KR20170041154A - Method for processing target object - Google Patents

Abstract

Provided is a method for realizing precise control of a minimum line width and stable reproducibility of the minimum line width in pattern formation on an object to be processed. The method includes a formation step of forming a silicon oxide film in a processing chamber by repeatedly executing a sequence including a first step of supplying a first gas containing aminosilane-based gas, a second step of purging a space in the processing chamber after the first step, a third step of generating a plasma of a second gas containing oxygen gas after the second step, and a fourth step of purging the space after the third step. The method further includes a preparation step executed before the target object is accommodated in the processing chamber and a processing step of performing an etching process on the target object. The preparation step is performed before the processing step. The formation step is performed in the preparation step and the processing step. In the first step, a plasma of the first gas is not generated.

Description

[0001] METHOD FOR PROCESSING TARGET OBJECT [0002]

An embodiment of the present invention relates to a method of treating an object to be processed, and more particularly to a method of performing surface treatment of a semiconductor substrate by using plasma.

In a manufacturing process of an electronic device called a semiconductor device, plasma processing of an object to be processed may be performed using a plasma processing apparatus. As a kind of plasma treatment, there is plasma etching. The plasma etching is performed to transfer the pattern of the mask provided on the etched layer to the etched layer. As the mask, a resist mask is generally used. The resist mask is formed by photolithography. Therefore, the limit dimension of the pattern formed on the etched layer depends on the resolution of the resist mask formed by the photolithography technique. However, resolution of the resist mask has a resolution limit. There is a growing demand for higher integration of electronic devices and it is required to form a pattern with a dimension smaller than the resolution limit of the resist mask. Therefore, as described in Patent Document 1, a technique of adjusting the dimension of the resist mask by forming a silicon oxide film on the resist mask and reducing the width of the opening provided by the resist mask is proposed .

(Prior art document)

(Patent Literature)

(Patent Document 1) Japanese Patent Laid-Open No. 2004-80033

On the other hand, with the recent miniaturization accompanied with the high integration of electronic devices, it is required to control the critical dimension (CD) with high accuracy in pattern formation on the object to be processed. From the viewpoint of mass production of electronic devices, reproducibility of a minimum line width that is stable in the long term is also required.

As a factor of the variation of the minimum line width in the plasma etching, generally, the component parts of the plasma processing apparatus exposed in the processing space where the plasma is generated (for example, the inner wall surface of the processing vessel for generating plasma, The inner wall surface of various pipes, and the like) changes, and the plasma state changes. Examples of factors that change the state of the surface of the component parts of the plasma processing apparatus that are exposed to the processing space include that the surface of the component is consumed due to long-term use of the plasma. Such a consumption causes the temperature of the surface of the component to fluctuate, and the rate of deposition of the radical also fluctuates due to the variation of the surface temperature.

Further, in the plasma treatment, particles which may be a factor of defects of the product may be generated. The particles can originate from the surface of the component parts of the plasma processing apparatus exposed to the processing space, and adhere to the wafer, leading to product defects. It is possible to prevent realization of a minimum line width with high precision and reproducibility of a stable minimum line width because the particles are prevented from being transferred by being attached to the pattern.

As described above, in the pattern formation on the object to be processed, a method for realizing the control of the minimum line width with high precision and the reproducibility of the stable minimum line width is required for miniaturization accompanied with high integration.

In one aspect, a method of treating an object to be treated is provided. The method according to this mode is characterized in that (a) a first step of supplying a first gas containing an aminosilane-based gas into a processing vessel of a plasma processing apparatus, a second step of purging a space in the processing vessel after the execution of the first step A third step of generating a plasma of a second gas containing oxygen gas in the processing vessel after the execution of the second processing, and a fourth step of purifying the space in the processing vessel after execution of the third processing To form a silicon oxide film in the processing container; (b) a preparation step to be performed before the object to be processed is received in the processing container; and (e) a processing step of performing an etching process on the object to be processed contained in the processing container. The preparation step is carried out before the treatment step. The forming step is carried out in the preparation step and also in the processing step. The first step does not generate the plasma of the first gas.

According to the above method, in the first step, the first gas containing the aminosilane-based gas is supplied into the processing vessel without generating the plasma, and thereafter, in the third step, the oxygen- 2 gas is generated and a thin silicon oxide film is formed. Therefore, the silicon oxide film of the thin film is uniformly and conformally formed on the surface of the object to be processed by the first step to the fourth step executed in the processing step. Since the first to fourth steps are repeatedly performed in the forming step executed in the processing step, the thickness of the silicon oxide film formed on the surface of the object to be processed can be precisely controlled. Therefore, the minimum line width of the pattern on the surface of the object to be processed can be precisely reduced by the silicon oxide film formed by the forming process, and miniaturization can be achieved accompanying high integration. In addition, the silicon oxide film is formed on the surface of the object to be processed by the forming process executed in the process step, and the inner surface of the various pipes connected to the process container and the inner surface of the process container A silicon oxide film is further formed as a protective film. Therefore, by the silicon oxide film formed on the inner surface of the processing vessel and on the inner surface of various pipes connected to the processing vessel, it is possible to sufficiently suppress the generation of particles generated from these surfaces and the change of the state of each surface , Stable minimum line width can be reproduced, and so on. In addition, the forming step is executed in the preparing step executed before the processing step, independently of the forming step executed in the processing step. Therefore, a silicon oxide film of a desired thickness corresponding to the thickness of the silicon oxide film removed by etching in the processing step is formed as a protective film on the inner surface of the processing vessel and the inner surface of various pipes connected to the processing vessel It is possible to sufficiently suppress the generation of particles generated from each of these surfaces and the change of the state of each surface without depending on the degree of etching performed in the treatment process.

In one embodiment, the first gas may comprise a monoaminosilane. Therefore, the first gas containing monoaminosilane can be used for the formation treatment.

In one embodiment, the aminosilane-based gas of the first gas may comprise an aminosilane having 1 to 3 silicon atoms. The aminosilane-based gas of the first gas may contain aminosilane having 1 to 3 amino groups. As described above, the aminosilane gas containing one to three silicon atoms can be used as the aminosilane gas of the first gas. The aminosilane gas of the first gas may contain aminosilane containing 1 to 3 amino groups.

In one embodiment, the method may further include a step of removing the silicon oxide film in the processing container after the processing object is removed from the processing container after the processing step. Therefore, even when the silicon oxide film remains in the processing vessel and in various piping connected to the processing vessel after the processing step, it is possible to reliably remove the silicon oxide film from the inside of the processing vessel and various pipes connected to the processing vessel .

In one embodiment, the object to be processed may include an etched layer and an organic film provided on the etched layer, and the process may include a step of etching the organic film by the plasma generated in the process container The forming process may be performed before the process of etching the organic film in the process step and the thickness of the silicon oxide film formed in the process container before the process of etching the organic film may be performed until the end of the process of etching the organic film, It can be made thicker than the thickness of the film to be etched and removed in the oxide film. Therefore, even after the etching of the organic film is completed, the silicon oxide film remains on the inner surface of the processing vessel and on the inner surface of various pipes connected to the processing vessel. It is possible to avoid such a situation that the state of each surface is changed and particles are generated from the respective surfaces. Further, since the formation step of forming the silicon oxide film is performed before the etching of the organic film is performed, the active species (for example, hydrogen radical) generated by the etching of the organic film is formed on the inner surface of the processing vessel and on the inner surface It is possible to sufficiently suppress the generation of particles from each of these surfaces and the change of the state of each of the surfaces.

In one embodiment, the thickness of the silicon oxide film formed in the processing vessel before the step of etching the organic film can be made thinner than the thickness of the film of the etched layer. Therefore, since the thickness of the silicon oxide film formed in the processing vessel and various pipes connected to the processing vessel is thinner than the thickness of the film to be etched, the silicon oxide film in various pipes connected to the processing vessel and the processing vessel, The processing for removing the silicon oxide film in the processing vessel and the various pipes connected to the processing vessel at the time of cleaning in various piping connected to the processing vessel and after the processing step is unnecessary do.

In one embodiment, the object to be processed may include an etching layer and an organic film provided on the etched layer, and the processing step may include a step of etching the organic film by plasma generated in the processing vessel The forming process may be performed before the process of etching the organic film in the process step and the first mask may be provided on the organic film. The process may be performed by a plasma generated in the process container, The step of etching the organic film may be performed after the step of etching the antireflection film, and in the processing step, the step of etching the organic film may be performed after the step of etching the antireflection film, The forming process can be executed between the step of etching the antireflection film and the step of etching the organic film, The method may further include a step of removing a region on the surface of the organic film in the silicon oxide film formed by the forming process by the plasma generated in the process container between the process of etching the film and the organic film.

