Plasma processing apparatus and substrate processing apparatus

Abstract

The invention provides a plasma processing apparatus and a substrate processing apparatus. The plasma processing apparatus includes: a processing chamber; a mounting table in the processing chamber; a gas supply unit for supplying a processing gas to the processing chamber; a first high-frequency power source for generating first high-frequency electric power for plasma generation; a second high-frequency power supply for generating high-frequency bias electric power; and a control unit capable of performing control so that the plasma processing apparatus executes a process including: (a) a step of preparing an object to be processed, which has a tapered opening formed thereon, on the mounting table; (b) forming a film on the side wall of the opening, wherein the thickness of the film is reduced along the depth direction of the opening; and (c) a step of enlarging the opening size of the lower portion of the opening. The present invention can suppress shape abnormality of a semiconductor pattern.

Description

[0001] This case is filed on February 21, 2020 、Application No. 202010106983.2 、The name of the invention is Substrate processing Method and substrate processing device A divisional application for a patent application. Technical Field

[0002] The invention relates to a substrate processing method and a substrate processing device. Background Art

[0003] As the integration of semiconductor devices progresses not only in the horizontal direction but also in the vertical direction, the aspect ratio of the pattern formed in the manufacturing process of the semiconductor device becomes larger. For example, in the manufacture of 3D NAND, a channel hole is formed in a direction that penetrates multiple metal wiring layers. In the case of forming a 64-layer memory cell, the aspect ratio of the channel hole is 45.

[0004] In order to form a pattern with a high aspect ratio with high precision, various methods have been proposed. For example, a method of suppressing lateral etching by repeatedly performing etching and film formation in an opening of a dielectric material formed in a substrate has been proposed (Patent Document 1). In addition, a method of combining etching and film formation to form a protective film for preventing lateral etching of a dielectric layer has been proposed (Patent Document 2).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: U.S. Patent Application Publication No. 2016 / 0343580

[0008] Patent Document 2: U.S. Patent Application Publication No. 2018 / 0174858 Summary of the invention

[0009] Technical problem to be solved by the invention

[0010] The present invention provides a technology capable of suppressing shape abnormality of a semiconductor pattern.

[0011] Technical solutions for solving technical problems

[0012] The substrate processing method implemented by the substrate processing device of one embodiment of the present invention includes step a) and step b). Step a) is a step of locally etching the processed body to form a recess. Step b) is a step of forming a film with different thicknesses along the depth direction of the recess on the side wall of the recess. Step b) includes step b-1) and step b-2). Step b-1) is a step of supplying a first reactant and causing the first reactant to be adsorbed on the side wall of the recess. Step b-2) is a step of supplying a second reactant and causing the first reactant to react with the second reactant to form a film.

[0013] Effects of the Invention

[0014] According to the present invention, it is possible to suppress shape abnormality of a semiconductor pattern. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a flowchart showing an example of the flow of a substrate processing method according to one embodiment.

[0016] Figure 2 This is a diagram for explaining an example of a pattern formed by a substrate processing method according to one embodiment.

[0017] Figure 3 It is a diagram for explaining suppression of shape abnormality of a semiconductor pattern in a substrate processing method according to one embodiment.

[0018] Figure 4 It is a diagram for explaining a first example of a substrate processing method according to one embodiment.

[0019] Figure 5 It is a diagram for explaining a second example of a substrate processing method according to an embodiment.

[0020] Figure 6 This is a diagram for explaining control of the coverage of a protective film formed by a substrate processing method according to one embodiment.

[0021] Figure 7 This is a diagram for explaining the film thickness of a protective film formed by a substrate processing method according to one embodiment.

[0022] Figure 8 This is a diagram for explaining the relationship between the film thickness of a protective film formed by a substrate processing method according to one embodiment and the pressure in a processing chamber.

[0023] Fig. 9 This is a diagram for explaining the improvement of the etching rate when using the substrate processing method according to one embodiment.

[0024] Fig.10 This is a flowchart showing an example of the flow of the substrate processing method according to the second embodiment.

[0025] Fig.11 This is a diagram showing an example of a pattern formed by the substrate processing method according to the second embodiment.

[0026] Fig.12 FIG. 1 is a first diagram for explaining suppression of opening clogging in a substrate processing method according to a second embodiment.

[0027] Fig.13 FIG. 2 is a second diagram for explaining suppression of opening clogging in the substrate processing method according to the second embodiment.

[0028] Fig.14 It is a diagram for explaining the substrate processing method according to the third embodiment.

[0029] Fig.15 This is a flowchart showing an example of the process of the substrate processing method according to the third embodiment.

[0030] Fig.16 This is a flowchart showing an example of the flow of the substrate processing method according to Modification Example 1.

[0031] Fig.17 This is a diagram for explaining an example of a processing target object processed by the substrate processing method according to Modification Example 1.

[0032] Fig.18 This is a flowchart showing an example of the process of the substrate processing method according to the fourth embodiment.

[0033] Fig.19 This is a diagram showing an example of an object to be processed by the substrate processing method according to the fourth embodiment.

[0034] Fig. 20 This is a diagram showing another example of an object to be processed by the substrate processing method according to the fourth embodiment.

[0035] Fig.21 This is a diagram for explaining the relationship between the temperature of the object to be processed and the amount of film formed.

[0036] Fig. 22 This is a diagram for explaining an example of a processed object processed by the substrate processing method according to Modification Example 3.

[0037] Fig.23 This is a diagram showing an example of a substrate processing apparatus according to an embodiment.

[0038] Description of Reference Numerals

[0039] 10. Substrate processing device

[0040] 12. Disposal Container

[0041] 14 Supporting part

[0042] 22 DC power supply

[0043] 24 Refrigerant flow path

[0044] 28 Gas supply passage

[0045] 30 Upper electrode

[0046] 32 Insulation shielding parts

[0047] 101, 101A, 101B substrate

[0048] 102, 102A, 102B Etching target film

[0049] 120, 120A, 120B masks

[0050] 130A, 130B protective film

[0051] 140 SiO 2 membrane

[0052] 150 SiN film

[0053] 160 Natural Oxide Film

[0054] 200, 200A, 200A' opening

[0055] 300, 301, 302, 304 protective film

[0056] 303 Preparatory membrane

[0057] ESC Electrostatic Chuck

[0058] ER marginal ring

[0059] HT Temperature Control Unit

[0060] HP Heater Power Supply

[0061] LE lower electrode

[0062] PD stage

[0063] Sp Processing Space

[0064] W chip. DETAILED DESCRIPTION

[0065] Hereinafter, the disclosed embodiment will be described in detail based on the accompanying drawings. In addition, the present embodiment is not limited thereto. In addition, each embodiment can be appropriately combined within the scope that does not cause a conflict in the processing content. In addition, the same reference numerals are marked on the same or corresponding parts in each of the accompanying drawings.

[0066] It is known that shape anomalies occur when etching patterns with a high aspect ratio. For example, when an opening is formed vertically, a shape anomaly occurs in which the inner circumference expands horizontally. Such shape anomalies are called bowing. In order to suppress the occurrence of shape anomalies, a method of forming a protective film on the side wall of the opening is proposed. In the formation of tiny patterns, it is also desirable to prevent the clogging of the opening caused by the protective film, the reduction of the etching rate caused by the film formation at the bottom of the opening, etc.

[0067] In addition, in the following description, "pattern" refers to all shapes formed on the substrate. Pattern refers to, for example, a hole, trench, line width and line spacing, etc., and a plurality of shapes formed on the substrate as a whole. In addition, "recess" refers to a part of a shape that is recessed in the thickness direction of the substrate among the patterns formed on the substrate. In addition, the recess has a "side wall" as the inner peripheral surface of the recessed shape, a "bottom" as the bottom part of the recessed shape, and a "top" as the substrate surface near the side wall continuous with the side wall. In addition, the space surrounded by the top is called an "opening". In addition, the term "opening" is used to indicate the space as a whole or an arbitrary position of the space surrounded by the bottom and side walls of the recess.

[0068] (An Example of a Flow of a Substrate Processing Method According to an Embodiment)

[0069] Figure 1This is a flowchart showing an example of a process of a substrate processing method according to one embodiment. First, a processed object is provided (step S100). For example, a substrate having a pattern with a high aspect ratio is arranged in a processing chamber. In addition, for example, a substrate without a pattern is arranged in a processing chamber, and the substrate is partially etched to form a pattern (step (a)). Next, a first gas (hereinafter referred to as a precursor or a first reactant) is introduced into the processing chamber (step S101, the first step or step (b-1)). Next, the processing chamber is purged to discharge the components of the first gas excessively adsorbed on the surface of the processed object (step S102). Next, a second gas (hereinafter referred to as a reaction gas or a second reactant) is introduced into the processing chamber (step S103, the second step or step (b-2)). Then, the processing chamber is purged to discharge the components of the excess second gas (step S104). In addition, step S100 and steps S101 to S104 can be performed in the same processing chamber (in-situ) or in different processing chambers (ex-situ). Next, it is determined whether the protective film formed on the processed object in steps S101 to S104 reaches a specified film thickness (step S105). The determination of whether the protective film reaches a specified film thickness can also be based on the number of executions of steps S101 to S104. In addition, it can also be based on the measured value of the film thickness of the protective film. The measured value can also include parameters indicating the state of the protective film such as the distribution of the film thickness. The measuring method of the protective film is not particularly limited, for example, it can be measured by an optical method. The film thickness can be measured in the case of in-situ using a measuring device pre-set in the processing chamber. On the other hand, in the case of ex-situ, it is measured using a measuring device set outside the above-mentioned processing chamber. As a result, if it is determined that the specified film thickness has not been reached (step S105, no), return to step S101 and repeat to step S104. In steps S101 to S104 of this case, the processing conditions can be adjusted based on the above-mentioned measured values. On the other hand, when it is determined that the specified film thickness has been reached (step S105, yes), the object to be processed is etched (step S106). At this time, the etching conditions can also be adjusted based on the measured values ​​measured in step S105. Then, it is determined whether the pattern after etching has become a specified shape (step S107). The judgment of whether the pattern after etching has become a specified shape can be made based on the execution time of step S106. In addition, it can also be made based on the measured value of the etched pattern shape. The method for measuring the pattern shape is not particularly limited, for example, it can be measured by an optical method. The measurement of the pattern shape can be performed in the case of in-situ using a measuring device pre-set in the processing chamber. On the other hand, in the case of ex-situ, it is performed using a measuring device set outside the above-mentioned processing chamber.As a result, if it is determined that the predetermined shape has not been formed (step S107, No), the process returns to step S101 and the process is repeated from step 1. On the other hand, if it is determined that the predetermined shape has been formed (step S107, Yes), the process is terminated. This is an example of the process flow of the substrate processing method of the embodiment.

[0070] exist Figure 1 In the process shown, the processing conditions in the first step and the second step are set so that the coverage of the protective film of at least one of the first gas and the second gas in the depth direction of the pattern changes. The coverage is the area ratio of the protective film formed to a certain amount of film thickness per unit area. That is, it is set so that the film thickness of the protective film formed by the first step and the second step changes in the depth direction of the pattern. In addition, the purging of steps S102 and S104 can also be omitted.

[0071] The determination in step S105 is made based on whether steps S101 to S104 have been executed a predetermined number of times. The determination in step S107 is made based on whether step S106 has been executed a predetermined number of times on the same object to be processed. The etching in step S106 may be executed a plurality of times.

[0072] In addition, step S101 and step S103 may be performed using plasma or may not be performed using plasma. In addition, each step may be performed in the same processing chamber while maintaining a reduced pressure atmosphere or may be performed while moving in different processing chambers. In addition, when performed in different processing chambers, the steps may be performed while maintaining a reduced pressure atmosphere or may be performed under a normal pressure atmosphere.

[0073] Figure 2 FIG. 1 is a diagram for explaining an example of a pattern formed by a substrate processing method according to an embodiment. Figure 2 , further illustrating a substrate processing method according to an embodiment.

[0074] Figure 2 The object S to be processed shown includes an etching target film 102 stacked on a substrate 101 and a mask 120. First, the object S to be processed is placed in a processing chamber. Next, in step S101, a first gas is introduced into the processing chamber. The first gas is adsorbed on the top 200T, the side wall 200S, and the bottom 200B of the opening 200 surrounding the object S to be processed, forming Figure 2 After the processing chamber is purged, a second gas is introduced into the processing chamber in step S103 ( Figure 2(B)). The processing conditions in steps S101 and S103 are set so that the reaction between the components of the second gas and the components of the first gas adsorbed on the object to be processed S is not completed on the entire surface of the object to be processed. After the processing time based on the set processing conditions has passed, the processing chamber is purged. The second gas reacts on the top 200T and the upper part of the side wall 200S to form a protective film 300 ( Figure 2 (C)). Then, by repeating steps S101 to S104, a protective film 301 having a desired film thickness is formed ( Figure 2 Then, in step S106, the etching target film 102 is etched. By forming the protective film 301 in advance on the portion where the shape abnormality is generated by etching, the shape abnormality after etching can be prevented from occurring.

