Plasma etching apparatus and substrate processing apparatus

Abstract

Provided is a technique with which it is possible to appropriately supply gas into a chamber. This plasma etching apparatus comprises a chamber, a substrate support disposed in the chamber, a gas supply unit that is configured to alternately supply a first processing gas and a second processing gas into the chamber, a plasma generation unit that is configured to generate a first plasma from the first processing gas and generate a second plasma from the second processing gas, an OES detection unit that is configured to detect OES light emission intensity in the chamber, an end point detection unit that is configured to detect an end point with respect to a substrate on the substrate support, and a control unit that is configured to control the gas supply unit, the substrate including a stack in which first films and second films are alternately laminated, and the control unit being configured to control the gas supply unit so as to perform steps (a) to (o).

Description

Plasma etching apparatus and substrate processing apparatus

[0001] SUMMARY OF THE INVENTION Exemplary embodiments of the present disclosure relate to plasma etching apparatus and substrate processing apparatus.

[0002] Japanese Patent Application Laid-Open No. 2003-129999 discloses a technique for generating plasma from a gas supplied into a chamber of a plasma processing apparatus and detecting light from the plasma.

[0003] JP 2016-100547 A

[0004] The present disclosure provides a technique for appropriately supplying gas into a chamber.

[0005] a plasma etching apparatus according to an exemplary embodiment of the present disclosure, the plasma etching apparatus comprising: a chamber; a substrate support disposed within the chamber; a gas supply unit configured to alternately supply a first process gas and a second process gas into the chamber; a plasma generation unit configured to generate a first plasma from the first process gas and a second plasma from the second process gas; an OES detection unit configured to detect an OES emission intensity within the chamber; an endpoint detection unit configured to detect an endpoint for a substrate on the substrate support; and a controller configured to control the gas supply unit, the substrate including a stack in which a first film and a second film are alternately stacked; and the controller performing the steps of: (a) supplying a first process gas into the chamber based on a predetermined recipe to etch the first film on the substrate on the substrate support with the first plasma generated from the first process gas; (b) determining a first OES reference parameter based on the OES emission intensity detected by the OES detection unit during the step (a); and (c) determining a first OES reference parameter based on the endpoint detected by the endpoint detection unit in the step (a). (d) determining a first gas control sequence for the first time period generated in step (c), the first gas control sequence including a transient change in the amount of the first process gas supplied into the chamber, the transient change being set to bring the OES emission intensity detected during step (a) closer to a first OES reference parameter; and (e) supplying a second process gas into the chamber based on a predetermined recipe, and generating a second plasma from the second process gas to generate a second plasma of the substrate. (f) determining a second OES reference parameter based on the OES emission intensity detected by the OES detection unit during step (e); (g) stopping the supply of the second process gas into the chamber based on the end point detected by the end point detection unit in step (e) to generate a second time period; and (h) determining a second gas control sequence for the second time period generated in step (g), wherein the second gas control sequence includes a transient change in the supply amount of the second process gas into the chamber, and the transient change is(i) supplying a first process gas into the chamber based on the first gas control sequence and etching a first film on the substrate with a first plasma generated from the first process gas; (j) stopping the supply of the first process gas into the chamber based on the end point detected by the end point detection unit in the step (i) and updating the first time; and (k) updating the first gas control sequence based on the first time updated in the step (j), the OES emission intensity detected during the step (i), and the first OES reference parameter. (l) supplying a second process gas into the chamber based on the second gas control sequence and etching a second film on the substrate with a second plasma generated from the second process gas; (m) stopping the supply of the second process gas into the chamber based on the end point detected by the end point detection unit in step (l) and updating the second time; (n) updating the second gas control sequence based on the second time updated in step (m), the OES emission intensity detected during step (l), and the second OES reference parameter; and (o) repeating steps (i) to (n).

[0006] According to one exemplary embodiment of the present disclosure, a technique can be provided that allows gas to be appropriately supplied into a chamber.

[0007] 1 is a diagram for explaining an example of the configuration of a plasma processing system; 2 is a diagram for explaining an example of the configuration of a plasma processing apparatus; 3 is a flowchart for explaining an example of a substrate processing method; 4 is a diagram for explaining an example of a film on a substrate; 5 is a diagram for explaining an example of a substrate when a first film is etched; 6 is a diagram for explaining an example of a substrate when a second film is etched; 7 is a diagram for explaining an example of a substrate when a laminated film is etched; 8 is a diagram for explaining an example of gas control of a first processing gas and a second processing gas; 9 is a diagram for explaining an example of gas control of a first processing gas and a second processing gas; 10 is a flowchart for explaining an example of gas control; 11 is a diagram for explaining an example of a configuration of a plasma processing apparatus having a pressure sensor; 12 is a flowchart for explaining an example of valve opening control; 13 is a diagram for explaining an example of a pressure waveform and a valve opening; 14 is a flowchart for explaining an example of gas control; 15 is a flowchart for explaining an example of gas control;

[0008] Hereinafter, each embodiment of the present disclosure will be described.

[0009] In one exemplary embodiment, a plasma processing apparatus includes a chamber, a substrate support disposed within the chamber, a gas supply configured to alternately supply a first process gas and a second process gas into the chamber, a plasma generation unit configured to generate a first plasma from the first process gas and a second plasma from the second process gas, an OES detection unit configured to detect an OES emission intensity within the chamber, an endpoint detection unit configured to detect an endpoint for a substrate on the substrate support, and a controller configured to control the gas supply. and a second film are alternately stacked, and the control unit performs the steps of: (a) supplying a first process gas into the chamber based on a predetermined recipe, and etching a first film on a substrate on a substrate support with a first plasma generated from the first process gas; (b) determining a first OES reference parameter based on an OES emission intensity detected by the OES detection unit during the step (a); (c) stopping the supply of the first process gas into the chamber based on an endpoint detected by the endpoint detection unit in the step (a), and generating a first time; and (d) determining a first time period based on the end point detected by the endpoint detection unit during the step (c). (e) supplying a second process gas into the chamber based on a predetermined recipe to etch a second film on the substrate with a second plasma generated from the second process gas; and (f) determining a first gas control sequence at a first time generated in (a), the first gas control sequence including a transient change in a supply amount of a first process gas into the chamber, the transient change being set to bring an OES emission intensity detected during step (a) closer to a first OES reference parameter. (g) determining a second OES reference parameter based on the S emission intensity; (g) stopping the supply of the second process gas into the chamber based on the end point detected by the end point detection unit in step (e) to generate a second time period; and (h) determining a second gas control sequence for the second time period generated in step (g), wherein the second gas control sequence includes a transient change in the supply amount of the second process gas into the chamber, and the transient change is set so as to bring the OES emission intensity detected during step (e) closer to the second OES reference parameter.(i) supplying a first process gas into the chamber based on a first gas control sequence and etching a first film on the substrate with a first plasma generated from the first process gas; (j) stopping the supply of the first process gas into the chamber based on the end point detected by the end point detection unit in the step (i) and updating the first time; (k) updating the first gas control sequence based on the first time updated in the step (j), the OES emission intensity detected during the step (i), and the first OES reference parameter; and (l) supplying a second process gas into the chamber based on a second gas control sequence. (m) stopping the supply of the second process gas into the chamber based on the endpoint detected by the endpoint detector in step (l) and updating the second time period; (n) updating the second gas control sequence based on the second time period updated in step (m), the OES emission intensity detected during step (l), and a second OES reference parameter; and (o) repeating steps (i) to (n).

[0010] In one exemplary embodiment, in step (k), the first gas control sequence is updated based on Iterative Learning Control (ILC).

[0011] In one exemplary embodiment, in step (n), the second gas control sequence is updated based on Iterative Learning Control (ILC).

[0012] In one exemplary embodiment, the apparatus further includes a pressure gauge configured to measure the pressure in the chamber and an exhaust system configured to exhaust the gas in the chamber, and the control unit is configured to control the exhaust system based on the measurement results of the pressure gauge and ILC (Iterative Learning Control) during at least a portion of steps (i) and (l).

[0013] In one exemplary embodiment, the exhaust system includes an exhaust valve configured to regulate the exhaust rate of gas within the chamber.

[0014] In one exemplary embodiment, the first film is a silicon oxide film and the second film is a silicon nitride film.

[0015] In one exemplary embodiment, the silicon oxide film is SiO ２ The silicon nitride film is a Si ３ N ４ It is a membrane.

