JP2013048186A - Replacement time determination device, replacement time determination method and plasma processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a replacement time determination device which can determine a time at which to replace electrodes constituting a plasma processing apparatus, and a replacement time determination method and a plasma processing system.SOLUTION: In a replacement time determination device, determination is made of a time at which to replace an electrode constituting a plasma processing apparatus, in which high frequency power is supplied to the electrode and, by plasma generated from gases introduced into a processing vessel, thin film on a substrate in the processing vessel is processed. The replacement time determination device comprises: integration means of integrating values related to processing conditions under which the thin film was processed with plasma; recording means in which integrated values corresponding to electrode replacement time concerning values related to the processing conditions of plasma processing are recorded; and determination means of determining the electrode replacement time on the basis of integrated values integrated by the integration means and the integrated values recorded in the recording means.

Description

  The present invention relates to an electrode replacement time determination device, a replacement time determination method, and a plasma processing system that constitute a plasma processing apparatus.

  An electrode of a plasma processing apparatus including an etching apparatus is etched by incident ions as the apparatus is operated. The consumption of the electrode due to this etching causes variations in the quality of the object to be processed and deterioration of the yield of the object to be processed. Therefore, there is a technique for improving the material and structure of the electrodes included in the plasma processing apparatus to improve the yield of the object to be processed (see, for example, Patent Documents 1 and 2).

JP-A-5-267235 JP 2006-287162 A

  However, even if the material and structure of the electrode included in the plasma processing apparatus are improved, the consumption of the electrode itself is not eliminated. Therefore, when it is time to replace the electrode, it is necessary to replace the electrode. In such a case, it is necessary to accurately determine the electrode replacement time in view of cost and yield.

  The present invention has been made in view of such circumstances. An object of the present invention is to provide a replacement time determination device, a replacement time determination method, and a plasma processing system that can determine the replacement time of the electrodes constituting the plasma processing apparatus.

  The replacement time determination device according to the present application is a plasma processing apparatus that supplies high-frequency power to an electrode and plasma-processes a thin film on a substrate in the processing container using plasma generated from a gas introduced into the processing container. In the replacement time determination device for determining an electrode replacement time, an integration unit that integrates a value related to a processing condition for plasma treatment of the thin film, and an integrated value corresponding to the electrode replacement time for the value related to the processing condition of the plasma processing are It is characterized by comprising recorded recording means, and determination means for determining the replacement time of the electrode based on the integrated value integrated by the integrating means and the integrated value recorded in the recording means.

  In the replacement time determination apparatus according to the present application, the plasma processing apparatus integrates values related to processing conditions in which the thin film on the substrate in the processing container is plasma processed. The replacement time determination device includes a recording unit in which an integrated value corresponding to the electrode replacement time is recorded with respect to a value related to the processing conditions of the plasma processing. The replacement time determination device determines the replacement time of the electrodes provided in the plasma processing apparatus based on the integrated integrated value and the integrated value recorded in the recording means.

  In the replacement time determination apparatus according to the present application, the plasma processing condition includes high-frequency power supplied to the electrode, pressure in the processing container, gas type, or gas flow rate.

  In the replacement time determination device according to the present application, the high-frequency power supplied to the electrode or the pressure, gas type, or gas flow rate in the processing container is integrated. The replacement time determination device includes a recording means in which an integrated value related to high-frequency power or pressure, gas type, or gas flow rate corresponding to electrode replacement is recorded. The replacement time determination device is configured to perform plasma processing based on the integrated value related to the integrated high-frequency power or pressure, gas type or gas flow rate, and the integrated value related to the high-frequency power or pressure, gas type or gas flow rate recorded in the recording means, respectively. The replacement time of the electrode provided in the apparatus is determined.

  In the replacement time determination device according to the present application, the integrating means integrates values related to the processing conditions of the plasma processing according to the composition of the gas introduced into the processing container, and the recording means corresponds to the processing conditions of the plasma processing. With respect to such a value, the integrated value corresponding to the electrode replacement time and the composition of the gas introduced into the processing vessel is recorded.

  In the replacement time determination device according to the present application, the values related to the processing conditions of the plasma processing are integrated for each gas composition related to the plasma processing. The replacement time determination device includes a recording unit in which an integrated value corresponding to the replacement of the electrode is recorded for each gas composition with respect to a value relating to the processing conditions of the plasma processing. The replacement time determination device determines the replacement time of the electrodes provided in the plasma processing apparatus based on the integrated integrated value and the integrated value recorded in the recording means.

  In the replacement time determination apparatus according to the present application, the plasma processing includes an etching process for a thin film on the substrate.

  In the replacement time determination apparatus according to the present application, the plasma processing includes etching processing on the thin film on the substrate.

  The replacement time determination method according to the present application is the replacement time determination method for determining the replacement time of electrodes constituting a plasma processing apparatus for plasma processing a thin film on a substrate, and integrating values related to processing conditions for plasma processing of the thin film. The electrode replacement time is determined on the basis of the integrated value corresponding to the electrode replacement time recorded in the recording means with respect to the integrated value and the value related to the plasma processing conditions.

  In the replacement time determination method according to the present application, the values relating to the processing conditions under which the plasma processing apparatus plasma-processes the thin film on the substrate are integrated. In the replacement time determination method, the electrode replacement is performed based on the integrated integrated value and the integrated value corresponding to the replacement time of the electrode provided in the plasma processing apparatus recorded in the recording unit with respect to the value relating to the processing conditions of the plasma processing. Determine the time.

