Film forming method and film forming apparatus

Abstract

The film formation method includes a step a), a step b), a step c), a step d), and a step e). In a step a), a substrate having a base film and a resist provided on the base film and having a predetermined pattern formed thereon is carried into a chamber, and in a step b), a gas of a first monomer is supplied into the chamber. In step c), a purge gas is supplied into the chamber. In step d), a gas of a second monomer is supplied into the chamber, thereby forming a polymer film on the surface of the substrate by a polymerization reaction between the first monomer and the second monomer. In step e), a purge gas is supplied into the chamber. In addition, the vapor pressure ratio of a monomer having a low saturated vapor pressure among the first monomer and the second monomer is 0.05 or less.

Description

TECHNICAL FIELD

[0001] Various aspects and embodiments of the present disclosure relate to a film formation method and a film formation apparatus. BACKGROUND

[0002] In Patent Document 1 described below, there is disclosed "a method for manufacturing a semiconductor device, including: a film formation step of forming a film having elasticity and being incompatible with a resist, by deteriorating a surface layer of the resist after being patterned, to cover a surface of the resist; and a heating step of heating the processed body on which the film is formed".

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENT

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-209270 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The present disclosure provides a film formation method and a film formation apparatus capable of improving the precision of a pattern formed on a substrate.

[0008] SOLUTION TO PROBLEM

[0009] A film formation method according to one aspect of the present disclosure includes a step a), a step b), a step c), a step d), and a step e). In the step a), a substrate having a base film and a resist is carried into a chamber, the resist being provided on the base film and having a predetermined pattern formed thereon. In the step b), a gas of a first monomer is supplied into the chamber. In the step c), a purge gas is supplied into the chamber. In the step d), a gas of a second monomer is supplied into the chamber, thereby forming a film of a polymer on a surface of the substrate by a polymerization reaction of the first monomer and the second monomer. In the step e), a purge gas is supplied into the chamber. In addition, a ratio of a vapor pressure of a monomer having a low saturated vapor pressure out of the first monomer and the second monomer is 0.05 or less.

[0010] EFFECT OF THE INVENTION

[0011] According to various aspects and embodiments of the present disclosure, it is possible to improve the precision of a pattern formed on a substrate. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a schematic diagram showing an example of a processing apparatus.

[0013] Figure 2 is a flowchart showing an example of a processing procedure of a substrate.

[0014] Figure 3A is a schematic view showing an example of a process of forming a film of a pattern forming polymer having a concave-convex.

[0015] Figure 3B is a schematic view showing an example of a process of forming a film of a pattern forming polymer having a concave-convex.

[0016] Figure 4A is a schematic view showing an example of a process of forming a film of a hole forming polymer.

[0017] Figure 4B is a schematic view showing an example of a process of forming a film of a hole forming polymer.

[0018] Figure 5A is a schematic view showing an example of a process of forming a film of a hole forming polymer.

[0019] Figure 5B is a schematic view showing an example of a process of forming a film of a hole forming polymer.

[0020] Figure 6 is a graph showing an example of a relationship between the number of times of repeating a film forming process and a change in thickness of a film of a polymer.

[0021] Figure 7A is a graph showing an example of a shape of an opening of a hole before a film of a polymer is formed.

[0022] Figure 7B is a graph showing an example of a shape of an opening of a hole after a film of a polymer is formed.

[0023] Figure 8A is a graph showing an example of a cross-sectional shape of a hole before a film of a polymer is formed.

[0024] Figure 8B is a graph showing an example of a cross-sectional shape of a hole after a film of a polymer is formed.

[0025] Figure 9A is a graph showing an example of a shape of an opening of a hole before a film of a polymer is formed.

[0026] Figure 9B is a graph showing an example of a shape of an opening of a hole after a film of a polymer is formed.

[0027] Figure 10A is a graph showing an example of a shape of an opening of a hole before a film of a polymer is formed.

[0028] Figure 10B is a graph showing an example of a shape of an opening of a hole after a film of a polymer is formed.

[0029] Figure 11A is a drawing illustrating an example of a linear shape of a resist before a polymer film is formed.

[0030] Figure 11B is a drawing illustrating an example of a linear shape of a resist after a polymer film is formed.

[0031] Figure 12A is a drawing illustrating an example of a shape of an opening of a hole of a resist in which a polymer film is not formed.

[0032] Figure 12B is a drawing illustrating an example of a shape of an opening of a hole of a substrate film after etching by a resist in which a polymer film is not formed.

[0033] Figure 13A is a drawing illustrating an example of a shape of an opening of a hole of a resist in which a polymer film is formed.

[0034] Figure 13B is a drawing illustrating an example of a shape of an opening of a hole of a substrate film after etching by a resist in which a polymer film is formed. DETAILED DESCRIPTION

[0035] Hereinafter, embodiments of a film forming method and a film forming apparatus will be described in detail based on the drawings. Furthermore, the disclosed film forming method and film forming apparatus are not limited by the following embodiments.

[0036] In addition, with miniaturization of processes, control of line width (CD: Critical Dimension) of a pattern formed on a substrate becomes more important. In order to form a desired CD pattern on a substrate with high precision, it is required to further improve precision of CD in a pattern formed on a resist.

[0037] Therefore, the present disclosure provides a technology capable of improving precision of a pattern formed on a substrate.

[0038] [Structure of processing apparatus 1]

[0039] Figure 1is a schematic view showing an example of a processing apparatus 1. In the present embodiment, the processing apparatus 1 is, for example, a capacitively coupled plasma processing apparatus. The processing apparatus 1 is an example of a film forming apparatus. The processing apparatus 1 includes a chamber 10, a gas supply portion 20, a power supply 30, and an exhaust system 40. In addition, the processing apparatus 1 includes a substrate support portion 11 and a gas introduction portion. The gas introduction portion is configured to introduce at least one gas into the chamber 10. The gas introduction portion includes a showerhead 13. The substrate support portion 11 is disposed in the chamber 10. The showerhead 13 is disposed above the substrate support portion 11. In one embodiment, the showerhead 13 constitutes at least a portion of a ceiling of the chamber 10. The chamber 10 has a processing space 10s defined by the showerhead 13, a side wall 10a of the chamber 10, and the substrate support portion 11.

[0040] The chamber 10 has at least one gas supply port for supplying at least one gas to the processing space 10s, and at least one gas exhaust port for exhausting the gas from the plasma processing space. The chamber 10 is formed of a conductor such as aluminum and is grounded. The showerhead 13 and the substrate support portion 11 are electrically insulated from the housing of the chamber 10. An opening portion 10b for carrying in and out of the chamber 10 a substrate W is formed in the side wall 10a of the chamber 10. The opening portion 10b is opened and closed by a gate valve G.