[0016] In one exemplary embodiment, a method for manufacturing a semiconductor device includes: a chamber; a substrate support disposed within the chamber; a gas supply configured to alternately supply a first process gas and a second process gas into the chamber; an OES detector configured to detect an OES emission intensity within the chamber; an endpoint detector configured to detect an endpoint for a substrate on the substrate support; and a controller configured to control the gas supply, wherein the controller performs the steps of: (a) supplying the first process gas into the chamber based on a predetermined recipe; (c) determining a first OES reference parameter based on the OES emission intensity detected during step (a); (c) stopping the supply of the first process gas into the chamber based on the end point detected by the end point detection unit in step (b) to generate a first time period; and (d) determining a first gas control sequence for the first time period generated in step (c), wherein the first gas control sequence includes a transient change in the supply amount of the first process gas into the chamber, and the transient change is set so as to bring the OES emission intensity detected during step (a) closer to the first OES reference parameter. (e) supplying a second process gas into the chamber based on a predetermined recipe; (f) determining a second OES reference parameter based on the OES emission intensity detected by the OES detection unit during step (e); (g) stopping the supply of the second process gas into the chamber based on the endpoint detected by the endpoint detection unit in step (e) to generate a second time period; and (h) determining a second gas control sequence for the second time period generated in step (g), wherein the second gas control sequence includes supplying the second process gas into the chamber. (i) supplying a first process gas into the chamber based on a first gas control sequence; (j) stopping the supply of the first process gas into the chamber based on an end point detected by an end point detection unit in the step (i) and updating the first time; and (k) calculating a time based on the first time updated in the step (j), the OES emission intensity detected during the step (i), and the first OES reference parameter.There is provided a substrate processing apparatus configured to control a gas supply unit to perform the steps of: (i) updating a first gas control sequence; (l) supplying a second process gas into a chamber based on the second gas control sequence; (m) stopping the supply of the second process gas into the chamber based on an end point detected by an end point detection unit in step (i) and updating the second time; (n) updating the second gas control sequence based on the second time updated in step (m), the OES emission intensity detected during step (i), and a second OES reference parameter; and (o) repeating steps (i) to (n).

[0017] In one exemplary embodiment, in step (k), the first gas control sequence is updated based on Iterative Learning Control (ILC).

[0018] In one exemplary embodiment, the substrate processing apparatus of claim 9, wherein in step (n), the second gas control sequence is updated based on Iterative Learning Control (ILC).

[0019] In one exemplary embodiment, the apparatus further includes a pressure gauge configured to measure the pressure in the chamber and an exhaust system configured to exhaust the gas in the chamber, and the control unit is configured to control the exhaust system based on the measurement results of the pressure gauge and ILC (Iterative Learning Control) during at least a portion of the interval between steps (i) to (n).

[0020] In one exemplary embodiment, the exhaust system includes an exhaust valve configured to regulate the exhaust rate of gas within the chamber.

[0021] In one exemplary embodiment, there is provided a substrate processing apparatus including: a chamber; a substrate support disposed within the chamber; a gas supply configured to supply a process gas into the chamber; an OES detector configured to detect an OES emission intensity within the chamber; and a controller configured to control the gas supply, wherein the controller is configured to control the gas supply to perform the following steps: (a) supplying the process gas into the chamber based on a predetermined recipe; (b) determining an OES reference parameter based on the OES emission intensity detected by the OES detector during step (a); (c) determining a gas control sequence, the gas control sequence including a transient change in the amount of process gas supplied into the chamber, the transient change being set to bring the OES emission intensity detected during step (a) closer to the OES reference parameter; (d) supplying the process gas into the chamber based on the gas control sequence; (e) updating the gas control sequence based on the OES emission intensity detected during step (d) and the OES reference parameter; and (f) repeating steps (a) to (e).

[0022] In one exemplary embodiment, in step (e), the gas control sequence is updated based on Iterative Learning Control (ILC).

[0023] In one exemplary embodiment, the apparatus further includes a pressure gauge configured to measure the pressure in the chamber and an exhaust system configured to exhaust the gas in the chamber, and the control unit is configured to control the exhaust system based on the measurement results of the pressure gauge and ILC (Iterative Learning Control) during at least a portion of the period during step (d).

[0024] In one exemplary embodiment, the exhaust system includes an exhaust valve configured to regulate the amount of gas exhausted from the chamber.

[0025] In one exemplary embodiment, a gas supply system includes a chamber, a substrate support disposed within the chamber, a gas supply configured to supply a process gas into the chamber, an OES detector configured to detect an OES emission intensity within the chamber, and a controller configured to control the gas supply, wherein the controller includes a processor and a memory, and the processor is configured to execute a pre-learning sequence and a substrate processing sequence, the pre-learning sequence including: (a) supplying a process gas into the chamber based on a predetermined recipe; (b) determining an OES reference parameter based on the OES emission intensity detected by the OES detector during step (a); and (c) determining a gas control sequence, The gas control sequence includes a transient change in the amount of process gas supplied into the chamber, the transient change being set so as to cause the OES emission intensity detected during step (a) to approach an OES reference parameter; (d) supplying the process gas into the chamber based on the gas control sequence; (e) updating the gas control sequence based on the OES emission intensity detected during step (d) and the OES reference parameter; (f) storing the gas control sequence updated in step (e) in a memory unit; and (g) repeating steps (d) to (f), wherein the substrate processing sequence supplies the process gas into the chamber based on the gas control sequence stored in the memory unit.

[0026] In one exemplary embodiment, in step (e), the gas control sequence is updated based on Iterative Learning Control (ILC).

[0027] In one exemplary embodiment, the apparatus further includes a pressure gauge configured to measure the pressure in the chamber and an exhaust system configured to exhaust the gas in the chamber, and the control unit is configured to control the exhaust system based on the measurement results of the pressure gauge and ILC (Iterative Learning Control) during at least a portion of the period during step (d).

[0028] In one exemplary embodiment, the exhaust system includes an exhaust valve configured to regulate the amount of gas exhausted from the chamber.

[0029] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings. In each drawing, the same or similar elements are designated by the same reference numerals, and redundant explanations will be omitted. Unless otherwise specified, the positional relationships, such as up, down, left, and right, will be described based on the positional relationships shown in the drawings. The dimensional ratios in the drawings do not represent actual ratios, and the actual ratios are not limited to the ratios shown in the drawings.

[0030] <Example of Plasma Processing System> FIG. 1 is a diagram illustrating an example of the configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust port is connected to an exhaust system 40 (described later). The substrate support 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0031] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma generated in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR plasma), helicon wave plasma (HWP), surface wave plasma (SWP), or the like. Various types of plasma generators may be used, including alternating current (AC) plasma generators and direct current (DC) plasma generators. In one embodiment, the AC signal (AC power) used in the AC plasma generator has a frequency in the range of 100 kHz to 10 GHz. Thus, AC signals include radio frequency (RF) signals and microwave signals. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0032] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 may be implemented by, for example, a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. This program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a random access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0033] The following describes a configuration example of a capacitively coupled plasma processing apparatus as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

[0034] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10 (also simply referred to as the "chamber"), a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one process gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0035] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 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 a substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also called a substrate support surface for supporting the substrate W, and the annular region 111b is also called a ring support surface for supporting the ring assembly 112.

[0036] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The 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 within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that the annular region 111b may also be provided by another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. Furthermore, at least one RF / DC electrode coupled to an RF power supply 31 and / or a DC power supply 32, which will be described later, may be disposed within the ceramic member 1111a. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal, which will be described later, is supplied to the at least one RF / DC electrode, the RF / DC electrode is also called a bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as multiple lower electrodes. Furthermore, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0037] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0038] The substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow passage 1110a, or a combination thereof. A heat transfer fluid such as brine or a gas flows through the flow passage 1110a. In one embodiment, the flow passage 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a.

[0039] The showerhead 13 is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The process gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas inlet may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0040] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of the at least one process gas.

[0041] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode and / or at least one upper electrode. This generates a plasma from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of the plasma generation unit 12. Furthermore, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, thereby attracting ion components in the formed plasma to the substrate W.

[0042] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0043] The second RF generator 31b is coupled to at least one lower electrode via at least one impedance matching circuit and is configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. 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 the range of 100 kHz to 100 MHz. In one embodiment, the second RF generator 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0044] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to the at least one lower electrode and configured to generate a first DC signal. The generated first DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to the at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0045] In various embodiments, the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof pulse waveform. In one embodiment, a waveform generator for generating the sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one period. The first and second DC generating units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0046] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include an exhaust valve and a vacuum pump. The exhaust valve adjusts the pressure in the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0047] In one embodiment, the plasma processing apparatus 1 may be a plasma etching apparatus. As shown in Figure 2, in one embodiment, the plasma processing apparatus 1 further includes a photodetector 200 configured to detect light within the chamber 10. In one embodiment, the photodetector 200 is disposed outside the chamber 10. The photodetector 200 may be configured to detect light within the chamber 10 through a window 210 provided in a sidewall 10a of the chamber 10.