In one embodiment, the object to be processed may include an etching layer, an organic film provided on the etched layer, and an antireflection film provided on the organic film, and the processing may be performed by plasma generated in the processing chamber, The forming step may be performed before the step of etching the organic film in the processing step, and the first mask may be provided on the antireflection film, and the processing step may be performed in the forming step Removing the region on the antireflection film and the region above the upper surface of the first mask by the plasma generated in the processing vessel after the silicon oxide film is formed on the first mask and the anti-reflection film, Forming a second mask based on a region above a side surface of the first mask, and a plasma generated in the processing vessel, The step of removing the first mask and the step of etching the antireflection film by the plasma generated in the processing vessel may be included and the step of etching the organic film may be performed after the step of etching the antireflection film, A third mask composed of a film can be formed.

In one embodiment, when the forming step is performed in the processing step, the temperature of the object to be processed in the first step is not lower than 0 degree Celsius, and the glass transition temperature (Glass transition point) or less. Therefore, in the case of using the monoaminosilane, the first step can be performed at a relatively low temperature at which the temperature of the object to be treated is not lower than 0 degrees Celsius and not higher than the glass transition temperature of the mask material of the first mask, .

As described above, in the pattern formation on the object to be processed, control of a minimum line width with high accuracy and stable reproducibility of a minimum line width can be realized for miniaturization accompanied with high integration.

1 is a flow chart illustrating a method of one embodiment.
2 is a view showing an example of a plasma processing apparatus.
3 is a view showing a form of formation of a protective film on the inner side of the processing container 12. Fig.
4 is a flow chart showing contents related to an embodiment of the wafer processing process shown in Fig.
5 is a cross-sectional view showing the state of an object to be processed before and after each step shown in Fig.
Fig. 6 is a cross-sectional view showing the state of the object to be processed after each step shown in Fig. 4; Fig.
Fig. 7 is a diagram schematically showing the formation of a protective film in the sequence for forming the protective film shown in Fig. 4. Fig.
8 is a timing chart relating to plasma generation in the sequence of forming the protective film shown in Fig.
Fig. 9 is a flowchart showing contents related to another embodiment of the wafer processing process shown in Fig. 1;
10 is a cross-sectional view showing the state of an object to be processed before and after each step shown in Fig.
Fig. 11 is a cross-sectional view showing the state of an object to be processed after each step shown in Fig. 9; Fig.
Fig. 12 is a cross-sectional view showing the state of an object to be processed after each step shown in Fig. 9 is performed.

Hereinafter, various embodiments will be described in detail with reference to the drawings. In the drawings, the same or equivalent parts are denoted by the same reference numerals.

1 is a flow chart illustrating a method of one embodiment. The method MT of the embodiment shown in Fig. 1 is a method of processing an object to be processed (hereinafter sometimes referred to as " wafer "). Further, in the method MT of the embodiment, it is possible to execute a series of processes using a single plasma processing apparatus.

2 is a view showing an example of a plasma processing apparatus. 2 schematically shows a cross-sectional structure of a plasma processing apparatus 10 usable in various embodiments of a method for treating an object to be processed. As shown in Fig. 2, the plasma processing apparatus 10 is a capacitively coupled plasma etching apparatus.

The plasma processing apparatus 10 includes a processing vessel 12, an exhaust port 12e, a loading and unloading port 12g, a support portion 14, a mount stand PD, a DC power source 22, a switch 23, The gas supply line 28, the upper electrode 30, the insulating shield member 32, the electrode plate 34, the gas discharge hole 34a, the electrode support 36, The gas diffusion chamber 36a, the gas communication hole 36b, the gas inlet 36c, the gas supply pipe 38, the gas source group GSG 40, the valve group VG 42, The first high frequency power source 62, the second high frequency power source 62, the second high frequency power source 62, the second high frequency power source 62, the second high frequency power source 62, A power source 64, a matching unit (MU) 66, a matching unit 68, a power source (PS) 70, a control unit Cnt, a focus ring FR, a heater power HP and a heater HT. The mount table PD includes an electrostatic chuck ESC and a lower electrode LE. The lower electrode LE includes a first plate 18a and a second plate 18b. The processing vessel 12 defines the processing space Sp.

The processing vessel 12 has a substantially cylindrical shape. The processing vessel 12 is made of, for example, aluminum. The inner wall surface of the processing vessel 12 is anodized. The processing vessel 12 is securely grounded.

The support portion 14 is provided on the bottom of the processing container 12 on the inner side of the processing container 12. The support portion 14 has a substantially cylindrical shape. The supporting portion 14 is made of, for example, an insulating material. The insulating material constituting the supporting portion 14 may contain oxygen such as quartz. The support portion 14 extends in the vertical direction from the bottom of the processing vessel 12 in the processing vessel 12. [

The stand-by PD is provided in the processing vessel 12. The mount table PD is supported by the support portion 14. [ The mount table PD holds the wafer W (e.g., the wafer W1 shown in Fig. 5, the wafer W2 shown in Fig. 10, and the like in the following description) on the upper surface of the mount table PD. The wafer W is an object to be processed. The mount table 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 metal, for example, aluminum. The first plate 18a and the second plate 18b have a substantially disk-like shape. The second plate 18b is provided on the first plate 18a. The second plate 18b is electrically connected to the first plate 18a.

The electrostatic chuck ESC is provided on the second plate 18b. The electrostatic chuck ESC has a structure in which electrodes of a conductive film are disposed between a pair of insulating layers or between a pair of insulating sheets. The direct current power source 22 is electrically connected to the electrode of the electrostatic chuck ESC via the switch 23. The electrostatic chuck ESC sucks the wafer W by an electrostatic force such as a Coulomb force generated by a DC voltage from the DC power supply 22.

The focus ring FR is disposed on the peripheral edge of the second plate 18b so as to surround the edge of the wafer W and the electrostatic chuck ESC. The focus ring FR is provided to improve the uniformity of the etching. The focus ring FR is made of a material suitably selected according to the material of the film to be etched, and may be made of, for example, quartz.

The refrigerant passage (24) is provided inside the second plate (18b). The refrigerant flow path 24 constitutes a temperature adjusting mechanism. The refrigerant is supplied to the refrigerant passage 24 from the chiller unit provided outside the processing vessel 12 via the pipe 26a. The refrigerant supplied to the refrigerant passage 24 is returned to the chiller unit via the pipe 26b. Thus, the refrigerant is supplied to the refrigerant passage 24 so as to circulate the refrigerant. By controlling the temperature of the coolant, the temperature of the wafer W supported by the electrostatic chuck ESC is controlled. The gas supply line 28 supplies a heat transfer gas, for example, He gas, from a heat transfer gas supply mechanism between the upper surface of the electrostatic chuck ESC and the back surface of the wafer W.

The heater HT is a heating element. The heater HT is embedded, for example, in the second plate 18b. The heater power HP is connected to the heater HT. Power is supplied from the heater power source HP to the heater HT to adjust the temperature of the mount stand PD and adjust the temperature of the wafer W mounted on the mount stand PD. Further, the heater HT can be embedded in the electrostatic chuck ESC.

The upper electrode 30 is disposed on the upper side of the mount table PD and opposed to the mount table PD. The lower electrode LE and the upper electrode 30 are provided approximately parallel to each other. A processing space Sp is provided between the upper electrode 30 and the lower electrode LE. The processing space Sp is a space area for performing the plasma processing on the wafer W.

The upper electrode 30 is supported on the upper portion of the processing container 12 through the insulating shielding member 32. The insulating shield member 32 is made of an insulating material and may contain oxygen, for example, 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. The electrode plate 34 has a plurality of gas discharge holes 34a. The electrode plate 34, in one embodiment, may be comprised of silicon. In another embodiment, the electrode plate 34 may be composed of silicon oxide.

The electrode support 36 supports the electrode plate 34 in a detachable manner and may be made of a conductive material such as aluminum. The electrode support 36 may have a water cooling structure. The gas diffusion chamber (36a) is provided inside the electrode support (36). Each of the plurality of gas communication holes 36b communicates with the gas discharge hole 34a. Each of the plurality of gas communication holes 36b extends downward (toward the mount table PD) from the gas diffusion chamber 36a.

The gas introduction port 36c guides the process gas to the gas diffusion chamber 36a. The gas inlet 36c is provided in the electrode support 36. [ The gas supply pipe 38 is connected to the gas inlet 36c.