  The plasma processing system according to the present application is a plasma processing system including a plasma processing apparatus that plasma processes a thin film on a substrate and a replacement time determination apparatus that determines a replacement time of an electrode constituting the plasma processing apparatus. The integration means for integrating the values relating to the processing conditions for plasma processing of the thin film, the recording means for recording the integration values corresponding to the electrode replacement time with respect to the values relating to the processing conditions for the plasma processing, and the integration means And determining means for determining the replacement time of the electrode based on the integrated value integrated and the integrated value recorded in the recording means.

  The plasma processing system according to the present application includes a plasma processing apparatus that performs plasma processing on a thin film on a substrate, and a replacement time determination device that determines a replacement time of an electrode constituting the plasma processing apparatus. The replacement time determination apparatus integrates values related to processing conditions in which the plasma processing apparatus plasma-processes the thin film on the substrate in the processing container. The replacement time determination apparatus includes a recording unit, and an integrated value relating to a value relating to a processing condition corresponding to an electrode replacement time included in the plasma processing apparatus is recorded in the recording unit. The replacement time determination device determines the replacement time of the electrodes provided in the plasma processing apparatus based on the integrated integrated value and the integrated value recorded in the recording means.

  According to the replacement time determination device and the like according to the present application, it is possible to determine the replacement time of the electrodes constituting the plasma processing apparatus.

It is a schematic sectional side view which shows an example of an etching apparatus. It is a block diagram which shows an example of the hardware group of an exchange time determination apparatus. It is explanatory drawing which showed schematically an example of the high frequency electric power profile. It is explanatory drawing which showed an example of the pressure profile schematically. It is explanatory drawing which showed an example of the record layout of a determination table. It is a flowchart which shows an example of the procedure of the replacement time determination process of an upper electrode. It is a flowchart which shows an example of the procedure of the replacement time determination process of an upper electrode.

Embodiments of the present invention will be described with reference to the drawings. The plasma processing system according to the present embodiment includes a replacement time determination device and a plasma processing device. The replacement time determination device determines the replacement time of the electrodes constituting the plasma processing apparatus. The electrode is, for example, an electrode provided in a PVD (Physical Vapor Deposition) device, a CVD (Chemical Vapor Deposition) device, an etching device, or the like, and is connected to a high frequency power source (RF power source). The CVD apparatus forms a film by causing a material gas, which is plasma-excited by an electrode supplied with high-frequency power (RF power), to react on a substrate. The PVD apparatus sputters a target material with Ar ions or the like plasma-excited by an electrode supplied with high-frequency power, and attaches the sputtered atoms and molecules to the substrate. The etching apparatus generates radicals and ions with an electrode to which high-frequency power is supplied, and etches a thin film on the substrate. Below, an etching apparatus is mentioned as an example of a plasma processing apparatus, and the replacement time determination apparatus which determines the replacement time of the electrode with which an etching apparatus is provided is demonstrated.
Note that the present invention is not limited to the following embodiments.

Embodiment 1
FIG. 1 is a schematic sectional side view showing an example of an etching apparatus 2. The etching device 2 is connected to the replacement time determination device 1 that is a computer by wire or wirelessly. The replacement time determination device 1 controls each component of the etching device 2, monitors a control parameter (processing condition) of the etching process, and records a time profile of the control parameter. The replacement time determination device 1 determines the electrode replacement time based on the recorded time profile relating to the etching process control parameter.

  A terminal device that controls each component of the etching apparatus 2 is separately provided between the etching apparatus 2 and the replacement time determination device 1, and the replacement time determination device 1 does not control each component of the etching device 2. It may be. In such a case, the replacement time determination device 1 receives information from the terminal device, thereby executing control parameter monitoring related to the etching process, recording of a time profile related to the control parameter, electrode replacement time determination processing, and the like.

  The etching apparatus 2 includes a dry etching apparatus such as a magnetron plasma etching apparatus, an ECR (Electron Cyclotron Resonance) plasma etching apparatus, and an ICP (Inductively coupled Plasma) etching apparatus. FIG. 1 shows an example of a single-field parallel plate type plasma etching apparatus without a magnetic field.

The etching apparatus 2 includes a processing container 20, a mounting table 3, a gas supply mechanism 4, a pressure gauge 5, and an exhaust mechanism 6.
The processing container 20 is a vacuum chamber for plasma-etching the thin film on the substrate S inside. The processing container 20 is made of a material having good thermal conductivity and conductivity, such as aluminum, and is grounded. A loading / unloading port 22 is formed in one side wall portion 21 of the processing container 20. The loading / unloading port 22 is configured to be opened and closed by a gate valve 23. A transport means (not shown) provided outside the processing container 20 loads the substrate S into the processing container 20 and unloads it from the processing container 20 via the loading / unloading port 22.
The substrate S includes a silicon wafer, a glass substrate, an organic substrate, and the like.

The mounting table 3 is a component for mounting the substrate S on the upper surface thereof, and is installed on the bottom surface inside the processing container 20. The mounting table 3 is made of, for example, aluminum and has a function as a lower electrode that is an anode electrode. The mounting table 3 includes a focus ring 31, a lift pin 32, a lift mechanism 33, and a bellows 34.
The focus ring 31 is an annular member made of, for example, ceramic, silicon, silica, silicon carbide, carbon, or the like, and is provided on the upper peripheral edge portion and the side surface portion of the mounting table 3. The focus ring 31 has a function of making the plasma uniform and ensuring in-plane uniformity of the etching rate.