[0041] The substrate support portion 11 includes a main body portion 111 and a ring assembly 112. The main body portion 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of the substrate W. The annular region 111b of the main body portion 111 encloses the central region 111a of the main body portion 111 when viewed from above. The substrate W is disposed on the central region 111a of the main body portion 111, and the ring assembly 112 is disposed on the annular region 111b of the main body portion 111 so as to surround the substrate W on the central region 111a of the main body portion 111. Thus, the central region 111a is also referred to as a substrate support surface for supporting the substrate W, and the annular region 111b is also referred to as a ring support surface for supporting the ring assembly 112.

[0042] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes an electrically conductive member. The electrically conductive member of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed in the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has a ring-shaped region 111b. Further, other members that surround the electrostatic chuck 1111, such as a ring-shaped electrostatic chuck (not shown), a ring-shaped insulating member (not shown), can also have the ring-shaped region 111b. In this case, the ring assembly 112 can be disposed on the ring-shaped electrostatic chuck or the ring-shaped insulating member, or on both the electrostatic chuck 1111 and the ring-shaped insulating member. In addition, at least one RF / DC electrode coupled to the RF (Radio Frequency) power source 31 and / or the DC (Direct Current) power source 32 described later can also be disposed in the ceramic member 1111a. In this case, the at least one RF / DC electrode functions as a lower electrode. The RF / DC electrode is also referred to as a bias electrode in a case where the bias RF signal and / or the DC signal described later is supplied to the at least one RF / DC electrode. Further, the electrically conductive member of the base 1110 and the at least one RF / DC electrode can function as a plurality of lower electrodes. In addition, the electrostatic electrode 1111b can also function as a lower electrode. Thus, the substrate support 11 includes at least one lower electrode.

[0043] The ring assembly 112 includes one or more ring-shaped members. In one embodiment, the one or more ring-shaped members include one or more edge rings and at least one cover ring. The edge rings are formed of an electrically conductive material or an insulating material, and the cover ring is formed of an insulating material.

[0044] In addition, the substrate support 11 can include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate W to a target temperature. The temperature adjustment module can include a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. A heat transfer fluid such as brine or gas flows in the flow path 1110a. In one embodiment, the flow path 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. In addition, the substrate support 11 can include a heat transfer medium supply portion configured to supply a heat transfer medium such as a heat transfer gas to a gap between the back surface of the substrate W and the central region 111a.

[0045] A through-hole, not shown, is formed in the electrostatic chuck 1111 below the central region 111a, and a lift pin, not shown, is inserted in the through-hole. The lift pin is lifted and lowered by a lift mechanism, not shown. By lifting and lowering the lift pin, the substrate W placed on the central region 111a can be lifted. For example, after the gate valve G is opened, the substrate W is carried into the chamber 10 by a conveyance robot, not shown, via the opening 10b, and is placed on the lift pin protruding from the upper surface of the electrostatic chuck 1111. Then, the substrate W is placed on the electrostatic chuck 1111 by lowering the lift pin, the gate valve G is closed, and processing of the substrate W is performed in the chamber 10. In addition, with respect to the processed substrate W, the substrate W is lifted from the upper surface of the electrostatic chuck 1111 by lifting the lift pin. Then, after the gate valve G is opened, the substrate W is carried out of the chamber 10 by the conveyance robot, not shown, via the opening 10b.

[0046] The shower head 13 is configured to introduce at least one kind of gas from the gas supply section 20 into the processing space 10s. The shower head 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas introduction ports 13c. The gas supplied to the gas supply port 13a is introduced into the processing space 10s from the plurality of gas introduction ports 13c through the gas diffusion chamber 13b. In addition, the shower head 13 includes at least one upper electrode (not shown). Further, the gas introduction section can include one or more side gas injectors (SGI) installed to one or more opening portions (not shown) formed in the side wall 10a in addition to the shower head 13.

[0047] The gas supply section 20 can include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply section 20 is configured to supply at least one kind of gas from each corresponding gas source 21 to the shower head 13 via each corresponding flow controller 22. Each flow controller 22 can include, for example, a mass flow controller or a pressure-controlled flow controller. Also, the gas supply section 20 can include one or more flow modulation devices that modulate or pulse the flow of at least one kind of gas.

[0048] The power supply 30 includes an RF power source 31 coupled to the chamber 10 via at least one impedance matching circuit. The RF power source 31 is configured to supply at least one RF signal (RF power) to the at least one lower electrode and / or the at least one upper electrode. Thereby, a plasma is formed from the at least one gas supplied to the processing space 10s. Thus, the RF power source 31 can function as at least a part of a plasma generation section configured to generate a plasma from the one or more gases in the chamber 10. Further, by supplying a bias RF signal to the at least one lower electrode, a bias potential can be generated at the substrate W, and ion components in the formed plasma can be introduced toward the substrate W.

[0049] In one embodiment, the RF power source 31 includes a first RF generation section 31a and a second RF generation section 31b. The first RF generation section 31a is configured to be coupled to the at least one lower electrode and / or the at least one upper electrode via at least one impedance matching circuit, and to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in a range of 10 MHz to 150 MHz. In one embodiment, the first RF generation section 31a can also be configured to generate a plurality of source RF signals having different frequencies. The generated one or more source RF signals are supplied to the at least one lower electrode and / or the at least one upper electrode.

[0050] The second RF generation section 31b is configured to be coupled to the at least one lower electrode via at least one impedance matching circuit, and to generate a bias RF signal (bias RF power). The bias RF signal can have the same frequency as the source RF signal, or can have a different frequency. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in a range of 100 kHz to 60 MHz. In one embodiment, the second RF generation section 31b can also be configured to generate a plurality of bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to the at least one lower electrode. Further, in various embodiments, at least one of the source RF signal and the bias RF signal can be pulsed.

