present invention.

The method for forming a deposited film according to the present embodiment is a method for forming a deposited film on a patterned substrate, and includes a deposition step of placing a substrate on an electrode and forming a deposited film on the substrate using a plasma obtained by plasmatizing a deposition gas with or without applying a bias power to the electrode. Further, the material constituting the pattern is at least one of a carbonaceous material, a siliceous material, and a metalliferous material. Furthermore, the deposition gas contains an unsaturated halogenated hydrocarbon (Halon). The unsaturated halogenated hydrocarbon is an unsaturated compound having a fluorine atom, a bromine atom and a carbon atom in the molecule, and the number of carbon atoms is 2 or 3. Further, when the bias power is applied, the power density of the bias power applied to the electrode is greater than 0W/cm ² and not more than 0.5W/cm ².

In addition, the unsaturated halogenated hydrocarbon is an unsaturated compound in which part or all of the halogen atoms of the hydrogen atoms are replaced with bromine atoms, among halogenated unsaturated hydrocarbons in which part or all of the hydrogen atoms of the unsaturated hydrocarbon are replaced with halogen atoms.

If the deposited film is formed by the above-described method, the deposited film can be formed on the patterned substrate with improved uniformity of film thickness. That is, although the deposited film has a top portion (i.e., a portion formed on the top surface of the head of the pattern (a surface substantially flat with the surface of the substrate)), a side wall portion (i.e., a portion formed on the side wall surface of the pattern (a surface substantially perpendicular to the surface of the substrate)), and a bottom portion (i.e., a portion formed on a portion of the surface of the substrate where the pattern is not formed), the deposited film having uniform thicknesses of the top portion, the side wall portion, and the bottom portion can be formed by the deposited film forming method according to the present embodiment.

For example, a deposited film can be formed in which the ratio of the film thickness of the top portion to the film thickness of the side wall portion is 0.3 to 3.5, and the ratio of the film thickness of the bottom portion to the film thickness of the side wall portion is 0.3 to 2.8. The closer the above-mentioned film thickness ratio is to 1, the more uniform the film thickness of the deposited film (the more uniform the film thickness of the deposited film).

The ratio of the film thickness of the head portion to the film thickness of the side wall portion is preferably 0.3 to 3.5, more preferably 0.6 to 3.2, still more preferably 1.0 to 3.0, and particularly preferably 0.7 to 1.6.

The ratio of the film thickness of the bottom portion to the film thickness of the side wall portion is preferably 0.3 to 2.8, more preferably 0.6 to 2.7, still more preferably 0.7 to 2.5, still more preferably 0.7 to 1.6, and particularly preferably 0.8 to 1.6.

In addition, even if the deposited film is a film in which at least a part of the side wall portion is formed to bury the gap between the side wall surfaces of the adjacent and opposing patterns. That is, even if gaps are formed between the side wall surfaces of adjacent and opposing patterns for the side wall portions of the deposited film.

The method for forming a deposited film according to the present embodiment can be used for manufacturing a semiconductor device. Although the deposited film formed during the manufacturing process of the semiconductor device is to be removed at the end, it has a function as a mask for performing a desired etching process. If the film thickness of the deposited film is uniform, the variation in the operation of the mask can be reduced, so that the accuracy of etching can be improved.

Although a large number of deposited films have been formed by the conventional Chemical Vapor Deposition (CVD) method, the deposited films can be formed by using an etching apparatus in the case of the method for forming a deposited film according to the present embodiment, and thus the number of steps for manufacturing a semiconductor device can be reduced, and productivity can be improved. In addition, in the case of the method for forming a deposited film according to the present embodiment, even if an etching apparatus is used, a pattern is not etched, and a deposited film can be formed. Therefore, the pattern shape formed on the substrate is difficult to collapse.

In the present invention, the main component constituting the deposited film is fluorocarbon and fluorocarbon polymer. The fluorocarbon and fluorocarbon polymer are produced by forming a deposition radical by plasma of an unsaturated halogenated hydrocarbon in a deposition gas.

The method for forming a deposited film according to the present embodiment will be described in further detail below with reference to the drawings.

< Substrate >

The type of the substrate on which the deposited film is formed by the deposited film forming method according to the present embodiment is not particularly limited, but a semiconductor substrate such as a silicon substrate may be used.

Pattern >, pattern >

The pattern is formed using a circuit formation technique such as photolithography and nanoimprinting, or a mask formed by plasma etching. The material constituting the pattern is at least one of a carbonaceous material, a siliceous material, and a metalliferous material. As a material constituting the pattern, 1 kind may be used alone, and 2 or more kinds may be used in combination.

The carbonaceous material is a compound having a carbon atom, and examples thereof include amorphous carbon (C) and photoresists.

The photoresist refers to a photosensitive composition whose physical properties such as solubility are changed by light, electron beam, or the like. Examples thereof include photoresists for g-line, h-line, i-line, krF, arF, F2, EUV, and the like. The composition of the photoresist is not particularly limited as long as it is generally used in the semiconductor manufacturing process, and examples thereof include compositions containing polymers synthesized from monomers selected from one of chain olefins, cyclic olefins, (meth) acryl-containing compounds, epoxy-containing compounds, siloxanes, and polyfunctional alcohols (e.g., ethylene glycol). In addition, "(meth) acryl" means a group of at least one of acryl and methacryl.

The silicon-containing material is a compound having a silicon atom or a silicon monomer, and examples of the compound having a silicon atom include silicon compounds such as silicon oxide and silicon nitride.