The lifting pins 32 are connected to the lifting mechanism 33, and at least three lifting pins 32 are provided inside the mounting table 2. The elevating pins 32 can project and retract with respect to the upper surface of the mounting table 3 by the elevating mechanism 33, and move the substrate S up and down with respect to the mounting table 3. When the substrate S is in a position lifted by the lift pins 32, the substrate S is placed and removed by a transport means (not shown).
The bellows 34 is a cylindrical member partially provided with pleats, and covers the elevating pins 32 in order to maintain the airtightness in the processing container 20.
The mounting table 3 may include a thermometer and a heating mechanism and a cooling mechanism that can be controlled by the replacement time determination device 1 inside. Thereby, the replacement time determination device 1 may control the temperature of the substrate S.

The gas supply mechanism 4 includes a shower head 40, an insulating member 411, a high frequency power supply unit 43, a gas supply path 44, a flow rate adjustment unit 45, a first gas supply unit 46, and a second gas supply unit 47.
The shower head 40 includes a flat upper electrode base 41 and a flat upper electrode 42. The shape of the shower head 40 may be a disk shape or a square plate shape.
The upper electrode base 41 is provided on the top plate of the processing container 20 via the insulating member 411 and is in an electrically floating state from the processing container 20. The upper electrode base 41 is connected to a high-frequency power source 43 for generating plasma. The high frequency power supply unit 43 is grounded.

  The upper electrode 42 is made of, for example, single crystal silicon, amorphous carbon, a Teflon (registered trademark) plate, a quartz plate, aluminum, or the like. The upper electrode 42 is fixed to the upper electrode base 41 with a bolt (not shown), and is disposed below the upper electrode base 41. The upper electrode 42 is electrically connected to the upper electrode base 41 and functions as a cathode electrode. The replacement time determination device 1 controls the high frequency power supply unit 43 to adjust the frequency of the voltage or alternating current applied to the upper electrode 42.

An etching gas diffusion space 412 is provided between the upper electrode base 41 and the upper electrode 42. A plurality of ventilation holes 421 are formed in the upper electrode 42 facing the upper surface of the mounting table 3, and the etching gas in the diffusion space 412 is supplied to the processing space above the mounting table 3 through the ventilation holes 421. . The insulating member 411 is provided with a thermometer 422. The thermometer 422 is, for example, a thermocouple (K-type thermocouple, Pt sensor, etc.), and is provided on the insulating member 411 in order to avoid the influence of a high-frequency voltage applied to the shower head 40. The replacement timing determination device 1 can monitor the temperature of the upper electrode 42 via the thermometer 422 by extrapolation.
The upper electrode 42 is a member that is gradually consumed due to etching by radicals and ions accompanying the etching process on the thin film on the substrate S.

The thermometer 422 may be provided on the upper electrode base 41 or the upper electrode 42. In such a case, the thermometer 422 may be covered with a protective tube having an insulating property.
The thermometer 422 may be an infrared radiation thermometer or a laser thermometer provided inside or outside the processing container 20. When measuring the temperature of the upper electrode 42 with an infrared radiation thermometer or a laser thermometer, the influence of the plasma, observation window, etc. occupying between the radiation detector or the light guide unit and the upper electrode 42 on the measurement value is corrected.
Further, the thermometer 422 may be a diode thermometer provided on the insulating member 411, the upper electrode base 41 or the upper electrode 42, such as a silicon diode thermometer, a GaAlAs diode thermometer, or the like.

One end of the gas supply path 44 is connected to an opening provided on the top plate of the processing container 20. The other end of the gas supply path 44 branches into two, a gas supply path 441 and a gas supply path 442, and is connected to the first gas supply section 46 and the second gas supply section 47 via the flow rate adjusting section 45, respectively. Yes.
The first gas supply unit 46 stores an etching gas for etching the thin film. The etching gas is a gas containing a halogen element, and is selected according to the material to be etched that forms the thin film. The etching gas is, for example, CF ₄ or CF ₆ , for example, HBr or Cl ₂ .
The second gas supply unit 47 stores an additive gas (for example, O ₂ or H ₂ ) for controlling the etching rate or the selection ratio. For example, when etching Si, it is known that the etching rate is dramatically improved when O ₂ is added to CF ₄ .
Note that the number of gas supply units may be increased or decreased according to individual etching processes. For example, Ar gas may be incorporated in the gas supply mechanism 4 as a third gas supply unit.

  The flow rate adjustment unit 45 includes two rows of open / close valves and mass flow controllers (MFCs) connected in series from upstream to downstream. Each row of the on-off valve and the mass flow controller is interposed between the first gas supply section 46 and the gas supply path 441 and between the second gas supply path 47 and the gas supply path 442, respectively. The flow rate adjusting unit 45 has a function of adjusting the supply amount of the etching gas and the additive gas and adjusting the mixing ratio of the etching gas and the additive gas based on an instruction from the replacement time determination device 1. The replacement time determination device 1 monitors the gas mixture ratio and the gas flow rate controlled by the flow rate adjusting unit 45.

  The pressure gauge 5 is, for example, a diaphragm type pressure gauge, a thermal conductivity type pressure gauge, a Pirani vacuum gauge, an ionization vacuum gauge, or the like. The pressure gauge 5 detects the pressure in the processing container 20 and outputs the detected pressure to the replacement time determination device 1.