[0051] Further, the power supply 30 can include a DC power source 32 coupled to the chamber 10. The DC power source 32 includes a first DC generation section 32a and a second DC generation section 32b. In one embodiment, the first DC generation section 32a is configured to be connected to the at least one lower electrode, and to generate a first DC signal. The generated first bias DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generation section 32b is configured to be connected to the at least one upper electrode, and to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0052] In various embodiments, at least one of the first DC signal and the second DC signal can also be pulsed. In this case, a sequence of voltage pulses is applied to the at least one lower electrode and / or the at least one upper electrode. The voltage pulses can have a pulse waveform that is rectangular, trapezoidal, triangular, or a combination thereof. In one embodiment, a waveform generating section for generating a sequence of voltage pulses from a DC signal is connected between the first DC generating section 32a and the at least one lower electrode. Thus, the first DC generating section 32a and the waveform generating section constitute a voltage pulse generating section. In the case where the second DC generating section 32b and the waveform generating section constitute a voltage pulse generating section, the voltage pulse generating section is connected to the at least one upper electrode. The voltage pulses can have a positive polarity, or a negative polarity. In addition, the sequence of voltage pulses can contain one or more positive polarity voltage pulses and one or more negative polarity voltage pulses in one cycle. Furthermore, the first and second DC generating sections 32a, 32b can be provided in addition to the RF power source 31, or the first DC generating section 32a can be provided instead of the second RF generating section 31b.

[0053] The exhaust system 40 can be connected to a gas exhaust port 10e provided at the bottom of the chamber 10, for example. The exhaust system 40 can include a pressure adjusting valve and a vacuum pump. The pressure adjusting valve adjusts the pressure in the processing space 10s. The vacuum pump can include a turbo molecular pump, a dry pump, or a combination thereof.

[0054] The control section 2 processes computer executable commands for causing each of the processing devices 1 to execute various processes described in the present disclosure. The control section 2 can be configured to control each element of the processing device 1 to execute various processes described herein. In one embodiment, the processing device 1 can include part or all of the control section 2. The control section 2 can include a processing section 2a1, a storage section 2a2, and a communication interface 2a3. The control section 2 is implemented by, for example, a computer 2a. The processing section 2a1 can be configured to perform various control actions by reading out a program from the storage section 2a2 and executing the read-out program. The program can be pre-stored in the storage section 2a2 or acquired via a medium as needed. The acquired program is stored in the storage section 2a2 and read out from the storage section 2a2 by the processing section 2a1 and executed. The medium can be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processing section 2a1 can be a CPU (Central Processing Unit). The storage section 2a2 can include a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 communicates with the processing device 1 via a communication line such as a LAN (Local Area Network).

[0055] [Process of substrate W]

[0056] Figure 2 is a flowchart illustrating an example of a process of the substrate W. Figure 2 Each of the processes illustrated is implemented by the control section 2 controlling each part of the processing device 1. Figure 2 The process illustrated is an example of a film formation method.

[0057] First, the substrate W is carried into the chamber 10 (step S10). Step S10 is an example of the process a). In the present embodiment, the substrate W has a base film and a resist provided on the base film with a predetermined pattern formed. In step S10, the control section 2 controls a driving mechanism of a lift pin not shown to cause a front end of the lift pin not shown to protrude from an upper surface of the electrostatic chuck 1111. Then, the control section 2 controls the gate valve G to open the gate valve G. The substrate W is carried into the chamber 10 by a conveyance robot not shown via the opening portion 10b and placed on the lift pin. Then, the control section 2 controls the driving mechanism of the lift pin to lower the lift pin. Thereby, the lift pin is lowered to place the substrate W on the electrostatic chuck 1111. Then, the control section 2 controls the gate valve G to close the gate valve G.

[0058] Next, a plasma is generated in the chamber 10 (step Sll). Step Sll is an example of the process f). In step Sll, oxygen gas is supplied from the gas supply part 20 to the chamber 10 via the shower head 13, and the oxygen gas is plasma- ized by the RF power supplied from the power source 30 to the chamber 10. Then, the surface of the substrate W (for example, the surface of the resist) is modified to a hydrophilic surface by the oxygen radicals contained in the plasma. Thereby, the surface of the substrate W becomes easy to adsorb the molecules of the monomer.

[0059] Further, the gas for the generation of the plasma is not limited to oxygen gas as long as it is an oxygen-containing gas. As the oxygen-containing gas, for example, H2O, NO, N2O, CO2, H2O2, and the like can be given. In addition, as another method of modifying the surface to a hydrophilic surface, exposure to the atmosphere after performing plasma treatment using a hydrogen-containing gas, argon, or the like can be given.

[0060] Next, a gas of the first monomer is supplied to the chamber 10 (step S12). Step S12 is an example of the process b). In the present embodiment, the first monomer is, for example, isocyanate. In step S12, the gas of the first monomer is supplied from the gas supply part 20 to the chamber 10 via the shower head 13. The molecules of the first monomer contained in the gas supplied to the chamber 10 are adsorbed to the surface of the substrate W. Step S12 is performed, for example, for 4 seconds.

[0061] Next, a purge gas is supplied to the chamber 10 (step S13). Step S13 is an example of the process c). In the present embodiment, the purge gas is a non-active gas such as nitrogen, a noble gas, or the like. In step S13, the purge gas is supplied from the gas supply part 20 to the chamber 10 via the shower head 13. The molecules of the first monomer that are excessively adsorbed to the surface of the substrate W are purged by the purge gas supplied to the chamber 10. Step S13 is performed, for example, for 4 seconds.

[0062] Next, a gas of the second monomer is supplied to the chamber 10 (step S14). Step S14 is an example of the process d). In the present embodiment, the second monomer is, for example, amine. In step S14, the gas of the second monomer is supplied from the gas supply part 20 to the chamber 10 via the shower head 13. The molecules of the second monomer contained in the gas supplied to the chamber 10 are polymerized with the molecules of the first monomer adsorbed to the surface of the substrate W. Further, a film of a polymer having a urea bond is formed on the surface of the substrate W by the polymerization of the molecules of the first monomer and the molecules of the second monomer. Step S14 is performed, for example, for 4 seconds.

[0063] Next, a purge gas is supplied into the chamber 10 (step S15). Step S15 is an example of the process e). In step S15, the purge gas is supplied from the gas supply portion 20 into the chamber 10 via the shower head 13. The molecules of the second monomer that are excessively adsorbed to the surface of the substrate W are purged by the purge gas supplied into the chamber 10. Step S15 is performed for, for example, 4 seconds.

[0064] Next, the control portion 2 determines whether the processes of steps S12 to S15 are repeated for a predetermined number of times (step S16). Hereinafter, the processes of steps S12 to S15 are described as a film formation process. In a case where the film formation process is not repeated for the predetermined number of times (step S16: No), the control portion 2 executes again the process shown in step S12. The predetermined number of times refers to the number of times the film formation process is repeated until a film of the polymer having a desired thickness is formed on the surface of the substrate W. In the present embodiment, the desired thickness of the film of the polymer is, for example, 1 nm to 2.5 nm. Further, the predetermined number of times can be one.