Silicon oxide is a compound having silicon and oxygen in an arbitrary ratio, and as an example, silicon dioxide (SiO ₂) is given. The purity of the silicon oxide is not particularly limited, but is preferably 30% by mass or more, more preferably 60% by mass or more, and still more preferably 90% by mass or more.

Silicon oxide is a compound having silicon and oxygen in an arbitrary ratio, and as an example, si ₃N₄ is given. Although the purity of the silicon nitride is not particularly limited, it is preferably 30% by mass or more, more preferably 60% by mass or more, and still more preferably 90% by mass or more.

The metal-containing material is a compound having a metal atom or a metal ion, a metal simple substance, or an alloy, and examples of the compound having a metal atom or a metal ion include metal oxides. Examples of the metal include hafnium, tungsten, aluminum, zirconium, cobalt, tin, ruthenium, and nickel.

As shown in the example of fig. 2, the pattern 22 formed on the substrate 21 is generally rectangular in cross section, and has a top surface 31 substantially parallel to the surface of the substrate 21 and a side wall surface 32 substantially perpendicular to the surface of the substrate 21, so that the deposition film 40 is formed on the top surface 31 and the side wall surface 32. Further, since a portion where the pattern 22 is not formed is present on the surface of the substrate 21, the deposited film 40 is also formed on the portion.

In the present embodiment, among the deposited films 40 formed on the substrate 21, the portion formed on the top surface 31 of the pattern 22 is referred to as a top portion 41, the portion formed on the side wall surface 32 of the pattern 22 is referred to as a side wall portion 42, and the portion formed on the portion 33 where the pattern 22 is not formed on the surface of the substrate 21 is referred to as a bottom portion 43.

< Deposition gas >)

In the method for forming a deposited film according to the present embodiment, a gas containing an unsaturated halogenated hydrocarbon is used as a deposition gas. The unsaturated halogenated hydrocarbon is an unsaturated compound having a fluorine atom, a bromine atom and a carbon atom in the molecule, and the number of carbon atoms is 2 or 3.

In the process of forming a deposited film, although a deposition gas is plasmatized to generate plasma, and the deposited film is formed by reactive species (depositional radicals) of the plasma contributing to the reaction of deposition, a bromine compound is generated from the depositional radicals because an unsaturated halogenated hydrocarbon has bromine atoms.

In the case of using a fluorocarbon-based gas as a deposition gas, although a fluorocarbon compound is generated from a depositional radical, when a bromine carbide compound and a fluorocarbon compound are compared, the boiling point of the bromine carbide compound is relatively low, and deposition is liable to be deposited. Therefore, the deposition amount to the sidewall surface of the pattern becomes larger than in the case of using the fluorocarbon-based gas as the deposition gas.

The unsaturated halogenated hydrocarbon is not particularly limited, and may be any unsaturated compound having a fluorine atom, a bromine atom, and a carbon atom in the molecule and having 2 or 3 carbon atoms, and examples thereof include an unsaturated halogenated hydrocarbon represented by the formula C ₂H_xBrF_(3-x) in which x is 0, 1, or 2, or an unsaturated halogenated hydrocarbon represented by the formula C ₃H_yBrF_(5-y) in which y is an integer of 0 to 4.

Examples of the unsaturated halogenated hydrocarbon represented by the formula C ₂H_xBrF_(3-x), wherein x is 0, 1 or 2, include bromotrifluoroethylene (C ₂BrF₃), 1-bromo-2-fluoroethylene (C ₂H₂ BrF) and 1-bromo-1-fluoroethylene (C ₂H₂ BrF).

Examples of the unsaturated halogenated hydrocarbon represented by the formula C ₃H_yBrF_(5-y), in which y is an integer of 0 to 4 inclusive, include 2-bromopentafluoropropene C ₃BrF₅, bromofluorocyclopropene (C ₃H₂ BrF), 3-bromo-2-fluoropropene (C ₃H₄ BrF), 3-bromo-3, 3-difluoropropene (C ₃H₃BrF₂), 2-bromo-3, 3-trifluoropropene (C ₃H₂BrF₃), and 1-bromo-2, 3-tetrafluoropropene (C ₃HBrF₄).

Of these unsaturated halogenated hydrocarbons, an unsaturated halogenated hydrocarbon having a number of carbon atoms of 2 is more preferable, and an unsaturated halogenated hydrocarbon having a chemical formula of C ₂H_xBrF_(3-x) in which x is 0, 1 or 2 is still more preferable.

The unsaturated halogenated hydrocarbon may be used alone in an amount of 1 or 2 or more.

The deposition gas may be a gas composed of only an unsaturated halogenated hydrocarbon, or may be a mixed gas containing an unsaturated halogenated hydrocarbon and an inert gas.

Although the type of the inert gas is not particularly limited, examples thereof include nitrogen (N ₂), helium (He), neon (Ne), argon (Ar), krypton (Kr) and xenon (Xe). The inert gas may be used alone in 1 kind or in combination of 2 or more kinds.

The deposition gas may be a mixed gas containing at least one member selected from the group consisting of fluorocarbon, hydrofluorocarbon, and hydrogen (H ₂) (hereinafter, also referred to as "additive gas"). That is, the deposition gas may be a mixed gas containing an unsaturated halogenated hydrocarbon and an additive gas, or a mixed gas containing an unsaturated halogenated hydrocarbon, an inert gas, and an additive gas. If the deposition gas contains an additive gas, the shape of the deposited film can be made better. As the additive gas, 1 kind may be used alone, and 2 or more kinds may be used in combination. The additive gas is added in an amount of preferably 0 to 200% by volume, more preferably 50 to 100% by volume, based on the unsaturated halogenated hydrocarbon.