The gas source group 40 is connected to the gas supply pipe 38 via the valve group 42 and the flow controller group 45. The gas source group 40 has a plurality of gas sources. The plurality of gas sources may include a source of an aminosilane-based gas, a source of a halogenated silicon gas, a source of an oxygen gas, a source of a hydrogen gas, a source of a nitrogen gas, a source of a fluorocarbon gas, have. As the aminosilane-based gas, a gas having a relatively small number of amino groups can be used, and for example, monoaminosilane (H ₃ -Si-R (R is an amino group which may contain an organic group and may be substituted)) is used . The aminosilane-based gas (gas contained in the first gas G1 described later) may contain aminosilane having 1 to 3 silicon atoms, or aminosilane having 1 to 3 amino groups . The aminosilane having 1 to 3 silicon atoms may be monosilane (monoaminosilane) having 1 to 3 amino groups, disilane having 1 to 3 amino groups, or trisilane having 1 to 3 amino groups have. Further, the aminosilane may have an amino group which may be substituted. The amino group may be substituted with any one of a methyl group, an ethyl group, a propyl group, and a butyl group. In addition, the above-mentioned methyl, ethyl, propyl or butyl group may be substituted by halogen. As the halogenated silicon gas, DCS (dichlorosilane) gas may be used. As the fluorocarbon gas, any fluorocarbon gas such as CF ₄ gas, C ₄ F ₆ gas and C ₄ F ₈ gas can be used. As the rare gas, any rare gas called He gas or Ar gas can be used.

The valve group 42 includes a plurality of valves. The flow controller group 45 includes a plurality of flow controllers, called mass flow controllers. Each of the plurality of gas sources of the gas source group 40 is connected to the gas supply pipe 38 via a corresponding valve of the valve group 42 and a corresponding flow controller of the flow controller group 45. Therefore, the plasma processing apparatus 10 can supply the gas from one or more gas sources selected from a plurality of gas sources of the gas source group 40 into the processing vessel 12 at individually adjusted flow rates Do. Further, in the plasma processing apparatus 10, a deposit shield 46 is detachably provided along the inner wall of the processing vessel 12. The deposit shield 46 is also provided on the outer periphery of the support portion 14. The deposit shield 46 prevents deposition of etching by-products (deposit) on the processing vessel 12 and can be constituted by coating an aluminum material with ceramics such as Y ₂ O ₃ . The deposit shield may be made of a material containing oxygen such as quartz in addition to Y ₂ O ₃ .

The exhaust plate 48 is provided on the bottom side of the processing vessel 12 and further between the supporting portion 14 and the side walls of the processing vessel 12. The exhaust plate 48 can be constituted by, for example, coating an aluminum material with ceramics such as Y ₂ O ₃ . The exhaust port 12e is provided in the processing container 12 below the exhaust plate 48. [ The 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 turbo molecular pump, and can decompress the space in the processing container 12 to a desired degree of vacuum. The loading / unloading port 12g is a loading / unloading port for the wafer W. The loading / unloading port 12g is provided on the side wall of the processing vessel 12. [ The loading / unloading port 12g is openable / closable by the gate valve 54. [

The first high frequency power source 62 is a power source for generating a first high frequency power for generating plasma and generates a high frequency power of 27 to 100 [MHz], for example, 40 [MHz]. The first high frequency power source 62 is connected to the upper electrode 30 via the matching unit 66. The matching device 66 is a circuit for matching the output impedance of the first high frequency power source 62 with the input impedance of the load side (lower electrode LE side). The first high frequency power source 62 may be connected to the lower electrode LE via the matching device 66. [

The second high frequency power source 64 is a power source for generating a second high frequency power for attracting ions to the wafer W, that is, a high frequency bias power, and has a frequency within a range of 400 [kHz] to 40.68 [ And generates a high-frequency bias power of [MHz]. The second high frequency power source 64 is connected to the lower electrode LE via the matching device 68. [ The matching unit 68 is a circuit for matching the output impedance of the second high frequency power supply 64 with the input impedance of the load side (lower electrode LE side). Further, the power source 70 is connected to the upper electrode 30. The power source 70 applies a voltage to the upper electrode 30 to attract the positive ions present in the processing space Sp to the electrode plate 34. [ In one example, the power source 70 is a DC power source that generates a negative DC voltage. When such a voltage is applied from the power source 70 to the upper electrode 30, the positive ions existing in the processing space Sp collide with the electrode plate 34. As a result, secondary electrons and / or silicon is emitted from the electrode plate 34.

The control unit Cnt is a computer having a processor, a storage unit, an input device, a display device, and the like, and controls each section of the plasma processing apparatus 10. Specifically, the control unit Cnt includes a valve group 42, a flow controller group 45, an exhaust unit 50, a first high frequency power source 62, a matching unit 66, a second high frequency power source 64, A power source 68, a power source 70, a heater power HP, and a chiller unit.

The control unit Cnt operates according to a program based on the inputted recipe, and sends out a control signal. The selection and flow rate of the gas supplied from the gas source group and the exhaust of the exhaust device 50 and the power supply from the first high frequency power supply 62 and the second high frequency power supply 64 The power supply from the power source 70, the power supply from the heater power HP, and the coolant flow rate and the coolant temperature from the chiller unit. Each step of the method for processing an object to be processed described in this specification can be executed by operating each part of the plasma processing apparatus 10 under the control of the control unit Cnt.

Referring again to Figure 1, the method MT will now be described in detail. Hereinafter, an example in which the plasma processing apparatus 10 is used in the method MT will be described. In the following description, reference is also made to Figs. 3, 4, 5, 9, and 10. Fig. 3 is a view showing a form of formation of a protective film on the inner side of the processing container 12. Fig. 4 is a flow chart showing contents related to an embodiment of the wafer processing process shown in Fig. 5 is a cross-sectional view showing the state of an object to be processed before and after each step shown in Fig. Fig. 9 is a flowchart showing contents related to another embodiment of the wafer processing process shown in Fig. 1; 10 is a cross-sectional view showing the state of an object to be processed before and after each step shown in Fig.

In the method MT shown in Fig. 1, first, in step S1, a dummy wafer is mounted on a mounting table PD of the processing container 12, a seasoning process is performed in the process container 12, The dummy wafer is taken out from the container 12. In step S1, as shown in state A1 in Fig. 3, the surface of all components of the plasma processing apparatus 10 inside the processing vessel 12 (for example, the inside of the processing vessel 12 for generating plasma The wall surface and the inner wall surface of various pipes such as the gas supply pipe 38 connected to the processing vessel 12 and the like) are exposed to the processing space Sp. Various piping such as the gas supply pipe 38 connected to the processing vessel 12 also communicate with the processing space Sp and are thus exposed to the processing space Sp.

The surface of all the components of the plasma processing apparatus 10 that is exposed to the processing space Sp or the like before carrying the wafer W to be processed into the processing vessel 12 in the subsequent step S2 (preparation step) (SiO ₂ ). The step of forming the protective film SXa1 performed in step S2 can be performed by the same sequence as the sequence SQ1 shown in Fig. 4 and the sequence SQ2 shown in Fig. The sequence SQ1 or the sequence SQ2 is included in the process of forming the protective film SX1 which is the silicon oxide film (SiO ₂ ) in FIG. 5 or the protective film SX2 which is the silicon oxide film (SiO ₂ ) in FIG. 10, Is carried out in the following step S4 (processing step). The process of forming the protective film SXa1 performed in step S2 will be described in detail in the description of the sequence SQ1 and the description of the sequence SQ2. 3, the protective film SXa1 is exposed to the processing space Sp by the step of forming the protective film SXa1 to be performed in the step S2, and the surface of all the constituent parts of the plasma processing apparatus 10, Regardless of the shape of the surface, it can be conformally formed with a uniform thickness LC1.

The wafer W (the wafer W1 shown in part (a) of FIG. 5 or the wafer W2 shown in part (a) of FIG. 10) of the object to be processed is carried into the processing container 12, PD.

In the succeeding step S4 (processing step), the wafer W accommodated in the processing vessel 12 is subjected to etching treatment. One embodiment of the concrete process contents of step S4 is shown in Fig. 4 and will be described later. Another embodiment of the process contents of step S4 is shown in Fig. 9 and will be described later. When the protective film SX1 is formed on the wafer W1 (Fig. 5) in the sequence SQ1 (Fig. 4) included in the step S4 or when the protective film SX2 is formed on the wafer W2 ) when formed, as shown in the state A3 in Figure 3, silicon oxide (SiO ₂₎ in the protective film SXa2 is, with respect to the entirety of the surface of the protective film SXa1, regardless of the shape of the surface of the protective film SXa1, uniform thickness Lt; RTI ID = 0.0 > LC2a. ≪ / RTI > The protective film SXa1 and the protective film SXa2 are both made of a silicon oxide film and have the same material and the same structure, and the protective film SXa1 and the protective film SXa2 constitute a single protective film SXa. The protective film SXa has a uniform thickness (LC1 + LC2a). Therefore, the protective film SXa can be conformally formed with uniform thicknesses (LC1 + LC2a) irrespective of the shape of the surface of all components of the plasma processing apparatus 10 exposed to the processing space Sp and the like have.