[0065] Further, the resist provided on the substrate W is sometimes deteriorated at a temperature of 130°C or higher. In addition, in order to cause the first monomer and the second monomer to undergo a polymerization reaction, a temperature of room temperature or higher is required. Therefore, the temperature of the substrate W in the film formation process is preferably maintained at a temperature in a range of, for example, 20°C or higher and 120°C or lower.

[0066] In a case where the film formation process is repeated for the predetermined number of times (step S16: Yes), an etching of the base film is performed (step S17). In step S17, an etching gas is supplied from the gas supply portion 20 into the chamber 10 via the shower head 13. In the present embodiment, the base film is, for example, a silicon oxide film, and the etching gas is, for example, a fluorine-containing gas. Then, an RF power for generating plasma is supplied from the power source 30 into the chamber 10, and the etching gas is plasma-ized in the chamber 10. In addition, an RF power for bias and a DC signal are supplied from the power source 30 into the chamber 10 as necessary. Then, the base film is etched along the pattern formed on the resist by active species, ions, and the like included in the plasma.

[0067] Next, the substrate W is carried out of the chamber 10 (step S18). In step S18, the control portion 2 controls the drive mechanism of the lift pins so that the front ends of the lift pins protrude from the upper surface of the electrostatic chuck 1111. Thereby, the processed substrate W is lifted from the electrostatic chuck 1111. Then, the control portion 2 controls the gate valve G so as to open the gate valve G. The processed substrate W is carried out of the chamber 10 by a conveyance robot not shown via the opening portion 10b. Then, the control portion 2 controls the gate valve G so as to close the gate valve G, and controls the drive mechanism of the lift pins so that the lift pins are lowered.

[0068] Next, the control section 2 determines whether or not the processing of the substrate W is ended (step S19). In the case where the processing of the substrate W is not ended (step S19: No), the control section 2 executes the processing shown in step S10 again. On the other hand, in the case where the processing of the substrate W is ended (step S19: Yes), the control section 2 ends the processing procedure of the substrate W shown in the present flowchart. Further, in the above-described processing procedure of the substrate W, an example in which steps S11 to S17 are implemented by one processing device is explained, but the disclosed technology is not limited to this. As another example, steps S11, steps S12 to S16, and step S17 can be implemented by respective devices, respectively.

[0069] [Process of forming a film of a polymer]

[0070] Figure 3A and Figure 3B are schematic diagrams showing an example of a process of forming a film of a polymer in a pattern having unevenness. On the surface of the resist 50, as shown in Figure 3A and Figure 3B , there are a convex portion 50a and a concave portion 50b caused by surface roughness of the resist 50. In Figure 3A and Figure 3B , the convex portion 50a and the concave portion 50b of the upper surface of the resist 50 are exemplified, but the same convex portion 50a and concave portion 50b as Figure 3A and Figure 3B exist also on the side surface of the resist 50.

[0071] In the case where the gas of the first monomer is supplied in step S12 of Figure 2 , the molecules of the first monomer are adsorbed along the surface of the resist 50. That is, as shown in Figure 3A , the molecules 55 of the first monomer are adsorbed in the same thickness on the convex portion 50a and the concave portion 50b of the surface of the resist 50.

[0072] Then, in the case where the purge gas is supplied in step S13 of Figure 2 , the molecules 55 of the first monomer excessively adsorbed on the surface of the resist 50 are purged. At this time, as shown in Figure 3B , the molecules 55 of the first monomer adsorbed on the convex portion 50a are purged more than the molecules 55 of the first monomer adsorbed on the concave portion 50b.

[0073] Then, in the case where the gas of the second monomer is supplied in step S14 of Figure 2 , the molecules of the second monomer are adsorbed along the surface of the resist 50 on which the molecules of the first monomer are adsorbed. Further, a film of a polymer having a urea bond is formed on the surface of the resist 50 by the polymerization reaction of the molecules of the first monomer and the molecules of the second monomer.

[0074] At this time, for example Figure 3B As shown, the number of first monomer molecules 55 adsorbed on convex portion 50a is less than the number of first monomer molecules 55 adsorbed on concave portion 50b. On the other hand, the number of first monomer molecules 55 adsorbed on concave portion 50b is greater than the number of first monomer molecules 55 adsorbed on convex portion 50a. Therefore, the thickness of the polymer film formed by the polymerization reaction with the molecules of the second monomer is thicker in concave portion 50b than in convex portion 50a. As a result, the height difference between convex portion 50a and concave portion 50b after the polymer film is formed is smaller than the height difference between convex portion 50a and concave portion 50b before the polymer film is formed. As a result, the surface roughness of resist 50 after the polymer film is formed is reduced compared to the surface roughness of resist 50 before the polymer film is formed. As a result, the difference between the pattern formed on resist 50 and the desired pattern can be reduced. Furthermore, by etching the underlying film under the resist 50 using the resist 50 after the polymer film is formed, the accuracy of the pattern formed on the underlying film can be improved.

[0075] Figure 4A and Figure 4B Schematic diagram showing an example of a process for forming a film of a pore-forming polymer. Figure 4A and Figure 4B As shown in FIG. 5 , a hole 51 is formed. However, the shape of the hole 51 may be an elliptical shape different from a perfect circle due to the surface roughness of the resist 50 .

[0076] exist Figure 2 When the gas of the first monomer is supplied in step S12, the molecules of the first monomer are adsorbed along the surface of the resist 50. That is, for example, Figure 4A As shown, the molecules 55 of the first monomer are adsorbed along the inner sidewalls of the pores 51 .

[0077] Then, in Figure 2 When the purge gas is supplied in step S13, the first monomer molecules 55 excessively adsorbed on the inner wall of the hole 51 are purged. Figure 4B As shown, in the elliptical hole 51 , the first monomer molecules 55 adsorbed on the inner wall portion 51 a having a smaller curvature are swept more than the first monomer molecules 55 adsorbed on the inner wall portion 51 b having a larger curvature.

[0078] Then, in Figure 2 When the second monomer gas is supplied in step S14, the second monomer molecules are adsorbed along the inner wall of the pores 51 where the first monomer molecules are adsorbed. Then, a polymer film having urea bonds is formed on the surface of the resist 50 by the polymerization reaction between the first monomer molecules and the second monomer molecules.