  The exhaust mechanism 6 includes an exhaust path 61, a pressure controller 62, and an exhaust device 63. One end of the exhaust path 61 is connected to an opening formed on the bottom surface of the processing container 20. An exhaust device 63 is connected to the other end of the exhaust path 61 via a pressure controller 62. The exhaust device 63 is a vacuum pump such as a turbo molecular pump, a dry pump, or a sputter ion pump, and is controlled by the replacement time determination device 1. The gas in the processing container 20 is exhausted from the exhaust path 61 to an external detoxification device (not shown) by the exhaust device 63.

  The pressure controller 62 is, for example, an APC (Auto Pressure Control) valve controlled by the replacement time determination device 1. The replacement timing determination device 1 adjusts the pressure in the processing container 20 by adjusting the opening of the APC valve based on the pressure in the processing container 20 received from the pressure gauge 5.

  FIG. 2 is a block diagram illustrating an example of a hardware group of the replacement time determination device 1. The replacement time determination device 1 includes a CPU (Central Processing Unit) (integration means, determination means) 11 and a RAM (Random Access Memory) 12. The CPU 11 includes a hard disk (recording unit) 13, a disk drive 14, a communication unit 15, a timer 16, a display unit 17, and an operation unit 18. Each component of the replacement time determination device 1 is connected via a bus 1b.

The CPU 11 controls each component of the replacement time determination device 1. The CPU 11 reads the program 1P recorded on the hard disk 13 and executes the program 1P.
The RAM 12 temporarily records work variables, data, and the like necessary during the process of the CPU 11. The RAM 12 is an example of a main storage device, and a flash memory, a memory card, or the like may be used instead of the RAM 12.

  The hard disk 13 records a program 1P executed by the CPU 11. The hard disk 13 may be installed inside the replacement time determination device 1 or may be installed outside the replacement time determination device 1. The hard disk 13 is an example of an auxiliary storage device such as a flash memory capable of recording a large amount of information, a CD (Compact Disc), a DVD (Digital Versatile Disk), a BD (Blu-ray Disc, registered trademark), or the like. It may be replaced by the optical disc 1a.

The hard disk 13 stores a recipe 1D, a profile file 1F, and a determination table 1T. In the recipe 1D, conditions for performing the etching process are recorded. The profile file 1F is a file that records a time profile of control parameters when performing an etching process. In the determination table 1T, an integrated value related to the control parameter of the etching process referred to for determining the replacement time of the upper electrode 42 is recorded.
When the etching apparatus 2 is continuously operated for a longer time than the replacement period of the upper electrode 42, the profile file 1F may not be recorded on the hard disk 13.

The disk drive 14 reads information from the optical disk 1a which is an external recording medium, and records information on the optical disk 1a.
The communication unit 15 is a modem, a LAN (Local Area Network) card, or the like, and is connected to the network N. The network N is a LAN, a WAN (Wide Area Network), the Internet, a VPN (Virtual Private Network), a telephone line network, or the like.

The timer 16 transmits the time count as a signal to the CPU 11.
The display part 17 has screens, such as a liquid crystal display and an organic EL (Electro-Luminescence) display, for example, and displays the various screens concerning the program 1P according to the instruction | indication from CPU11. The display unit 17 may include a speaker that outputs sound.

  The operation unit 18 includes input devices such as a keyboard, a mouse, and a touch panel on which a user performs various inputs. The operation unit 18 generates an input signal based on an operation by the user. The generated input signal is transmitted to the CPU 11 via the bus 1b.

Next, operations of the replacement time determination device 1 and the etching device 2 will be described.
The gate valve 23 of the etching apparatus 2 is opened, and the substrate S is transported to a predetermined position above the mounting table 3 by transport means (not shown). The raising / lowering pin 32 is raised, and the board | substrate S is delivered to the front-end | tip of the raising / lowering pin 32 from a conveyance means. The conveying means is moved out of the processing container 20. The lift pins 32 are lowered to place the substrate S on the placement table 3. The gate valve 23 is closed.

The exhaust device 63 is operated, and the inside of the processing container 20 is adjusted to the pressure set in the recipe 1D by the pressure regulator 62. With the start of this pressure control, the CPU 11 records the pressure value from the pressure gauge 5 in the RAM 12 at predetermined time intervals according to the time of the timer 16.
The flow rate adjusting unit 45 supplies the etching gas and the additive gas to the processing container 20 from the first gas supply unit 46 and the second gas supply unit 47, respectively. Here, the CPU 11 records the gas type, gas flow rate, and gas mixture ratio set in the recipe 1D in the RAM 12 at predetermined time intervals according to the time of the timer 16.

  The etching gas and the additive gas are sufficiently mixed in the gas supply path 44 and the diffusion space 412, and discharged to the processing space inside the processing container 20 through the vent hole 421. At this time, high frequency power is supplied from the high frequency power supply unit 43 to the upper electrode 42. Plasma is formed in the processing space above the substrate S, and the thin film on the substrate S is etched. Here, the CPU 11 records the high-frequency power set in the recipe 1D in the RAM 12 at predetermined time intervals according to the time of the timer 16. Further, the CPU 11 records the temperature of the upper electrode 42 detected by the thermometer 422 in the RAM 12 at a predetermined time interval according to the time of the timer 16.