Then, in the next step S5, the wafer W is carried out from the inside of the processing container 12. [ In step S6, the protective film SXa remaining inside the various pipes such as the gas supply pipe 38 connected to the inside of the processing vessel 12 and the processing vessel 12 is removed. By this process, as shown in state A4 in Fig. 3, the surfaces of all the components of the plasma processing apparatus 10 in the processing space Sp are all exposed to the processing space Sp. In the case where the etching process in which all the protective film SXa is removed in step S4 is performed, the step S6 is not necessary.

In the subsequent step S7, when the sequence of steps S2 to S6 is to be performed on other wafers (step S7: NO), the process goes to step S2, and if there is no other wafer to perform the sequence of steps S2 to S6 S7: Yes) Terminate execution of method MT.

Next, one embodiment of the processing contents of step S4 in Fig. 1 will be described in detail with reference to Fig. In the following description, reference is made to Figs. 5, 6, 7, and 8. Fig. Fig. 6 is a cross-sectional view showing the state of the object to be processed after each step of the method shown in Fig. 4; Fig. Fig. 7 is a diagram schematically showing the formation of a protective film in the sequence for forming the protective film shown in Fig. 4. Fig. 8 is a timing chart relating to plasma generation in the sequence of forming the protective film shown in Fig.

Step S4 after the processes S1, S2, and S3 are shown in Fig. First, in step S41a, the wafer W1 shown in part (a) of FIG. 5 is prepared as the wafer W shown in FIG. The wafer W1 prepared in the step S41a has the substrate SB1, the etched layer EL1, the organic film OL1, the antireflection film AL1, and the mask MK11 as shown in part (a) of Fig. The etched layer EL1 is provided on the substrate SB1. The etched layer EL1 is a layer composed of a material selectively etched with respect to the organic film OL1, and an insulating film is used. The etched layer EL1 is, for example, may be of a silicon oxide (SiO _2). The etched layer EL1 has a thickness LD. The etched layer EL1 may be made of another material such as polycrystalline silicon.

The organic film OL1 is provided on the etched layer EL1. The organic film OL1 is a layer containing carbon, for example, a SOH (spin-on hard mask) layer. The antireflection film AL1 is a silicon-containing antireflection film and is provided on the organic film OL1.

The mask MK11 is provided on the antireflection film AL1. The mask MK11 is a resist mask composed of a resist material and is manufactured by patterning the resist layer by photolithography. The mask MK11 partially covers the antireflection film AL1. The mask MK11 defines an opening for partially exposing the antireflection film AL1. The pattern of the mask MK11 is, for example, a line-and-space pattern. Also, the mask MK11 may have a pattern that provides a circular opening in plan view. Alternatively, the mask MK11 may have a pattern that provides an elliptical opening in plan view.

In step S41a, the wafer W1 shown in part (a) of FIG. 5 is prepared, and the wafer W1 is accommodated in the processing container 12 of the plasma processing apparatus 10 and mounted on the mount table PD.

Subsequent to step S41a, step S41b is executed. In step S41b, secondary electrons are irradiated onto the wafer W1. Specifically, hydrogen gas and rare gas are supplied into the processing vessel 12, and high-frequency power is supplied from the first high-frequency power source 62, thereby generating plasma. A negative DC voltage is applied to the upper electrode 30 by the power source 70. [ As a result, positive ions in the processing space Sp are attracted to the upper electrode 30, and the positive ions collide with the upper electrode 30. As the positive ions collide with the upper electrode 30, secondary electrons are emitted from the upper electrode 30. The emitted secondary electrons are irradiated on the wafer W1, whereby the mask MK11 is modified. When the level of the absolute value of the negative DC voltage applied to the upper electrode 30 is high, positive ions collide with the electrode plate 34, so that silicon, which is a constituent material of the electrode plate 34, It is emitted with the car electrons. The released silicon bonds with oxygen emitted from the components of the plasma processing apparatus 10 exposed to the plasma. The oxygen is released, for example, from a support 14, an insulating shield member 32, and a member called a deposit shield 46. By such a combination of silicon and oxygen, a silicon oxide compound is produced, and the silicon oxide compound is deposited on the wafer W1 to cover and protect the mask MK11. By the effect of these reforming and protection, the damage of the mask MK11 by the subsequent process is suppressed. In step S41b, the bias power of the second high frequency power supply 64 may be minimized to suppress the release of silicon for modification by secondary electron irradiation or formation of a protective film.

In the succeeding step S41c, the anti-reflection film AL1 is etched. Specifically, a process gas containing a fluorocarbon gas is supplied into the processing vessel 12 from a selected gas source among a plurality of gas sources of the gas source group 40. Then, high-frequency power is supplied from the first high-frequency power source 62. And supplies a high-frequency bias power from the second high-frequency power supply 64. [ By operating the exhaust device 50, the pressure in the space in the processing container 12 is set to a predetermined pressure. As a result, a plasma of a fluorocarbon gas is generated. The active species containing fluorine in the generated plasma etches the region exposed from the mask MK11 in the entire region of the antireflection film AL1. Thus, as shown in the section (b) of FIG. 5, the mask ALM1 is formed from the antireflection film AL1. The mask (first mask) for the organic film OL1 formed by the process S41c has the mask MK11 and the mask ALM1.

5, a protective film (protective film PF1) of silicon oxide is formed on the surface of the mask MK11, the surface of the mask ALM1 and the surface of the organic film OL1 in the same manner as in the step S41b do.

Continuing to step S41d, in step S4 shown in Fig. 4, the sequence SQ1 is executed one or more times. The sequence SQ1 includes steps S41e (first step), step S41f (second step), step S41g (third step) and step S41h (fourth step). In step S41e, the first gas G1 containing silicon is introduced into the processing vessel 12. [ The first gas G1 is an aminosilane-based gas. The first gas G1 of the aminosilane-based gas is supplied from the selected gas source among the plurality of gas sources of the gas source group 40 into the processing vessel 12. [ The first gas G1 is, as an aminosilane-based gas, mono-aminosilanes (H ₃ -Si-R (R is an amino group)) is used. In step S41e, the plasma of the first gas G1 is not generated.

As shown in part (a) of Fig. 7, molecules of the first gas G1 are attached to the surface of the wafer W1 as a reaction precursor. The molecules of the first gas G1 (monoaminosilane) are attached to the surface of the wafer W1 by chemical adsorption based on chemical bonds, and no plasma is used. In step S41e, the temperature of the wafer W1 is not lower than 0 degrees Celsius and not higher than the glass transition temperature of the material contained in the mask MK11 (for example, not higher than 200 degrees Celsius). In addition, gases other than monoaminosilane can be used as long as they can be attached to the surface by chemical bonding in the temperature range and contain silicon. Since diaminosilane (H ₂ -Si-R ₂ (R is an amino group) and triaminosilane (H-Si-R 3 (R is an amino group)) have a more complicated molecular structure than monoamino silane, In order to realize the formation of a uniform film in some cases, heat treatment may be carried out in order to self-decompose the amino group.

The reason why the monoaminosilane-based gas is selected as the first gas G1 is that the monoaminosilane has a relatively high electronegativity and has a molecular structure having polarity so that the chemical adsorption can be performed relatively easily . The layer Ly1 formed by attaching the molecules of the first gas G1 to the surface of the wafer W1 is in a state close to the monomolecular layer (single layer) because the attachment is chemisorption. The smaller the amino group (R) of the monoaminosilane is, the smaller the molecular structure of the molecule adsorbed on the surface of the wafer W1 is, and thus the steric hindrance due to the molecular size is reduced. And the layer Ly1 can be formed with a uniform film thickness with respect to the surface of the wafer W1. For example, the mono-aminosilanes _{(H 3 -Si-R) H} 3 -Si-O in the reaction precursor by the reaction of the OH group and the surface of the wafer W1 is formed to be included in the first gas G1, therefore, ₃ H A single layer Ly1 of -Si-O is formed. Thus, with respect to the surface of the wafer W1, the layer Ly1 of the reaction precursor can be conformally formed with a uniform film thickness without depending on the pattern density of the wafer W1.

In step S41e, not only the surface of the wafer W1 but also the surface of the protective film SXa1 exposed to the processing space Sp of the processing vessel 12 (including the inside of various pipes connected to the processing vessel 12) Simultaneously with the formation of the layer Ly1, the same layer (monolayer) as the layer Ly1 can be formed conformally with a uniform film thickness regardless of the shape of the surface of the protective film SXa1 by the first gas G1.