Examples of the fluorocarbon include carbon tetrafluoride (CF ₄), hexafluoro-1, 3-butadiene (C ₄F₆), octafluorocyclobutane (C ₄F₈) and octafluorocyclopentene (C ₅F₈).

Examples of the hydrofluorocarbon include trifluoromethane (CHF ₃), difluoromethane (CH ₂F₂) and fluoromethane (CH ₃ F).

The concentration of the unsaturated halogenated hydrocarbon in the deposition gas is not particularly limited, and may be set to be more than 0% by volume and 100% by volume or less. However, in order to make the pattern difficult to etch and to make the deposition radicals more formed, it is preferable that the concentration of the unsaturated halogenated hydrocarbon in the deposition gas is 3% by volume or more and 70% by volume or less. In order to facilitate adjustment of the film thickness of the deposited film, it is more preferable that the concentration of the unsaturated halogenated hydrocarbon in the deposition gas is 5% by volume or more and 15% by volume or less.

< Deposition procedure >)

The deposition step in the method for forming a deposited film according to the present embodiment is performed by generating plasma by plasmatizing a deposition gas using an etching apparatus or the like. The type of the plasma source for converting the deposition gas into plasma is not particularly limited, and a commercially available plasma generator may be used. For example, high-frequency discharge plasmas such as inductively coupled (ICP: inductively Coupled Plasma) and capacitively coupled plasmas (CCP: CAPACITIVELY COUPLED PLASMA) are used.

The plasma etching apparatus of fig. 1 described in detail later is a plasma etching apparatus in which ICP is a plasma source.

In the method for forming a deposited film according to the present embodiment, even if the plasma generation chamber and the chamber in which the substrate is provided are distinguished, plasma may be generated in the plasma generation chamber outside the chamber (that is, even if remote plasma is used).

In performing the deposition step, a patterned substrate is placed on a1 st electrode (for example, a lower electrode) among at least 1 st electrodes disposed in a chamber of a plasma etching apparatus, for example, and a deposition gas is introduced into the chamber. Then, the deposition gas is plasmatized to generate plasma, and a bias power having a specific power density or less (including a power density of 0W/cm ²) is applied to the 1 st electrode to form a deposition film on the substrate. In the case where the plasma generating device is an ICP or CCP, the 1 st electrode is a lower electrode of the ICP or CCP. In the case where the plasma generator is a CCP, the plasma generator includes a2 nd electrode facing the 1 st electrode, and the 2 nd electrode is an upper electrode of the CCP.

The amount of the deposition gas used in the method for forming a deposition film according to the present embodiment, for example, the total flow rate of the deposition gas into the chamber for performing the deposition step in the plasma etching apparatus, can be adjusted in accordance with the internal volume of the chamber, the exhaust capability, the processing pressure, and the like.

[ Conditions of deposition Process ]

The pressure conditions in the deposition step in the deposition film formation method according to the present embodiment are not particularly limited, but are preferably 0.2Pa to 133.3Pa, more preferably 1Pa to 13.3Pa, still more preferably 1Pa to 10Pa, still more preferably 1Pa to 5Pa, from the viewpoint of forming a deposition film having a uniform film thickness on the surface of the substrate.

Although the film thickness of the bottom portion of the deposited film tends to be insufficient when the pressure is high, if the pressure is within the above range, the bottom portion of the sufficient film thickness is easily obtained, and the sidewall portions of the same extent of film thickness as the top portion and the bottom portion of the head are easily obtained.

In the plasma etching apparatus, for example, an electric field and a magnetic field are formed by applying a high-frequency source power to a radio frequency RF (radio frequency) coil, and a deposition gas is plasmatized to generate plasma. The source power is not particularly limited, but is preferably greater than 0W and not more than 3000W, more preferably from 100W to 1500W, and still more preferably from 200W to 1000W. When the source power is within the above range, a deposited film having a uniform film thickness can be formed at a sufficient speed while suppressing etching of the pattern.

In the case where the 2 nd electrode is present as in the case where the plasma generator is a CCP, the power density of the power applied to the 2 nd electrode is preferably set to be more than 0W/cm ² and 10W/cm ² or less, more preferably set to be 0.3W/cm ² or more and 5W/cm ² or less, and still more preferably set to be 0.6W/cm ² or more and 3W/cm ² or less. The power density of the power applied to the 2 nd electrode is the power per unit area applied to the electrode surface of the 2 nd electrode.

Although the temperature conditions of the deposition step in the deposition film formation method according to the present embodiment are not particularly limited, the temperature of the substrate at the time of deposition film formation is preferably from-20 ℃ to 250 ℃, more preferably from-20 ℃ to 100 ℃, and even more preferably from 0 ℃ to 70 ℃. When the temperature of the substrate at the time of formation of the deposited film is within the above-mentioned numerical range, the deposited film is hard to peel off, and the deposited film is hard to be etched.

In the formation of the deposited film, the power density of the bias power applied to the electrode (1 st electrode) must be set to 0W/cm ² or more than 0W/cm ² and 0.5W/cm ² or less. Further, in order to suppress etching at the time of forming a deposited film, it is preferable to set the power density of the bias power applied to the electrode (1 st electrode) to be more than 0W/cm ² and 0.3W/cm ² or less, and more preferably to be more than 0W/cm ² and 0.2/cm ² W or less. The power density of the bias power applied to the electrode (1 st electrode) is the power per unit area applied to the electrode surface of the electrode (1 st electrode).