The gas converted into plasma flows along the thin film surface on the substrate S to the peripheral side, and is exhausted from the exhaust path 61 to the outside of the processing container 20. When the etching process based on the recipe 1D is completed, the supply of high-frequency power to the upper electrode 42 is stopped. The pressure in the processing container 20 is returned to the original state. The transfer means carries the substrate S from the mounting table 3 to the outside of the processing container 20 in the reverse order to the loading of the substrate S, and the series of etching processes is completed.
The CPU 11 stops recording in the RAM 12 regarding the pressure, gas type, gas flow rate, gas mixture ratio, high frequency power and temperature, and records the time profile of the control parameters of these etching processes recorded in the RAM 12 in the hard disk 13. .

The next substrate S is carried into the processing container 20 and the etching process is performed again. The etching process performed one after another may be repeated under the same conditions, or may be repeated under different conditions each time. This etching condition is based on a device production plan and may be different for each factory and each etching apparatus 2.
As described above, the CPU 11 additionally records the time profile of the control parameter in the profile file 1F of the hard disk 13 for each etching process. Thus, the time profile of the control parameter is accumulated in the hard disk 13 from the start of the operation of the etching apparatus 20.

  FIG. 3 is an explanatory diagram schematically showing an example of a high-frequency power profile. The horizontal axis in FIG. 3 represents time, and the vertical axis represents high-frequency power supplied to the upper electrode 42. The time profile of the high frequency power supplied to the upper electrode 42 is different for each etching process, and shows a different shape and size on the graph of FIG.

  FIG. 4 is an explanatory diagram schematically showing an example of a pressure profile. The horizontal axis in FIG. 4 indicates time, and the vertical axis indicates the pressure (degree of vacuum) in the processing container 20. The pressure in the processing container 20 is different for each etching process, and shows different shapes and sizes on the graph of FIG.

  Several control parameters for etching a thin film on the substrate S are known. Among the control parameters, there is a parameter corresponding to the etching rate of the upper electrode 42. The parameters corresponding to the etching rate of the upper electrode 42 include, for example, high-frequency power supplied to the upper electrode 42, pressure (gas pressure) in the processing container 20, and gas composition (mixing ratio).

  The electron density and ion density related to the etching rate increase almost in proportion to the high frequency power. Since the radical generation rate is proportional to the electron density, the radical density also increases in proportion to the high frequency power. Then, it is considered that the consumption of the upper electrode 42 is proportional to the time integral value of the high frequency power. However, the radical density may not increase due to various secondary reactions occurring in the gas phase.

When the high frequency power is constant, the plasma density tends to increase when the pressure is increased. However, if the pressure is increased too much, the plasma density will decrease. Moreover, when the pressure is lowered too much, the plasma density is lowered.
When the pressure is too high, ion-molecule collision occurs in the sheath, and the ion energy is reduced, so that the etching rate is reduced. On the other hand, when etching Si, since the chemical reaction is the main, the etching rate greatly depends on the radical concentration, and increases as the pressure increases.
The pressure is usually set to a different value between isotropic etching and anisotropic etching, and a different value is also set depending on the material to be processed.

  As the etching gas, a gas containing a halogen element is often used in order to generate a highly volatile product by reacting with the material to be etched. A specific etching gas is selected in consideration of a difference between isotropic etching and anisotropic etching, a difference in materials to be etched, and the like. When the composition (type and mixing ratio) of the etching gas is different, the influence on the consumption of the upper electrode 42 is also different.

  Since the etching proceeds with time, the integrated value obtained by integrating the value of the control parameter of the etching process with the cycle time required for the etching process correlates with the degree of consumption of the upper electrode 42. The integrated value here is, for example, the sum of areas in the etching processing time indicated by the graphs of FIGS. In FIG. 4, the area sum that is not the etching processing time (the time during which pressure is reduced) is excluded from the integrated value.

  FIG. 5 is an explanatory diagram showing an example of a record layout of the determination table 1T. The determination table includes columns of ID, gas composition, electric energy (power integrated value), and pressure integrated value. The ID is an identification symbol that identifies a record of the determination table 1T. The gas composition is the kind of etching gas and its mixing ratio. The electric energy is a time integral value of the high-frequency power supplied to the upper electrode 42, and its unit is Ws. That is, the amount of power is electrical energy. The pressure integrated value is a time integrated value of pressure, and its unit is Pa · s.

The determination table 1T of FIG. 5 is created by performing etching on the upper electrode 42 and the thin film on the substrate S in advance by changing the control parameters of the etching process and evaluating the thin film after etching. The method for evaluating the thin film is not particularly limited, and a stylus profilometer, ellipsometry, FTIR (Fourier Transform Infrared Spectroscopy), Raman scattering, or the like may be used. Based on the evaluation result of the thin film, the degree of wear of the upper electrode 42 is also evaluated.
For example, the record with ID = 0001 indicates that when the gas composition is CF ₄ (70%) + C ₃ F ₈ (30%) and the electric energy is 1 Ws, it is time to replace the upper electrode 42. Yes. For example, in the record with ID = 0005, when the gas composition is CF ₄ (70%) + C ₃ F ₈ (30%), when the electric energy is 5 Ws and the integrated pressure value is 6 Pa · s, the upper electrode 42 indicates that it is time for replacement.

  Note that the determination table 1T of FIG. 5 may be created based on the degree of wear of the upper electrode 42. The degree of wear of the upper electrode 42 is set by measuring the thinning, warping or distortion of the upper electrode 42 with the naked eye or by a meter. On the other hand, the time integral value of the control parameter of the etching process is separately calculated, and the electric energy or the pressure integrated value corresponding to the degree of consumption that requires replacement of the upper electrode 42 is recorded in the determination table 1T for each gas composition.