In the succeeding step S41f, the space in the processing container 12 is purged. Specifically, the first gas G1 supplied in the step S41e is exhausted. In step S41f, an inert gas, such as nitrogen gas, may be supplied as the purge gas to the processing container 12. [ That is, the purging of the step S41f may be either gas purging for flowing an inert gas into the processing vessel 12 or purging by vacuum suction. In step S41f, the molecules excessively deposited on the wafer W1 can also be removed. As a result, the reaction precursor layer Ly1 becomes an extremely thin monolayer.

In the succeeding step S41g, the plasma P1 of the second gas containing oxygen gas is generated in the processing vessel 12. [ In step S41g, the temperature of the wafer W1 at the time when plasma P1 of the second gas is generated is not lower than 0 degrees Celsius and not higher than the glass transition temperature of the material contained in the mask MK11 (for example, 200 degrees Celsius or less). Specifically, a second gas containing oxygen gas is supplied into the processing vessel 12 from a selected gas source among a plurality of gas sources of the gas source group 40. Then, high-frequency power is supplied from the first high-frequency power source 62. In this case, the bias power of the second high frequency power source 64 may be applied. Further, it is also possible to generate plasma by using only the second high frequency power source 64 without using the first high frequency power source 62. By operating the exhaust device 50, the pressure in the space in the processing container 12 is set to a predetermined pressure.

As described above, the molecules (molecules constituting the monolayer of the layer Ly1) attached to the surface of the wafer W1 by the execution of the step S41e include a combination of silicon and hydrogen. The bond energy of silicon and hydrogen is lower than the bond energy of silicon and oxygen. 7, when plasma P1 of the second gas containing oxygen gas is generated, an active species of oxygen, for example, an oxygen radical, is generated, and hydrogen of a molecule constituting the monolayer of layer Ly1 Is replaced with oxygen, and a layer Ly2 which is a silicon oxide film is formed as a monolayer, as shown in Fig.

In the succeeding step S41h, the space in the processing container 12 is purged. Specifically, the second gas supplied in the step S41g is exhausted. In step S41h, an inert gas, such as nitrogen gas, may be supplied as the purge gas to the processing container 12. [ That is, the purging of the process S41h may be either gas purging to flow the inert gas into the processing vessel 12 or purging by vacuum suction.

In the above-described sequence SQ1, purging is carried out in the step S41f, and in the succeeding step S41g, the hydrogen of the molecules constituting the layer Ly1 is replaced with oxygen. Therefore, similarly to the ALD method, by performing the sequence SQ1 once, the silicon oxide layer Ly2 is conformally formed on the surface of the wafer W1 at a thin and uniform film thickness regardless of the roughness of the mask MK11 .

In step S41i subsequent to the sequence SQ1, it is determined whether or not the execution of the sequence SQ1 is ended. More specifically, in step S41i, it is determined whether or not the number of executions of the sequence SQ1 has reached a predetermined number of times. The determination of the number of times of execution of the sequence SQ1 is to determine the thickness of the film of the protective film SX1 formed on the wafer W1. That is, the thickness of the protective film SX1 finally formed on the wafer W1 is substantially determined by the product of the film thickness of the silicon oxide film formed by executing the sequence SQ1 once and the number of times of execution of the sequence SQ1. Therefore, the number of times of execution of the sequence SQ1 is set according to the desired thickness of the protective film SX1 formed on the wafer W1.

When it is determined in step S41i that the number of executions of the sequence SQ1 has not reached the predetermined number (step S41i: NO), the execution of the sequence SQ1 is repeated again. On the other hand, if it is determined in step S41i that the number of executions of the sequence SQ1 has reached the predetermined number (step S41i: YES), the execution of the sequence SQ1 is terminated. As a result, as shown in FIG. 5, a protective film SX1 which is a silicon oxide film is formed on the surface of the wafer W1. That is, since the sequence SQ1 is repeated a predetermined number of times, the protective film SX1 having a predetermined film thickness is formed conformally on the surface of the wafer W1 with a uniform film thickness irrespective of the density of the mask MK11.

Here, the generation timing of the plasma in the sequence SQ1 is shown in Fig. FIG. 8 shows that the sequence SQ1 is repeated at least three times. "ON" shown in FIG. 8 indicates a state in which plasma is generated, and "OFF" shown in FIG. 8 indicates a state in which no plasma is generated. As shown in Fig. 8, in sequence SQ1, no plasma is generated in step S41e, and plasma is generated in step S41g only.

5, the protective film SX1 includes a region R11, a region R21, and a region R31. The region R31 is an area extending along the side surface of the mask MK11 and the side surface of the mask ALM1. The region R31 extends from the surface of the organic film OL1 to below the region R11. The region R11 extends above the upper surface of the mask MK11 and on the region R31. The region R21 extends on the surface of the organic film OL1 between the adjacent regions R31. As described above, since the sequence SQ1 forms the protective film SX1 in the same manner as the ALD method, the film thicknesses of the regions R11, R21, and R31 are substantially the same regardless of the density of the mask MK11.

Here, the formation of the protective film in the processing vessel 12 at the time of executing the sequence SQ1 will be described. By forming the protective film SX1 on the surface of the wafer W1 and repeating the sequence SQ1, the protective film SXa2 shown in the state A3 in Fig. 3 is formed on the surface of the protective film SXa1 in the processing space Sp and the like. Therefore, the thickness LC2b of the protective film SX1 becomes substantially equal to the thickness LC2a of the protective film SXa2. That is, the sequence SQ1 is repeated in the step S4 shown in Fig. 4, so that the protective film SXa2 having the same thickness as that of the protective film SX1 is formed conformally on the surface of the protective film SXa1 with a uniform film thickness.

Also, the protective film SXa1 shown in state A2 and state A3 in Fig. 3 is formed in step S2 by the same sequence as sequence SQ1. Therefore, the protective film SXa1 having the predetermined film thickness LC1 is formed on the surface of all the component parts of the plasma processing apparatus 10 exposed in the processing space Sp by repeating the sequence for a predetermined number of times in step S2 Is formed conformally at a uniform film thickness in the processing space Sp and the like.

Returning to Fig. In the process S41j subsequent to the process S41i, the protective film SX1 is etched (etched back) so as to remove the region R11 and the region R21. In order to remove the region R11 and the region R21, an anisotropic etching condition is required. Therefore, in step S41j, a process gas containing a fluorocarbon gas is supplied from the selected gas source among the plurality of gas sources of the gas source group 40 into the processing vessel 12. [ Then, high-frequency power is supplied from the first high-frequency power source 62. And supplies a high-frequency bias power from the second high-frequency power supply 64. [ By operating the exhaust device 50, the pressure in the space in the processing container 12 is set to a predetermined pressure. As a result, a plasma of a fluorocarbon gas is generated. The active species containing fluorine in the generated plasma preferentially etches the region R11 and the region R21 by drawing in the vertical direction by the high-frequency bias power. As a result, as shown in part (a) of FIG. 6, the area R11 and the area R21 are selectively removed, and the mask MS1 is formed by the remaining area R31. The mask MS1, the protective film PF1 and the mask ALM1 constitute a mask MK21 on the surface of the organic film OL1.

In the succeeding step S41k, the organic film OL1 is etched. Specifically, a process gas containing a nitrogen gas and a hydrogen gas is supplied into the processing vessel 12 from a selected gas source among a plurality of gas sources of the gas source group 40. Then, high-frequency power is supplied from the first high-frequency power source 62. And supplies a high-frequency bias power from the second high-frequency power supply 64. [ By operating the exhaust device 50, the pressure in the space in the processing container 12 is set to a predetermined pressure. As a result, a plasma of a process gas containing nitrogen gas and hydrogen gas is generated. The hydrogen radical, which is the active species of hydrogen in the generated plasma, etches the region exposed from the mask MK21 in the entire region of the organic film OL1. As a result, as shown in part (b) of Fig. 6, the mask OLM1 is formed from the organic film OL1. As the gas for etching the organic film OL1, a process gas containing oxygen may be used. Further, the width of the opening provided by the mask OLM1 becomes substantially equal to the width of the opening provided by the mask MK21.

In the succeeding step S41m, the etched layer EL1 is etched. Specifically, the process gas is supplied into the processing container 12 from a selected gas source among a plurality of gas sources of the gas source group 40. The process gas can be appropriately selected depending on the material constituting the etched layer EL1. For example, when the etched layer EL1 is composed of silicon oxide, the process gas may include a fluorocarbon gas. Then, high-frequency power is supplied from the first high-frequency power source 62. And supplies a high-frequency bias power from the second high-frequency power supply 64. [ By operating the exhaust device 50, the pressure in the space in the processing container 12 is set to a predetermined pressure. Thereby, a plasma is generated. The active species in the generated plasma etches the entire region of the etched layer EL1, the region exposed from the mask OLM1. 6, the pattern of the mask OLM1 is transferred to the etched layer EL1.