[0075] (Suppression of shape abnormality)

[0076] Figure 3 It is a diagram for explaining suppression of shape abnormality of a semiconductor pattern by a substrate processing method according to one embodiment. Figure 3 The processed object S shown in (A) and Figure 2 Similarly, the object S shown in (D) has a protective film 301 formed on the top 200T and the side wall 200S. During etching, arcs are often generated at the position where the mask is switched to the etching target film. For example, Figure 3 In (A), the arc bend is mostly generated at the position shown by R1. Figure 3 In the example, the protective film 301 is formed to become thinner in the depth direction of the pattern at the position R1. Therefore, the processed body S after etching is as shown in (B), and the opening size is uniformed in the depth direction by reducing the protective film 301 more in R1. By repeatedly etching, the protective film 301 can be further reduced, and the opening size is roughly uniformed from the upper part to the lower part of the opening 200 as shown in (C), for example, to become the shape shown in (D). In the case where an arc of the protective film 301 due to etching is generated (equivalent to "No" in step S107), step 1 and step 2 are performed again to form the protective film 301 again. As described above, by a substrate processing method of one embodiment, the shape abnormality of the semiconductor pattern can be suppressed.

[0077] (ALD control for changing film thickness in the depth direction of the pattern)

[0078] As described above, the substrate processing method of the embodiment forms a protective film with a reduced coverage (film thickness) in the depth direction on the inner peripheral surface of the opening. Methods for forming the protective film include chemical vapor deposition (Chemical Vapor Deposition), atomic layer deposition (Atomic Layer Deposition: ALD), etc. The substrate processing method of the embodiment utilizes the self-controllability of the film formed by ALD to form a protective film with a different coverage in the depth direction of the opening and different film thickness in the depth direction of the opening.

[0079] Before describing the substrate processing method of the embodiment, the so-called ALD is described. ALD generally includes four processing steps. First, a first gas (also called a precursor) is introduced into a processing chamber equipped with a processed object such as a substrate. The first material contained in the first gas is adsorbed on the surface of the processed object. After the surface is covered with the first material, the processing chamber is exhausted. Next, a second gas (also called a reaction gas) containing a second material that reacts with the first material is introduced into the processing chamber. The second material reacts with the first material on the processed object to form a film. The film formation is completed by completing the reaction with the first material on the surface. ALD forms a film by self-controlled adsorption and reaction of a substance pre-existing on the surface of the processed object by a specified material. Therefore, ALD generally achieves conformal film formation by setting sufficient processing time.

[0080] In this regard, the substrate processing method of this embodiment sets processing conditions so that the self-controlled adsorption or reaction on the surface of the object to be processed does not complete. There are at least the following two processing methods.

[0081] (1) The precursor is adsorbed on the entire surface of the object to be processed. The reaction gas introduced later is controlled so as not to spread over the entire surface of the object to be processed.

[0082] (2) The precursor is adsorbed only on a portion of the surface of the object to be processed. The reaction gas introduced later is controlled so that a film is formed only on the surface portion where the precursor is adsorbed.

[0083] A substrate processing method according to one embodiment uses the method (1) or (2), for example, to suppress the formation of a protective film on the lower side wall and the bottom of the opening of a semiconductor pattern.

[0084] Figure 4 It is a diagram for explaining a first example of a substrate processing method according to one embodiment. Figure 4 The object to be processed shown includes an etching target film EL1 formed on a substrate (not shown) and a mask MA. A recess having an opening OP is formed in a stacked body of the etching target film EL1 and the mask MA.

[0085] First, a precursor P ( Figure 4 By setting a sufficient treatment time to adsorb the precursor P, the precursor P is adsorbed on the entire surface of the treated object ( Figure 4 (B)). When the adsorption of the precursor P is completed, the processing chamber is purged. Next, the reaction gas R is introduced into the processing chamber ( Figure 4 (C)). The introduced reaction gas R reacts with the precursor P on the object to be processed to gradually form a protective film PF from above the mask MA. Here, the reaction gas R is purged before the formed protective film PF reaches below the etching target film EL1. By performing such a process, it is possible to use the ALD method while not forming the protective film PF on the entire side wall of the recess but only forming the protective film PF on the upper part of the mask MA and the etching target film EL1 ( Figure 4 (D)). Figure 4 In (D), the protection film PF is formed above the side wall and the top of the recessed portion, but is not formed below the side wall and the bottom.

[0086] Figure 5 It is a diagram for explaining a second example of a substrate processing method according to an embodiment. Figure 5 The processed object shown is Figure 4 The same shape as the object being processed.

[0087] exist Figure 5 In the example, the precursor P is adsorbed only on the upper part of the object to be processed ( Figure 5 After the precursor P is purged, the reaction gas R is introduced into the processing chamber ( Figure 5 At this time, the reaction gas R reacts to form a film only at the position where the precursor P is adsorbed, so the protective film PF is formed only above the object to be processed ( Figure 5 (C)).

[0088] (Processing conditions for selective adsorption and reaction)

[0089] As described above, in the substrate processing method of one embodiment, the adsorption of the precursor in the second example or the reaction of the reaction gas in the first example is caused to occur in a predetermined portion of the pattern. For example, in order to form a protective film only in the upper portion of the opening of the pattern, the processing conditions are adjusted so that the adsorption of the precursor or the reaction of the reaction gas occurs only in the upper portion of the opening of the pattern.

[0090] The processing parameters adjusted to achieve the above-mentioned substrate processing method include, for example, the temperature of the mounting table on which the processed object is mounted, the pressure in the processing chamber, the flow rate and introduction time of the introduced precursor, the gas flow rate and introduction time of the introduced reaction gas, the processing time, etc. In addition, in the case of a process using plasma, the film formation position can also be adjusted by adjusting the value of the high frequency (RF) electric power applied to generate plasma.

[0091] Figure 6 1 is a diagram for explaining the control of the coverage of a protective film formed by a substrate processing method according to an embodiment. Figure 6 In the figure, the horizontal axis represents the processing time and the vertical axis represents the coverage. In addition, the solid line represents the coverage of the top of the concave portion (TOP) of the pattern, the dashed line represents the coverage of the middle part of the side wall (MIDDLE) in the concave portion, and the dotted line represents the coverage of the bottom of the concave portion (BOTTOM). Figure 6 It indicates a general tendency, not a precise numerical value.

[0092] like Figure 6 As shown in FIG. 1 , when a film is formed in a concave portion of a pattern, the speed of film formation (adsorption or reaction) is different at the top, the center of the sidewall, and the bottom of the concave portion. Film formation progresses gradually from the top side where the precursor or reaction gas first enters to the bottom. First, as Figure 6 As shown by the solid line in the middle, the coverage rate gradually increases at the top, and the film formation is completed first among all parts (time T 1 , coverage 100%). Then, as shown by the dot-dash line, film formation is performed on the central portion of the side wall slightly later than the top portion, and at a time slightly later than the time when film formation on the top portion is completed (T 2 ) film formation is completed. Then, as shown by the dotted line, the bottom film is formed, and the latest among all parts is at time T 3 Film formation is completed.

[0093] Therefore, at time T 1 Later than time T 3 When the adsorption of the precursor or the reaction of the reaction gas is completed at an earlier time, the precursor is adsorbed or a protective film is formed on the top of the recess, but the process can be completed without completing the adsorption or protective film formation on the center or bottom of the side wall.

[0094] exist Figure 6In the figure, the coverage is plotted with the processing time as the processing parameter on the horizontal axis. Alternatively, the coverage can be adjusted by keeping the processing time constant and changing the temperature of the stage, the pressure in the processing chamber, the gas flow rate (dilution) of the precursor or reaction gas, and the absolute value of the high-frequency (RF) electric power applied to generate the plasma. For example, by setting the temperature of the stage to be lower, the film formation below the pattern can be slowed down. In addition, by setting the pressure in the processing chamber to be lower, the film formation below the pattern can be slowed down. In addition, by setting the flow rate of the precursor contained in the introduced gas to be lower, the progress of adsorption below the pattern can be slowed down. In addition, by setting the flow rate of the introduced reaction gas to be lower, the film formation below the pattern can be slowed down. In addition, when using plasma, by setting the absolute value of the high-frequency electric power applied to generate the plasma to be lower, the film formation below the pattern can be slowed down.

[0095] For example, when other processing conditions are the same, the temperature of the mounting table, the pressure in the processing chamber, the dilution of the introduced gas (precursor), and the absolute value of the high-frequency electric power are each set to a value lower than the value at which the precursor is adsorbed on the entire surface of the processed object. In addition, for example, when other processing conditions are the same, the temperature of the mounting table, the pressure in the processing chamber, and the absolute value of the high-frequency electric power are each set to a value lower than the value at which the reaction of the reaction gas is completed on the entire surface of the processed object. In addition, for example, when other processing conditions are the same, the dilution of the introduced gas (reaction gas) is set to a value higher than the value at which the reaction of the reaction gas is completed on the entire surface of the processed object.

[0096] In the substrate processing method of one embodiment, the processing conditions are adjusted as described above, for example, the processing is terminated in a state where the adsorption of the precursor as shown in Example 2 or the reaction of the reaction gas as shown in Example 1 is unsaturated. Therefore, the substrate processing method of one embodiment can form a protective film only above the pattern.

[0097] (Thickness of Protective Film Formed by Substrate Processing Method of One Embodiment)

[0098] Figure 7 The present invention is a diagram for explaining the film thickness of a protective film formed by a substrate processing method according to an embodiment. As described above, in one embodiment, the processing conditions are adjusted so that the protective film is formed above the pattern. The present inventors have studied the film thickness of a protective film formed by processing a processed object by a substrate processing method according to an embodiment. Figure 7(A) is a schematic diagram of a processing target used in the experiment. The processing target includes: an etching target film EL1; a mask MA formed on the etching target film EL1; and a recess having an opening OP formed in the mask MA and the etching target film EL1. Figure 7 (A) shows a state where the protection film PF is formed on the entire inner surface of the recess. CD is a lateral dimension (hereinafter referred to as an opening dimension) at any position of the space surrounded by the side wall of the recess.

[0099] Figure 7 (B) is a diagram in which the opening size of the object to be processed in the initial state, the opening size after processing in Example 1, and the opening size after processing in Reference Example 1 are plotted in correspondence with the depth in the etching target film EL1. The initial state is the state before the protective film PF is formed. Example 1 is a case where a protective film is formed on the object to be processed by a substrate processing method of one embodiment. Specifically, it is a case where the processing time in the reaction of the reaction gas is shortened (reference Figure 6 Time T 2 Reference Example 1 is a case where a protective film is formed on a processed object by conventional ALD. Conventional ALD is an ALD method that takes sufficient time to perform the adsorption and reaction of the precursor and the reaction gas on the entire surface of the processed object until completion, thereby achieving conformal film formation.

[0100] like Figure 7 As shown in (B), first, in the initial state, the opening size is about 40 nanometers (nm) at a depth of about 0.0 micrometers (μm), and about 30nm at a depth of about 1.4μm, and the opening size decreases as the depth increases. In contrast, after the usual ALD is performed, a protective film is formed with a substantially constant film thickness that is independent of the depth. At a depth of about 0.0μm, the opening size is about 25nm, and at a depth of about 1.4μm, the opening size is about 18nm. Although there are some errors due to the depth, a protective film of about 12 to 15nm is formed. In contrast, after processing based on a substrate processing method according to one embodiment (Example 1), at a depth of about 0.0μm, the opening size is 30nm, and at a depth of about 0.4μm, it is about 34nm, and at a depth of about 1.3μm, it is about 30nm. That is, the film thickness of the protective film formed from the top to the bottom of the recess decreases approximately gradually. As described above, the protective film formed by the substrate processing method of one embodiment has a film thickness that gradually changes from the upper part to the lower part of the concave portion. That is, the substrate processing method of one embodiment uses the ALD method while not forming a conformal protective film but forming a so-called sub-conformal protective film.