[0048] In one embodiment, the photodetector 200 includes an OES (Optical Emission Spectroscopy) detection unit 250 and an end point detection unit 251 .

[0049] The OES detector 250 is configured to detect the OES emission intensity in the chamber 10. The end point detector 251 is configured to detect the end point for the substrate W on the substrate support 11.

[0050] The OES detection unit 250 and the end point detection unit 251 are connected to the control unit 2, and are configured so that the detection results of the OES detection unit 250 and the end point detection unit 251 are output to the control unit 2. The OES detection unit 250 and the end point detection unit 251 may be substantially the same device, or may be different devices.

[0051] <Example of Substrate Processing Method> FIG. 3 is a flowchart showing an example of a substrate processing method (hereinafter also referred to as "this processing method") in one embodiment. In one embodiment, this processing method includes a plasma etching process that etches a film on a substrate W using plasma. As shown in FIG. 3, in one embodiment, this processing method includes a step ST1 of providing a substrate, a step ST2 of etching a film stack on the substrate, and a step ST3 of determining whether or not step ST2 needs to be repeated. In one embodiment, steps ST1, ST2, and ST3 are performed in this order. In one embodiment, the processing in each step is performed in a plasma processing apparatus 1. In the following example, a control unit 2 controls each unit of the substrate processing apparatus 1 to perform this processing method.

[0052] (Process ST1: Providing a Substrate) In one embodiment, in process ST1, a substrate W is provided in the chamber 10 as shown in Fig. 2. In one embodiment, the substrate W is carried into the chamber 10 by a transport arm, placed on the substrate support part 11 by a lifter, and held on the substrate support part 11 by suction.

[0053] 4 is a diagram illustrating an example of the configuration of a substrate W provided in step ST1. The substrate W includes an underlayer film UF, a stacked film SF on the underlayer film UF, and a mask MK on the stacked film SF. The substrate W may be used in the manufacture of semiconductor devices. Examples of semiconductor devices include memory devices such as DRAMs and 3D-NAND flash memories, and logic devices.

[0054] In one embodiment, the base film UF is a silicon wafer or an organic film, a dielectric film, a metal film, a semiconductor film, or the like formed on a silicon wafer. The base film UF may be configured by stacking a plurality of films.

[0055] In one embodiment, the stacked film SF is a film to be etched in this processing method. In one embodiment, the stacked film SF includes two or more different types of silicon-containing films. In one embodiment, the stacked film SF includes a stacked structure in which silicon oxide films SF1 and silicon nitride films SF2 are alternately stacked. The stacked film SF has a silicon oxide film SF1 at the top, and the silicon oxide films SF1 and silicon nitride films SF2 are alternately arranged from top to bottom. The silicon oxide film SF1 is a silicon oxide film having a thickness of 100 Å or less. ２ The silicon nitride film SF2 may be a Si ３ N ４ The stacked film SF may be a film. The silicon oxide film SF1 is an example of a first film, and the silicon nitride film SF2 is an example of a second film. The stacked film SF may have a thickness of 5 μm or more, or 10 μm or more. The stacked film SF may have 20 layers or more, 50 layers or more, or 100 layers or more. The stacked film SF may include two or more films selected from the group consisting of a single crystal silicon film, a polycrystalline silicon film, a silicon oxide film, and a silicon nitride film.

[0056] In one embodiment, the mask MK is a film that functions as a mask in etching the stacked film SF. The mask MK may be a hard mask. The mask MK includes at least one film selected from the group consisting of a carbon-containing film, a silicon-containing film, and a metal-containing film. The mask MK may be a single-layer mask made of one film, or may be a multi-layer mask made of two or more films. The mask MK may have a thickness of 10 μm or less, or 5 μm or less.

[0057] The mask MK has a sidewall S1 that defines at least one opening OP1 on the stacked film SF. The opening OP1 is a space on the stacked film SF and is surrounded by the sidewall S1 of the mask MK. That is, the upper surface of the stacked film SF has an area covered by the mask MK and an area exposed at the bottom of the opening OP1.

[0058] The opening OP1 may have any shape when viewed from above the substrate W, i.e., when the substrate W is viewed from top to bottom in FIG. 4 . The shape may be, for example, a circle, an ellipse, a rectangle, a line, or a combination of one or more of these. The mask MK may have multiple side walls S1, and the multiple side walls may define multiple openings OP1. The multiple openings OP1 may each have a linear shape and be arranged at regular intervals to form a line-and-space pattern. Alternatively, the multiple openings OP1 may each have a hole shape and form an array pattern.

[0059] Each film constituting the substrate W (base film UF, stacked film SF, mask MK) may be formed by chemical vapor deposition (CVD), atomic layer deposition (ALD), molecular layer deposition (MLD), spin coating, or the like. The opening OP1 in the mask MK may be formed by etching. The opening OP1 in the mask MK may be formed by lithography. Each film may be a flat film or may be a film having irregularities. The substrate W may further have another film below the base film UF.

[0060] At least a part of the process of forming the base film UF, the silicon-containing film SiF, and the mask MK on the substrate W may be performed in the chamber 10 as part of step ST1. For example, the opening OP1 in the mask MK may be formed by etching in step ST1. In this case, the formation of the mask MK in step ST1 and step ST2, which will be described later, may be performed consecutively in the chamber 10. In one embodiment, the substrate W may be provided in the chamber 10 after all or part of the film on the substrate W has been formed in an apparatus or chamber external to the plasma processing apparatus 1.

[0061] In one embodiment, the temperature of the substrate support 11 or the substrate W may be controlled to a given temperature by a temperature adjustment module. Controlling the temperature of the substrate support 11 or the substrate W to a given temperature may include setting the temperature of the heat transfer fluid flowing through the flow path 1110a or the heater temperature to a given temperature, or setting them to a temperature different from the given temperature. The given temperature may be, for example, 50°C or lower or -50°C or higher. The given temperature may be 0°C or lower. Note that the timing at which the temperature of the substrate support 11 or the substrate W starts to be controlled to a given temperature may be before or after the substrate W is provided to the substrate support 11, or may be simultaneous with the provision of the substrate W. The temperature of the substrate support 11 or the substrate W may be changed in each of the processes ST1, ST2-1, and ST2-2.

[0062] 3, the process ST2 includes a process ST2-1 for etching the silicon oxide film SF1 and a process ST2-2 for etching the silicon nitride film SF2. In the process ST2, the process ST2-1 and the process ST2-2 are alternately performed a predetermined number of times.

[0063] (Step ST2-1: Etching of Silicon Oxide Film SF1) In step ST2-1, a first process gas is supplied into the chamber 10 from the gas supply unit 20 shown in FIG. 2. The first process gas contains a gas that generates activated species necessary for etching the silicon oxide film SF1. The first process gas may contain a fluorocarbon gas (CF-based gas). In one embodiment, the first process gas may contain a fluorocarbon gas, an oxygen-containing gas, and an inert gas.

[0064] Fluorocarbon gas is C ４ F ６ Gas, C ４ F ８ Gas, C ３ F ８ Gas, CF ４ Gas, C ２ F ２ Gas, C ２ F ４ Gas, C ３ F ６ Gas and C ５ F ８The gas may be at least one selected from the group consisting of gases.

[0065] In step ST2-1, a first plasma is generated from the first process gas supplied into the chamber 10, and the silicon oxide film SF1 is etched by the first plasma.

[0066] 2 supplies a source RF signal to the lower electrode of the substrate support 11 and / or the upper electrode of the shower head 13. This generates a high-frequency electric field between the shower head 13 and the substrate support 11, and a first plasma is generated from the first process gas in the chamber 10. At this time, a bias signal may be supplied to the lower electrode of the substrate support 11. In this case, a bias potential is generated between the plasma and the substrate W. Active species such as ions and radicals in the plasma are attracted to the substrate W, and the silicon oxide film SF1 is etched by the active species. The bias signal may be a bias RF signal supplied from the RF power supply 31 or a bias DC signal supplied from the DC power supply 32.

[0067] 5, in one embodiment, in step ST2-1, one layer of silicon oxide film SF1 is etched from a portion exposed in the opening OP1. The next silicon nitride film SF2 is exposed at the bottom of the recess formed in the opening OP1 by step ST2-1.