  The CPU 11 adds the time profile of the monitored control parameter to the profile file 1F recorded on the hard disk 13 when the etching process on the thin film on one substrate S is completed. The CPU 11 integrates each control parameter recorded in the profile file 1F with time, and refers to the determination table 1T to determine the replacement time of the upper electrode 42. At that time, the replacement time of the upper electrode 42 may be determined based on one control parameter, or the replacement time of the upper electrode 42 may be determined based on a plurality of combined control parameters. .

  FIG. 6 is a flowchart illustrating an example of the procedure of the replacement timing determination process for the upper electrode 42. CPU11 determines whether the etching process by the etching apparatus 2 was complete | finished (step S101). If the CPU 11 determines that the etching process by the etching apparatus 2 has not been completed (step S101: NO), the process returns to step S101.

  When the CPU 11 determines that the etching process by the etching apparatus 2 has been completed (step S101: YES), the CPU 11 adds the time profile of the control parameter related to the latest etching process to the profile file 1F (step S102). The CPU 11 reads the profile file 1F from the hard disk 13 to the RAM 12 (step S103). Based on the profile file 1F, the CPU 11 performs time integration on the high-frequency power and pressure or the high-frequency power or pressure for each gas composition (step S104). In step S <b> 104, the CPU 11 acquires the electric energy and pressure integrated value, or the electric energy or pressure integrated value for each gas composition.

  The CPU 11 searches the determination table 1T for a record of the acquired power amount and pressure integrated value for each gas composition (step S105). Here, the CPU 11 uses records such as ID = 0001 and 0002 in FIG. When the CPU 11 searches for the electric energy and the pressure integrated value, for example, a record such as ID = 0005, 0006 in FIG. 5 is used.

  The CPU 11 determines whether the search is successful (step S106). CPU11 complete | finishes a process, when it determines with the search not having succeeded (step S106: NO). If the CPU 11 determines that the search is successful (step S106: YES), the CPU 11 displays a notification for urging the replacement of the upper electrode 42 on the display unit 17 (step S107), and ends the process.

Note that when the etching apparatus 2 is continuously operated for a longer time than the replacement period of the upper electrode 42, Step S102 and Step S103 are not necessary. In such a case, when the CPU 11 determines that the etching process by the etching apparatus 2 has ended (step S101: YES), the CPU 11 executes step S104 based on the time profile of the control parameter stored in the RAM 12.
Alternatively, when the etching apparatus 2 is continuously operated for a longer time than the replacement period of the upper electrode 42, Step S102, Step S103, and Step S104 may not be performed. In such a case, the CPU 11 does not record the time profile of the control parameter in the RAM 12. The CPU 11 repeats the control parameter integration process every predetermined time counted by the timer 16. When the CPU 11 determines that the etching process by the etching apparatus 2 has been completed (step S101: YES), the CPU 11 executes step S105 based on the integrated values of the control parameters that are sequentially integrated.

In step S106, the CPU 11 may determine whether or not the acquired power amount and pressure integrated value are within a predetermined range from the power amount and pressure integrated value recorded in the determination table 1T. For example, when the acquired power amount is within a range of 95% or more and 105% or less of the power amount of the determination table, the CPU 11 determines that the search is successful, and the acquired power amount is the power amount of the determination table 1T. If it is smaller than 95% and larger than 105%, it may be determined that the search is not successful.
In step S <b> 107, the CPU 11 may output a sound prompting replacement of the upper electrode 42 from a speaker built in the display unit 17.

  The electric energy or the pressure integrated value recorded in the determination table 1T may be used as a threshold to be compared with the time integrated value. For example, in step S105, the CPU 11 reads the electric energy and the pressure integrated value from the determination table 1T, and sets the read electric energy and pressure integrated value as a threshold value. Next, in step S <b> 106, the CPU 11 determines whether or not to replace the upper electrode 42 by comparing the time integral value related to the high-frequency power or pressure with the threshold value acquired from the determination table 1 </ b> T. If the CPU 11 determines to replace the upper electrode 42, the process proceeds to step S107. If the CPU 11 determines not to replace the upper electrode 42, the process ends. When the CPU 11 determines to replace the upper electrode 42, the time integral value may be larger or smaller than the threshold value. The replacement standard for the upper electrode 42 is set in advance in the program 1 for each control parameter of the etching process or for each combination of the control parameters of the etching process.

According to the replacement time determination device 1, it is possible to determine the time to replace the electrode of the etching device 2.
Conventionally, the electrodes of the etching apparatus 2 are replaced after the degree of wear is determined from the number of processed substrates S, the number of processing times, the accumulated processing time, and the like. However, the etching conditions are usually changed in accordance with the recipe 1D for each etching process, and even when the standard limit value relating to the number of processed substrates S, the number of processes, the accumulated processing time, etc. is exceeded. The upper electrode 42 may still be available. Even if the standard limit value is not exceeded, the upper electrode 42 may be consumed to the extent that it should be replaced.
The replacement time determination device 1 obtains the integrated value of the time profile for the control parameter of the etching process. The replacement time determination device 1 refers to the determination table 1T in which an integrated value corresponding to the degree of wear that requires replacement is recorded in advance, and determines whether or not the upper electrode 42 should be replaced from the calculated integrated value. The replacement time determination device 1 can reduce the cost and improve the yield by determining the replacement time of the upper electrode 42 based on the time profile of the control parameter depending on the usage environment of the etching device 2.