By appropriately setting the conditions of the deposition process, that is, the source power, bias power, the temperature and pressure of the substrate, the concentration of the unsaturated halogenated hydrocarbon in the deposition gas, and the like, and performing the deposition process, a deposited film is formed, and the uniformity of the film thickness of the deposited film can be further improved.

Etching apparatus

An example of a plasma etching apparatus capable of performing the method for forming a deposited film according to the present embodiment will be described below with reference to fig. 1. A method of forming a deposited film on the surface of a substrate having a pattern formed thereon will be described with reference to the plasma etching apparatus shown in fig. 1. The plasma etching apparatus of fig. 1 is a plasma etching apparatus in which ICP is a plasma source. First, a plasma etching apparatus of fig. 1 will be described.

The plasma etching apparatus of fig. 1 includes:

a chamber 1 in which deposition film formation is performed,

A lower electrode 2 (corresponding to the "1 st electrode") for supporting a counter electrode of a substrate 20 for forming a deposition film in the chamber 1,

A bias power source (not shown) for applying bias power to the counter electrode,

An RF coil 15 for forming an electric field and a magnetic field for plasmatizing the deposition gas in the chamber 1,

A source power supply (not shown) for applying a high-frequency source power to the RF coil 15,

A vacuum pump 13 for depressurizing the interior of the chamber 1,

A pressure gauge 14 for measuring the pressure in the chamber 1,

Sensor 16 for acquiring plasma luminescence with generation of plasma, and

A spectroscope 17 for spectroscopically monitoring the temporal change of the plasma luminescence (light of a wavelength ranging from, for example, an ultraviolet light region to a visible light region) by spectroscopically dispersing the plasma luminescence acquired by the sensor 16.

An example of the substrate 20 is shown in fig. 2. Fig. 2 is a schematic cross-sectional view of a silicon substrate 21 having a pattern 22 formed on a surface thereof. The pattern 22 is composed of at least one of a carbon-containing material, a silicon-containing material, and a metal-containing material (e.g., photoresist, silicon oxide, silicon nitride, metal oxide, etc.).

As the sensor 16, for example, a CCD (Charge-Coupled Device) image sensor can be used. However, instead of providing the sensor 16 and the spectroscope 17, a peeping window may be provided in the chamber 1, and the interior of the chamber 1 may be visually observed from the peeping window to confirm the temporal change in the plasma emission.

The chamber 1 further includes a deposition gas supply unit for supplying a deposition gas into the chamber 1. The deposition gas supply section includes an unsaturated halogenated hydrocarbon gas supply section 3 for supplying an unsaturated halogenated hydrocarbon, an inert gas supply section 4 for supplying an inert gas, a deposition gas supply pipe 11 for connecting the unsaturated halogenated hydrocarbon gas supply section 3 and the chamber 1, and an inert gas supply pipe 12 for connecting the inert gas supply section 4 to an intermediate portion of the deposition gas supply pipe 11.

When the unsaturated halogenated hydrocarbon gas is supplied as the deposition gas to the chamber 1, the unsaturated halogenated hydrocarbon gas is supplied from the unsaturated halogenated hydrocarbon gas supply unit 3 to the deposition gas supply pipe 11, and the unsaturated halogenated hydrocarbon gas is supplied to the chamber 1 through the deposition gas supply pipe 11.

The pressure in the chamber 1 before the deposition gas is supplied is not particularly limited as long as it is lower than the supply pressure of the deposition gas or lower than the supply pressure of the deposition gas, but is preferably, for example, 10 ^-5 Pa or higher and less than 100kPa, more preferably, 1Pa or higher and 80kPa or lower.

When a mixed gas of an unsaturated halogenated hydrocarbon gas and an inert gas is supplied as a deposition gas, the unsaturated halogenated hydrocarbon gas is supplied from the unsaturated halogenated hydrocarbon gas supply unit 3 to the deposition gas supply pipe 11, and the inert gas is supplied from the inert gas supply unit 4 to the deposition gas supply pipe 11 via the inert gas supply pipe 12. Therefore, the unsaturated halogenated hydrocarbon gas and the inert gas are mixed in the middle portion of the deposition gas supply pipe 11 to form a mixed gas, and the mixed gas is supplied to the chamber 1 through the deposition gas supply pipe 11.

In the case where a mixed gas of an unsaturated halogenated hydrocarbon gas, an inert gas, and the additive gas is supplied as a deposition gas, the configuration of the deposition gas supply unit may be the same as that of the case where a mixed gas of an unsaturated halogenated hydrocarbon gas and an inert gas is supplied as a deposition gas, with the configuration of the unsaturated halogenated hydrocarbon gas supply unit 3, the inert gas supply unit 4, the deposition gas supply pipe 11, the inert gas supply pipe 12, and the additive gas supply unit and the additive gas supply pipe.

When forming a deposition film using such a plasma etching apparatus, the substrate 20 is placed on the lower electrode 2 disposed in the chamber 1, the pressure in the chamber 1 is reduced to, for example, 1Pa to 10Pa inclusive by the vacuum pump 13, and then a deposition gas is supplied into the chamber 1 by the deposition gas supply unit. The lower electrode 2 is one of two electrodes constituting a counter electrode.

When a source power of a high frequency (for example, 13.56 MHz) is applied to the RF coil 15, electrons are accelerated by forming an electric field and a magnetic field inside the chamber 1, and the accelerated electrons collide with unsaturated halogenated hydrocarbon molecules in the deposition gas to regenerate ions and electrons, and as a result, discharge is caused to form plasma. The generation of plasma can be confirmed using the sensor 16 and the spectroscope 17.