[0068] (Step ST2-2: Etching of Silicon Nitride Film SF2) In step ST2-2, a second process gas is supplied into the chamber 10 from the gas supply unit 20 shown in FIG. 2. The second process gas contains a gas that generates activated species necessary for etching the silicon nitride film SF2. The second process gas may contain a hydrofluorocarbon gas (CHF-based gas). In one embodiment, the second process gas may contain a hydrofluorocarbon gas, an oxygen-containing gas, and an inert gas.

[0069] Hydrofluorocarbon gas is CHF ３ Gas, CH ２ F ２ Gas, CH ３ F gas, C ３ H ２F ４ Gas, C ４ H ２ F ６ Gas, C ２ HF ５ Gas, C ２ H ２ F ４ Gas, C ２ H ３ F ３ Gas, C ２ H ４ F ２ Gas, C ３ HF ７ Gas, C ３ H ２ F ２ Gas, C ３ H ２ F ６ Gas, C ３ H ３ F ５ Gas, C ４ H ５ F ５ Gas, C ４ H ２ F ８ Gas, C ５ H ２ F ６ Gas, C ５ H ２ F １０ Gas and C ５ H ３ F ７ The gas may be at least one selected from the group consisting of gases.

[0070] In step ST2-2, a second plasma is generated from the second process gas supplied into the chamber 10, and the silicon nitride film SF2 is etched by the second plasma.

[0071] In one embodiment, a source RF signal is supplied from the RF power supply 31 shown in FIG. 2 to the lower electrode of the substrate support 11 and / or the upper electrode of the shower head 13. As a result, a high-frequency electric field is generated between the shower head 13 and the substrate support 11, and a second plasma is generated from the second process gas in the chamber 10. At this time, a bias signal may be supplied to the lower electrode of the substrate support 11. In this case, a bias potential is generated between the plasma and the substrate W. Active species such as ions and radicals in the plasma are attracted to the substrate W, and the silicon nitride film SF2 is etched by the active species. The bias signal may be a bias RF signal supplied from the RF power supply 31 or a bias DC signal supplied from the DC power supply 32.

[0072] 6, in one embodiment, in step ST2-2, one layer of silicon nitride film SF2 is etched from the portion exposed in the opening OP1. The next silicon oxide film SF1 is exposed at the bottom of the recess formed in the opening OP1 by step ST2-2.

[0073] 3, it can be determined whether one cycle of processing including steps ST2-1 and ST2-2 has been performed a predetermined number of times. The predetermined number of times can be 2 or more, 5 or more, 10 or more, 50 or more, or 100 or more. If it is determined in step ST3 that one cycle of processing has not been performed the predetermined number of times, the process returns to step ST2, and steps ST2-1 and ST2-2 are performed again.

[0074] If it is determined in step ST3 that one cycle of steps ST2-1 and ST2-2 has been performed a predetermined number of times, the method ends. The etching of the stacked film SF may be performed until the base film UF is exposed, as shown in FIG.

[0075] <Example of Gas Control> A description will be given of the control of the process gas supplied into the chamber 10 in this processing method. The control unit 2 controls the gas supply unit 20 to control the process gas (hereinafter also referred to as "this gas control").

[0076] 8 and 9 are diagrams illustrating an example of the main gas control of the first process gas and the second process gas. In one embodiment, the main gas control of the first process gas and the second process gas may have a repetition period A(k) (k is a period number and is an integer equal to or greater than 0). Each repetition period A(k) includes a first gas switching step C1, a first film etching step C2, a second gas switching step C3, and a second film etching step C4, in this order. The first film etching step C2 may be a step of etching a silicon oxide film SF1 as a first film, and the second film etching step C4 may be a step of etching a silicon nitride film SF2 as a second film. FIG. 8 illustrates an example of the main gas control in an initial period A(0) (k=0) and a first period A(1) (k=1) of the repetition period A(k). FIG. 9 shows an example of this gas control in the first period A(1) (k=1) and the second period A(2) (k=2) of the repeating period A(k).

[0077] In each repeating cycle A(k), the first process gas may be supplied from just before the start of the first film etching step C2 to just before the end of the first film etching step C2, and may not be supplied in other sections. The times of the first gas switching step C1 and the second gas switching step C3 may be fixed, and the times of the first film etching step C2 and the second film etching step C4 may be variable.

[0078] 10 is a flowchart illustrating an example of the gas control executed in the plasma processing apparatus 1. In one embodiment, the gas control includes steps ST-a to ST-o.

[0079] In one embodiment, step ST-a may be performed after the substrate W is provided on the substrate support 11 in the chamber 10 (after step ST1).

[0080] In step ST-a, a first process gas is supplied into chamber 10 based on a predetermined recipe, and a first film is etched by a first plasma generated from the first process gas. In step ST-a, for example, the first process gas is supplied at a constant supply rate (in a rectangular waveform) in an initial period A(0) (k=0) of the repetition period A(k) shown in FIG.

[0081] During the process ST-a, the OES detection unit 250 detects the OES emission intensity in the chamber 10. The end point detection unit 251 detects the end point for the substrate W on the substrate support unit 11. The end point may be the time when the first film is etched and the second film below the first film is exposed.

[0082] 10, a first OES reference parameter Pb1 is determined based on the OES emission intensity detected by the OES detection unit 250 during step ST-a. In one embodiment, as shown in FIG. 8, the first OES reference parameter Pb1 may have a constant value obtained by subtracting a background level Pref from the detected OES emission intensity Pt, and setting a predetermined quantile (e.g., the top 90%) of the resulting value as a reference amplitude value ΔP1(0) (k=0). Note that the OES emission intensity detected in the first gas switching step C1 of the initial period A(0) (k=0) may be used as the background level Pref.

[0083] In process ST-c shown in FIG. 10 , the supply of the first process gas into chamber 10 is stopped based on the end point detected by end point detection unit 251 in process ST-a, and a first time T1(1) (k=1) is generated. As shown in FIG. 8 , first time T1(1) (k=1) is related to the supply time of the first process gas in the next first cycle A(1) (k=1), and may be, for example, the time of the first film etching step C2 in the next first cycle A(1) (k=1). The first time T1(1) (k=1) may be generated based on the time t1(0) (k=0) from the start of the first film etching step C2 in the initial cycle A(0) (k=0) to the detection of the end point by end point detection unit 251. The first time T1(1) (k=1) may be calculated using the formula: time t1(0) × (1 + α). α may be an overetching rate for making the etching time longer than time t1(0) (k=0). α may be set so that etching of the entire surface of the substrate is completed.

[0084] In process ST-d shown in FIG. 10, a first gas control sequence S1(1)(k=1) of a first period A(1)(k=1) at a first time T1(1)(k=1) generated in process ST-c is determined. As shown in FIG. 8, the first gas control sequence S1(1)(k=1) of the first period A(1)(k=1) includes a transient change in the supply rate of the first process gas into chamber 10. The transient change is set so as to bring the OES emission intensity Pt detected during process ST-a closer to the first OES reference parameter Pb1. The transient change includes a change over time. For example, the supply rate of the first process gas in the first gas control sequence S1(1)(k=1) is initially greater than that in the initial recipe and then gradually decreases. In this case, the first time T1(1) (k=1) is set as the time of the first film etching step C2, and the transient change in the supply rate of the first process gas in the first gas control sequence S1(1) (k=1) of the first period A(1) (k=1) is calculated based on the first time T1(1) (k=1). The transient change in the supply rate of the first process gas in the first gas control sequence S1(1) (k=1) may be calculated based on iterative learning control (ILC).

[0085] In step ST-e, a second process gas is supplied into chamber 10 based on a predetermined recipe, and the second film is etched by a second plasma generated from the second process gas. In step ST-e, for example, the second process gas is supplied at a constant supply rate (in a rectangular waveform) in an initial period A(0) (k=0) of the repetition period A(k) shown in FIG.

[0086] During step ST-e, the OES detection unit 250 detects the OES emission intensity in the chamber 10. The end point detection unit 251 detects the end point for the substrate W on the substrate support unit 11. The end point may be the time when the second film is etched and the first film below the second film is exposed.

[0087] 10, a second OES reference parameter Pb2 ​​is determined based on the OES emission intensity detected by the OES detection unit 250 during step ST-e. In one embodiment, as shown in FIG. 8, the second OES reference parameter Pb2 ​​may have a constant value obtained by subtracting a background level Pref from the detected OES emission intensity Pt, and setting a predetermined quantile (e.g., the top 90%) of the resulting value as a reference amplitude value ΔP2(0) (k=0). Note that the OES emission intensity detected in the first gas switching step C1 of the initial period A(0) (k=0) may be used as the background level Pref.