  The gas flow rate may be added to the parameter for determining the replacement time of the upper electrode 42. The etching rate increases as the gas flow rate of the etching gas increases. However, if the etching gas is too much, it is considered that the pressure increases, the plasma density decreases, and consequently the etching rate decreases. Therefore, the CPU 11 records the time profile of the gas flow rate in the profile file 1F when the etching process is completed. The CPU 11 calculates an integrated value obtained by integrating the gas flow rate over time. In the determination table 1T, the integrated value of the gas flow rate corresponding to the replacement timing of the upper electrode 42 is recorded in advance for each gas composition. Further, the integrated value of the gas flow rate combined with the electric energy or the integrated pressure value is also recorded in the determination table 1T. The replacement time determination device 1 refers to the determination table 1T and determines whether or not the upper electrode 42 should be replaced from the calculated integrated value of the gas flow rate or the integrated value related to other control parameters and the gas flow rate.

  The temperature of the upper electrode 42 may be added to the parameter for determining the replacement time of the upper electrode 42. For example, the higher the temperature, the faster the reaction rate between the radical and the material substance of the upper electrode 42. Therefore, the CPU 11 records the time profile of the temperature of the upper electrode 42 detected by the thermometer 422 in the profile file 1F when the etching process is completed. The CPU 11 calculates an integrated value obtained by integrating the temperature over time. In the determination table 1T, the integrated value of the temperature corresponding to the replacement timing of the upper electrode 42 is recorded in advance for each gas composition. Furthermore, the integrated value of the temperature combined with the electric energy or the integrated pressure value is also recorded in the determination table 1T. The replacement time determination device 1 refers to the determination table 1T and determines whether or not the upper electrode 42 should be replaced from the calculated integrated value of temperature or an integrated value related to other control parameters and temperature.

The etching apparatus 2 is not limited to a single wafer type that processes the substrates S one by one, but may be a batch type that processes a plurality of substrates S at a time.
The electrode structure of the etching apparatus 2 is a face down deposition in which the upper electrode 42 and the lower electrode are horizontally arranged and the substrate S is placed on the lower electrode. However, the electrode structure of the etching apparatus 2 may be a deposit up (face up deposition) in which the upper electrode 42 and the lower electrode are horizontally arranged and the substrate S is installed on the upper electrode 42. In the case of deposition up, the thin film formed on the lower surface of the substrate S is etched. In the case of deposition up, the electrode to be determined for determining the replacement time is the lower electrode. That is, the determination target electrode for determining the replacement time is not limited to the upper electrode, and may be the lower electrode.
The electrode structure of the etching apparatus 2 may be IVE (Interdigital Vertidal Electrodes). The IVE has a structure in which a plurality of electrodes are vertically arranged in a comb shape. In the case of IVE, the electrode to be determined for determining the replacement time is a side electrode. That is, the electrode to be determined for determining the replacement time is not limited to the upper or lower electrode, and may be a side electrode.

Embodiment 2
The second embodiment relates to a mode in which the replacement timing of the upper electrode 42 is determined in consideration of the change in the gas composition related to the etching process.
The gas composition of the etching process performed by the etching apparatus 2 may differ for every etching process. In such a case, since the reactivity of the upper electrode 42 with respect to the material substance varies depending on the difference in gas composition, the degree of consumption of the upper electrode 42 changes. Therefore, the degree of contribution that the control parameter contributes to the consumption of the upper electrode 42 is set for each etching process. For example, the contribution of the control parameter to the consumption of the upper electrode 42 in the etching process with a certain gas composition is 0.3, and the contribution of the control parameter to the consumption of the upper electrode 42 in the etching process with another gas composition is 0.1. And so on. The replacement time determination device 1 adds the contributions of all etching processes, and determines the replacement time of the upper electrode 42 based on the added contributions.

  The CPU 11 adds the time profile of the monitored control parameter to the profile file 1F recorded on the hard disk 13 when the etching process on the thin film on one substrate S is completed. The CPU 11 integrates each control parameter recorded in the profile file 1F with the etching processing time, and calculates a contribution for determining the replacement timing of the upper electrode 42 for each control parameter with reference to the determination table 1T. To do. The CPU 11 adds the calculated contributions and determines the replacement time of the upper electrode 42.

FIG. 7 is a flowchart illustrating an example of the procedure of the replacement timing determination process for the upper electrode 42. In the following processing, it is assumed that time profiles of high frequency power and pressure are recorded in the profile file 1F.
CPU11 determines whether the etching process by the etching apparatus 2 was complete | finished (step S201). If the CPU 11 determines that the etching process by the etching apparatus 2 has not been completed (step S201: NO), the process returns to step S201.

  When the CPU 11 determines that the etching process by the etching apparatus 2 has been completed (step S201: YES), the CPU 11 adds the time profile of the control parameter related to the latest etching process to the profile file 1F (step S202). The CPU 11 reads the profile file 1F from the hard disk 13 to the RAM 12 (step S203). Based on the profile file 1F, the CPU 11 performs time integration of the high-frequency power and pressure for one etching process (step S204). In step S204, the CPU 11 acquires the electric energy and the integrated pressure value for one etching process.