When plasma is generated, a deposition film is formed on the surface of the substrate 20. Details are described with reference to fig. 2. Since the active species (deposition radicals) of the plasma are pulled in the direction of the electric field formed between the counter electrodes (that is, because of having anisotropy) by the potential difference generated between the counter electrodes to which the bias power having a specific power density or less (including a power density of 0W/cm ²) is applied, it is not easy to deposit a deposition film by depositing on the sidewall surface of the pattern when the deposition film is formed by using the etching apparatus, and it is not easy to form a deposition film that improves the uniformity of the film thickness.

However, in the method for forming a deposited film according to the present embodiment, since the power density of the bias power applied to the lower electrode 2 (1 st electrode) is 0W/cm ² or more than 0W/cm ² and 0.5W/cm ² or less, the anisotropy becomes weak, and deposition is easily deposited on the sidewall surface of the pattern. Accordingly, the deposition film 40 is uniformly formed on the top surface 31 and the side wall surface 32 of the pattern 22, and the portion 33 of the surface of the substrate 21 where the pattern 22 is not formed.

That is, among the deposited films 40 formed on the substrate 21, the crown portion 41 (the portion formed on the crown surface 31), the sidewall portion 42 (the portion formed on the sidewall surface 32), and the bottom portion 43 (the portion formed on the portion 33 where the pattern 22 is not formed among the surfaces of the substrate 21), as shown in fig. 2, the film thickness is uniform.

As described above, even if the deposited film 40 is formed so as to bury the gap G formed between the side wall surfaces 32, 32 of the adjacent and opposed patterns 22, 22 in at least a part of the side wall portion 42 (see fig. 3). As can be seen from fig. 3, the gap G is filled with the deposited film 40 (sidewall portion 42). In the portion formed to bury the gap G in the sidewall 42, the sidewall 42 and the bottom 43 may be integrated.

A technique of forming a deposited film such that a sidewall portion fills a gap between adjacent and opposing sidewall surfaces of a pattern (hereinafter, a process of forming a deposited film such that a sidewall portion fills the gap is referred to as "burying", and a sidewall portion formed such that the gap is buried is referred to as "burying") may be applied as an example of a double patterning process as a semiconductor microfabrication technique.

In the double patterning, although the etching process is performed after the implantation, the deposited film 140 deposited on the original pattern 122 (composed of the 1 st pattern 122A and the 2 nd pattern 122B) is removed, when the recess 150 is present on the upper surface of the implantation portion (the surface substantially parallel to the substrate surface) (see fig. 4), the upper surface of the implantation portion is lower than the upper surface of the 2 nd pattern 122B after the etching process (see fig. 5).

In double patterning, since the original pattern 122A and the buried portion constituting the new pattern are used as etching masks, and the original pattern 122B and the underlying film 120 on the substrate are further etched (see fig. 6), the thickness of the etching masks varies when the upper surface of the buried portion is lower than the upper surface of the 2 nd pattern 122B. If the thickness of the etching mask varies, the variation in the shape of the underlying film 120 after etching is a factor of the variation, and is therefore undesirable. For this reason, the upper surface of the embedded portion (the side wall portion 42) is preferably flat as shown in fig. 3, without a recess.

The conditions of the deposition process for forming the deposited film so that the sidewall portion fills the gap are the same as those of the deposition process described above, but the higher the bias power, the more likely the upper surface of the buried portion tends to be flat, so that the power density of the bias power is preferably greater than 0W/cm ² and 0.5W/cm ² or less, more preferably 0.1W/cm ² or more and 0.5W/cm ² or less, and still more preferably 0.3W/cm ² or more and 0.5W/cm ² or less.

Further, in the case of forming a pattern of a gap to be buried, when the ratio of the height of the pattern to the size (width) of the gap (hereinafter, referred to as "deep-height ratio") is large, deposition is difficult on the side wall surface of the pattern, and it is difficult to completely bury the gap by deposition. Therefore, the depth-to-height ratio is preferably greater than 0 and 15 or less, more preferably from 0.5 to 5 or less, and still more preferably from 1 to 3 or less.

The processing time for the implantation is as follows. The size of the gap to be filled is X (nm), and the deposition rate of the sidewall is Y (nm/s). The minimum processing time also requires the time to deposit the full buried gap and, furthermore, does not require the deposition of a flat top surface of the buried portion. Therefore, the processing time is preferably not less than (X/2)/Y seconds and not more than 6X (X/2)/Y seconds, more preferably not less than 2X (X/2)/Y seconds and not more than 5X (X/2)/Y seconds, and still more preferably not less than 3X (X/2)/Y seconds and not more than 4X (X/2)/Y seconds. That is, the processing time for the implantation is preferably 1 to 6 times, more preferably 2 to 5 times, still more preferably 3 to 4 times, the time required for slightly burying the side wall portion in the gap.

The depth (recess amount) of the recess 50 formed in the upper surface of the re-buried portion is as follows. The ratio of the depression amount C to the height H of the pattern 22 is defined as a depression ratio (refer to fig. 7). The dent ratio is preferably 0 to 0.1, more preferably 0 to 0.05, still more preferably 0 to 0.01.

The deposition film 40 is derived from an unsaturated halogenated hydrocarbon as a deposition gas. For example, in the case where the unsaturated halogenated hydrocarbon is 1-bromo-1-fluoroethylene, the 1-bromo-1-fluoroethylene is decomposed by plasma to form CF ₂, and polytetrafluoroethylene is formed from the CF ₂. The generated polytetrafluoroethylene is deposited on the substrate 21 to form the deposited film 40.