[0101] Figure 8This is a diagram for explaining the relationship between the distribution of the film thickness in the depth direction of the protective film formed by the substrate processing method according to one embodiment and the pressure in the processing chamber. When the processing conditions other than the pressure are constant, the total deposition amount of the deposited film varies greatly due to the pressure. Therefore, the total deposition amount obtained by accumulating the film thickness of the deposited film to a depth of 1.5 μm is normalized to "1", and the ratio of the deposition amount from a depth of 0 μm to a predetermined depth is plotted to show the difference between the conditions. Figure 8 Reference Example 1 is a case where a protective film is formed on a processed object by conventional ALD. In conventional ALD, conformal film formation is achieved, so the film thickness is constant in the depth direction. Figure 8 In the graph of , draw a curve. Figure 7 The distribution of film thickness when the pressure in the processing chamber during the reaction of the reaction gas is changed to 200 mTorr (mT), 20 mT, and 10 mT under the processing conditions of Example 1 in (B). Figure 8 As shown in the figure, at any pressure value, the total deposition amount of the deposited film at the shallow depth position is larger than that of Reference Example 1. That is, it indicates that a sub-conformal protective film is formed. It can be seen that the total deposition amount of the deposited film at the shallow depth position is larger, especially when the pressure is 10mT. In other words, the film thickness of the protective film changes according to the depth, and the film thickness increases closer to the top, so it is advantageous to set the pressure in the processing chamber to be lower.

[0102] In addition, the inventors used oxygen (O 2 ) as the reaction gas, and a substrate with a pattern having an aspect ratio of about 10 as the processed object, the research Figure 7 The thickness change of the protective film caused by the dilution of oxygen during the reaction of the reaction gas in the processing conditions of Example 1 in (B). The dilution of oxygen refers to the ratio of the rare gas to the total flow rate of oxygen and dilution gas. The dilution of the rare gas can be replaced by the partial pressure of oxygen. In addition, the rare gas refers to a gas composed of non-reactants such as rare gases that does not contribute to the reaction. O is used as the reaction gas. 2 As a rare gas, argon gas is used, and these are mixed in a predetermined ratio. As a result, the film thickness of the protective film varies depending on the depth of the concave portion. 2 The higher the dilution, the greater the film thickness variation. The inventors believe that this is because O radicals are easily distributed at the bottom of the concave portion, and the amount of O radicals supplied to the bottom can be suppressed by increasing the dilution.

[0103] As described above, the substrate processing method according to one embodiment forms a film having different coverage and film thickness in the depth direction of a pattern and having self-controllability by adjusting the processing conditions while using the ALD method.

[0104] (Improvement in etching rate)

[0105] Fig. 9 This is a diagram for explaining the improvement of the etching rate in the substrate processing method according to one embodiment. Fig. 9 The experimental results are shown in which a mask (MA) of a silicon oxynitride film is stacked on an amorphous carbon layer as an etching target film (EL1), and the amorphous carbon layer is etched using a pattern formed on the mask.

[0106] Fig. 9 The leftmost side (initial state) of the processing target object at the start of the processing is shown. In the initial state, the opening size is slightly larger near the top of the etching target film EL1, and becomes a shape that tapers toward the depth direction.

[0107] Fig. 9 The second figure from the left (reference example 1) shows the result of directly etching the object to be processed in the initial state. In reference example 1, the opening size produces a large and wide arc under the mask ( Fig. 9 The part indicated by "A1" in FIG. Fig. 9 The second figure from the right (reference example 2) shows the result of etching after forming a protective film by conventional ALD. Compared with reference example 1, although the generation of arcs directly below the mask and in the etching target film is suppressed ( Fig. 9 However, the depth of the recess formed by etching is greatly reduced. Fig. 9 The rightmost figure (Example 1) is the result of etching after forming a protective film using a substrate processing method of an embodiment. Compared with Reference Example 2, the degree of suppressing the generation of arc is almost the same ( Fig. 9 However, the depth of the recess formed by etching is greatly increased.

[0108] In the case where a protective film is formed by conventional ALD, a protective film is formed not only on the sidewall of the recess but also on the bottom of the recess. Therefore, the protective film acts as an etch stop layer and the etching rate is reduced. In contrast, in the substrate processing method of the embodiment, film formation at the bottom of the recess is suppressed, and a protective film is formed on the sidewall of the recess. Therefore, the protective film formed at the bottom of the recess does not become an etch stop layer, and the reduction in the etching rate can be suppressed.

[0109] In addition, the substrate processing method of one embodiment can suppress the film formation on the side wall near the bottom of the concave portion, so that the size of the bottom of the concave portion can be controlled. For example, in the case of a concave portion whose diameter decreases from the top to the bottom, the protective film can be used to suppress the change in the size of the side wall and achieve control to increase the size of the bottom.

[0110] In addition, the substrate processing method of one embodiment uses the ALD method to form a film, so that the film thickness can be finely controlled. Therefore, it is possible to prevent the opening of the top of the recess from being clogged.

[0111] (Type of film on the treated object)

[0112] In addition, the film type of the etching target film 102 in the embodiment is not particularly limited. The etching target film 102 may be, for example, a silicon-containing film, a carbon-containing film, an organic film, a metal film, etc. The silicon-containing film may be a silicon dielectric film, examples of which include silicon oxide film, silicon nitride film, silicon oxynitride film, silicon carbide, etc.

[0113] In addition, the film type of the protective films 300 and 301 formed by the substrate processing method of the above-mentioned embodiment can be the same type as the etching target film 102. For example, the protective films 300 and 301 can be silicon-containing films, carbon-containing films, organic films, metal films, etc. The carbon-containing film can be, for example, an amorphous carbon layer (ACL) or a spin-on carbon (Spin-on-Carbon) film. In addition, the silicon-containing dielectric film can be, for example, a silicon oxide film (SiO), a silicon nitride film (SiN), a silicon nitride oxide film (SiON) or a combination thereof. The metal film is a titanium (Ti) film, a tungsten (W) film, etc. As described above, by making the protective films 300 and 301 and the etching target film 102 the same type of film, the control of the subsequent processing becomes easy. For example, the etching rates of the protective films 300 and 301 and the etching target film 102 can be made consistent during etching. Therefore, the size of the bottom 200B can be easily controlled during etching after the protective films 300 and 301 are formed. For example, if the protective films 300 and 301 are made of a different type of film from the etching target film 102, the protective films 300 and 301 are not removed in the subsequent etching step and remain, and the bottom 200B of the etching target film 102 is excessively reduced. In contrast, if the protective films 300 and 301 and the etching target film 102 are made of the same type of film, it is easy to control the amount of removal by etching. In addition, when the protective films 300 and 301 are removed in the subsequent process, they are removed together with the etching target film 102 without providing a separate removal step for the protective films 300 and 301.

[0114] The etching target film 102 may be a stacked film including a plurality of layers, such as an ONON (silicon oxide film / silicon nitride film) film or an OPOP (silicon oxide film / polysilicon) film.

[0115] In addition, when a silicon oxide film is formed as the protective films 300 and 301, an aminosilane-based precursor, SiCl 4 、SiF 4 etc., the reaction gas can use O 2In addition, when a silicon nitride film is formed as the protective film 300, 301, an aminosilane-based precursor, SiCl 4 , dichlorosilane (DCS), hexachlorodisilane (HCDS), etc. The reaction gas can use N 2 NH 3 In addition, as a method for forming an organic film as the protective film 300, 301, molecular layer deposition (Molecular Layer Deposition: MLD) can be used. In addition, when a titanium film or a titanium oxide film is formed as the protective film 300, 301, TDMAT (tetrakis(dimethylamino)titanium: tetrakis(dimethylamino)titanium), titanium tetrachloride (TiCl 4 ), the reaction gas can use a reducing gas or an oxidizing gas. In addition, when forming a tungsten film, the precursor can use WF 6 , the reaction gas can use a reducing gas.

[0116] In addition, in order to control the depth of the formed protective films 300 and 301, a precursor can be selected. For example, among aminosilane-based gases, as a choice of precursor for forming protective films 300 and 301 only above the pattern, it is preferred to use aminosilane (divalent aminosilane or trivalent aminosilane) gas having 2 or 3 amino groups compared to aminosilane (monovalent aminosilane) gas having 1 amino group. In addition, in order to form protective films 300 and 301 at a deeper position of the pattern, it is preferred to use monovalent aminosilane gas. In addition, by combining processing parameters such as processing time, temperature of the mounting table, and pressure in the processing chamber, the controllability of the unsaturated state can be improved.

[0117] In addition, plasma may be generated during the supply of precursors and reactive gases. For example, plasma may be used to dissociate the precursors and reactive gases, generating free radicals of the precursor with higher adsorption and free radicals of the reactive gases with higher reactivity, thereby promoting the adsorption of the precursor and the reaction of the reactive gases. In addition, it is not necessary to generate plasma only when the precursors and reactive gases react fully and spontaneously.

[0118] In addition, the substrate processing method of the above embodiment is not limited to 3D NAND, DRAM, etc., and can be applied to the manufacture of semiconductor devices with patterns having a high aspect ratio. For example, it can be applied to the processing of organic films with a high aspect ratio used in multilayer resist masks, etc. In addition, here, the high aspect ratio means that the ratio of the depth of the concave portion to the width is at least 5 or 10 or more.

[0119] (Second Embodiment - Control Using an Inhibition Factor)

[0120] Fig.10 This is a flowchart showing an example of the flow of the substrate processing method according to the second embodiment. Fig.11 : is a diagram showing an example of a pattern formed by the substrate processing method of the second embodiment. Fig.11 The processed object shown in (A) and Figure 2 The same as the object to be processed shown in (A). In the above-mentioned first embodiment, by adjusting the adsorption position and the reaction position of at least one of the first gas and the second gas, sub-conformal film formation is achieved. In the second embodiment, the adsorption position of the precursor is also controlled by forming a factor (hereinafter also referred to as an inhibitor) that hinders the adsorption of the precursor on a part of the surface of the object to be processed in advance. For example, a factor is formed on the upper part of the object to be processed by CVD, and the factor is a factor that forms a hydrophobic group that hinders the adsorption of the precursor.

[0121] First, a processed object is provided (step S200). For example, a substrate having a pattern with a high aspect ratio formed thereon as in the first embodiment is arranged in a processing chamber. Alternatively, for example, a substrate without a pattern formed thereon is arranged in the processing chamber, and the substrate is partially etched to form a pattern. Next, a gas containing an inhibitory factor that inhibits the adsorption of the first gas is introduced into the processing chamber (step S201). The gas containing the inhibitory factor is, for example, a carbon-containing gas. The carbon-containing gas is, for example, a fluorocarbon gas, a fluorohydrocarbon gas, or a hydrocarbon gas. In Fig.11 In (A), when plasma CVD is performed using a fluorocarbon gas, a fluorocarbon film is formed as an inhibitor layer IN. Fig.11 In (A), when plasma CVD is performed using a fluorocarbon gas, a fluorocarbon film is formed as an inhibitor layer IN. Fig.11 In (A), when plasma CVD is performed using hydrocarbon gas, a hydrocarbon film is formed as an inhibitor layer IN. Fluorocarbon film, fluorocarbon film and hydrocarbon film are hydrophobic films. Here, the processing conditions of plasma CVD are adjusted as follows: Fig.11 The inhibitor layer IN is formed as shown in (B). Fig.11 In the example of (B), the inhibitor layer IN is formed on the top 200T and the bottom 200B.

[0122] Then, if Fig.11 As shown in (C), the first gas (precursor P, first reactant) is introduced into the processing chamber (step S202, first step). The precursor P is not adsorbed on the portion where the inhibitor layer IN is formed. Therefore, the precursor P is selectively adsorbed on the side wall 200S (refer to Fig.11After the processing chamber is purged (step S203), the second gas (reaction gas R, second reactant) is introduced into the processing chamber (step S204, step S205). Fig.11 (E)). The reaction gas R reacts with the atoms of the precursor P only at the position where the precursor P is adsorbed to form the protective film 302. Therefore, Fig.11 As shown in (E), the protective film 302 is formed only on the side wall 200S. Then, the processing chamber is purged (step S205). Steps S206 to S208 are similar to Figure 1 Steps S105 to S107 are the same.

[0123] In the second embodiment, for example, aminosilane-based gas, silicon-containing gas, titanium-containing gas, hafnium-containing gas, tantalum-containing gas, zirconium-containing gas, organic-containing gas, etc. can be used as the precursor P. The precursor P is adsorbed only in the region where the inhibitor layer IN is not formed to form a precursor layer. In addition, plasma may not be generated when the precursor P is adsorbed.

[0124] After the introduction of the precursor P and before the introduction of the reaction gas R, the purge step is performed using an inert gas such as argon or nitrogen gas to reduce or remove the precursor P remaining in the main gas phase in the processing chamber. In addition, the purge step can also be performed by evacuating the processing chamber. The excess attached precursor P is removed by purging, and the precursor layer becomes approximately a monomolecular layer.

[0125] In addition, the reaction gas R is an oxygen-containing gas, a nitrogen-containing gas, a hydrogen-containing gas, etc. The reaction gas R may contain, for example, O 2 Gas, CO 2 Gas, NO gas, SO 2 Gas, N 2 Gas, H 2 Gas, NH 3 The precursor layer is modified by the reaction gas R to form the protective film 302, and the surface of the inhibitor layer IN is removed, so that the film thickness of the inhibitor layer IN is reduced or removed.