Here, the thickness of the protective film SXa formed in the processing vessel 12 will be described. The thickness (LC1 + LC2a) of the protective film SXa formed in the processing vessel 12 before the step S41k for etching the organic film OL1 is the thickness (LC1 + LC2a) of the film that is etched and removed in the protective film SXa until the end of the step S41k for etching the organic film OL1 Is thicker than the thickness (LE) and satisfies the relationship of LE < (LC1 + LC2a). The thickness (LC1 + LC2a) of the protective film SXa formed in the processing vessel 12 before the step S41k for etching the organic film OL1 is thinner than the thickness LD of the film E1 to be etched, and (LC1 + LC2a ) &Lt; LD. Further, the thickness (LC1 + LC2a) of the film of the protective film SXa can satisfy both the above-mentioned magnitude relation. That is, the relationship of LE < (LC1 + LC2a) < LD can be satisfied. Further, in the case of (LC1 + LC2a) <LD, the protective film SXa in the processing vessel 12 is completely removed until the completion of the step S41m, so that the processing of the step S6 is unnecessary.

By the execution of the step S4 shown in Fig. 4 described above, the following effect is obtained. In the step S41e, the first gas G1 containing the aminosilane-based gas is supplied into the processing vessel 12 without generating the plasma, and thereafter, in the step S41g, the second gas containing the oxygen gas The plasma P1 is generated to form the protective film SX1 of the thin silicon oxide film. Therefore, the protective film SX1 is formed uniformly and conformally on the surface of the wafer W1 by the steps S41e to S41h (sequence SQ1) executed in the step S4 shown in Fig. The sequence SQ1 is repeatedly executed in the forming process (the process from step S41e to step S41i (Yes)) executed in step S4 shown in Fig. 4, so that the thickness of the protective film SX1 formed on the surface of the wafer W1 is precisely Can be controlled. Therefore, the minimum line width of the pattern on the surface of the wafer W1 can be precisely reduced by the protective film SX1 formed by the forming process including the sequence SQ1 of a plurality of times, and miniaturization accompanying high integration can be achieved.

In addition, the protective film SX1 of the silicon oxide film is formed on the surface of the wafer W1 by the forming process (the process from the step S41e to the step S41i (example)) executed in the step S4 shown in Fig. 4, A silicon oxide film is formed as a protective film (protective film SXa2) with the same thickness as that of the protective film SX1 on the inner surface of the processing vessel 12 and the inner surface of various pipes connected to the processing vessel 12. [ Therefore, by the protective film SXa2 formed on the inner surface of the processing vessel 12 and on the inner surface of various pipes connected to the processing vessel 12, the generation of particles generated from these surfaces and the change It is possible to reproduce a stable minimum line width and the like.

Also, independently of the forming step (step S41e to step S41i (Yes)) executed in step S4 shown in Fig. 4, it is also formed in step S2 of the preparing step, which is performed before step S4 shown in Fig. 4 (The process from step S41e to step S41i (Yes)) is executed. 4, the silicon oxide film of the desired thickness corresponding to the thickness of the silicon oxide film to be removed by etching is formed on the inner surface of the processing vessel 12 and on the surface of the various pipes connected to the processing vessel 12 The occurrence of particles generated from each of these surfaces and the change in the state of each of the surfaces can be sufficiently suppressed without depending on the degree of etching performed in step S4 shown in Fig. .

Also, because the mono-amino-silane (H ₃ -Si-R (R is an amino group)) to be carried out the first process is formed by using a gas G1 (step from after the process up to step S41i S41d (YES)), including, The protective film SX1 and the protective film SXa can be formed conformally and precisely at a uniform thickness with respect to the surface shape, similarly to the case of the ALD method.

Further, when monoaminosilane is used, the wafer W1 can be processed at a relatively low temperature of not less than 0 degrees Celsius and the glass transition temperature of the material contained in the mask MK11, so that the wafer W1 can be heated A process for performing the above process is not required.

Even when the silicon oxide film remains in the processing vessel 12 and in various piping connected to the processing vessel 12 after the step S4 shown in Fig. 4, by executing the step S6, It is possible to reliably remove the silicon oxide film from the interior of the processing vessel 12 and various piping connected to the processing vessel 12.

The thickness (LC1 + LC2a) of the protective film SXa formed in the processing vessel 12 before the step S41k for etching the organic film OL1 is etched in the protective film SXa until the end of the step S41k for etching the organic film OL1, Is greater than the thickness LE of the underlying film. Thus, even after the etching of the organic film OL1 by the process S41k is finished, the silicon oxide film remains on the inner surface of the processing container 12 and on the inner surface of various pipes connected to the processing container 12. Therefore, That is, when the silicon oxide film is removed during etching, and the respective surfaces are exposed, the states of the respective surfaces are changed, and particles and the like can be avoided from the respective surfaces. In addition, since the formation step (steps from step S41e to step S41i (Yes)) for forming the protective film SX1 is performed before the etching of the organic film OL1 by the step S41k is performed, the active species generated by etching of the organic film OL1 Radicals can be prevented from reacting with the inner surface of the processing vessel 12 and with the inner surface of various pipes connected to the processing vessel 12 and thus the generation of particles from each of these surfaces, It is possible to sufficiently suppress the change of the state of Fig.

The thickness (LC1 + LC2a) of the protective film SXa formed in the processing vessel 12 before the step S41k for etching the organic film OL1 is thinner than the thickness LD of the film of the etched layer EL1. Since the thickness of the protective film SXa formed in the processing vessel 12 and the various piping connected to the processing vessel 12 is thinner than the thickness of the film to be etched EL1 in the processing vessel 12 and the processing vessel 12 12 are removed by etching of the etched layer EL1, in the cleaning of various piping connected to the processing vessel 12 and the processing vessel 12 performed after the step S4, A process (step S6) for removing the silicon oxide film in the processing vessel 12 and various pipes connected to the processing vessel 12 becomes unnecessary.

Next, another embodiment of the processing contents of step S4 in Fig. 1 will be described in detail with reference to Fig. In the following description, reference is made to Figs. 10, 11 and 12. Fig. Figs. 11 and 12 are cross-sectional views showing the state of the object to be processed after each step shown in Fig.

In step S4 shown in Fig. 9, first, in step S42a, the wafer W2 shown in part (a) of Fig. 10 is prepared as a wafer W shown in Fig. The wafer W2 prepared in step S42a has a substrate SB2, an etched layer EL2, an organic film OL2, an antireflection film AL2, and a mask MK12 (first mask) as shown in part (a) of Fig. The etched layer EL2 is provided on the substrate SB2. The etched layer EL2 is a layer composed of a material selectively etched with respect to the organic film OL2. The etched layer EL2 is, for example, may be of a silicon oxide (SiO _2). The etched layer EL2 may be made of another material such as polycrystalline silicon. The organic film OL2 is provided on the etched layer EL2. The organic film OL2 is a layer containing carbon, for example, a SOH (spin-on hard mask) layer. The antireflection film AL2 is a silicon-containing antireflection film and is provided on the organic film OL2.

The mask MK12 is provided on the antireflection film AL2. The mask MK12 is a resist mask composed of a resist material, and is manufactured by patterning the resist layer by photolithography. The mask MK12 partially covers the antireflection film AL2. The mask MK12 defines an opening for partially exposing the antireflection film AL2. The pattern of the mask MK12 is, for example, a line-and-space pattern. Also, the mask MK12 may have a pattern that provides a circular opening when viewed in plan view. Alternatively, the mask MK12 may have a pattern providing an elliptical opening in plan view.

In step S42a, the wafer W2 shown in part (a) of FIG. 10 is prepared, and the wafer W2 is accommodated in the processing container 12 of the plasma processing apparatus 10 and mounted on the mount table PD.

Subsequent to step S42a, step S42b is executed. Since the process contents of the process S42b are the same as the process contents of the process S41b, the mask MK12 is modified by the process of the step S42b, the silicon oxide is deposited on the wafer W2, So as to be protected.

Subsequent to step S42b, the sequence SQ2 and the step S42g are executed. The process S42g is executed subsequently to the sequence SQ2. The sequence SQ2 includes steps S42c (first step), step S42d (second step), step S42e (third step) and step S42f (fourth step). The processes S42c, S42d, S42e, and S42f are the same as the processes S41e, S41f, S41g, and S41h of the sequence SQ1 shown in FIG. 4, respectively. That is, the sequence SQ2 is the same processing as the sequence SQ1 shown in Fig. The process S42g is the same process as the process S41i shown in Fig. Therefore, when it is determined in step S42g that the number of executions of the sequence SQ2 has reached the predetermined number (step S42g: YES), the execution of the sequence SQ2 is ended. As shown in part (b) A protective film SX2 which is a silicon oxide film is formed. That is, the sequence SQ2 is repeated a predetermined number of times so that the protective film SX2 having a predetermined film thickness is formed on the surface of the wafer W2 conformally at a uniform film thickness regardless of the density of the mask MK12.