The supply amount of the deposition gas to the chamber 1 or the concentration of the unsaturated halogenated hydrocarbon gas in the deposition gas (mixed gas) can be adjusted by controlling the flow rates of the unsaturated halogenated hydrocarbon gas and the inert gas by mass flow controllers (not shown) provided in the deposition gas supply pipe 11 and the inert gas supply pipe 12, respectively.

The method for forming a deposited film according to the present embodiment can be used for deep etching described below. An example of the deep trench etching will be described with reference to fig. 8 to 12.

A film 23 made of an etching target (for example, silicon oxide) that is an etching target of deep etching is formed on a substrate 21 such as a silicon substrate, and a pattern 22 made of, for example, a carbon-containing material (for example, a photoresist) is formed on the film 23, whereby the substrate 21 on which the pattern 22 is formed is obtained (see fig. 8).

Although the substrate 21 on which the pattern 22 is formed is etched in depth, first, the 1 st etching step is performed to transfer the pattern 22 to the film 23, thereby forming the recess 24 (see fig. 9). After the 1 st etching step, the 1 st deposition step is performed on the substrate 21 on which the pattern 22 is formed, and a deposited film 40 is formed on the top surface and the side wall surfaces of the pattern 22 and on the side surfaces of the recess 24 (see fig. 10). In the 1 st deposition step, a deposition gas containing an unsaturated halogenated hydrocarbon such as bromotrifluoroethylene is used.

Next, the substrate 21 on which the pattern 22 is formed is subjected to the 2 nd etching step subsequent to the 1 st deposition step, and the depth of the recess 24 is further increased (see fig. 11). At this time, the recess 24 is deeply dug, and the deposited film 40 formed on the top head surface and the side wall surfaces of the pattern 22 and on the side surfaces of the recess 24 is removed.

Next, the 2 nd etching step is performed on the substrate 21 on which the pattern 22 is formed, and a deposition film 40 is formed on the top surface of the head and the side wall surfaces of the pattern 22 and on the side surfaces of the recess 24, as in the 1 st deposition step (see fig. 12).

Thus, by alternately repeating the etching process and the deposition process, deep etching can be performed. In the etching process at this time, the reduction in thickness of the pattern 22 is suppressed by the deposited film 40 formed on the top surface of the head of the pattern 22. Further, by the deposited film 40 formed on the side surface of the concave portion 24, the side surface of the concave portion 24 is suppressed from being etched and the size of the concave portion 24 in the radial direction (i.e., the direction orthogonal to the depth direction) is enlarged (concave). Further, since the reduction in thickness of the pattern 22 or the inward recessing of the recessed portion 24 is suppressed, if the recessed portion 24 of a certain shape is easily formed by the deep etching.

The amount of dishing (hereinafter, also referred to as "dishing amount") generated in the etching step is preferably small, more preferably from-30 nm to 30nm, still more preferably from-10 nm to 10nm, and still more preferably from-5 nm to 5 nm.

The amount of concavity is defined as follows. The description will be given with reference to fig. 13. A film 23 composed of an etching target object to be etched by deep etching is laminated on the substrate 21, and a pattern 22 is formed on the film 23. Then, in the film 23, a recess 24 formed by transferring the pattern 22 is formed by etching. The recess 24 is a through hole penetrating the film 23 in the thickness direction. The diameter of the top 24t of the recess 24, that is, the diameter of the boundary between the pattern 22 and the film 23 is set to Dt, and the diameter of the inner recess 24b of the recess 24, that is, the diameter of the portion of the side surface of the recess 24 where the inner recess is generated, which is etched most in the radial direction of the recess 24 (the direction orthogonal to the depth direction of the recess 24), is set to Db. At this time, a value obtained by subtracting the diameter Dt of the top portion 24t from the diameter Db of the concave portion 24b is defined as the concave amount.

When the recess 24 is recessed by etching, the following defects may occur. That is, when the wiring material 25 such as metal is incorporated into the recess 24 after the pattern 22 is removed after etching, a gap 26 called a void or seam may be generated in the recess 24b or the like in the recess 24 (see fig. 14).

After the wiring material 25 such as metal is put into the recess 24, the substrate 21 is supplied to a polishing step or a cleaning step of polishing the excessive wiring material 25, but when the gap 26 is generated in the wiring material 25 in the recess 24, the abrasive used in the polishing step or the cleaning step after the polishing step is likely to be a foreign matter remaining in the gap 26 (see fig. 15). Such foreign matter is undesirable because it causes a decrease in wafer yield and abnormal characteristics.

Examples (example)

The present invention will be described in more detail by the following examples and comparative examples.

Example 1

A deposited film was formed on the surface of the substrate by using an ICP etching apparatus RIE-200iP manufactured by Samco corporation, which has substantially the same constitution as the plasma etching apparatus shown in FIG. 1.

The substrate has substantially the same structure as the substrate of fig. 2. That is, a linear pattern made of silicon oxide is formed on a silicon substrate. The cross-sectional shape of the pattern was substantially rectangular, and the thickness (height) thereof was 300nm. The substrate was fabricated as follows.

A silicon oxide film having a film thickness of 300nm is formed on a silicon substrate, and a photoresist pattern (not shown) patterned by lines and gaps having a width of 250nm is formed on the silicon oxide film. The photoresist pattern is formed by photolithography using KrF photoresist. The silicon oxide film is etched by plasma etching using the photoresist pattern as a mask, thereby forming a line pattern made of silicon oxide. Thereafter, the remaining photoresist pattern is removed by oxygen plasma.