[0079] At this time, for example as shown in Figure 4B , the number of molecules 55 of the first monomer adsorbed to the inner wall portion 51a of small curvature is less than the number of molecules 55 of the first monomer adsorbed to the inner wall portion 51b of large curvature. On the other hand, the number of molecules 55 of the first monomer adsorbed to the inner wall portion 51b of large curvature is more than the number of molecules 55 of the first monomer adsorbed to the inner wall portion 51a of small curvature. Therefore, regarding the thickness of the film of the polymer formed by the polymerization reaction with the molecules of the second monomer, the thickness of the inner wall portion 51b of large curvature is thicker than the thickness of the inner wall portion 51a of small curvature. Thereby, the shape of the hole 51 after the film of the polymer is formed becomes a shape closer to a perfect circle than the shape of the hole 51 before the film of the polymer is formed. Thereby, it is possible to make the shape of the hole 51 close to the desired shape. Also, by etching the base film of the lower layer of the resist 50 by the hole 51 after the film of the polymer is formed, it is possible to increase the accuracy of the shape of the hole formed in the base film.

[0080] Figure 5A and Figure 5B is a schematic view showing an example of the formation process of the film of the polymer in the two holes that are communicated. In the resist 50, for example as shown in Figure 5A and Figure 5B , the adjacent holes 52 are formed. However, the adjacent two holes 52 sometimes become a shape different from a perfect circle due to the surface roughness of the resist 50, and a so-called kissing defect is generated by the communicated portion 52a between the adjacent two holes 52 being communicated.

[0081] In a case where the gas of the first monomer is supplied in the step S12 of Figure 2 , the molecules of the first monomer are adsorbed along the surface of the resist 50. That is, for example as shown in Figure 5A , the molecules 55 of the first monomer are adsorbed along the inner side walls of the two holes 52 and the communicated portion 52a.

[0082] Then, in a case where the purge gas is supplied in the step S13 of Figure 2 , the molecules 55 of the first monomer that are excessively adsorbed to the inner side walls of the holes 52 and the communicated portion 52a are purged. In this case, for example as shown in Figure 5B , the molecules 55 of the first monomer adsorbed to the inner side walls of the holes 52 are purged more than the molecules 55 of the first monomer adsorbed to the inner side walls of the communicated portion 52a.

[0083] Then, in a case where the gas of the second monomer is supplied in the step S14 of Figure 2In the case where the gas of the second monomer is supplied in step S14, the molecules of the second monomer are adsorbed along the inner side walls of the pores 52 and the communication portions 52a in which the molecules of the first monomer are adsorbed. Further, a film of the polymer having the urea bond is formed on the surface of the resist 50 by the polymerization reaction of the molecules of the first monomer and the molecules of the second monomer.

[0084] At this time, for example as shown in Figure 5B , the number of the molecules 55 of the first monomer adsorbed to the inner side walls of the pores 52 is less than the number of the molecules 55 of the first monomer adsorbed to the inner side walls of the communication portions 52a. On the other hand, the number of the molecules 55 of the first monomer adsorbed to the inner side walls of the communication portions 52a is more than the number of the molecules 55 of the first monomer adsorbed to the inner side walls of the pores 52. Therefore, regarding the film of the polymer formed by the polymerization reaction with the molecules of the second monomer, the film of the inner side walls of the communication portions 52a is thicker than the film of the inner side walls of the pores 52. Thereby, the communication portions 52a are clogged by the film of the polymer. Thereby, it is possible to make the two pores 52 adjacent to each other into independent pores 52 which are not communicated. Further, by etching the substrate film of the lower layer of the resist 50 after the formation of the film of the polymer, it is possible to increase the accuracy of the shape of the pores formed in the substrate film.

[0085] [Relationship between film thickness and vapor pressure ratio]

[0086] Figure 6 is a graph showing an example of the relationship between the number of repetitions of the film formation processing and the change in the thickness of the film of the polymer. In Figure 6 , experiments were performed regarding different vapor pressure ratios for the monomer having a lower saturated vapor pressure between the first monomer and the second monomer. In the present embodiment, the first monomer is isocyanate and the second monomer is amine, and the saturated vapor pressure of isocyanate is lower than that of amine. Therefore, the vapor pressure ratio of isocyanate is shown in Figure 6

[0087] In the case where the partial pressure of the gas of the monomer is set to P1 and the saturated vapor pressure of the gas of the monomer is set to P0, the vapor pressure ratio P r is represented by the following formula (1).

[0088] P r = P1 / P0 ···· (1)

[0089] For example as shown in Figure 6 , the higher the vapor pressure ratio, the greater the increase rate of the thickness of the film of the polymer with respect to the number of times of the film formation processing, and the lower the vapor pressure ratio, the smaller the increase rate of the thickness of the film of the polymer with respect to the number of times of the film formation processing.

[0090] ​When forming a pattern smaller than tens of nanometers, if the polymer film formed on the resist is too thick, the pattern may be buried within the polymer film. Furthermore, if the polymer film formed on the resist is too thin, the precision of the resist pattern may not be sufficiently improved, and the precision of the pattern formed on the substrate using the resist may also be insufficient. Therefore, the thickness of the polymer film formed on the resist is preferably within the range of 1 nm to 2.5 nm.

[0091] Reference Figure 6 When the vapor pressure ratio is 0.07 or more, the thickness of the polymer film increases in accordance with the number of repetitions of the film forming process, and sometimes becomes 2.5 nm or more. On the other hand, when the vapor pressure ratio is 0.05, although the thickness of the polymer film increases in accordance with the number of repetitions of the film forming process, the increase in film thickness becomes slow when the film thickness is about 2.0 nm. Figure 6 Based on the trend shown, it is believed that when the vapor pressure ratio is less than 0.05, the thickness of the polymer film is within the range of 1 nm to 2 nm. If the variation in the thickness of the polymer film can be suppressed within the range of 1 nm to 2.5 nm, it is easy to form a polymer film within the preferred thickness range. Therefore, in this embodiment, in order to form a polymer film with a thickness within the preferred range, the vapor pressure ratio is preferably 0.05 or less.

[0092] [Experimental Results]

[0093] Figure 7A : is a diagram showing an example of the shape of the opening of the hole 60 before forming a polymer film. Figure 7A In the embodiment, a plurality of holes 60 are formed in the resist 61. Figure 7A In FIG. 5 , the average CD value of the opening portion of the hole 60 is 16.6 nm, and the LCDU (Local Critical Dimension Uniformity) is 4.5 nm.

[0094] On the other hand, Figure 7A When a polymer film having a thickness of 2 nm is formed on the resist 61 shown in FIG. 1 , the state of the hole 60 becomes, for example, as shown in FIG. Figure 7B Like that. Figure 7B : is a diagram showing an example of the shape of the opening of the hole 60 after the polymer film is formed. Figure 7B The average CD value of the opening of the hole 60 is 12.9 nm, and the LCDU is 3.3 nm. Figure 7A and Figure 7B , the LCDU of the opening portion of the hole 60 is improved by about 22%.