The protective film SX2 includes a region R12, a region R22, and a region R32 as shown in (b) of FIG. The region R32 is an area extending along the side surface on the side of the mask MK12. The region R32 extends from the surface of the antireflection film AL2 to below the region R12. The region R12 extends over the upper surface of the mask MK12 and over the region R32. The region R22 extends between the adjacent regions R32 and on the surface of the antireflection film AL2. As described above, since the sequence SQ2 forms the protective film SX2 in the same manner as the ALD method, the film thicknesses of the regions R12, R22, and R32 are substantially the same regardless of the density of the mask MK12.

The protective film SX2 is formed on the surface of the wafer W2 and the sequence SQ2 is repeatedly performed so that the protective film SXa2 shown in the state A3 in Fig. 3 is formed on the surface of the protective film SXa1 in the processing space Sp and the like. Therefore, the thickness LC2b of the protective film SX2 becomes substantially equal to the thickness LC2a of the protective film SXa2. That is, the sequence SQ2 is repeated in the step S4 shown in Fig. 9, so that the protective film SXa2 having the same thickness as that of the protective film SX2 is conformally formed at a uniform film thickness, . In steps S42c and S42e, the temperature of the wafer W2 is not lower than 0 degrees Celsius and not higher than the glass transition temperature of the material included in the mask MK12 (for example, not higher than 200 degrees Celsius).

The protective film SXa1 shown in state A2 and state A3 in Fig. 3 is also formed in step S2 by the same sequence as sequence SQ2. Therefore, the protective film SXa1 having the predetermined film thickness LC1 is formed on the surface of all the component parts of the plasma processing apparatus 10 exposed in the processing space Sp by repeating the sequence for a predetermined number of times in step S2 Is formed conformally at a uniform film thickness in the processing space Sp and the like.

Returning to Fig. In step S42h following step S42g, the protective film SX2 is etched (etched back) so as to remove the area R12 and the area R22. In order to remove the region R12 and the region R22, an anisotropic etching condition is required. Therefore, in step S42h, a process gas containing a fluorocarbon gas is supplied from the selected gas source among the plurality of gas sources of the gas source group 40 into the processing container 12. [ Then, high-frequency power is supplied from the first high-frequency power source 62. And supplies a high-frequency bias power from the second high-frequency power supply 64. [ By operating the exhaust device 50, the pressure in the space in the processing container 12 is set to a predetermined pressure. As a result, a plasma of a fluorocarbon gas is generated. The active species containing fluorine in the generated plasma preferentially etches the region R12 and the region R22 by drawing in the vertical direction by the high-frequency bias power. As a result, as shown in part (a) of FIG. 11, the area R12 and the area R22 are selectively removed, and the mask MK22 (second mask) is formed by the remaining area R32.

In the succeeding step S42i, the mask MK12 is removed. Specifically, a process gas containing oxygen gas is supplied into the processing vessel 12 from a selected gas source among the plurality of gas sources of the gas source group 40. Then, high-frequency power is supplied from the first high-frequency power source 62. And supplies a high-frequency bias power from the second high-frequency power supply 64. [ By operating the exhaust device 50, the pressure in the space in the processing container 12 is set to a predetermined pressure. As a result, a plasma of the process gas containing oxygen gas is generated. As for the active species of oxygen in the generated plasma, the mask MK12 is etched as shown in the section (b) of Fig. As a result, the mask MK12 is removed, and the mask MK22 is left on the antireflection film AL2.

In the subsequent step S42j, the anti-reflection film AL2 is etched. Specifically, a process gas containing a fluorocarbon gas is supplied into the processing vessel 12 from a selected gas source among a plurality of gas sources of the gas source group 40. Then, high-frequency power is supplied from the first high-frequency power source 62. And supplies a high-frequency bias power from the second high-frequency power supply 64. [ By operating the exhaust device 50, the pressure in the space in the processing container 12 is set to a predetermined pressure. As a result, a plasma of a fluorocarbon gas is generated. The active species containing fluorine in the generated plasma etches the region exposed from the mask MK22 in the entire region of the antireflection film AL2 as shown in part (a) of Fig.

In the succeeding step S42k, the organic film OL2 is etched. Specifically, a process gas containing a nitrogen gas and a hydrogen gas is supplied into the processing vessel 12 from a selected gas source among a plurality of gas sources of the gas source group 40. Then, high-frequency power is supplied from the first high-frequency power source 62. And supplies a high-frequency bias power from the second high-frequency power supply 64. [ By operating the exhaust device 50, the pressure in the space in the processing container 12 is set to a predetermined pressure. As a result, a plasma of a process gas containing nitrogen gas and hydrogen gas is generated. The hydrogen radical, which is the active species of hydrogen in the generated plasma, etches the region exposed from the mask MK22 in the entire region of the organic film OL2. As a result, as shown in part (b) of Fig. 12, a mask MK32 (third mask) is formed from the organic film OL2. As the gas for etching the organic film OL2, a process gas containing oxygen may be used.

In the succeeding step S42m, the etched layer EL2 is etched. Specifically, the process gas is supplied into the processing container 12 from a selected gas source among a plurality of gas sources of the gas source group 40. The process gas can be appropriately selected depending on the material constituting the etched layer EL2. For example, when the etched layer EL2 is composed of silicon oxide, the process gas may include a fluorocarbon gas. Then, high-frequency power is supplied from the first high-frequency power source 62. And supplies a high-frequency bias power from the second high-frequency power supply 64. [ By operating the exhaust device 50, the pressure in the space in the processing container 12 is set to a predetermined pressure. Thereby, a plasma is generated. The active species in the generated plasma etches the entire region of the etched layer EL2, the region exposed from the mask MK32. 12, the pattern of the mask MK32 is transferred to the etched layer EL2.

Here, the thickness of the protective film SXa formed in the processing vessel 12 will be described. The thickness (LC1 + LC2a) of the protective film SXa formed in the processing vessel 12 before the step S42k for etching the organic film OL2 is equal to or larger than the thickness (LC1 + LC2a) of the film etched and removed in the protective film SXa until the end of the step S42k for etching the organic film OL2 Is thicker than the thickness (LE) and satisfies the relationship of LE < (LC1 + LC2a). The thickness (LC1 + LC2a) of the protective film SXa formed in the processing container 12 before the step S42k for etching the organic film OL2 is smaller than the thickness LD of the film of the etched layer EL2, ) &Lt; LD. Further, the thickness (LC1 + LC2a) of the film of the protective film SXa can satisfy both the above-mentioned magnitude relation. That is, the relationship of LE < (LC1 + LC2a) < LD can be satisfied. Further, in the case of (LC1 + LC2a) <LD, the protective film SXa in the processing vessel 12 is completely removed until the completion of the step S42m, so that the processing of the step S6 is unnecessary.

By the execution of step S4 shown in Fig. 9 described above, the following effects are obtained. In step S42c, the first gas G1 containing the aminosilane-based gas is supplied into the processing vessel 12 without generating plasma, and thereafter, in step S42e, the second gas containing the oxygen gas The plasma P1 is generated to form the protective film SX2 of the thin silicon oxide film. Therefore, the protective film SX2 is formed uniformly and conformally on the surface of the wafer W2 by the steps S42c to S42f (sequence SQ2) executed in the step S4 shown in Fig. 9, since the sequence SQ2 is repeatedly executed, the thickness of the protective film SX2 formed on the surface of the wafer W2 can be precisely adjusted (step S42c to step S42g) Can be controlled. Therefore, the minimum line width of the pattern on the surface of the wafer W2 can be precisely reduced by the protective film SX2 formed by the forming process including the sequence SQ2 for a plurality of times, and it is possible to miniaturize the wafer W2 accompanied with high integration.

The protective film SX2 of the silicon oxide film is formed on the surface of the wafer W2 by the forming process (the process from the step S42c to the step S42g (Yes)) executed in the step S4 shown in Fig. 9, The silicon oxide film is formed as a protective film (protective film SXa2) with the same thickness as that of the protective film SX2 on the inner surface of the processing vessel 12 and the inner surface of various piping connected to the processing vessel 12. [ Therefore, by the protective film SXa2 formed on the inner surface of the processing vessel 12 and on the inner surface of various pipes connected to the processing vessel 12, the generation of particles generated from these surfaces and the change It is possible to reproduce a stable minimum line width and the like.