The volume of the interior of the chamber of the etching apparatus was 463000 cm ³, and the deposition gas was a mixed gas of bromotrifluoroethylene gas and argon gas. The concentration of the bromotrifluoroethylene gas in the deposition gas was adjusted to 20 vol% by setting the flow rate of the bromotrifluoroethylene gas to 10sccm and the flow rate of the argon to 90sccm by a mass flow controller. Here, sccm is the volume flow per 1 minute (cm ³) normalized at 0 ℃,1 atm.

The substrate thus manufactured is placed on a lower electrode provided in the chamber. The electrode area of the lower electrode was 324cm ². The process pressure in the chamber was set to 3Pa, the source power was set to 500W, the bias power was set to 50W, the substrate temperature was set to 20 ℃, and the flow rate of bromotrifluoroethylene gas, the flow rate of argon gas, the process pressure, the source power and the bias power were monitored at any time, and the deposition film was formed for 10 minutes while confirming that the set value and the execution value of each were not different. The occurrence of plasma was confirmed by monitoring the temporal change of plasma emission with a sensor or visually. The processing conditions are set so that the attention pattern is not etched.

When the formation of the deposited film was completed, the substrate was taken out from the chamber of the etching apparatus, and the substrate was taken out, and cut using a diamond cutter so that the cut surface became an observation surface, to prepare rectangular chips having dimensions of 5mm in the vertical direction and 3mm in the horizontal direction. The film thickness of the deposited film was measured by analyzing the small piece with a Scanning Electron Microscope (SEM) manufactured by hitachi technologies corporation at a magnification of 100000. The film thickness was measured for the top, side wall and bottom of the deposited film (see fig. 2). The ratio of the film thickness at the top of the head to the film thickness at the side wall and the ratio of the film thickness at the bottom to the film thickness at the side wall are calculated, respectively. The results are shown in Table 1.

Examples 2 to 14 and comparative examples 1 to 3

A deposited film was formed in the same manner as in example 1, except that the types and flow rates of the deposition gases and various processing conditions were set as described in table 1. The film thickness of the deposited film was measured in the same manner as in example 1, and the film thickness ratio was calculated. The results are shown in Table 1. In addition, the column "C ₂H₂ BrF" of the deposition gas described in Table 1 is 1-bromo-1-fluoroethylene, and "C ₄F₆" is hexafluoro-1, 3-butadiene.

Although comparative example 1 is an example in which the deposition gas does not contain an unsaturated halogenated hydrocarbon, deposition is difficult at the corner between the top surface and the side wall surface of the pattern, and therefore, an overhang deposited in an eave-like deposition is generated on the top surface of the head. Further, the film thickness of the sidewall portion of the deposited film is smaller than the film thicknesses of the top and bottom portions of the head. This is because, when a deposited film is formed by using an etching apparatus, the anisotropy becomes high, and thus the deposition property onto the sidewall surface of the pattern becomes low.

Although comparative example 2 is an example in which the bias power is relatively large compared to example 2, etching was performed until the silicon substrate was etched with the top film thickness thin and the bottom deposited film not deposited.

Although comparative example 3 was also an example in which the bias power was large, etching was performed in the same manner as comparative example 2.

In contrast, in examples 1 to 9, the deposition was also sufficiently deposited at the corner portion between the top surface and the side wall surface of the pattern, and therefore the deposited protruding portion was deposited on the top surface of the pattern so as not to generate an eave. Further, even for the ratio of the film thickness of the top portion to the film thickness of the side wall portion and the ratio of the film thickness of the bottom portion to the film thickness of the side wall portion, the values were close to 1, and it was found that the thicknesses of the top portion, the side wall portion, and the bottom portion were formed uniformly as compared with comparative examples 1 to 3.

Embodiment 10 is an example in which the deposition time is increased relative to embodiment 9, and the deposited film is formed such that the sidewall portions bury the gaps formed between the sidewall surfaces of the adjacent and opposite patterns. The deposition time of example 10 was set to 1.5 times the time required for the sidewall portion to bury the above gap.

As is clear from table 1, example 10 is similar to examples 1 to 9, and deposition films having uniform thicknesses at the top, side wall and bottom of the head can be formed as compared with comparative examples 1 to 3. The thickness of the side wall portion was 50% of the gap. Further, the thickness of the bottom portion is set to the thickness of the bottom portion formed on a portion where the gap is not buried with the side wall portion.

Further, the amount of the recess formed in the upper surface of the buried portion was measured for example 10, and found to be 10nm. Since the ratio of the recess amount to the height of the pattern (300 nm), i.e., the recess ratio, was 0.03, it was confirmed that the upper surface of the buried portion was flat.

On the other hand, in examples 11 to 14 in which the bias power was not applied (that is, the power density of the bias power was 0W/cm ²), the ratio of the film thickness at the top of the head to the film thickness at the side wall portion and the ratio of the film thickness at the bottom to the film thickness at the side wall portion were slightly larger than in examples 1 to 10 in which the power density of the bias power was more than 0W/cm ² and 0.5W/cm ² or less.

Example 15 and reference example 1

Embodiment 15 is an embodiment of the deep trench etching described above. The substrate used in example 15 had substantially the same structure as the substrate of fig. 9. That is, a silicon oxide film having a thickness of 2 μm was formed on a silicon substrate. A pattern made of a photoresist is further formed on the silicon oxide film. The pattern has a through hole (recess) penetrating the pattern in the thickness direction. The diameter of the through hole was 250nm.