[0095] Figure 8Ais a view showing an example of the cross-sectional shape of the hole 60 before a polymer film is formed. In Figure 8A , the resist 61 laminated on the base film 62 is formed with a plurality of holes 60. In Figure 8A , the average value of the height of the resist 61 is 39.0 nm, and the average value of the CD of the opening portion of the hole 60 is 16.9 nm.

[0096] On the other hand, in the case where a polymer film of 2 nm in thickness is formed on the resist 61 shown in Figure 8A , the state of the hole 60 becomes, for example, as shown in Figure 8B . Figure 8B is a view showing an example of the cross-sectional shape of the hole 60 after a polymer film is formed. In Figure 8B , the average value of the height of the resist 61 is 39.2 nm, and the average value of the CD of the opening portion of the hole 60 is 16.0 nm. It is considered that a polymer film is also formed inside the hole 60, and not only the opening portion of the hole 60 but also the LCDU inside the hole 60 is improved. Further, in Figure 8A and Figure 8B , the width of the hole 60 at the position shown by a broken line is measured as the CD.

[0097] Figure 9A is a view showing an example of the shape of the opening portion of the hole before a polymer film is formed. In Figure 9A , the resist 61 is formed with a plurality of holes 60, and the interval of the adjacent holes 60 is wider than in Figure 7A . In Figure 9A , the average value of the CD in the x direction of the opening portion of the hole 60 is 33.0 nm, and the average value of the CD in the y direction is 32.2 nm. In addition, the LCDU is 3.5 nm.

[0098] On the other hand, in the case where a polymer film of 2.5 nm in thickness is formed on the resist 61 shown in Figure 9A , the state of the hole 60 becomes, for example, as shown in Figure 9B . Figure 9B is a view showing an example of the shape of the opening portion of the hole after a polymer film is formed. In Figure 9B , the average value of the CD in the x direction of the opening portion of the hole 60 is 25.4 nm, and the average value of the CD in the y direction is 26.3 nm. In addition, the LCDU is 1.5 nm. Comparing Figure 9A and Figure 9B , the LCDU of the opening portion of the hole 60 is improved by about 57%.

[0099] Figure 10A is a view showing an example of the shape of the opening portion of the hole before a polymer film is formed. In Figure 10AIn the resist 61 shown in FIG. 1, a plurality of holes 60 are formed, and a part of the holes 60 (e.g., the hole 60a and the hole 60b) are communicated.

[0100] On the other hand, in the case where a film of a polymer having a thickness of 2.5 nm is formed on the resist 61 shown in FIG. 1, the state of the resist 61 becomes, for example, as shown in FIG. 2. Figure 10A Figure 10B Figure 10B is a view showing an example of the shape of the opening of the hole after the formation of the film of the polymer. Figure 10A In the resist 61 shown in FIG. 1, a plurality of holes 60 are formed, and a part of the holes 60 (e.g., the hole 60a and the hole 60b) are communicated. Figure 10B In the resist 61 shown in FIG. 1, a plurality of holes 60 are formed, and a part of the holes 60 (e.g., the hole 60a and the hole 60b) are communicated. Figure 10A Figure 10B

[0101] Figure 11A is a view showing an example of the shape of the opening of the hole after the formation of the film of the polymer. Figure 11A In the resist 61 shown in FIG. 1, a plurality of holes 60 are formed, and a part of the holes 60 (e.g., the hole 60a and the hole 60b) are communicated. Figure 11A In the resist 61 shown in FIG. 1, a plurality of holes 60 are formed, and a part of the holes 60 (e.g., the hole 60a and the hole 60b) are communicated.

[0102] On the other hand, in the case where a film of a polymer having a thickness of 2.5 nm is formed on the resist 61 shown in FIG. 1, the state of the resist 61 becomes, for example, as shown in FIG. 2. Figure 11A Figure 11B Figure 11B is a view showing an example of the shape of the opening of the hole after the formation of the film of the polymer. Figure 11B In the resist 61 shown in FIG. 1, a plurality of holes 60 are formed, and a part of the holes 60 (e.g., the hole 60a and the hole 60b) are communicated. Figure 11A Figure 11B

[0103] Figure 12A is a view showing an example of the shape of the opening of the hole after the formation of the film of the polymer. Figure 12A In the resist 61 shown in FIG. 1, a plurality of holes 60 are formed, and a part of the holes 60 (e.g., the hole 60a and the hole 60b) are communicated. Figure 12A In the resist 61 shown in FIG. 1, a plurality of holes 60 are formed, and a part of the holes 60 (e.g., the hole 60a and the hole 60b) are communicated.

[0104] Figure 12B is a view showing an example of the shape of the opening of the hole after the formation of the film of the polymer. Figure 12A ​​​​​​​​In the case where the resist 61 shown in the figure etches the base film 62, the base film 62 is formed, for example Figure 12B The hole 60' shown in the figure is transferred to the base film 62. Figure 12A The shape of the hole 60 shown in FIG. 6 is such that an elliptical hole 60' is formed in the base film 62. Figure 12B In FIG. 5 , the average value of the difference between the CD in the x-direction and the CD in the y-direction of the opening of the hole 60 ′ is 3.1 nm.

[0105] Figure 13A : is a diagram showing an example of the shape of the opening of the hole 60 of the resist 61 forming the polymer film. Figure 13A In the process, a polymer film with a thickness of 2 nm is formed on the resist 61. As a result, the opening of each hole 60 becomes smaller than Figure 12A The opening of the hole 60 shown is close to a perfect circle. Figure 13A The average value of the difference between the CD in the x-direction and the CD in the y-direction of the opening of the hole 60 is 1.6 nm. Figure 12A and Figure 13A The average value of the difference between the CD in the x-direction and the CD in the y-direction of the opening of the hole 60 is improved by about 62%.

[0106] Figure 13B 1 is a diagram showing an example of the shape of the opening of the hole in the base film after etching through the resist 61 formed with the polymer film. Figure 13A In the case where the resist 61 shown in the figure etches the base film 62, the base film 62 is formed, for example Figure 13B The hole 60' shown in the figure is transferred to the base film 62. Figure 13A The shape of the hole 60 shown in FIG. 6 is such that the base film 62 is formed with an opening having a larger diameter than that of the base film 62. Figure 12B The opening of the hole 60' shown is a hole 60' that is close to a perfect circle. Figure 13B The average value of the difference between the CD in the x-direction and the CD in the y-direction of the opening of the hole 60' is 1.2 nm. Figure 12B and Figure 13B The average value of the difference between the CD in the x-direction and the CD in the y-direction of the opening of the hole 60 is improved by about 61%.