[0126] The purging step after the formation of the protective film 302 is performed using an inert gas such as argon or nitrogen to reduce or eliminate the reaction gas R remaining in the processing chamber. In addition, the purging step can be performed by evacuating the processing chamber.

[0127] As described above, when the protective film 302 is formed using an inhibitor, the formation position and film thickness of the protective film 302 can be further adjusted. In addition, the formation position of the protective film 302 can be controlled in the same manner as in the first embodiment. Therefore, according to the second embodiment, the protective film 302 can be prevented from being formed on the top by using an inhibitor, and the protective film 302 can be prevented from being formed below the side wall by adjusting the processing conditions. Therefore, according to the second embodiment, in addition to the effects obtained in the first embodiment, clogging of the openings during the formation of the protective film can be more effectively prevented.

[0128] Fig.12 and Fig.13 It is a diagram for explaining the suppression of opening clogging based on the substrate processing method according to the second embodiment. Fig.12 (A) and (B) represent the CD dimensions in the depth direction from the interface between the mask and the etched film in the pattern of the processed object in the initial state and after film formation. In addition, the difference between the CD dimension in the initial state and the CD dimension after film formation divided by 2 represents the amount of film formed on the side wall (sheet side) of the pattern. Fig.12 In (A), the dotted line indicates the initial state of the object to be processed. The dashed line indicates the result of film formation by conventional ALD on the object to be processed in the initial state (Reference Example 1). The solid line indicates the result of film formation by conventional ALD after forming an inhibitor layer by plasma CVD on the object to be processed in the initial state (Reference Example 2). Fig.12 In (B), the dotted line represents the initial state of the object to be processed. The dashed line represents the result of film formation on the object to be processed in the initial state by the substrate processing method of the first embodiment (Example 1). The solid line represents the result of film formation on the object to be processed in the initial state by the substrate processing method of the second embodiment (Example 2).

[0129] like Fig.12 As shown in (A), in the case of conventional ALD film formation, when an inhibitor layer is used, the formation of a protective film can be suppressed to a depth of about 0.6 μm under the mask. However, at a depth deeper than about 0.6 μm, a protective film is formed substantially conformally. On the other hand, Fig.12 As shown in (B), when a film is formed by the substrate processing method of the second embodiment, the inhibitor layer is used, so that the thickness of the protective film from the mask to a depth of about 0.6 μm can be suppressed to about 1 / 2, and at a position deeper than about 0.6 μm, the formation of the protective film can be suppressed in the same manner as when the inhibitor layer is not used. As described above, by using the inhibitor layer, the film thickness of the protective film on the upper part of the pattern can be suppressed to be smaller. In addition, the film thickness difference of the protective film in the depth direction of the pattern can be maintained.

[0130] in addition, Fig.13 Schematically shows Fig.12 The states of the openings at the top of the mask in the initial state, Reference Example 1, Reference Example 2, Example 1, and Example 2, respectively. In the initial state, the opening size near the top of the mask is about 45 nanometers (nm). In contrast, the opening size is reduced to about 30 nm when the film is formed by conventional ALD (Reference Example 1). On the other hand, the opening size is maintained at about 42 nm when the film is formed by conventional ALD (Reference Example 2) on the basis of the formation of an inhibitor layer. In contrast, when the film is formed by the substrate processing method of the first embodiment (Example 1), the opening size is about 21 nm. On the other hand, when the film is formed after the inhibitor layer is formed by the substrate processing method of the second embodiment (Example 2), the opening size is maintained at about 40 nm. As described above, as in the second embodiment, by using the inhibitor layer to suppress the film formation near the top of the mask, there is an effect of preventing the opening from being blocked.

[0131] In addition, in the second embodiment, by adjusting the formation position of the inhibitor layer, a protective film can be formed at an arbitrary position. Therefore, the protective film can be formed at a desired position while adjusting the film thickness of the protective film in accordance with the shape abnormalities of the preset pattern such as arcing and necking. In addition, by making the formation position of the inhibitor layer correlated with the aspect, the film formation position on the side wall can be adjusted. In addition, by changing the composition of the inhibitor layer, it is also possible to hinder the adsorption of the ALD precursor and the adsorption of the reaction gas. For example, when a carbon-containing inhibitor layer is formed, oxidation can be hindered, and when a CF-containing inhibitor layer is formed, the adsorption of the precursor can be hindered.

[0132] (Third embodiment)

[0133] In the first and second embodiments, the coverage is changed in the height direction of the pattern with a high aspect ratio to form a film. However, the embodiment disclosed herein is applicable not only to the pattern with a high aspect ratio, but also to the pattern with a low aspect ratio, for example, a pattern with an aspect ratio of less than 5. Therefore, as the third embodiment, an embodiment applicable to the pattern with a low aspect ratio is described. In addition, in the following description, "low aspect ratio" means an aspect ratio of less than 5.

[0134] Fig.14 It is a diagram for explaining the substrate processing method according to the third embodiment. Fig.14 The processed object and Figure 3 The object S to be processed shown is the same, and includes an etching target film 102 stacked on a substrate 101 and a mask 120 .

[0135] First, a target object ( Fig.14In this case, the aspect ratio calculated from the upper surface of the mask 120 may be less than 5, and the aspect ratio calculated from the upper surface of the etching target film 102 may be about 1 to 2.

[0136] Next, a process is performed to narrow the lateral width of the opening 200 formed in the object to be processed, that is, the width of the top 200T. For example, a preliminary film 303 is formed on the upper portion of the side wall 200S by chemical vapor deposition (CVD) or physical vapor deposition (PVD). The preliminary film 303 is mainly formed using a process condition that forms the preliminary film 303 on the upper portion of the side wall 200S but does not form the preliminary film 303 on the lower portion of the side wall 200S and the bottom 200B. Fig.14 (B)).

[0137] Next, similarly to the first embodiment, the protective film 304 is formed by ALD under the condition that the process is completed in a state where the adsorption of the precursor or the reaction of the reaction gas is not saturated, that is, the process is not completed to the bottom surface. At this time, the protective film 304 is formed on the side wall 200S and is not formed on the bottom 200B ( Fig.14 (C)).

[0138] Next, the etching target film 102 is etched ( Fig.14 (D)). When the depth of the concave portion reaches a preset size, or when the etching processing time reaches a preset processing time, the etching is terminated. The end time of the etching can be set arbitrarily.

[0139] Next, the reserve film 303 and the protective film 304 remaining on the top 200T and the upper portion of the side wall 200S are removed. Fig.14 (E)).

[0140] As described above, according to the substrate processing method of the third embodiment, etching is performed after pre-covering the position where shape abnormalities such as bowing occur, that is, the portion of the etching target film 102 directly below the mask 120 with the protective film 300, thereby suppressing shape abnormalities such as bowing.

[0141] In addition, by the substrate processing method of the third embodiment, a sub-conformal ALD film can be formed on a pattern with a small aspect ratio, for example, less than 5. In the first and second embodiments, when a protective film is formed on a pattern with a high aspect ratio, control is performed so that the amount of film formed gradually decreases from the upper part of the side wall to the lower part. However, when the aspect ratio of the pattern formed on the processed object is small, the precursor and the reaction gas will reach the bottom of the recess in a short time. Therefore, it is difficult to form a sub-conformal ALD film on a pattern with a low aspect ratio. On the other hand, when CVD or PVD is used for a pattern with a low aspect ratio, it is difficult to control the film thickness slightly.

[0142] Therefore, in the third embodiment, when the aspect ratio of the pattern formed on the object to be processed is small, processing to reduce the opening size of the pattern is performed in advance ( Fig.14 (B)). By performing this treatment, the aspect ratio of the pattern is increased, and the amount of the inhibitory precursor and the reaction gas entering the opening is suppressed. Therefore, according to the third embodiment, a sub-conformal ALD film is formed even for a pattern with a low aspect ratio, and a fine film thickness control can be achieved.

[0143] Fig.15 This is a flowchart showing an example of the process of the substrate processing method of the third embodiment. First, a processing object is provided on which a mask 120 is formed on an etching object film 102, and a pattern for etching is formed on the mask 120 (step S1501). The processing object in a state where no pattern is formed can also be introduced into a chamber and partially etched to form a pattern on the mask. Next, the etching object film 102 is etched (step S1502). It is determined whether the depth of the recessed portion formed in the etching object film 102 after etching reaches a specified value (step S1503). If it is determined that the specified value has not been reached (step S1503, no), return to step S1502 to repeatedly etch. On the other hand, if it is determined that the specified value has been reached (step S1503, yes), it is determined whether the aspect ratio of the recessed portion is greater than a specified value (for example, 10) (step S1504). If it is judged that the aspect ratio is less than the specified value (step S1504, No), a preliminary film 303 is formed to narrow the width of the opening 200 (step S1505). Then, the process returns to step S1504. On the other hand, if it is judged that the aspect ratio is greater than the specified value (step S1504, Yes), a protective film 304 is formed (step S1506). The process for forming the protective film 304 is the same as the process for forming the protective film in the first embodiment. For example, it is possible to perform Figure 1 The protective film 304 is formed by performing steps S101 to S105. After the protective film 304 is formed, etching is further performed (step S1507). Then, it is determined whether the processed body has formed a specified shape (step S1508). For example, it is determined whether the depth of the recess formed in the etching object film 102 by etching has reached a predetermined depth. Then, if it is determined that the specified shape has not been formed (step S1508, no), the process returns to step S1504 and is repeated. On the other hand, if it is determined that the specified shape has been formed (step S1508, yes), the process is terminated. In this way, the substrate processing method of the third embodiment is terminated.

[0144] As described above, in the third embodiment, even for a pattern with a low aspect ratio, the aspect ratio can be increased by performing a process of narrowing the opening in advance, thereby forming a protective film by sub-conformal ALD.

[0145] In the third embodiment, "low aspect ratio" is defined as an aspect ratio of less than 5, and the process of the third embodiment is applied to patterns with low aspect ratios. However, for patterns with an aspect ratio of more than 5, when the aspect ratio is reduced to less than 10, it is sometimes difficult to achieve sub-conformal film formation. Therefore, the method of the third embodiment can also be applied to patterns with an aspect ratio of 5 to 10.

[0146] In addition, the preliminary film 303 is preferably formed of a material that can be removed in subsequent processing. For example, the preliminary film 303 is formed of SiO 2 , SiN, SiC, etc. 2 In the case of the preliminary film 303, the aminosilane-based gas, SiCl 4 、SiF 4 In addition, when forming the SiN preliminary film 303, aminosilane-based gas, SiCl 4 , DCS, HCDS, etc. are used as precursors. In addition, for example, the preliminary film 303 may be an organic film such as a carbon film, a metal film containing titanium (Ti) or tungsten (W), or the like.

[0147] (Variation 1 - Change of processing conditions according to mask thickness)

[0148] The first to third embodiments have been described above. Each embodiment can be modified. Fig.16 This is a flowchart showing an example of the flow of the substrate processing method according to Modification Example 1. Fig.17 This is a diagram for explaining an example of an object to be processed by the substrate processing method according to Modification 1. Modification 1 is to reduce the film thickness of the mask during the process of processing the object to be processed by the method according to the first embodiment or the second embodiment.

[0149] Fig.17 The processed object S1 shown in (A) is Figure 2 In the substrate processing method of the first modification, the processing from providing the object S1 to be processed (step S100) to etching (step S106) is the same as that of the first embodiment. Through the processing from step S100 to step S106, for example, Fig.17 (B) shows the object S1 to be processed. In the object S1 to be processed, an etching target film 102A and a mask 120A are formed on a substrate 101A. Then, a recess having an opening 200A is formed in the etching target film 102A and the mask 120A. A protective film 130A is formed above the top and side walls of the recess. The protective film 130A is formed to the point directly below the mask 120A where shape abnormalities due to etching are likely to occur. In addition, the inner wall of the protective film 130A is reduced by etching. From Fig.17When steps S101 to S106 are further repeatedly performed in the state shown in (B), the top of the mask 120A is gradually reduced, and the distance from the top of the mask 120A to the upper surface of the etching target film 102A changes ( Fig.17 In this case, when the protective film 130A is formed without changing the processing conditions of the first step and the second step, the position where the protective film 130A is formed is lower than the position directly below the mask 120A where the shape abnormality is likely to occur.