[0088] In process ST-g shown in FIG. 10 , the supply of the second process gas into chamber 10 is stopped based on the endpoint detected by endpoint detection unit 251 in process ST-e, and a second time T2(1) (k=1) is generated. As shown in FIG. 8 , second time T2(1) (k=1) is related to the supply time of the second process gas in the next first cycle A(1) (k=1), and may be, for example, the time of the second film etching step C4 in the next first cycle A(1) (k=1). The second time T2(1) (k=1) may be generated based on the time t2(0) (k=0) from the start of the second film etching step C4 in the initial cycle A(0) (k=0) to the detection of the endpoint by endpoint detection unit 251. The second time T2(1) (k=1) may be calculated using the formula: time t2(0) × (1 + α). α may be an overetching rate for making the etching time longer than time t2(0) (k=0). α may be set so that etching of the entire surface of the substrate is completed.

[0089] In process ST-h shown in FIG. 10, a second gas control sequence S2(1)(k=1) for the first period A(1)(k=1) at the second time T2(1)(k=1) generated in process ST-g is determined. As shown in FIG. 8, the second gas control sequence S2(1)(k=1) for the first period A(1)(k=1) includes a transient change in the supply rate of the second process gas into chamber 10. The transient change is set so as to bring the OES emission intensity Pt detected during process ST-e closer to the second OES reference parameter Pb2. The transient change includes a change over time. For example, the supply rate of the second process gas in the second gas control sequence S2(1)(k=1) is initially greater than that in the initial recipe and then gradually decreases. In this case, the second time T2(1) (k=1) is set as the time of the second film etching step C4, and the transient change in the supply rate of the second process gas in the second gas control sequence S2(1) (k=1) of the first period A(1) (k=1) is calculated based on the second time T2(1) (k=1). The transient change in the supply rate of the second process gas in the second gas control sequence S2(1) (k=1) may be calculated based on iterative learning control (ILC).

[0090] 10 , a first process gas is supplied into the chamber 10 based on the first gas control sequence S1(1) (k=1) of the first period A(1) (k=1), and a subsequent first film is etched by a first plasma generated from the first process gas. During the process ST-i, the OES detection unit 250 detects the OES emission intensity Pt in the chamber 10. The end point detection unit 251 detects the end point for the substrate W on the substrate support 11. The end point may be the point at which the first film is etched and the second film underlying the first film is exposed.

[0091] In process ST-j shown in FIG. 10 , the supply of the first process gas into chamber 10 is stopped based on the endpoint detected by endpoint detection unit 251 in process ST-i, and the first time T1(1) (k=1) of first cycle A(1) is updated to the first time T1(2) (k=2) of second cycle A(2). The first time T1(2) (k=2) of second cycle A(2) shown in FIG. 9 may be generated based on the time t1(1) (k=1) from the start of the first film etching step C2 in first cycle A(1) to the detection of the endpoint by endpoint detection unit 251. The first time T1(2) (k=2) of second cycle A(2) may be calculated using the formula: time t1(1) × (1 + α). α may be an over-etching rate for extending the etching time beyond time t1(1) to complete etching of the entire surface of the substrate.

[0092] In step ST-k shown in FIG. 10, the first gas control sequence S1(1) (k=1) of the first period A(1) is updated to the first gas control sequence S1(2) (k=2) of the second period A(2) based on the first time T1(2) of the second period A(2) updated in step ST-j, the OES emission intensity Pt detected during step ST-i, and the first OES reference parameter Pb1.

[0093] The first gas control sequence S1(2) (k=2) of the second period A(2) includes a transient change in the supply rate of the first process gas into the chamber 10. The transient change is set so as to bring the OES emission intensity Pt detected during process ST-i closer to the first OES reference parameter Pb1. The transient change includes a time-dependent change. Here, the first time T1(2) (k=2) is set as the time of the first film etching step C2 of the second period A(2), and the transient change in the supply rate of the first process gas in the first gas control sequence S1(2) (k=2) is calculated based on the first time T1(2) (k=2). The transient change in the supply rate of the first process gas in the first gas control sequence S1(2) (k=2) may be calculated based on iterative learning control (ILC).

[0094] 10 , a second process gas is supplied into the chamber 10 based on the second gas control sequence S2(1) (k=1) of the first period A(1) (k=1), and a second film is etched using a second plasma generated from the second process gas. During the process ST-1, the OES detection unit 250 detects the OES emission intensity Pt in the chamber 10. The end point detection unit 251 detects the end point for the substrate W on the substrate support 11. The end point may be the point at which the second film is etched and the first film below the second film is exposed.

[0095] In step ST-m shown in FIG. 10 , the supply of the second process gas into chamber 10 is stopped based on the endpoint detected by endpoint detection unit 251 in step ST-1, and the second time T2(1) (k=1) of first cycle A(1) is updated to the second time T2(2) (k=2) of second cycle A(2). The second time T2(2) (k=2) of second cycle A(2) shown in FIG. 9 may be generated based on the time t2(1) (k=1) from the start of second film etching step C4 in first cycle A(1) to the detection of the endpoint by endpoint detection unit 251. The second time T2(2) (k=2) of second cycle A(2) may be calculated using the formula: time t2(1) × (1 + α). α may be an over-etching rate for extending the etching time beyond time t2(1) to complete etching of the entire surface of the substrate.

[0096] In step ST-n shown in FIG. 10, the second gas control sequence S2(1) (k=1) of the first cycle A(1) is updated to the second gas control sequence S2(2) (k=2) of the second cycle A(2) based on the second time T2(2) of the second cycle A(2) updated in step ST-m, the OES emission intensity Pt detected during step ST-1, and the second OES reference parameter Pb2.

[0097] The second gas control sequence S2(2) (k=2) of the second period A(2) includes a transient change in the supply rate of the second process gas into the chamber 10. The transient change is set so as to bring the OES emission intensity Pt detected during step ST-1 closer to the second OES reference parameter Pb2. The transient change includes a time-dependent change. In this case, the second time T2(2) (k=2) is set to the time of the second film etching step C4 of the second period A(2), and the transient change in the supply rate of the second process gas in the second gas control sequence S2(2) (k=2) is calculated based on this time. The transient change in the supply rate of the second process gas in the second gas control sequence S2(2) (k=2) may be calculated based on iterative learning control (ILC).

[0098] 10, steps ST-i to ST-n are repeated multiple times. That is, the process includes a step ST-i in which a first process gas is supplied into chamber 10 based on a first gas control sequence S1(k (k is 1 or more)) and a first film is etched by a first plasma generated from the first process gas, a step ST-j in which the supply of the first process gas into chamber 10 is stopped based on an end point detected by end point detection unit 251 in step ST-i and a step ST-j in which a first time T1(k) is updated to a first time T1(k+1), and a step ST-j in which the first gas control sequence S1(k) is updated to a first gas control sequence S1(k+1) based on the first time T1(k+1) updated in step ST-j, an OES emission intensity Pt detected during step ST-i, and a first OES reference parameter Pb1 determined based on the OES emission intensity Pt. The process repeats the following steps: a step ST-k in which a second process gas is supplied into chamber 10 based on a second gas control sequence S2(k (k is 1 or more)) and a second film is etched by a second plasma generated from the second process gas; a step ST-m in which the supply of the second process gas into chamber 10 is stopped based on the end point detected by end point detection unit 251 in step ST-l and the second time T2(k) is updated to a second time T2(k+1); and a step ST-n in which the second gas control sequence S2(k) is updated to a second gas control sequence S2(k+1) based on the second time T2(k+1) updated in step ST-m, the OES emission intensity Pt detected during step ST-l, and the second OES reference parameter Pb2. In one embodiment, the number of repetitions is set based on the number of stacked layers of the first film and the second film. When the number of repetitions exceeds a predetermined number, the gas control is terminated.

[0099] According to this exemplary embodiment, the plasma processing apparatus 1 includes a chamber 10, a substrate support unit 11, a gas supply unit 20, a plasma generation unit 12, an OES detection unit 250, an end-point detection unit 251, and a control unit 2. The control unit 2 is configured to control the gas supply unit 20 to perform steps ST-a to ST-o. This determines a gas control sequence so that the OES emission intensity in the chamber 10 detected by the OES detection unit 250 approaches the OES reference parameter, thereby enabling the supply of processing gas into the chamber 10 to be appropriate. This results in improved controllability of substrate processing in the chamber.

[0100] In the exemplary embodiment, the first time T1(k+1) associated with the supply time of the first process gas in the repetition cycle A(k+1) is generated based on the time t1(k) from the start of the first film etching step C2 in the immediately preceding repetition cycle A(k) until the end point is detected by the end point detection unit 251. However, the first time T1(k+1) may be generated based on the time t1(k or less) from the start of the first film etching step C2 in a plurality of past repetition cycles A(k or less) until the end point is detected by the end point detection unit 251. The first time T1(k+1) may be an average of the times t1(k or less) in the past repetition cycles A(k or less). Similarly, the second time T2(k+1) associated with the supply time of the second process gas in the repetition cycle A(k+1) may be an average of the times t2(k or less) in the past repetition cycles A(k or less).