In addition, independently of the forming step (step S42c to step S42g (Yes)) executed in step S4 shown in Fig. 9, it is also possible to form it in step S2 of the preparation step before step S4 shown in Fig. 9 (The process from step S42c to step S42g (example)) is executed. 9, the silicon oxide film of the desired thickness corresponding to the thickness of the silicon oxide film to be removed by etching is formed on the inner surface of the processing vessel 12 and on the surface of the various pipes connected to the processing vessel 12 The generation of particles generated from each of these surfaces and the change in the state of each of the surfaces can be sufficiently suppressed without depending on the degree of etching performed in step S4 shown in Fig. .

Also, because the mono-amino-silane (H ₃ -Si-R (R is an amino group)) to be carried out the first process is formed by using a gas G1 (step from after the step S42b to the step S42g (Examples)) including, The protective film SX2 and the protective film SXa can be formed conformally and precisely at a uniform thickness with respect to the surface shape, similarly to the case of the ALD method.

Further, when monoaminosilane is used, the wafer W2 can be processed at a relatively low temperature of not less than 0 degrees Celsius and the glass transition temperature of the material contained in the mask MK12, so that the wafer W2 can be heated A process for performing the above process is not required.

Even when the silicon oxide film remains in the processing vessel 12 and in various piping connected to the processing vessel 12 after the step S4 shown in Fig. 9, by executing the step S6, It is possible to reliably remove the silicon oxide film from the interior of the processing vessel 12 and various piping connected to the processing vessel 12.

The thickness (LC1 + LC2a) of the protective film SXa formed in the processing vessel 12 before the step S42k for etching the organic film OL2 is etched and removed in the protective film SXa until the end of the step S42k for etching the organic film OL2 Is greater than the thickness LE of the underlying film. Thus, even after the etching of the organic film OL2 by the step S42k is completed, the silicon oxide film remains on the inner surface of the processing container 12 and on the inner surface of various pipes connected to the processing container 12. Therefore, In other words, the silicon oxide film is removed during the etching, and the surfaces are exposed, so that the state of each surface changes and particles can be avoided from the respective surfaces. In addition, since the formation step (steps from step S42c to step S42g (Yes)) for forming the protective film SX2 is performed before the etching of the organic film OL2 by the step S42k is performed, the active species produced by etching of the organic film OL2 Radicals can be prevented from reacting with the inner surface of the processing vessel 12 and with the inner surface of various pipes connected to the processing vessel 12 and thus the generation of particles from each of these surfaces, It is possible to sufficiently suppress the change of the state of Fig.

The thickness LC1 + LC2a of the protective film SXa formed in the processing vessel 12 before the step S42k for etching the organic film OL2 is smaller than the thickness LD of the film of the etched layer EL2. Since the thickness of the protective film SXa formed in the processing vessel 12 and the various piping connected to the processing vessel 12 is thinner than the thickness of the film to be etched EL2 in the processing vessel 12 and the processing vessel 12 The protective film SXa in the various piping connected to the processing vessel 12 is removed by the etching of the etched layer EL2 so that during the cleaning in the processing vessel 12 after the step S4 and various piping connected to the processing vessel 12 A process (step S6) for removing the silicon oxide film in the processing vessel 12 and various pipes connected to the processing vessel 12 becomes unnecessary.

While the principles of the present invention have been shown and described in the preferred embodiments, those skilled in the art will appreciate that the present invention can be modified in arrangement and detail without departing from such principles. The present invention is not limited to the specific configuration disclosed in this embodiment. Accordingly, all modifications and variations coming within the spirit and scope of the appended claims are claimed.

10: Plasma processing device
12: Processing vessel
12e: Exhaust
12g: Incoming exit
14: Support
18a: first plate
18b: second plate
22: DC power source
23: Switch
24: refrigerant passage
26a and 26b: piping
30: upper electrode
32: Insulating shield member
34: Electrode plate
34a: gas discharge hole
36: Electrode support
36a: gas diffusion chamber
36b: gas passage hole
36c: gas inlet
38: gas supply pipe
40: gas source group
42: valve group
45: Flow controller group
46: Deposition shield
48: exhaust plate
50: Exhaust system
52: Exhaust pipe
54: Gate valve
62: first high frequency power source
64: Second high frequency power source
66, 68: Matching machine
70: Power supply
A1, A2, A3, A4: Status
AL1, AL2: antireflection film
ALM1, MK11, MK12, MK21, MK22, MK32, MS1, OLM1: mask
Cnt:
EL1, EL2: etched layer
ESC: electrostatic chuck
FR: Focus ring
G1: First gas
HP: Heater power
HT: Heater
LE: Lower electrode
Ly1, Ly2: Layer
MT: How
OL1, OL2: organic film
P1: Plasma of the second gas
PD: Mounting table
PF1, SX1, SX2, SXa, SXa1, SXa2:
R11, R12, R21, R22, R31, R32:
SB1, SB2: substrate
Sp: Processing space
W, W1, W2: Wafer

Claims (11)

A method for processing an object to be processed,
A first step of supplying a first gas containing an amino silane-based gas into a processing vessel of a plasma processing apparatus; a second step of purging a space in the processing vessel after execution of the first step; A third step of generating a plasma of a second gas containing oxygen gas in the processing vessel after execution and a fourth step of purifying a space in the processing vessel after execution of the third processing is repeatedly executed A forming step of forming a silicon oxide film in the processing container,
Before the object to be processed is accommodated in the processing container,
A processing step of performing an etching process on the object to be processed accommodated in the process container
And,
The preparation step is carried out before the treatment step,
Wherein the forming step is carried out in the preparing step and is executed in the processing step,
Wherein the first step is a step of generating plasma of the first gas
A method for treating an object to be treated.
The method according to claim 1,
Wherein the first gas comprises monoaminosilane.
The method according to claim 1,
Wherein the aminosilane-based gas of the first gas comprises aminosilane having 1 to 3 silicon atoms.
The method according to claim 1,
Wherein the aminosilane gas of the first gas comprises aminosilane having 1 to 3 amino groups.
5. The method according to any one of claims 1 to 4,
Further comprising the step of removing the silicon oxide film in the processing container after the processing object is removed from the processing container after the processing step.
5. The method according to any one of claims 1 to 4,
Wherein the object to be processed comprises an etched layer and an organic film provided on the etched layer,
The processing step includes a step of etching the organic film by plasma generated in the processing vessel,
Wherein the forming step is performed before the step of etching the organic film in the processing step,
The thickness of the silicon oxide film formed in the processing vessel before the step of etching the organic film is thicker than the thickness of the film which is etched in the silicon oxide film until the end of the step of etching the organic film,
A method for treating an object to be treated.
The method according to claim 6,
Wherein the thickness of the silicon oxide film formed in the processing vessel before the step of etching the organic film is thinner than the thickness of the film of the etched layer.

5. The method according to any one of claims 1 to 4,
Wherein the object to be processed comprises an etched layer and an organic film provided on the etched layer,
The processing step includes a step of etching the organic film by plasma generated in the processing vessel,
Wherein the forming step is performed before the step of etching the organic film in the processing step,
On the organic film, a first mask is provided,
The process further comprises a step of etching the antireflection film having a resist mask thereon by the plasma generated in the processing bath to form the first mask from the antireflection film,
The step of etching the organic film is performed after the step of etching the anti-reflection film,
In the processing step, the forming step is executed between a step of etching the anti-reflection film and a step of etching the organic film,
The processing step is a step of removing a region on the surface of the organic film among the silicon oxide film formed by the forming step by the plasma generated in the processing vessel between the forming step and the step of etching the organic film Further comprising a step
A method for treating an object to be treated.
5. The method according to any one of claims 1 to 4,
Wherein the object to be processed comprises an etched layer, an organic film provided on the etched layer, and an antireflection film provided on the organic film,
The processing step includes a step of etching the organic film by plasma generated in the processing vessel,
Wherein the forming step is performed before the step of etching the organic film in the processing step,
On the antireflection film, a first mask is provided,
In the above process,
Wherein the silicon oxide film is formed on the first mask and the anti-reflection film by the plasma generated in the processing chamber after the silicon oxide film is formed on the first mask and the anti- Forming a second mask based on a region above the side surface of the first mask among the silicon oxide films;
A step of removing the first mask by a plasma generated in the processing vessel,
A step of etching the antireflection film by a plasma generated in the processing vessel
/ RTI &gt;
Wherein the step of etching the organic film is performed after the step of etching the anti-reflective film, and the step of forming the third mask composed of the organic film
A method for treating an object to be treated.
9. The method of claim 8,
Wherein the temperature of the object to be processed in the first step is not less than 0 degrees Celsius and the glass transition temperature of the material contained in the first mask is not more than A method for treating an object to be treated.
10. The method of claim 9,
Wherein the temperature of the object to be processed in the first step is not less than 0 degrees Celsius and the glass transition temperature of the material contained in the first mask is not more than A method for treating an object to be treated.

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