[0150] Therefore, in variant example 1, after etching (step S106) and step S107, it is determined whether the film thickness of the mask 120A is a specified value (step S108). The determination of whether the film thickness of the mask 120A is a specified value can be made based on the film thickness of the mask 120A before the processing of the processed body S1 and the number of executions of steps S101 to S106. In addition, the determination of whether the film thickness of the mask 120A is a specified value can be made based on the measured value of the film thickness. In addition, the method for measuring the film thickness is not particularly limited, for example, the film thickness can be measured by an optical method. Then, when it is determined that the film thickness of the mask 120A is a specified value (step S108, yes), the processing conditions of the first step or the second step are set again (step S109). For example, when the processing conditions are set so that the coverage in the first step changes along the depth direction of the pattern, the processing conditions are changed so that the first gas is adsorbed only above the pattern. For example, the processing time of the next first step is shortened compared to the processing time of the previous first step. In addition, for example, when the processing conditions are set so that the coverage in the second step changes along the depth direction of the pattern, the processing conditions are changed so that the first gas reacts only at the upper part of the pattern. For example, the temperature of the processing chamber is lowered. On the other hand, when it is determined that the film thickness of the mask 120A is not the specified value (step S108, No), the processing conditions are not changed and the process returns to step S101.

[0151] As described above, by adjusting the processing conditions according to the film thickness of the mask 120A, the protective film 130A can be selectively formed at a location where shape abnormality is likely to occur. Fig.17 In the case of the object to be processed (C), the film thickness of the mask 120A is half of that at the beginning of the process, and the distance from the top to the etching target film 102A becomes shorter. In this case, the process conditions are changed to shorten the distance in the depth direction of the protective film 130A. Fig.17 As shown in (D), the protective film 130A can still be formed at a position directly below the mask 120A where shape abnormality is likely to occur.

[0152] In addition, when the etching target film 102A is bowed, the pattern shape can be corrected by updating the processing conditions and executing steps S101 to S104.

[0153] As described above, in the case where the aspect ratio of the recessed portion having the opening 200A increases by etching (step S106) after performing the first and second steps, the processing conditions may be changed. For example, the processing conditions of at least one of the first step (step b-1) and the second step (step b-2) may be changed according to the increase in the aspect ratio. For example, the transport amount of the free radicals generated in the second step may be increased. That is, the processing conditions may be changed so that as the number of etchings (step S106) increases, the position where the protective film 130A is formed is above the etching object film 102A. In addition, regarding the processing conditions, when the first and second steps are repeated, different processing conditions may be used each time, or different processing conditions may be used after the first and second steps are repeated several times. In addition, the processing conditions may be appropriately changed according to major factors other than the film thickness of the mask.

[0154] (Fourth embodiment)

[0155] In the first embodiment, it is described that when a concave portion whose diameter decreases from the top to the bottom is formed, control can be achieved by increasing the size of the bottom while suppressing the dimensional change of the side wall by the protective film (see paragraph 0044). As a fourth embodiment, the size control of the concave portion is further described. The substrate processing method of the fourth embodiment can increase the degree of freedom of shape control of the formed pattern.

[0156] Fig.18 This is a flowchart showing an example of the process of the substrate processing method according to the fourth embodiment. Fig.19 , Fig. 20 It is a diagram showing an example of a processing target object processed by the substrate processing method according to the fourth embodiment.

[0157] First, a processed object S2 (see Fig.19 (A)) (step S1800). The object to be processed S2 includes a substrate 101B, an etching target film 102B formed on the substrate 101B, and a mask 120B (see Fig.19 (A)). The mask 120B includes an opening 200A'. The opening 200A' includes a bottom 201 and a side wall 202. The bottom 201 of the opening 200A' reaches the etching target film 102B. In step S1800, the etching target film 102B is partially etched through the mask 120B.

[0158] Next, similarly to the first embodiment, the protective film 130A is formed by the first step (step S1801), purging (step S1802), the second step (step S1803), and purging (step S1804). Fig.17). When the protective film 130A reaches the predetermined film thickness (step S1805, yes), the object S2 is etched (step S1806). On the other hand, when it is determined that the protective film 130A does not have the predetermined film thickness (step S1805, no), the process returns to step S1801 and the process is repeated. The process of steps S1801 to S1806 is the same as Fig.16 The processing of steps S101 to S106 is the same as that of steps S1802 and S1804, and the purging of steps S1802 and S1804 can be omitted. In addition, in the present embodiment, when etching the object S2 in step S1806, if the arc described in the first embodiment does not occur or the influence caused by the arc is small, the processing of steps S1801 to S1804 can also be omitted.

[0159] Next, it is determined whether the depth of the opening 200A' formed in the processed body S2 has reached a specified value (step S1807). For example, it is determined whether the depth of the opening 200A' has reached the upper surface position of the substrate 101B. In the case where it is determined that the depth of the opening 200A' has not reached the upper surface position of the substrate 101B (step S1807, no), the process returns to step S1805 and is repeated. On the other hand, in the case where it is determined that the depth of the opening 200A' has reached the upper surface position of the substrate 101B (step S1807, yes), it is determined whether the opening size of the bottom 201 is above a specified value (step S1808). The opening size of the bottom 201 is the lateral dimension of the bottom 201. The lateral dimension of the bottom 201 is hereinafter referred to as the bottom CD (Critical Dimension). The "specified value" of step S1807 and step S1808 is set in advance based on the device design, etc.

[0160] Here, regarding the opening 200A', the shape of the side wall 202 extending in the vertical direction from the top to the bottom 201 is set to an ideal shape. And the "predetermined value" of step S1808 is set to the bottom CD of the ideal shape. Thus, Fig.19 In this case, in step S1808, it is determined that the bottom CD is less than the specified value (step S1808, No). When it is determined that the bottom CD is less than the specified value, a protective film 130B is formed (step S1809, refer to Fig.19 (C)). The protective film 130B is formed on the top 203 and the side wall 202 of the opening 200A'. Fig.19 In the example of (C), the protective film 130B is formed so that the film thickness gradually decreases from the upper side to the lower side of the side wall 202. The method for forming the protective film 130B can be the same as that for the protective film 130A (see Fig.17) Also, subconformal ALD can be used, and plasma CVD (PECVD) can be used. When PECVD is used, for example, SiCl can be used as the process gas. 4 , O 2 and a rare gas. As the rare gas, for example, Ar, He, or Kr can be used. In addition, the chamber pressure can be 10 mTorr to 1 Torr, and the high frequency (RF) electric power can be 50 W or more.

[0161] Next, the object S2 to be processed with the protective film 103B formed thereon is etched (corrected) (step S1810). At this time, the portion of the side wall 202 covered by the protective film 130B is not etched, and the lower portion which is not covered or the protective film 130B is thinner than the upper portion is etched to have a wider width than the upper portion (see Fig.19 After etching in step S18010, the process returns to step S1808.

[0162] If it is determined in step S1808 that the bottom CD is greater than the specified value (step S1808, yes), the process ends. For example, if the specified value in step S1808 is set to be substantially the same as the size of the top of the opening, the shape of the processed object S2 at the end of the process becomes, for example, Fig.19 The shape shown in (D).

[0163] In addition, the etching of step S1806 and the etching of step S1810 are performed under different processing conditions. In the etching of step S1806, the processing conditions are set so that the opening 200A' is deepened mainly in the depth direction. On the other hand, in the etching of step S1810, the processing conditions are set so that the bottom 201 of the opening 200A' is expanded in the lateral direction. For example, the processing conditions of step S1806 are set to achieve anisotropic etching, and the processing conditions of step S1810 are set to achieve isotropic etching. Regarding the processing of step S1810, it is also possible to use, instead of etching, a method such as the later-described modification 3, namely COR (Chemical Oxide Removal: chemical removal of oxide) to achieve it.

[0164] For example, when the etching target film 102B is a silicon oxide film (SiO 2 ), in the etching of step S1806, a fluorocarbon (CF)-based etching gas is used. For example, C 4 F 6 , C 4 F 8 In addition, CF-based gas, argon (Ar) and oxygen (O 2 ) can also be added 3 F, CH2 F 2 , CHF 3 On the other hand, in the etching of step S1810, a fluorine-containing gas can be used as the etching gas. For example, NF 3 .

[0165] In addition, for example, when the etching target film 102B is an organic film, an oxygen-containing gas can be used in the etching of step S1806. 2 ,CO,CO 2 In this case, oxygen-containing gas can also be used as etching gas in step S1810.

[0166] In addition, as a processing condition other than the processing gas, it is preferred that the chamber pressure is about 10 to 30 mTorr during the processing of step S1806 and is above 100 mTorr during the processing of step S1810. In addition, the high frequency (RF) voltage for plasma generation applied during plasma generation is set to be higher during the processing of step S1806 than during the processing of step S1810.

[0167] In addition, when the method of Modification 3 is used in step S1810, fluorine-containing gas and NH 3 A mixed gas or N 2 and H 2 As the fluorine-containing gas, NF 3 , SF 6 , CF series gases.

[0168] As described above, in the substrate processing method of the fourth embodiment, after forming an opening of a desired depth, a film having different thicknesses along the depth direction of the opening is formed to etch the object to be processed. Therefore, the size of the lower part of the opening not covered by the film can be expanded in the lateral direction, and the size of the opening can be adjusted. Therefore, according to the fourth embodiment, the abnormality of the shape of the pattern in the etching target film can be suppressed to a smaller level.

[0169] The substrate processing method of the fourth embodiment may be performed not only after the bottom 201 of the opening 200A' reaches the upper surface position of the substrate 101B, but also during the etching of the etching target film 102B. Fig. 20 An example is shown in which the substrate processing method according to the fourth embodiment is applied while the etching target film 102B is being etched.

[0170] Fig. 20 The processed object S2 shown in (A) and Fig.19 The same as the processed object S2 shown in (A). Fig.19 Until the state (A) becomes the state (B), in the stage of digging the opening 200A', it can be obtained Fig. 20 For example, in Fig.18 In step S1807, the "predetermined value" is set to a depth that does not reach the substrate 101B. Then, at the stage where the bottom 201 of the opening 200A' is located in the etching target film 102B, step S1808 is executed. In addition, for example, based on the execution time of steps S1800 and S1806, step S1808 is executed at the stage where the bottom 201 of the opening 200A' is located in the etching target film 102B. Then, from Fig. 20 (B) From the state shown in step S1809, the protective film formation is performed (see Fig. 20 (C)) and the etching of step S1810 ( Fig. 20 As described above, by changing the judgment process, it is possible to Fig. 20 The process for increasing the bottom CD is started from the state (B). Therefore, the shape of the opening 200A' can be adjusted while suppressing damage to the substrate 101B.

[0171] As described above, in the substrate processing method of the fourth embodiment, the protection film 130B can be formed when the bottom 201 of the opening 200A' is located inside the etching target film 102B. Therefore, according to the fourth embodiment, the reduction of the bottom CD can be suppressed and the occurrence of bowing can be suppressed.

[0172] (Bottom CD judgment)

[0173] The determination method of the above step S1808 is not limited. For example, the bottom CD can be determined by checking the shape of the processed object S2 by an optical method or the like. In addition, the bottom CD can also be determined based on the number of executions or execution time of steps S1801 to S1804 and step S1806. In addition, when step S1810 is executed, the bottom CD can also be determined based on the execution time of step S1810. The "specified value" of step S1808 is set in advance based on the design value.

[0174] (Judgment on whether a protective film needs to be formed)

[0175] In addition, before step S1809, it is determined whether a protective film needs to be formed (step S1809). The determination method is not particularly limited. For example, it can be determined whether the protective film 130B needs to be formed based on the thickness and / or position of the protective film 130B remaining on the sidewall 202. In addition, for example, it can also be determined whether the protective film 130B needs to be formed based on the number of executions or the execution time of steps S1801 to S1804 and step S1806. In addition, when the protective film ( Fig.17 , 130A) formed in steps S1801 to S1804 remains, it is determined whether step S1809 needs to be executed based on the thickness and / or position of the protective film.

[0176] In addition, steps S1808 and the determination of whether a protective film needs to be formed can also be executed together. For example, the process can be ended when the number of executions of steps S1801 to S1804 and step S1806 reaches a value V1. In addition, the protective film 130B can be formed when the number of executions of steps S1801 to S1804 and step S1806 is less than a value V2 (V2 < V1). In addition, etching (S1810) can be performed without forming the protective film 130B when the number of executions of steps S1801 to S1804 and step S1806 is less than a value V3 (V3 < V2).

[0177] (Film type)

[0178] The film types of the etching target film 102B, the mask 120B, and the protective film 130B are not particularly limited. For example, the substrate 101B can be a silicon wafer. The etching target film 102B can be a dielectric film, such as a silicon-containing dielectric film. The etching target film 102B can be formed by laminating multiple films. For example, the etching target film 102B can be a film layer formed by laminating a silicon oxide film and a silicon nitride film in sequence. The etching target film 102B can be a film layer formed by laminating a silicon oxide film and a polysilicon film in sequence. The mask 120B can be a carbon-containing film. The carbon-containing film can be formed by an amorphous carbon layer (ACL) and a spin-on carbon film (SOC). In addition, the mask 120B can be formed by a metal film. In addition, Fig.19 , Fig. 20 Although not shown in the figure, there can be a silicon oxynitride film (SiON) and a backside anti-reflection coating (BARC) having the same opening pattern as the mask 120B formed on the mask 120B. The protective film 130B can be a silicon-containing film. In addition, the film types of the mask 120B and the etching target film 102B can be of the same type.