[0101] 11 , the plasma processing apparatus 1 may include a pressure gauge 300 configured to measure the pressure inside the chamber 10, and the control unit 2 may be configured to control the exhaust system 40 based on the measurement results of the pressure gauge 300 and ILC (Iterative Learning Control) during at least a portion of the steps STi- to ST-n. The exhaust system 40 may include an exhaust valve configured to adjust the amount of gas exhausted from the chamber 10. The pressure inside the chamber 10 during the repetition period A(k) may be measured, and the valve aperture of the exhaust system 40 may be controlled to reduce pressure fluctuations. The valve aperture may be controlled by ILC (Iterative Learning Control).

[0102] In one embodiment, the valve opening control may include steps ST-a to ST-f shown in FIG.

[0103] In process ST-a, gases (e.g., a first process gas and a second process gas) are supplied into the chamber 10 based on the valve control sequence VS(k), while the gas inside the chamber 10 is exhausted by the exhaust system 40. At this time, the pressure Pc inside the chamber 10 is measured by a pressure gauge 300 as shown in FIG.

[0104] In the process ST-b, a valve control sequence VS(k+1) is determined. The valve control sequence VS includes a transient change in the opening and closing degree of the exhaust valve of the exhaust system 40, and the transient change may be set so as to bring the pressure Pc measured during the process ST-a closer to the set pressure Pd.

[0105] In process ST-c, gas (e.g., a first processing gas and a second processing gas) is supplied into the chamber 10 based on the valve control sequence VS(k+1) determined in process ST-b, while the gas in the chamber 10 is exhausted by the exhaust system 40.

[0106] In the process ST-d, the valve control sequence VS(k+1) is updated based on the pressure Pc detected during the process ST-c and the set pressure Pd.

[0107] In step ST-e, steps ST-a to ST-d are repeated.

[0108] Although the above embodiment has been described as gas control in substrate processing using plasma, gas control in substrate processing without using plasma may also be applicable. That is, in the steps ST-a, ST-e, ST-i, and ST-l shown in FIG. 10, the substrate may be processed without generating plasma.

[0109] In the above embodiment, the substrate processing to which the gas control is applied is to etch a stacked film SF formed by alternately stacking silicon oxide films SF1 and silicon nitride films SF2, but the type of film to be etched and the number of stacked films are not limited to this. The film to be etched by the gas control may be a single layer or multiple layers. The gas type of the processing gas to which the gas control is applied may be two or more, or may be one.

[0110] For example, this gas control may include steps ST-a to ST-f shown in FIG.

[0111] In step ST-a, a processing gas is supplied into chamber 10 based on a predetermined recipe. At this time, the substrate may be processed by plasma generated from the processing gas. Alternatively, the substrate may be processed without generating plasma.

[0112] In step ST-b, an OES reference parameter Pb is determined based on the OES emission intensity detected by the OES detection unit during step ST-a.

[0113] In process ST-c, a gas control sequence S(k+1) is determined. The gas control sequence S(k+1) includes a transient change in the amount of processing gas supplied into the chamber, and the transient change may be set so as to bring the OES emission intensity detected during process ST-a closer to the OES reference parameter Pb.

[0114] In step ST-d, the process gas is supplied into the chamber based on the gas control sequence S(k+1) determined in step ST-c.

[0115] In step ST-e, the gas control sequence S(k+1) is updated based on the OES emission intensity detected during step ST-d and the OES reference parameter Pb.

[0116] In step ST-f, steps ST-a to ST-e are repeated.

[0117] This gas control may be applied to a pre-learning sequence that is executed before a substrate processing sequence is performed. In this case, processing unit 2a1 of control unit 2 may execute the pre-learning sequence and then execute the substrate processing sequence.

[0118] For example, the pre-learning sequence may include steps ST-a to ST-g shown in FIG.

[0119] In step ST-a, a processing gas is supplied into the chamber 10 based on a predetermined recipe. At this time, the substrate may be processed by plasma generated from the processing gas.

[0120] In step ST-b, an OES reference parameter Pb is determined based on the OES emission intensity detected by the OES detection unit during step ST-a.

[0121] In process ST-c, a gas control sequence S(k+1) is determined. The gas control sequence S(k+1) includes a transient change in the amount of processing gas supplied into the chamber, and the transient change may be set so as to bring the OES emission intensity detected during process ST-a closer to the OES reference parameter Pb.

[0122] In step ST-d, the process gas is supplied into the chamber based on the gas control sequence S(k+1) determined in step ST-c.

[0123] In step ST-e, the gas control sequence S(k+1) is updated based on the OES emission intensity detected during step ST-d and the OES reference parameter Pb.

[0124] In step ST-f, the gas control sequence updated in step ST-e is stored in storage unit 2a2.

[0125] In step ST-g, steps ST-a to ST-f are repeated.

[0126] The pre-learning sequence may be performed while processing a product wafer or while processing a dummy wafer.

[0127] The substrate processing sequence supplies the processing gas into the chamber based on the gas control sequence stored in the memory unit 2a2, thereby allowing the substrate to be plasma-etched.

[0128] The substrate processing to which the above gas control is applied is not limited to etching processing, but may be other substrate processing such as film formation processing.

[0129] Embodiments of the present disclosure further include the following aspects.

[0130] a gas supply unit configured to alternately supply a first process gas and a second process gas into the chamber; a plasma generation unit configured to generate a first plasma from the first process gas and a second plasma from the second process gas; an OES detection unit configured to detect an OES emission intensity in the chamber; an endpoint detection unit configured to detect an endpoint for a substrate on the substrate support unit; and a controller configured to control the gas supply unit, wherein the substrate includes a stack in which first and second films are alternately stacked, and the controller is configured to: (a) supply the first process gas into the chamber based on a predetermined recipe, and etch the first film of the substrate on the substrate support unit with the first plasma generated from the first process gas; and (b) determine a first OES reference parameter based on the OES emission intensity detected by the OES detection unit during the step (a). (c) stopping the supply of the first process gas into the chamber based on the end point detected by the end point detection unit in the step (a) to generate a first time period; (d) determining a first gas control sequence for the first time period generated in the step (c), the first gas control sequence including a transient change in the supply amount of the first process gas into the chamber, the transient change being set so as to bring the OES emission intensity detected during the step (a) close to the first OES reference parameter; (e) supplying the second process gas into the chamber based on the predetermined recipe, and etching the second film on the substrate with the second plasma generated from the second process gas; and (f) determining a second OES reference parameter based on the OES emission intensity detected by the OES detection unit during the step (e). (g) stopping the supply of the second process gas into the chamber based on the end point detected by the end point detection unit in the step (e) to generate a second time period;(h) determining a second gas control sequence for the second time generated in step (g), the second gas control sequence including a transient change in the supply amount of the second process gas into the chamber, the transient change being set so as to bring the OES emission intensity detected during step (e) closer to the second OES reference parameter; (i) supplying the first process gas into the chamber based on the first gas control sequence and etching the first film on the substrate with the first plasma generated from the first process gas; (j) stopping the supply of the first process gas into the chamber based on the end point detected by the end point detection unit in step (i) and updating the first time; (k) updating the first gas control sequence based on the first time updated in step (j), the OES emission intensity detected during step (i), and the first OES reference parameter; (l) supplying the second process gas into the chamber based on the second gas control sequence, and etching the second film on the substrate with the second plasma generated from the second process gas; (m) stopping the supply of the second process gas into the chamber based on an end point detected by the end point detection unit in the step (l) and updating the second time; (n) updating the second gas control sequence based on the second time updated in the step (m), an OES emission intensity detected during the step (l), and the second OES reference parameter; and (o) repeating the steps (i) to (n).

[0131] (Supplementary Note 2) The plasma etching apparatus according to Supplementary Note 1, wherein in the step (k), the first gas control sequence is updated based on iterative learning control (ILC).

[0132] (Supplementary Note 3) The plasma etching apparatus according to Supplementary Note 1 or 2, wherein in the step (n), the second gas control sequence is updated based on iterative learning control (ILC).

[0133] (Supplementary Note 4) The plasma etching apparatus according to any one of Supplementary Notes 1 to 3, further comprising: a pressure gauge configured to measure the pressure inside the chamber; and an exhaust system configured to exhaust gas from the chamber, wherein the control unit is configured to control the exhaust system based on the measurement results of the pressure gauge and ILC (Iterative Learning Control) during at least a portion of the steps (i) and (l).