[0107] The above describes the embodiment. As described above, the film forming method in the embodiment includes the process a), the process b), the process c), the process d), and the process e). In the process a), the substrate (the substrate W) having the base film (the base film 62) and the resist (the resist 50, the resist 61) provided on the base film and formed with a predetermined pattern is carried into the chamber (the chamber 10). In the process b), the gas of the first monomer is supplied into the chamber. In the process c), the purge gas is supplied into the chamber. In the process d), the gas of the second monomer is supplied into the chamber, thereby forming the film of the polymer on the surface of the substrate by the polymerization reaction of the first monomer and the second monomer. In the process e), the purge gas is supplied into the chamber. In addition, the ratio of the vapor pressure of the monomer having a low saturated vapor pressure among the first monomer and the second monomer is 0.05 or less. Thus, the precision of the pattern formed on the substrate can be improved.

[0108] In addition, in the above-described embodiment, the process b), the process c), the process d), and the process e) can be repeated a plurality of times in this order. By controlling the number of repetitions, the film of the polymer having a desired thickness can be easily formed on the surface of the substrate.

[0109] In addition, the film forming method in the above-described embodiment can further include the process f). The process f) is performed before the process b), and in the process f), the oxygen is supplied into the chamber and the oxygen is plasma-processed in the chamber. Thus, the film of the polymer can be efficiently formed on the resist.

[0110] In addition, in the above-described embodiment, in the process b), the process c), the process d), and the process e), the temperature of the substrate is maintained in a range of 20°C or higher and 120°C or lower. Thus, the film of the polymer can be formed by the polymerization reaction of the first monomer and the second monomer while avoiding deterioration of the resist.

[0111] In addition, in the above-described embodiment, the first monomer is an isocyanate, the second monomer is an amine, and the urea bond is included in the film of the polymer formed on the substrate. Thus, the film of the polymer, which can improve the precision of the pattern formed on the substrate, can be easily formed.

[0112] Further, the film formation apparatus (processing apparatus 1) in the above-described embodiment has a chamber (chamber 10) having a gas supply port (gas supply port 13a) and a gas discharge port (gas discharge port 10e), a substrate support portion (substrate support portion 11) provided in the chamber and supporting a substrate (substrate W) having a base film (base film 62) and a resist (resist 50, resist 61) provided on the base film and formed with a predetermined pattern, a lift mechanism that lifts a lift pin supporting the substrate, a gas supply portion (gas supply portion 20) that supplies a gas into the chamber, and a control portion (control portion 2). The control portion performs process a), process b), process c), process d), and process e). In process a), the control portion places the substrate carried into the chamber on the substrate support portion by the lift pin by controlling the lift mechanism. In process b), the control portion supplies a gas of a first monomer into the chamber by controlling the gas supply portion. In process c), the control portion supplies a purge gas into the chamber by controlling the gas supply portion. In process d), the control portion supplies a gas of a second monomer into the chamber by controlling the gas supply portion, thereby forming a film of a polymer on the surface of the substrate by polymerization reaction of the first monomer and the second monomer. In process e), the control portion supplies a purge gas into the chamber by controlling the gas supply portion. Further, the ratio of the vapor pressure of the monomer having a low saturated vapor pressure among the first monomer and the second monomer is 0.05 or less. Thus, the precision of the pattern formed on the substrate can be improved.

[0113] [Others]

[0114] Further, the technology disclosed in the present application is not limited to the above-described embodiments, and various modifications can be made within the scope of the gist thereof.

[0115] For example, in the above-described embodiment, an isocyanate is used as the first monomer, and an amine is used as the second monomer to form a film of a polymer having a urea bond (-NH-CO-NH-) on the surface of the substrate W, but the disclosed technology is not limited thereto. For example, a carboxylic anhydride can be used as the first monomer, and an amine can be used as the second monomer to form a film of a polymer having an imide bond (-CO-N(-)-CO-) on the surface of the substrate W. Alternatively, an epoxide can be used as the first monomer, and an amine can be used as the second monomer to form a film of a polymer having a 2-aminoethanol bond (-NH-CH2-CH(OH)-) on the surface of the substrate W. Alternatively, an isocyanate can be used as the first monomer, and an alcohol can be used as the second monomer to form a film of a polymer having a urethane bond (-NH-CO-O-) on the surface of the substrate W. Alternatively, an acyl halide can be used as the first monomer, and an amine can be used as the second monomer to form a film of a polymer having an amide bond (-NH-CO-) on the surface of the substrate W.

[0116] Further, in the above-described embodiment, as an example of a plasma source, a processing apparatus 1 using a capacitively coupled plasma (CCP) for processing is described, but the plasma source is not limited to the capacitively coupled plasma. As a plasma source other than the capacitively coupled plasma, for example, an inductively coupled plasma (ICP), a microwave-excited surface wave plasma (SWP), an electron cyclotron resonance plasma (ECP), a helicon wave-excited plasma (HWP), and the like can be given.

[0117] Further, it should be understood that the embodiments disclosed herein are illustrative in all respects and are not restrictive. Indeed, the embodiments described above can be embodied in a multitude of ways. Further, the embodiments described above can be implemented in various manners without departing from the scope of the appended claims and their equivalents.

[0118] Further, with respect to the above-described embodiments, the following supplementary notes are disclosed.

[0119] (Supplementary Note 1)

[0120] A film forming method, comprising the following steps:

[0121] Step a) of carrying a substrate having a base film and a resist into a chamber, the resist being provided on the base film and formed with a predetermined pattern;

[0122] Step b) of supplying a gas of a first monomer into the chamber;

[0123] Step c) of supplying a purge gas into the chamber;

[0124] Step d) of forming a film of a polymer on a surface of the substrate by a polymerization reaction of the first monomer and a second monomer by supplying a gas of the second monomer into the chamber; and

[0125] Step e) of supplying a purge gas into the chamber,

[0126] wherein a ratio of a vapor pressure of a monomer having a low saturated vapor pressure between the first monomer and the second monomer is 0.05 or less.

[0127] (Supplementary Note 2)

[0128] The film forming method according to Supplementary Note 1, wherein

[0129] The step b), the step c), the step d), and the step e) are repeated a plurality of times in this order.

[0130] (Supplementary Note 3)

[0131] The film forming method according to any one of the following Notes 1 to 3,

[0132] Further comprising a step f) of supplying oxygen into the chamber and plasma- ionizing the oxygen in the chamber before the step b).