[0179] In the substrate processing method of the embodiment, when the etching target film 102B is a silicon-containing dielectric film, the mask 120B can be a carbon-containing film such as ACL and SOC. In addition, when the etching target film 102B is a polysilicon film, the mask 120B can be a silicon oxide film formed using TEOS (tetraethyl orthosilicate).

[0180] In addition, in the substrate processing method of the fourth embodiment, plasma may or may not be used in the protective film formation in step S1809 and the etching in step S1810.

[0181] The substrate processing method of the fourth embodiment can be applied to patterns of various aspect ratios including not only patterns with high aspect ratios but also patterns with low aspect ratios. For example, the substrate processing method of the fourth embodiment can be suitably applied to patterns with aspect ratios of 10 to 20.

[0182] (Variation 2 - Adjustment of film thickness within the wafer surface)

[0183] In the first embodiment, the coverage and film thickness of the protective film are adjusted by adjusting the processing conditions. The processing conditions in the first step and the second step can be adjusted in the following two aspects.

[0184] (1) Controlling the film formation position in the depth direction of the pattern by controlling the amount of precursor and reaction gas introduced

[0185] (2) Control the thickness of the protective film formed

[0186] In the first and second embodiments, the film formation position is controlled mainly from the viewpoint of (1). In Modification 2, the processing conditions are further controlled from the viewpoint of (2). Fig.21 This is a diagram for explaining the relationship between the temperature of the object to be processed and the amount of film formed. The wafer to be processed in the substrate processing device is, for example, a disk-shaped wafer with a diameter of about 300 mm. It is known that when a wafer is subjected to film forming processing, the amount of film formed varies according to the temperature of the wafer. Fig.21 (A) shows the relationship between the temperature of the wafer and the amount of film formed. As shown in (A), when the wafer temperature becomes higher, the amount of film formed increases, and when the wafer temperature becomes lower, the amount of film formed decreases.

[0187] In variant 2, the wafer support table (electrostatic chuck) is divided into a plurality of concentric areas so that the temperature of each area can be independently controlled. Therefore, the thickness of the protective film formed at any position can be controlled to a desired thickness. For example, it is known that during etching and other processes, the shape abnormality (such as an arc) becomes smaller at the center of the wafer, and the shape abnormality becomes larger at the edge of the wafer. In such a case, control is performed so that the temperature of the center portion, which tends to have a smaller shape abnormality, is lower than that of the edge portion, which tends to have a larger shape abnormality. When control is performed as described above, the thickness of the protective film formed can be adjusted according to the radial position of the wafer, and the in-plane uniformity of the size of the opening formed can be improved.

[0188] In addition, for film thickness control, such as Fig.21 As shown in (B), multiple areas divided in the radial and circumferential directions can be independently temperature controlled, thereby improving the uniformity in the surface and making it possible to utilize temperature control. For example, it is also possible to change the thickness of the protective film formed according to the position of the wafer to form openings of different shapes.

[0189] (Variant 3 - Removal of Oxide Film)

[0190] When manufacturing a semiconductor device, a natural oxide film is sometimes formed on a wafer W. Sometimes the natural oxide film is removed, and sometimes other films around it are removed or damaged. Therefore, it is preferable to remove the natural oxide film without damaging the surrounding films. The substrate processing method of this embodiment can change the film formation amount in the depth direction of the pattern. Therefore, a protective film is not formed on the oxide film formed at the bottom of the recess, and a protective film can be formed on other parts to suppress damage when removing the natural oxide film.

[0191] Fig. 22 This is a diagram for explaining an example of a processed object processed by the substrate processing method according to Modification Example 3. Fig. 22 (A) is a diagram showing an example of a workpiece on which an oxide film is formed. The workpiece (for example, a semiconductor wafer W) has an SiO2 film formed on a silicon (Si) layer 101C as a base. 2 Film 140. In SiO 2 The film 140 is formed with a pattern. Fig. 22 In the pattern, a concave portion reaching the Si layer 101C is formed in the SiO 2 Film 140. SiO 2 The upper surface of the film 140 and the side wall of the recess are covered with the SiN film 150. In addition, in the wafer W, a natural oxide film 160 (SiO 2 ) The Si layer 101C shows a changed pattern because the portion of the natural oxide film 160 that becomes the bottom of the concave portion is changed to silicon germanium or the like.

[0192] The substrate processing method of the modification example 3 forms a protective film 300C whose thickness decreases in the depth direction on the side wall of the concave portion using steps S101 to S104 of the first embodiment. The substrate processing method of the first embodiment does not form a film on the bottom of the concave portion, but forms a film on the side wall and the top. Therefore, it is possible to form Fig. 22 The protective film 300C shown in (B) is then etched after the protective film 300C is formed. The sidewalls are covered by the protective film 300C, so damage to the SiN film 150 under the protective film 300C can be suppressed, and the natural oxide film 160 at the bottom and the protective film 300C on the sidewalls can be removed. As a result, Fig. 22 The processed object shown in (C).

[0193] As described above, when the protective film 300C is formed using sub-conformal ALD, it is possible to form a film on the sidewalls and top instead of the bottom of the recess, so that the natural oxide film 160 can be removed without reducing the etching rate at the bottom. In addition, by forming the protective film 300C on the sidewalls of the recess, the etching of SiO can be suppressed. 2 Damage to the SiN film 140 and the SiN film 150.

[0194] In the above embodiments, an example of using a protective film to suppress the occurrence of shape abnormalities in a semiconductor pattern is described. However, this is not limiting, and when a shape abnormality occurs in a mask during pattern formation, the substrate processing method of the embodiment can be used to correct the shape abnormality.

[0195] (Conditioning in the chamber)

[0196] However, in the above-mentioned embodiment, for example, the Figure 1 The film formation of steps S101 to S104 and the etching of step S106. In this case, the by-products generated by etching adhere to the chamber and may affect the conditions during film formation. In contrast, when only the film formation process of the same film is performed in one chamber, the same type of film as the film formed on the processed object is incidentally formed on the surface of other parts of the inner wall of the chamber. Therefore, there is a possibility that the state of the film formed by film formation is different when only film formation is performed in one chamber and when both film formation and etching are performed in one chamber.

[0197] Therefore, after performing the etching of this embodiment (for example Figure 1 After step S106 is performed, conditioning of the surface exposed in the plasma space in the chamber can be performed. The conditioning can be performed by (1) cleaning in the chamber and (2) coating in the chamber.

[0198] Cleaning in the chamber is performed, for example, by converting a predetermined cleaning gas into plasma in the chamber and then exhausting the plasma. O 2 , CO 2 Oxygen-containing gases, H 2 NH 3 The cleaning method is not particularly limited. The cleaning in the chamber is performed under conditions that remove carbon and fluorine adhering to the outermost surface (the inner surface of the chamber), for example.

[0199] In addition, the coating in the chamber is performed by turning a predetermined coating gas into plasma in the chamber and then exhausting it. 4 , aminosilane-based gases and other silicon-containing gases and O 2 CVD, ALD, etc., using oxygen-containing gases to form a silicon oxide film (SiO 2 ) etc. In addition, the coating method is not particularly limited. In addition, the coating material is not particularly limited. The coating is performed, for example, after the plasma treatment using fluorine (CF etc.). By coating, the byproducts exposed on the outermost surface of the chamber are covered and not exposed to the plasma processing space.

[0200] In addition, the cleaning and coating for conditioning are performed under the condition that not only the periphery of the mounting table on which the object to be processed is mounted but also the entire inner wall of the chamber is the object of processing. In addition, the cleaning and coating for conditioning can be performed each time a plasma treatment is performed, or can be performed each time a predetermined number of plasma treatments are performed. Thus, it is possible to prevent the inner surface to which the by-products are attached from being exposed to the plasma treatment space. Therefore, it is possible to prevent the conditions and states in the chamber from changing during each treatment, and to stabilize the state of the formed film.

[0201] (Other Modifications)

[0202] In the above embodiment, the first step and the second step may be repeated any number of times as one cycle. In addition, in the above embodiment, a film formed by ALD is described as an example of a film having self-controllability. This is not limited to this, and for example, a self-assembled monolayer (SAM) may be used as a protective film.

[0203] (An Example of a Substrate Processing Apparatus According to an Embodiment)

[0204] Fig.23 This is a diagram showing an example of a substrate processing apparatus according to an embodiment used to execute the substrate processing method according to the embodiment. Fig.23 Schematically shows a cross-sectional structure of a substrate processing apparatus 10 that can be used in various embodiments of the substrate processing method of the embodiment. Fig.23 As shown, the substrate processing device 10 is a plasma etching device having parallel flat electrodes, and includes a processing container 12. The processing container 12 has a substantially cylindrical shape and defines a processing space Sp. The processing container 12 is made of, for example, aluminum, and its inner wall surface is anodized. The processing container 12 is safely grounded.

[0205] A substantially cylindrical support portion 14 is provided at the bottom of the processing container 12. The support portion 14 is made of, for example, an insulating material. The insulating material constituting the support portion 14 may contain oxygen, such as quartz. The support portion 14 extends vertically from the bottom of the processing container 12 in the processing container 12. In addition, a stage PD is provided in the processing container 12. The stage PD is supported by the support portion 14.

[0206] The stage PD holds the wafer W described above on its upper surface. The main surface FW of the wafer W is the opposite side of the back surface of the wafer W in contact with the upper surface of the stage PD, and faces the upper electrode 30. The stage PD has a lower electrode LE and an electrostatic chuck ESC. The lower electrode LE includes a first plate 18a and a second plate 18b. The first plate 18a and the second plate 18b are made of a metal such as aluminum and are substantially disc-shaped. The second plate 18b is provided on the first plate 18a and is electrically connected to the first plate 18a.

[0207] An electrostatic chuck ESC is provided on the second plate 18b. The electrostatic chuck ESC has a structure in which an electrode as a conductive film is arranged between a pair of insulating layers or between a pair of insulating sheets. The DC power supply 22 is electrically connected to the electrode of the electrostatic chuck ESC via a switch 23. When the wafer W is placed on the mounting table PD, it is in contact with the electrostatic chuck ESC. The back side (the side opposite to the main surface FW) of the wafer W is in contact with the electrostatic chuck ESC. The electrostatic chuck ESC adsorbs the wafer W by electrostatic force such as Coulomb force generated by the DC voltage from the DC power supply 22. Thus, the electrostatic chuck ESC can hold the wafer W.

[0208] A focus ring ER is arranged on the peripheral portion of the second plate 18b so as to surround the edge of the wafer W and the electrostatic chuck ESC. The focus ring ER is provided to improve the uniformity of etching. The focus ring ER is made of a material appropriately selected according to the material of the film to be etched, and can be made of, for example, silicon or quartz.

[0209] A coolant flow path 24 is provided inside the second plate 18b. The coolant flow path 24 constitutes a temperature control mechanism. A coolant is supplied to the coolant flow path 24 from a cooling unit (not shown) provided outside the processing container 12 via a pipe 26a. The coolant supplied to the coolant flow path 24 is returned to the cooling unit via a pipe 26b. In this way, the coolant is supplied in a manner of circulating in the coolant flow path 24. By controlling the temperature of the coolant, the temperature of the wafer W supported by the electrostatic chuck ESC can be controlled.

[0210] The plasma processing apparatus 10 is provided with a gas supply passage 28. The gas supply passage 28 supplies a heat transfer gas such as He gas from a heat transfer gas supply mechanism to a position between the upper surface of the electrostatic chuck ESC and the back surface of the wafer W.

[0211] The substrate processing apparatus 10 is provided with a temperature adjustment unit HT for adjusting the temperature of the wafer W. The temperature adjustment unit HT is built into the electrostatic chuck ESC. The temperature adjustment unit HT is connected to a heater power supply HP. By supplying electric power from the heater power supply HP to the temperature adjustment unit HT, the temperature of the electrostatic chuck ESC can be adjusted, so that the temperature of the wafer W placed on the electrostatic chuck ESC can be adjusted. In addition, the temperature adjustment unit HT can also be embedded in the second plate 18b.

[0212] In addition, the plasma processing apparatus 10 includes an upper electrode 30. The upper electrode 30 is disposed above the mounting table PD and opposite to the mounting table PD. The lower electrode LE and the upper electrode 30 are disposed substantially parallel to each other to form a parallel plate motor. A processing space Sp for processing a wafer W is formed between the upper electrode 30 and the lower electrode LE.