[0134] (Supplementary Note 5) The plasma etching apparatus according to Supplementary Note 4, wherein the exhaust system includes an exhaust valve configured to adjust the amount of gas exhausted from the chamber.

[0135] (Supplementary Note 6) The plasma etching apparatus according to any one of Supplementary Notes 1 to 5, wherein the first film is a silicon oxide film, and the second film is a silicon nitride film.

[0136] (Note 7) The silicon oxide film is SiO ２ The silicon nitride film is a Si ３ N ４ 7. The plasma etching apparatus of claim 6, wherein the plasma etching apparatus is a membrane.

[0137] (Supplementary Note 8) A gas supply system comprising: a chamber; a substrate support disposed within the chamber; a gas supply unit configured to alternately supply a first process gas and a second process gas into the chamber; an OES detector configured to detect an OES emission intensity within the chamber; an end point detector configured to detect an end point for a substrate on the substrate support; and a controller configured to control the gas supply unit, wherein the controller is configured to: (a) supply the first process gas into the chamber based on a predetermined recipe; (b) determine a first OES reference parameter based on the OES emission intensity detected by the OES detector during the step (a); and (c) stop supplying the first process gas into the chamber based on the end point detected by the end point detector in the step (b), and generate a first time. (d) determining a first gas control sequence for the first time generated in step (c), the first gas control sequence including a transient change in the supply amount of the first process gas into the chamber, the transient change being set so as to bring the OES emission intensity detected during step (a) closer to the first OES reference parameter; (e) supplying the second process gas into the chamber based on the predetermined recipe; (f) determining a second OES reference parameter based on the OES emission intensity detected by the OES detection unit during step (e); and (g) stopping the supply of the second process gas into the chamber based on the end point detected by the end point detection unit in step (e), and generating a second time. (h) determining a second gas control sequence for the second time generated in step (g), the second gas control sequence including a transient change in the supply amount of the second process gas into the chamber, the transient change being set to bring the OES emission intensity detected during step (e) closer to the second OES reference parameter; (i) supplying the first process gas into the chamber based on the first gas control sequence;(j) stopping the supply of the first process gas into the chamber based on the end point detected by the end point detection unit in the step (i) and updating the first time; (k) updating the first gas control sequence based on the first time updated in the step (j), an OES emission intensity detected during the step (i), and the first OES reference parameter; (l) supplying the second process gas into the chamber based on the second gas control sequence; (m) stopping the supply of the second process gas into the chamber based on the end point detected by the end point detection unit in the step (l) and updating the second time; (n) updating the second gas control sequence based on the second time updated in the step (m), an OES emission intensity detected during the step (l), and the second OES reference parameter; and (o) repeating the steps (i) to (n).

[0138] (Supplementary Note 9) The substrate processing apparatus according to Supplementary Note 8, wherein in the step (k), the first gas control sequence is updated based on iterative learning control (ILC).

[0139] (Supplementary Note 10) The substrate processing apparatus according to Supplementary Note 8 or 9, wherein in the step (n), the second gas control sequence is updated based on iterative learning control (ILC).

[0140] (Supplementary Note 11) The substrate processing apparatus according to any one of Supplementary Notes 8 to 10, further comprising: a pressure gauge configured to measure the pressure inside the chamber; and an exhaust system configured to exhaust gas from the chamber, wherein the control unit is configured to control the exhaust system based on the measurement results of the pressure gauge and ILC (Iterative Learning Control) during at least a portion of the steps (i) to (n).

[0141] (Supplementary Note 12) The substrate processing apparatus according to Supplementary Note 11, wherein the exhaust system includes an exhaust valve configured to adjust the amount of gas exhausted from the chamber.

[0142] (Supplementary Note 13) A gas control system comprising: a chamber; a substrate support disposed in the chamber; a gas supply unit configured to supply a process gas into the chamber; an OES detector configured to detect an OES emission intensity in the chamber; and a controller configured to control the gas supply unit, wherein the controller performs the following steps: (a) supplying the process gas into the chamber based on a predetermined recipe; (b) determining an OES reference parameter based on the OES emission intensity detected by the OES detector during the step (a); (c) determining a gas control sequence, the gas control sequence including a transient change in the amount of the process gas supplied into the chamber, the transient change being set so as to bring the OES emission intensity detected during the step (a) close to the OES reference parameter; (d) supplying the process gas into the chamber based on the gas control sequence; and (e) updating the gas control sequence based on the OES emission intensity detected during the step (d) and the OES reference parameter. (f) repeating steps (a) to (e).

[0143] (Supplementary Note 14) The substrate processing apparatus according to Supplementary Note 13, wherein in the step (e), the gas control sequence is updated based on iterative learning control (ILC).

[0144] (Supplementary Note 15) The substrate processing apparatus according to Supplementary Note 13 or 14, further comprising: a pressure gauge configured to measure the pressure in the chamber; and an exhaust system configured to exhaust gas from the chamber, wherein the control unit is configured to control the exhaust system based on the measurement results of the pressure gauge and ILC (Iterative Learning Control) during at least a portion of the step (d).

[0145] (Supplementary Note 16) The substrate processing apparatus according to Supplementary Note 15, wherein the exhaust system includes an exhaust valve configured to adjust the amount of gas exhausted from the chamber.

[0146] (Supplementary Note 17) A system comprising: a chamber; a substrate support disposed in the chamber; a gas supply unit configured to supply a process gas into the chamber; an OES detection unit configured to detect an OES emission intensity in the chamber; and a control unit configured to control the gas supply unit, wherein the control unit includes a processing unit and a storage unit, and the processing unit is configured to execute a pre-learning sequence and a substrate processing sequence, the pre-learning sequence comprising: (a) supplying the process gas into the chamber based on a predetermined recipe; (b) determining an OES reference parameter based on the OES emission intensity detected by the OES detection unit during the step (a); (c) determining a gas control sequence, the gas control sequence including a transient change in the amount of the process gas supplied into the chamber, the transient change being set so as to bring the OES emission intensity detected during the step (a) close to the OES reference parameter; and (d) supplying the process gas into the chamber based on the gas control sequence. (e) updating the gas control sequence based on the OES emission intensity detected during the step (d) and the OES reference parameters; (f) storing the gas control sequence updated in the step (e) in the memory unit; and (g) repeating steps (d) to (f), wherein the substrate processing sequence supplies the processing gas into the chamber based on the gas control sequence stored in the memory unit.

[0147] (Supplementary Note 18) The substrate processing apparatus according to Supplementary Note 17, wherein in the step (e), the gas control sequence is updated based on iterative learning control (ILC).

[0148] (Supplementary Note 19) The substrate processing apparatus according to Supplementary Note 17 or 18, further comprising: a pressure gauge configured to measure the pressure in the chamber; and an exhaust system configured to exhaust gas from the chamber, wherein the control unit is configured to control the exhaust system based on the measurement results of the pressure gauge and ILC (Iterative Learning Control) during at least a portion of the step (d).

[0149] (Supplementary Note 20) The substrate processing apparatus according to Supplementary Note 19, wherein the exhaust system includes an exhaust valve configured to adjust the amount of gas exhausted from the chamber.

[0150] The above embodiments are described for the purpose of explanation and are not intended to limit the scope of the present disclosure. Various modifications can be made to the above embodiments without departing from the scope and spirit of the present disclosure. For example, some components in one embodiment can be added to other embodiments. Also, some components in one embodiment can be replaced with corresponding components in other embodiments.