[0133] (Note 4)

[0134] The film forming method according to any one of the following Notes 1 to 3,

[0135] In the step b), the step c), the step d), and the step e), the temperature of the substrate is maintained in a range of 20°C or higher and 120°C or lower.

[0136] (Note 5)

[0137] The film forming method according to any one of the following Notes 1 to 4,

[0138] The first monomer is an isocyanate,

[0139] The second monomer is an amine,

[0140] The polymer film formed on the substrate contains a urea bond.

[0141] (Note 6)

[0142] The film forming method according to any one of the following Notes 1 to 4,

[0143] The first monomer is a carboxylic anhydride,

[0144] The second monomer is an amine,

[0145] The polymer film formed on the substrate contains an imide bond.

[0146] (Note 7)

[0147] The film forming method according to any one of the following Notes 1 to 4,

[0148] The first monomer is an epoxide,

[0149] The second monomer is an amine,

[0150] The polymer film formed on the substrate contains a 2-aminoethanol bond.

[0151] (Note 8)

[0152] The film forming method according to any one of the following Notes 1 to 4,

[0153] The first monomer is an isocyanate,

[0154] the second monomer is an alcohol,

[0155] a urethane bond is contained in the polymer film formed on the substrate.

[0156] (Paragraph 9)

[0157] The film forming method according to any one of Paragraphs 1 to 4, wherein

[0158] the first monomer is an acyl halide,

[0159] the second monomer is an amine,

[0160] an amide bond is contained in the polymer film formed on the substrate.

[0161] (Paragraph 10)

[0162] A film forming apparatus comprising:

[0163] a chamber having a gas supply port and a gas discharge port;

[0164] a substrate support portion provided in the chamber, which supports a substrate having a base film and a resist, the resist being provided on the base film and formed with a predetermined pattern;

[0165] a lift mechanism which lifts a lift pin supporting the substrate;

[0166] a gas supply portion which supplies a gas into the chamber; and

[0167] a control portion,

[0168] wherein the control portion executes the following processes:

[0169] process a) in which the substrate carried into the chamber is placed on the substrate support portion by the lift pin through control of the lift mechanism;

[0170] process b) in which a gas of a first monomer is supplied into the chamber through control of the gas supply portion;

[0171] process c) in which a purge gas is supplied into the chamber through control of the gas supply portion;

[0172] process d) in which a gas of a second monomer is supplied into the chamber through control of the gas supply portion, whereby a polymer film is formed on the surface of the substrate through polymerization reaction of the first monomer and the second monomer; and

[0173] process e) in which a purge gas is supplied into the chamber through control of the gas supply portion,

[0174] wherein the ratio of the vapor pressure of the monomer having a low saturated vapor pressure in the first monomer and the second monomer is 0.05 or less.

[0175] BRIEF DESCRIPTION OF DRAWINGS

[0176] G: gate valve; W: substrate; 1: processing device; 2: control section; 2a: computer; 10: chamber; 10a: side wall; 10b: opening portion; 10e: gas exhaust port; 10s: processing space; 11: substrate support section; 111: main body section; 112: ring assembly; 13: shower head; 13a: gas supply port; 13b: gas diffusion chamber; 13c: gas introduction port; 20: gas supply section; 21: gas source; 22: flow controller; 30: power supply; 31: RF power supply; 32: DC power supply; 40: exhaust system; 50: resist; 50a: convex portion; 50b: concave portion; 51: hole; 51a: inner wall portion; 51b: inner wall portion; 52: hole; 52a: communication portion; 55: molecule of first monomer; 60: hole; 61: resist; 62: base film.

Claims

1. A film forming method comprising the following steps: a) a step of carrying a substrate having a base film and a resist into a chamber, the resist being provided on the base film and formed with a predetermined pattern; b) a step of supplying a gas of a first monomer into the chamber; c) a step of supplying a purge gas into the chamber; d) a step of supplying a gas of a second monomer into the chamber, thereby forming a polymer film on a surface of the substrate by polymerization of the first monomer and the second monomer; and e) a step of supplying a purge gas into the chamber, wherein a ratio of vapor pressure of a monomer having a low saturated vapor pressure between the first monomer and the second monomer is 0.05 or less.

2. The film forming method according to claim 1, wherein the steps b), c), d), and e) are repeated a plurality of times in this order.

3. The film forming method according to claim 1 or 2, wherein a step f) of supplying an oxygen-containing gas into the chamber and plasma- ionizing the oxygen-containing gas in the chamber is further included, the step f) being performed before the step b).

4. The film forming method according to claim 1 or 2, wherein in the steps b), c), d), and e), a temperature of the substrate is maintained in a range of 20°C or higher and 120°C or lower.

5. The film forming method according to claim 1 or 2, wherein the first monomer is an isocyanate, the second monomer is an amine, and a urea bond is included in the polymer film formed on the substrate.

6. The film forming method according to claim 1 or 2, wherein the first monomer is a carboxylic anhydride, the second monomer is an amine, and an imide bond is included in the polymer film formed on the substrate.

7. The film forming method according to claim 1 or 2, wherein the first monomer is an epoxide, the second monomer is an amine, and a 2-aminoethanol bond is included in the polymer film formed on the substrate.

8. The film forming method according to claim 1 or 2, wherein the first monomer is an isocyanate, the second monomer is an alcohol, and a urethane bond is included in the polymer film formed on the substrate.

9. The film forming method according to claim 1 or 2, wherein the first monomer is an acyl halide, the second monomer is an amine, and an amide bond is included in the polymer film formed on the substrate.

10. A film forming apparatus comprising: a chamber having a gas supply port and a gas discharge port; a substrate support portion provided in the chamber and supporting a substrate having a base film and a resist, the resist being provided on the base film and formed with a predetermined pattern; a lift mechanism lifting a lift pin supporting the substrate; a gas supply portion supplying a gas into the chamber; and a control portion, wherein the control portion executes the following steps: a) a step of placing the substrate carried into the chamber on the substrate support portion by the lift pin through control of the lift mechanism. Process b) supplying a first monomer gas into the chamber by controlling the gas supply section; Process c) supplying a purge gas into the chamber by controlling the gas supply section; Process d) supplying a second monomer gas into the chamber by controlling the gas supply section, thereby forming a polymer film on the surface of the substrate by polymerization of the first monomer and the second monomer; and Process e) supplying a purge gas into the chamber by controlling the gas supply section, wherein the ratio of the vapor pressure of the monomer having a low saturated vapor pressure between the first monomer and the second monomer is 0.05 or less.

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