[0213] The upper electrode 30 is supported on the upper part of the processing container 12 via an insulating shielding member 32. The insulating shielding member 32 is made of an insulating material, for example, it may contain oxygen like quartz. The upper electrode 30 may include an electrode plate 34 and an electrode support 36. The electrode plate 34 faces the processing space Sp, and a plurality of gas exhaust holes 34a are provided on the electrode plate 34. The electrode plate 34 is made of silicon (hereinafter sometimes referred to as silicon) in one embodiment. In other embodiments, the electrode plate 34 may contain silicon oxide.

[0214] The electrode support 36 supports the electrode plate 34 in a manner that the electrode plate 34 can be freely attached and detached, and can be made of a conductive material such as aluminum. The electrode support 36 can have a water cooling structure. A gas diffusion chamber 36a is provided inside the electrode support 36. A plurality of gas flow holes 36b connected to the gas discharge hole 34a extend downward from the gas diffusion chamber 36a.

[0215] The substrate processing device 10 includes a first high-frequency power supply 62 and a second high-frequency power supply 64. The first high-frequency power supply 62 is a power supply for generating high-frequency electric power for plasma generation, and generates high-frequency electric power with a frequency of 27 to 100 [MHz], and in one example, a high-frequency electric power of 60 [MHz]. In addition, the first high-frequency power supply 62 has a pulse form and can be controlled at a frequency of 0.1 to 50 [kHz] and a duty ratio of 5 to 100%. The first high-frequency power supply 62 is connected to the lower electrode LE via a matching device 66. The matching device 66 is a circuit for matching the output impedance of the first high-frequency power supply 62 with the input impedance of the load side (the upper electrode LE side). In addition, the first high-frequency power supply 62 can also be connected to the upper electrode 30 via the matching device 66.

[0216] The second high-frequency power source 64 is a power source for generating a second high-frequency power, i.e., a high-frequency bias power, for introducing ions into the wafer W. The second high-frequency power source 64 generates a high-frequency bias power with a frequency in the range of 400 [kHz] to 40.68 [MHz], and in one example, generates a high-frequency bias power with a frequency of 13.56 [MHz]. In addition, the second high-frequency power source 64 has a pulse form and can be controlled at a frequency of 0.1 to 50 [kHz] and a duty ratio of 5 to 100%. The second high-frequency power source 64 is connected to the lower electrode LE via a matching device 68. The matching device 68 is a circuit for matching the output impedance of the second high-frequency power source 64 with the input impedance of the load side (lower electrode LE side).

[0217] The substrate processing device 10 further includes a power supply 70. The power supply 70 is connected to the upper electrode 30. The power supply 70 applies a voltage to the upper electrode 30 for introducing positive ions present in the processing space Sp to the electrode plate 34. In one example, the power supply 70 is a DC power supply that generates a negative DC voltage. When such a voltage is applied from the power supply 70 to the upper electrode 30, the positive ions present in the processing space S collide with the electrode plate 34. As a result, secondary electrons and / or silicon are released from the electrode plate 34.

[0218] An exhaust plate 48 is provided at the bottom side of the processing chamber 12 and between the support portion 14 and the side wall of the processing chamber 12. The exhaust plate 48 can be provided by, for example, placing Y 2 O 3 The processing chamber 12 is formed by covering an aluminum material with ceramics such as aluminum. An exhaust port 12e is provided below the exhaust plate 48 and in the processing chamber 12. An exhaust device 50 is connected to the exhaust port 12e via an exhaust pipe 52. The exhaust device 50 has a vacuum pump such as a turbomolecular pump, which can reduce the pressure in the processing chamber 12 to a desired vacuum degree. In addition, a wafer W delivery port 12g is provided on the side wall of the processing chamber 12, and the delivery port 12g can be opened and closed by a gate valve 54.

[0219] The gas source group 40 has a plurality of gas sources. The plurality of gas sources may include: a gas source of an aminosilane-based gas containing organic matter, a fluorocarbon-based gas (C x F y Gas sources include gas sources of various gases such as a gas source of a gas (x, y are integers of 1 to 10), a gas source of a gas having oxygen atoms (such as oxygen), and a gas source of an inert gas. As the inert gas, any gas such as nitrogen gas, Ar gas, and He gas can be used.

[0220] The valve group 42 includes a plurality of valves, and the flow controller group 44 includes a plurality of flow controllers such as mass flow controllers. The plurality of gas sources of the gas source group 40 are connected to the gas supply pipe 38 and the gas supply pipe 82 via the corresponding valves of the valve group 42 and the corresponding flow controllers of the flow controller group 44. Therefore, the substrate processing apparatus 10 can supply the gas from one or more gas sources selected from the plurality of gas sources of the gas source group 40 to the processing container 12 at individually adjusted flow rates.

[0221] A gas inlet port 36c is provided in the processing container 12. The gas inlet port 36c is provided above the wafer W disposed on the mounting table PD in the processing container 12. The gas inlet port 36c is connected to one end of a gas supply pipe 38. The other end of the gas supply pipe 38 is connected to a valve group 42. The gas inlet port 36c is provided in the electrode support 36. The gas supplied from the gas inlet port 36c to the processing space Sp through the gas diffusion chamber 36a is supplied to the space region between the wafer W and the upper electrode 30 above the wafer W.

[0222] The processing container 12 is provided with a gas inlet 52a. The gas inlet 52a is provided on the side of the wafer W disposed on the mounting table PD in the processing container 12. The gas inlet 52a is connected to one end of the gas supply pipe 82. The other end of the gas supply pipe 82 is connected to the valve group 42. The gas inlet 52a is provided on the side wall of the processing container 12. The gas supplied from the gas inlet 52a to the processing space Sp is supplied to the space region between the wafer W and the upper electrode 30 above the wafer W.

[0223] In the substrate processing apparatus 10, a deposit shield 46 is detachably provided along the inner wall of the processing chamber 12. A deposit shield 46 is also provided on the outer periphery of the support portion 14. The deposit shield 46 prevents the etching byproducts (deposits) from adhering to the processing chamber 12. The deposit shield 46 can be formed by covering the Y 2 O 3 The sediment shield can be made of ceramics other than Y 2 O 3 In addition, it is composed of a material containing oxygen such as quartz.

[0224] The control unit Cnt is a computer having a processor, a storage unit, an input device, a display device, etc. Fig.23 The various components of the substrate processing apparatus 10 are shown.

[0225] The control unit Cnt operates according to a computer program (a program based on an inputted scheme) for controlling each part of the substrate processing apparatus 10 in each step of the substrate processing method of one embodiment, and sends a control signal. Each part of the substrate processing apparatus 10 is controlled by the control signal from the control unit Cnt. Specifically, the control unit Cnt Fig.23 In the substrate processing apparatus 10 shown, the selection and flow rate of the gas supplied from the gas source group 40, the exhaust of the exhaust device 50, the power supply from the first high-frequency power supply 62 and the second high-frequency power supply 64, the voltage application from the power supply 70, the power supply from the heater power supply HP, the refrigerant flow rate and refrigerant temperature from the cooling unit, etc. are controlled by using control signals. In addition, each step of the substrate processing method disclosed in this specification can be executed by operating each part of the substrate processing apparatus 10 based on the control of the control unit Cnt. The storage unit of the control unit Cnt can read and store a computer program for executing the substrate processing method of one embodiment and various data for executing the method.

[0226] (Effects of Embodiments)

[0227] The substrate processing method of the above-mentioned embodiment includes step a) and step b). In step a), the processed body is locally etched to form a recess. In step b), a film with different thicknesses is formed on the sidewall of the recess along the depth direction of the recess. Step b) includes step b-1) and step b-2). In step b-1), the first reactant is supplied so that the first reactant is adsorbed on the sidewall of the recess. In step b-2), the second reactant is supplied so that the first reactant reacts with the second reactant to form a film. Therefore, according to the embodiment, the film thickness of the film formed for the pattern with a high aspect ratio can be changed in the depth direction. Therefore, according to the embodiment, the film thickness can be changed in the depth direction in advance at the position of the pattern where the shape abnormality is easy to occur to form a protective film. Therefore, according to the embodiment, the shape abnormality of the semiconductor pattern can be suppressed. In addition, according to the embodiment, in order to form a self-controllable film such as an ALD film, the film thickness of the protective film formed can be precisely controlled. Therefore, according to the embodiment, the clogging of the opening of the pattern can be suppressed. In addition, according to the embodiment, by suppressing the formation of a protective film at the bottom of the pattern, it is possible to prevent corrosion and increase the etching rate. In addition, according to the embodiment, by adjusting the processing conditions of step b-1) and step b-2), the coverage of the protective film along the depth direction of the pattern can be greatly changed.

[0228] In addition, in an embodiment, in step b), b-1) does not allow the first reactant to be adsorbed onto the entire surface of the recess, and / or b-2) does not allow the first reactant to react with the second reactant on the entire surface of the recess. That is, the substrate processing method of the embodiment can be terminated before the adsorption of the entire surface in the depth direction of the pattern of the first reactant is completed. Therefore, by adjusting the processing conditions in step b-1), the position where the protective film is formed can be adjusted. In addition, in an embodiment, step b-2) can be terminated before the reaction in the entire surface in the depth direction of the pattern of the second reactant is completed. Therefore, by adjusting the processing conditions in step b-2), the position where the protective layer is formed can be adjusted. For example, the reduction in etching rate can be suppressed by not forming a protective layer at the bottom.

[0229] In addition, the substrate processing method of the embodiment may further include the step c) of etching the bottom of the concave portion after b) to form a concave portion with a high aspect ratio. Therefore, according to the embodiment, the pattern after forming the protective layer can be further processed to achieve a desired shape.

[0230] In addition, in the substrate processing method of the embodiment, step b) may be performed after step c). Therefore, according to the embodiment, when the protective film disappears by etching, the protective film is formed again to form a desired pattern.

[0231] In addition, in the substrate processing method of the embodiment, the object to be processed may include a substrate, an etching target film formed on the above-mentioned substrate, and a mask formed on the above-mentioned etching target film. Moreover, the substrate processing method may further include a step d) of forming a preliminary film on the upper part of the above-mentioned mask to reduce the opening size of the above-mentioned recess. Therefore, the substrate processing method of the embodiment, for example, forms a preliminary film on the upper part of the pattern formed on the object to be processed by chemical vapor deposition or physical vapor deposition, which can reduce the opening size of the top of the recess. Therefore, the substrate processing method of the embodiment can increase the aspect ratio of the recess. Therefore, according to the embodiment, film formation using sub-conformal ALD can also be achieved for recesses with low aspect ratios.

[0232] In addition, in the substrate processing method of the embodiment, step d) may be performed before step b). Therefore, according to the embodiment, sub-conformal ALD can be performed after the aspect ratio of the recessed portion is corrected.

[0233] In addition, in the substrate processing method of the embodiment, step d may be performed when the aspect ratio of the concave portion is less than 10). In addition, in the substrate processing method of the embodiment, step d may be performed when the ratio of the depth dimension from the upper surface of the mask to the bottom of the concave portion to the top opening dimension of the concave portion is less than 15). In addition, in the substrate processing method of the embodiment, step a) and step b may be repeatedly performed when the aspect ratio of the concave portion is greater than 10, or when the ratio of the depth dimension from the upper surface of the mask to the bottom of the concave portion to the top opening dimension of the concave portion is less than 15). Therefore, according to the embodiment, when the aspect ratio of the concave portion becomes low, a process of interrupting the sub-conformal ALD and increasing the aspect ratio can be performed. In addition, sub-conformal ALD can be effectively performed during the period when the aspect ratio of the concave portion is high. As described above, according to the embodiment, film formation can be performed after adjusting the aspect ratio of the concave portion to a value suitable for film formation control.

[0234] In addition, in the substrate processing method of the embodiment, after step a) or step c), at least one of the processing conditions of b-1) and b-2) may be changed according to the aspect ratio of the concave portion. Therefore, according to the embodiment, a protective film suitable for the state of the pattern after etching can be formed to continue the processing of the pattern.

[0235] In addition, in the substrate processing method of the embodiment, in step b) which is repeatedly performed n times (n is a natural number greater than 2), the processing conditions may be changed between the nth processing and the (n-1)th processing. Thus, the position and / or thickness of the film formed in the repeatedly performed b) may also be changed. Therefore, according to the embodiment, the shape and / or position of the formed film can be adjusted more finely.

[0236] In addition, in the substrate processing method of the embodiment, the first reactant and the second reactant used in the n'th processing and the (n'-1)th processing can be changed in the step b) repeatedly performed n' times (n' is a natural number greater than 2). Thus, the position and / or thickness of the film formed in the repeatedly performed b) can also be changed. Therefore, according to the embodiment, the shape and / or position of the formed film can be adjusted more finely.