[0151] 1: Plasma processing apparatus, 2: Control unit, 10: Chamber, 11: Substrate support unit, 12: Plasma generation unit, 20: Gas supply unit, 250: OES detection unit, 251: End point detection unit, W: Substrate

Claims

a gas supply unit configured to alternately supply a first process gas and a second process gas into the chamber; a plasma generation unit configured to generate a first plasma from the first process gas and a second plasma from the second process gas; an OES detection unit configured to detect an OES emission intensity in the chamber; an endpoint detection unit configured to detect an endpoint for a substrate on the substrate support unit; and a controller configured to control the gas supply unit, wherein the substrate includes a stack in which first and second films are alternately stacked, and the controller is configured to: (a) supply the first process gas into the chamber based on a predetermined recipe, and etch the first film of the substrate on the substrate support unit with the first plasma generated from the first process gas; and (b) determine a first OES reference parameter based on the OES emission intensity detected by the OES detection unit during the step (a). (c) stopping the supply of the first process gas into the chamber based on the end point detected by the end point detection unit in the step (a) to generate a first time period; (d) determining a first gas control sequence for the first time period generated in the step (c), the first gas control sequence including a transient change in the supply amount of the first process gas into the chamber, the transient change being set so as to bring the OES emission intensity detected during the step (a) close to the first OES reference parameter; (e) supplying the second process gas into the chamber based on the predetermined recipe, and etching the second film on the substrate with the second plasma generated from the second process gas; and (f) determining a second OES reference parameter based on the OES emission intensity detected by the OES detection unit during the step (e). (g) stopping the supply of the second process gas into the chamber based on the end point detected by the end point detection unit in the step (e) to generate a second time period;(h) determining a second gas control sequence for the second time generated in step (g), the second gas control sequence including a transient change in the supply amount of the second process gas into the chamber, the transient change being set so as to bring the OES emission intensity detected during step (e) closer to the second OES reference parameter; (i) supplying the first process gas into the chamber based on the first gas control sequence and etching the first film on the substrate with the first plasma generated from the first process gas; (j) stopping the supply of the first process gas into the chamber based on the end point detected by the end point detection unit in step (i) and updating the first time; (k) updating the first gas control sequence based on the first time updated in step (j), the OES emission intensity detected during step (i), and the first OES reference parameter; (l) supplying the second process gas into the chamber based on the second gas control sequence, and etching the second film on the substrate with the second plasma generated from the second process gas; (m) stopping the supply of the second process gas into the chamber based on an end point detected by the end point detection unit in the step (l) and updating the second time; (n) updating the second gas control sequence based on the second time updated in the step (m), an OES emission intensity detected during the step (l), and the second OES reference parameter; and (o) repeating the steps (i) to (n).

2. The plasma etching apparatus according to claim 1, wherein in step (k), the first gas control sequence is updated based on ILC (Iterative Learning Control).

3. The plasma etching apparatus according to claim 2, wherein in step (n), the second gas control sequence is updated based on ILC (Iterative Learning Control).

4. The plasma etching apparatus of claim 3, further comprising: a pressure gauge configured to measure the pressure inside the chamber; and an exhaust system configured to exhaust the gas inside the chamber, wherein the control unit is configured to control the exhaust system based on the measurement results of the pressure gauge and ILC (Iterative Learning Control) during at least a portion of the steps (i) and (l).

5. The plasma etching apparatus of claim 4, wherein the exhaust system includes an exhaust valve configured to adjust the amount of gas exhausted from the chamber.

6. The plasma etching apparatus according to claim 1, wherein the first film is a silicon oxide film, and the second film is a silicon nitride film.

7. The silicon oxide film is SiO ２ The silicon nitride film is a Si ３ N ４ The plasma etching apparatus of claim 6, wherein the plasma etching apparatus is a membrane.

8. A method for manufacturing a semiconductor device, comprising: a chamber; a substrate support disposed within the chamber; a gas supply configured to alternately supply a first process gas and a second process gas into the chamber; an OES detector configured to detect an OES emission intensity within the chamber; an endpoint detector configured to detect an endpoint for a substrate on the substrate support; and a controller configured to control the gas supply, wherein the controller is configured to: (a) supply the first process gas into the chamber based on a predetermined recipe; (b) determine a first OES reference parameter based on the OES emission intensity detected by the OES detector during the step (a); and (c) stop supplying the first process gas into the chamber based on the endpoint detected by the endpoint detector in the step (b), and generate a first time. (d) determining a first gas control sequence for the first time generated in step (c), the first gas control sequence including a transient change in the supply amount of the first process gas into the chamber, the transient change being set so as to bring the OES emission intensity detected during step (a) closer to the first OES reference parameter; (e) supplying the second process gas into the chamber based on the predetermined recipe; (f) determining a second OES reference parameter based on the OES emission intensity detected by the OES detection unit during step (e); and (g) stopping the supply of the second process gas into the chamber based on the end point detected by the end point detection unit in step (e), and generating a second time. (h) determining a second gas control sequence for the second time generated in step (g), the second gas control sequence including a transient change in the supply amount of the second process gas into the chamber, the transient change being set to bring the OES emission intensity detected during step (e) closer to the second OES reference parameter; (i) supplying the first process gas into the chamber based on the first gas control sequence;(j) stopping the supply of the first process gas into the chamber based on the end point detected by the end point detection unit in the step (i) and updating the first time; (k) updating the first gas control sequence based on the first time updated in the step (j), an OES emission intensity detected during the step (i), and the first OES reference parameter; (l) supplying the second process gas into the chamber based on the second gas control sequence; (m) stopping the supply of the second process gas into the chamber based on the end point detected by the end point detection unit in the step (l) and updating the second time; (n) updating the second gas control sequence based on the second time updated in the step (m), an OES emission intensity detected during the step (l), and the second OES reference parameter; and (o) repeating the steps (i) to (n).

9. The substrate processing apparatus according to claim 8, wherein in step (k), the first gas control sequence is updated based on iterative learning control (ILC).

10. The substrate processing apparatus according to claim 9, wherein in step (n), the second gas control sequence is updated based on ILC (Iterative Learning Control).

11. The substrate processing apparatus of claim 10, further comprising: a pressure gauge configured to measure the pressure inside the chamber; and an exhaust system configured to exhaust gas from the chamber, wherein the control unit is configured to control the exhaust system based on the measurement results of the pressure gauge and ILC (Iterative Learning Control) during at least a portion of the steps (i) to (n).

12. The substrate processing apparatus of claim 11, wherein the exhaust system includes an exhaust valve configured to adjust the amount of gas exhausted from the chamber.

13. A system comprising: a chamber; a substrate support disposed within the chamber; a gas supply unit configured to supply a process gas into the chamber; an OES detector configured to detect an OES emission intensity within the chamber; and a controller configured to control the gas supply unit, wherein the controller performs the following steps: (a) supplying the process gas into the chamber based on a predetermined recipe; (b) determining an OES reference parameter based on the OES emission intensity detected by the OES detector during the step (a); (c) determining a gas control sequence, the gas control sequence including a transient change in the amount of the process gas supplied into the chamber, the transient change being set so as to bring the OES emission intensity detected during the step (a) close to the OES reference parameter; (d) supplying the process gas into the chamber based on the gas control sequence; and (e) updating the gas control sequence based on the OES emission intensity detected during the step (d) and the OES reference parameter. (f) repeating steps (a) to (e).

14. The substrate processing apparatus according to claim 13, wherein in step (e), the gas control sequence is updated based on iterative learning control (ILC).

15. The substrate processing apparatus according to claim 14, further comprising: a pressure gauge configured to measure the pressure inside the chamber; and an exhaust system configured to exhaust gas from the chamber, wherein the control unit is configured to control the exhaust system based on the measurement results of the pressure gauge and ILC (Iterative Learning Control) during at least a portion of the period during step (d).

16. The substrate processing apparatus of claim 15, wherein the exhaust system includes an exhaust valve configured to adjust the amount of gas exhausted from the chamber.

17. A system comprising: a chamber; a substrate support disposed within the chamber; a gas supply configured to supply a process gas into the chamber; an OES detection unit configured to detect an OES emission intensity within the chamber; and a control unit configured to control the gas supply unit, wherein the control unit includes a processing unit and a memory unit, and the processing unit is configured to execute a learning sequence and a substrate processing sequence, the learning sequence comprising: (a) supplying the process gas into the chamber based on a predetermined recipe; (b) determining an OES reference parameter based on the OES emission intensity detected by the OES detection unit during the step (a); (c) determining a gas control sequence, the gas control sequence including a transient change in the amount of the process gas supplied into the chamber, the transient change being set so as to bring the OES emission intensity detected during the step (a) close to the OES reference parameter; and (d) supplying the process gas into the chamber based on the gas control sequence. (e) updating the gas control sequence based on the OES emission intensity detected during the step (d) and the OES reference parameters; (f) storing the gas control sequence updated in the step (e) in the memory unit; and (g) repeating steps (d) to (f), wherein the substrate processing sequence supplies the processing gas into the chamber based on the gas control sequence stored in the memory unit.

18. The substrate processing apparatus according to claim 17, wherein in step (e), the gas control sequence is updated based on iterative learning control (ILC).

19. The substrate processing apparatus according to claim 18, further comprising: a pressure gauge configured to measure the pressure inside the chamber; and an exhaust system configured to exhaust gas from the chamber, wherein the control unit is configured to control the exhaust system based on the measurement results of the pressure gauge and ILC (Iterative Learning Control) during at least a portion of the period during step (d).

20. The substrate processing apparatus of claim 19, wherein the exhaust system includes an exhaust valve configured to adjust the amount of gas exhausted from the chamber.

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