And alternately repeating the etching process and the deep etching of the deposition process on the substrate. Namely, the 1 st etching step, the 1 st deposition step, the 2 nd etching step, the 2 nd deposition step and the 3 rd etching step are performed in the stated order.

The etching gas used in the 1 st, 2 nd and 3 rd etching steps is a mixed gas of octafluorocyclobutane, oxygen and argon. The deposition gas used in the 1 st and 2 nd deposition steps is bromotrifluoroethylene gas. Etching conditions and deposition conditions in the respective steps are described below. The etching conditions in the 1 st, 2 nd and 3 rd etching steps are all the same as described below. The deposition conditions in the 1 st and 2 nd deposition steps are the same as described below.

[1 St, 2 nd and 3 rd etching Process ]

Plasma source: capacitively coupled plasma

Pressure: 4Pa

RF power (27 MHz): 1.85W/cm ² (value per 324cm ² electrode area)

RF power (2 MHz): 6.17W/cm ² (value per 324cm ² electrode area)

Flow of octafluorocyclobutane: 20sccm

Flow rate of oxygen: 10sccm

Flow rate of argon: 400sccm

Temperature of the substrate: 20 DEG C

Etching time: 120 seconds

[1 St and 2 nd deposition Process ]

Plasma source: inductively coupled plasma

Pressure: 1Pa

Source power: 0.93W/cm ² (value per 324cm ² electrode area)

Bias power rate: 0.03W/cm ² (value per 324cm ² electrode area)

Flow of bromotrifluoroethylene: 20sccm

Temperature of the substrate: 40 DEG C

Deposition time: 120 seconds

The diameter of the top of the concave portion and the diameter of the concave portion formed in the substrate of example 15 by deep etching were measured using an electron microscope (see fig. 13). As a result, the diameter of the top of the recess was 222nm, and the diameter of the inner recess of the recess was 222nm. Therefore, the amount of dishing was 0nm.

In reference example 1, the same substrate as that used in example 15 was used, and in the deep trench etching performed in example 15, the deposition step was not performed, and only the 360-second etching step was performed. Even for reference example 1, the diameter of the top portion of the concave portion formed on the substrate by etching and the diameter of the concave portion were measured using an electron microscope as in the case of example 15. As a result, the diameter of the top of the recess was 220nm, and the diameter of the inner recess of the recess was 255nm. Thus, the amount of dishing was 35nm.

When the amounts of dishing of example 15 and reference example 1 were compared, the amount of dishing of example 15 was smaller than that of reference example 1. Therefore, as in example 15, if the etching process and the deposition process were repeated, it was confirmed that the amount of dishing could be reduced.

Description of the drawings

1 Chamber

2 Lower electrode

3 Unsaturated halogenated hydrocarbon gas supply unit

4 Inactive gas supply part

11 Piping for supplying deposition gas

12 Pipe for supplying inert gas

13 Vacuum pump

14 Pressure gauge

15 RF coil

16 Sensor

17 Light splitter

20 Substrate

21 Substrate

22 Pattern

31 Top of head

32 Side wall surface

33 Portion of the surface of the substrate where no pattern is formed

40 Deposited film

41 Head top

42 Side wall portion

43 Bottom part

Claims

1. A method for forming a deposited film on a substrate having a pattern formed thereon,

The deposition gas contains an unsaturated halogenated hydrocarbon as an unsaturated compound having fluorine atoms, bromine atoms and carbon atoms in the molecule and the number of carbon atoms is 2 or 3,

The bias power applied to the electrode has a power density of greater than 0W/cm ² and less than 0.5W/cm ² with the bias power applied.

2. The method for forming a deposited film according to claim 1, wherein the number of carbon atoms of the unsaturated halogenated hydrocarbon is 2.

3. The method for forming a deposited film according to claim 1 or 2, wherein the unsaturated halogenated hydrocarbon is an unsaturated compound represented by a chemical formula C ₂H_xBrF_(3-x), wherein x is 0,1 or 2.

4. The method for forming a deposited film according to claim 1 or 2, wherein the deposition gas further contains an inert gas.

5. The method for forming a deposited film according to claim 4, wherein the inert gas is at least one of nitrogen, helium, neon, argon, krypton, and xenon.

6. The method for forming a deposited film according to claim 1 or 2, wherein the deposition gas further contains at least one selected from the group consisting of fluorocarbon, hydrofluorocarbon, and hydrogen.

7. The method for forming a deposited film according to claim 6, wherein the fluorocarbon is at least one of carbon tetrafluoride, hexafluoro-1, 3-butadiene, octafluorocyclobutane and octafluorocyclopentene.

8. The method for forming a deposited film according to claim 6, wherein the hydrofluorocarbon is at least one of trifluoromethane, difluoromethane and fluoromethane.

9. The method for forming a deposited film according to claim 1 or 2, wherein the deposited film has a crown portion, a side wall portion, and a bottom portion, the crown portion being a portion formed on a crown face of the pattern, the side wall portion being a portion formed on a side wall face of the pattern, the bottom portion being a portion formed on a portion of a surface of the substrate where the pattern is not formed, a ratio of a film thickness of the crown portion to a film thickness of the side wall portion, and a ratio of a film thickness of the bottom portion to a film thickness of the side wall portion being each 0.7 or more and 1.6 or less.

10. The method for forming a deposited film according to claim 1 or 2, the deposited film having a sidewall portion which is a portion formed on a sidewall surface of the pattern, at least a portion of the sidewall portion being formed so as to bury a gap between adjacent and opposing sidewall surfaces of the pattern.