[0237] In addition, the substrate processing method of the embodiment may also include step a), step b) and step e). In step a), the object to be processed placed on the mounting table in the processing chamber is etched to form a recess. In step b), a film having different thicknesses along the depth direction of the recess is formed on the side wall of the recess. In step e), while suppressing the change of the opening size of the upper part of the recess by the film formed in step b), the object to be processed is etched so that the opening size of the lower part of the recess not covered by the film formed in step b) is expanded in the lateral direction.

[0238] In addition, in the substrate processing method of the embodiment, in step e), the opening size of the lower part of the recessed portion not covered by the film may be enlarged in the longitudinal direction in addition to the lateral direction. In addition, in the case of including the step of etching the bottom of the recessed portion to form a recessed portion with a high aspect ratio after step b), in step c), the bottom of the recessed portion may be etched by anisotropic etching, and in step e), the opening size of the lower part of the recessed portion may be enlarged in the lateral direction by isotropic etching.

[0239] In addition, in the substrate processing method of the embodiment, in step b), a plurality of independently temperature-controllable regions of a mounting table on which the object to be processed is mounted may be controlled to have different temperatures according to the respective in-plane positions of the plurality of regions. Thus, the thickness of the formed film may also be changed according to the temperature of the plurality of regions. Therefore, according to the embodiment, the state of film formation may be adjusted by controlling the temperature of the mounting table.

[0240] In addition, in the substrate processing method of the embodiment, step a), step b) and step c) may be repeatedly performed at least n times (n" is a natural number greater than 2). Then, in the (n"-1)th step b-2), each of the multiple regions whose temperature can be independently controlled on the mounting table for mounting the processed object may be controlled to a first temperature distribution. Thus, a first film having a first film thickness distribution in the depth direction may be formed. In addition, in the n"th step b-2), each of the multiple regions may be controlled to a second temperature distribution. Thus, a second film having a second film thickness distribution in the depth direction may be formed. Therefore, according to the embodiment, the state of film formation can be adjusted by controlling the temperature of the mounting table.

[0241] In addition, in the substrate processing method of the embodiment, the pressure of the processing chamber in step b-1) can also be set to a value lower than the pressure for completing the process of adsorbing the first reactant on the entire surface in the depth direction of the recessed portion when other processing conditions are the same. In addition, the processing time in step b-1) can also be set to a time shorter than the processing time for completing the process of adsorbing the first reactant on the entire surface in the depth direction of the recessed portion when other processing conditions are the same. In addition, the dilution of the first reactant in step b-1) can also be set to a value higher than the dilution for completing the process of adsorbing the first reactant on the entire surface in the depth direction of the recessed portion when other processing conditions are the same. In addition, the temperature of the mounting table of the object to be processed in step b-1) can also be set to a temperature lower than the temperature for completing the process of adsorbing the first reactant on the entire surface in the depth direction of the recessed portion when other processing conditions are the same. In addition, when plasma is generated in step b-1), the absolute value of the high frequency electric power (RF) applied to generate the plasma may be set to a value smaller than the absolute value for completing the process of adsorbing the second reactant on the entire surface in the depth direction of the concave portion when other process conditions are the same. As described above, by adjusting the process conditions in step b-1), the coverage in the depth direction of the concave portion can be changed, thereby achieving adsorption of the components included in the first reactant on the object to be processed.

[0242] In addition, in the substrate processing method of the embodiment, the pressure of the processing chamber in step b-2) can also be set to a value lower than the pressure for completing the reaction of the second reactant on the entire surface in the depth direction of the recess when other processing conditions are the same. In addition, the processing time in step b-2) can also be set to a time shorter than the processing time for completing the reaction of the second reactant on the entire surface in the depth direction of the recess when other processing conditions are the same. In addition, the dilution of the second reactant in step b-2) can also be set to a value higher than the dilution for completing the reaction of the second reactant on the entire surface in the depth direction of the recess when other processing conditions are the same. In addition, the temperature of the mounting table of the processed body in step b-2) can also be set to a temperature lower than the temperature for completing the reaction of the second reactant on the entire surface in the depth direction of the recess when other processing conditions are the same. In addition, when plasma is generated in step b-2), the absolute value of the high frequency (RF) electric power applied to generate plasma may be set to a value smaller than the absolute value for completing the reaction of the second reactant on the entire surface in the depth direction of the recessed portion when other processing conditions are the same. As described above, by adjusting the processing conditions in step b-2), the coverage in the depth direction of the recessed portion can be changed to achieve the reaction of the components contained in the second reactant on the surface of the object to be processed.

[0243] Furthermore, the substrate processing method of the above embodiment may further include a step f) of forming an inhibitor for inhibiting adsorption of the first reactant on the sidewall of the recess before b-1). Therefore, according to the embodiment, the protective film can be formed at any position.

[0244] In addition, the substrate processing method of the above embodiment may also include, after step a), a step g) of applying a coating to cover the byproducts attached to the inner wall of the processing chamber. Therefore, according to the embodiment, it is possible to prevent the conditions and states in the processing chamber from changing. Therefore, according to the embodiment, it is possible to stabilize the state of the formed film.

[0245] In addition, in the substrate processing method of the above embodiment, step b) may also include steps b-3), b-4), and b-5). In step b-3), a parameter representing the state of the formed film is measured. In step b-4), based on the measured value, it is determined whether the film has reached a predetermined state. In step b-5), if the film has not reached a predetermined state, the processing conditions are adjusted based on the measured value, and steps b-1) and b-2) are repeated.

[0246] In addition, the substrate processing device of the above embodiment includes one or more processing chambers and a control unit, wherein at least one of the one or more processing chambers is configured to be capable of etching, and at least one of the processing chambers is configured to be capable of forming a film. The processing chamber includes a gas supply unit for supplying a processing gas to the interior of the processing chamber. The control unit causes each unit to perform a substrate processing method. The substrate processing method includes steps a) and b). In step a), the processed body is locally etched to form a recess. In step b), a film having different thicknesses along the depth direction of the recess is formed on the side wall of the recess. In addition, step b) includes steps b-1) and b-2). Step b-1) supplies a first reactant to a processing chamber configured to form a film, so that the first reactant is adsorbed to the side wall of the recess. Step b-2) supplies a second reactant to a processing chamber configured to form a film, so that the first reactant reacts with the second reactant to form a film. Therefore, according to the embodiment, the film thickness of the film formed on the pattern with a high aspect ratio can be changed along the depth direction. Therefore, according to an embodiment, a protective film can be formed by changing the film thickness in the depth direction in advance at a position of a pattern where shape abnormalities are likely to occur. Therefore, according to an embodiment, shape abnormalities of semiconductor patterns can be suppressed. In addition, according to an embodiment, in order to form a self-controllable film such as an ALD film, the film thickness of the formed protective film can be precisely controlled. Therefore, according to an embodiment, clogging of the openings of the pattern can be suppressed. In addition, according to an embodiment, by suppressing the formation of a protective film at the bottom of the pattern, corrosion resistance can be prevented and the etching rate can be increased. In addition, according to an embodiment, by adjusting the processing conditions of step b-1) and step b-2), the coverage of the protective film in the depth direction of the pattern can be greatly changed.

[0247] In addition, in the substrate processing apparatus of the above-mentioned embodiment, the processing chamber configured to perform etching may be the same processing chamber as the processing chamber configured to form a film, and steps a) and b) may be performed in the same processing chamber.

[0248] In addition, in the substrate processing apparatus of the above embodiment, the processing chamber configured to perform etching may be a processing chamber different from the processing chamber configured to form the above film. Furthermore, the control unit may cause each unit to execute the substrate processing method, and the substrate processing method further includes the step of h) transporting the substrate between the processing chamber configured to perform etching and the processing chamber configured to form the film.

[0249] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive. The above-described embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

Claims

1. A plasma processing device, characterized in that: include: a processing chamber; a loading platform in the processing chamber; A gas supply unit, used for supplying a processing gas to the processing chamber; A first high-frequency power source for generating a first high-frequency electric power for generating plasma; a second high-frequency power source for generating high-frequency bias electric power; and Control Department, The control unit is capable of controlling the plasma processing device to perform a process including the following steps: (a) preparing a workpiece having a tapered opening on the mounting table; (b) forming a film having a thickness that becomes thinner along a depth direction of the opening on a side wall of the opening; and (c) A step of enlarging the opening size of the lower portion of the opening.

2. The plasma processing device according to claim 1, wherein: In the above (c), the opening size of the lower portion is enlarged while the change in the opening size of the upper portion of the opening is suppressed by the film.

3. The plasma processing device according to claim 1 or 2, characterized in that: The (c) includes the step of etching the bottom of the opening.

4. The plasma processing device according to claim 3, wherein: The control unit can perform control so that (b) and (c) are repeatedly performed during the process performed by the plasma processing apparatus.

5. The plasma processing device according to any one of claims 1 to 4, characterized in that: The control unit can control so that the process performed by the plasma processing apparatus further includes: (d) after the step (c), etching the bottom of the opening.

6. The plasma processing device according to any one of claims 1 to 5, characterized in that: The control unit is capable of controlling so that the process performed by the plasma processing device in (b) includes: (b-1) supplying a first reactant and causing the first reactant to be adsorbed onto a side wall of the opening; and (b-2) A step of supplying a second reactant to allow the first reactant and the second reactant to react to form a film.

7. The plasma processing apparatus according to claim 6, wherein: In the above (b-1), the first reactant is not adsorbed onto the entire surface of the opening, and / or, In the above (b-2), the first reactant and the second reactant are not allowed to react on the entire surface of the opening.

8. The plasma processing apparatus according to claim 6, wherein: The control unit can control the plasma processing apparatus to perform a process further including: before the step (b-1), forming an inhibitor that inhibits adsorption of the first reactant on a side wall of the opening.

9. The plasma processing device according to any one of claims 6 to 8, characterized in that: The control unit can control the plasma processing apparatus to perform the following processing: after (c), at least one of the processing conditions of (b-1) and (b-2) is changed according to the aspect ratio of the opening.

10. The plasma processing device according to any one of claims 1 to 9, characterized in that: The object to be processed includes a substrate, an etching target film formed on the substrate, and a mask formed on the etching target film. The control unit is capable of controlling the plasma processing apparatus to perform a process further including: (e) a step of forming a preliminary film on an upper portion of the mask to reduce an opening size of the opening, performed after (a) and before (b).

11. A substrate processing device, characterized in that: include: A first chamber configured to be capable of performing etching; a second chamber configured to form a membrane; and Control Department, The control unit is capable of controlling the substrate processing device to perform a process including the following steps: (a) a step of placing a processing object having a tapered opening in the first chamber; (b) forming a film having a thickness that becomes thinner along a depth direction of the opening on a side wall of the opening; (c) a step of transporting the object to be processed from the first chamber to the second chamber; (d) placing the object to be processed on which the film is formed in the second chamber; and (e) A step of enlarging the opening size of the lower portion of the opening.

12. The substrate processing device according to claim 11, characterized in that: In the above (e), the opening size of the lower portion is enlarged while the change in the opening size of the upper portion of the opening is suppressed by the film.

13. The substrate processing device according to claim 11 or 12, characterized in that: The (e) includes the step of etching the bottom of the opening.

14. The substrate processing device according to claim 13, characterized in that: The control unit can control the substrate processing apparatus to perform a process that further includes: (f) a step of transporting the object to be processed from the second chamber to the first chamber, And repeat the steps from (b) to (f).

15. The substrate processing device according to any one of claims 11 to 14, characterized in that: The control unit can control so that the processing performed by the substrate processing device further includes: (g) after (e), a step of etching the bottom of the opening.

16. The substrate processing device according to any one of claims 11 to 15, characterized in that: The control unit is capable of controlling so that the processing performed by the substrate processing device in (b) includes: (b-1) supplying a first reactant and causing the first reactant to be adsorbed onto a side wall of the opening; and (b-2) A step of supplying a second reactant to allow the first reactant and the second reactant to react to form a film.

17. The substrate processing device according to claim 16, characterized in that: In the above (b-1), the first reactant is not adsorbed onto the entire surface of the opening, and / or, In the above (b-2), the first reactant and the second reactant are not allowed to react on the entire surface of the opening.

18. The substrate processing device according to claim 16, characterized in that: The control unit can control the substrate processing apparatus to perform a process further including: before the step (b-1), forming an inhibitory factor that inhibits adsorption of the first reactant on a side wall of the opening.

19. The substrate processing device according to any one of claims 16 to 18, characterized in that: The control unit can control the substrate processing apparatus to perform the following processing: after (e), at least one of the processing conditions of (b-1) and (b-2) is changed according to the aspect ratio of the opening.

20. The substrate processing device according to any one of claims 11 to 19, characterized in that: The object to be processed includes a substrate, an etching target film formed on the substrate, and a mask formed on the etching target film. The control unit is capable of controlling so that the processing performed by the substrate processing device also includes: (h) a step of forming a preliminary film on the upper part of the mask to reduce the opening size of the opening, which is performed after (a) and before (b).

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