The CPU 11 calculates a contribution for determining the replacement time of the upper electrode 42 (S205). Hereinafter, a method for calculating the contribution in step S205 will be described. In step S204, the electric energy and pressure integrated value acquired for an etching process are x1 (Ws) and y1 (Pa · s), respectively, and the gas composition of the etching process is CF ₄ (70%) + C ₃ F _8. (30%). The CPU 11 searches the determination table 1T for a record in which the gas composition is CF ₄ (70%) + C ₃ F ₈ (30%) and the electric energy and the integrated pressure value are recorded. Here, it is assumed that the CPU 11 has retrieved the record with ID = 0005 in FIG.

  The CPU 11 uses the power amount value 5 (Ws) and the pressure integrated value value 6 (Pa · s) corresponding to ID0005 in FIG. 5, and the power amount x1 (Ws) and the pressure integrated value y1 (Pa · s). The contribution is the sum of the normalized values of. That is, (x1 / value 5) + (y1 / value 6) is set as the contribution.

In step S204, the electric energy and pressure integrated values acquired for another etching process are x2 (Ws) and y2 (Pa · s), respectively, and the gas composition of the etching process is Ar (90%) + C ₄ F _8. (10%). The CPU 11 searches the determination table 1T for a record in which the gas composition is Ar (90%) + C ₄ F ₈ (10%) and the electric energy and the integrated pressure value are recorded. Here, it is assumed that the CPU 11 has retrieved the record with ID = 0006 in FIG.

  The CPU 11 uses the electric energy value 7 (Ws) and the integrated pressure value 8 (Pa · s) corresponding to ID 0006 in FIG. 5, and the acquired electric energy x2 (Ws) and integrated pressure value y2 for another etching process. The sum of values obtained by normalizing (Pa · s) is defined as the contribution. That is, (x2 / value 7) + (y2 / value 8) is set as the contribution.

  The CPU 11 determines whether or not the contribution has been calculated for the time profile of the control parameters related to the entire etching process recorded in the pattern file 1F (step S206). If the CPU 11 determines that the contribution has not been calculated for the time profile of the control parameter related to the entire etching process recorded in the pattern file 1F (step S206: NO), the process returns to step S204. CPU11 which returned to step S204 performs step S204 and step S205 about another etching process.

When the CPU 11 determines that the contribution has been calculated for the time profile of the control parameters related to the entire etching process recorded in the pattern file 1F (step S206: YES), the CPU 11 determines whether the sum of contributions is 1 (step S206). S207). That is, in the above example, the CPU 11
(X1 / value 5) + (y1 / value 6)
+ (X2 / value 7) + (y2 / value 8)
+ ...
Is determined to be 1.

CPU11 complete | finishes a process, when it determines with the sum of contributions not being 1 (step S207: NO). When the CPU 11 determines that the sum of contributions is 1 (step S207: YES), the CPU 11 displays a notification for urging replacement of the upper electrode 42 on the display unit 17 (step S208), and ends the process.
In step S207, the CPU 11 may determine whether the sum of contributions is within a predetermined range from 1. For example, when the sum of contributions is 0.95 or more and 1.05 or less, the CPU 11 determines that the sum of contributions is 1, and the sum of contributions is less than 0.95 and greater than 1.05. In this case, it may be determined that the sum of contributions is not 1.

  According to the replacement time determination device 1, even when a plurality of types of etching processes with different gas compositions are performed a plurality of times before the upper portion is replaced, the time for replacing the electrode of the etching device 2 is determined. be able to.

  The CPU 11 may read the program 1P or the determination table 1T from the optical disk 1a, magnetic tape, magnetic disk, magneto-optical disk, or the like via the disk drive 14. Further, a semiconductor memory 1c such as a flash memory in which the program 1P or the determination table 1T is recorded, a magnetic tape, a magnetic disk, a magneto-optical disk, or the like may be mounted in the replacement time determination apparatus 1. Furthermore, the CPU 11 can also download the program 1P or the determination table 1T from an external information processing device or recording device (not shown) via the communication unit 15.

  The second embodiment is as described above, and the other parts are the same as those of the first embodiment. Accordingly, the corresponding parts are denoted by the same reference numerals, and detailed description thereof is omitted.

DESCRIPTION OF SYMBOLS 1 Replacement time determination apparatus 11 CPU (integration means, determination means)
12 RAM
13 Hard disk (recording means)
16 timer 2 etching apparatus 20 processing container 22 loading / unloading port 23 gate valve 3 mounting table 31 focus ring 32 lifting pin 33 lifting mechanism 34 bellows 4 gas supply mechanism 40 shower head 41 upper electrode base 412 diffusion space 42 upper electrode 421 vent hole 411 insulation Member 43 High-frequency power supply unit 44, 441, 442 Gas supply path 45 Flow rate adjusting unit 46 First gas supply unit 47 Second gas supply unit 5 Pressure gauge 6 Exhaust mechanism 61 Exhaust path 62 Pressure controller 63 Exhaust device S Non-processed substrate 1P Program 1D Recipe 1F Profile file 1T Judgment table

Claims (6)

Replacement time for determining the replacement time of the electrode constituting the plasma processing apparatus for supplying high-frequency power to the electrode and plasma-treating the thin film on the substrate in the processing container by plasma generated from the gas introduced into the processing container In the judgment device,
Integrating means for integrating values related to processing conditions for plasma processing the thin film;
Recording means in which the integrated value corresponding to the electrode replacement time and the electrode replacement time with respect to the value relating to the processing conditions of the plasma processing is recorded,
A replacement time determination device comprising: determination means for determining the replacement time of the electrode based on the integrated value integrated by the integration means and the integrated value recorded in the recording means. The replacement time determination device according to claim 1, wherein the processing conditions of the plasma processing include high-frequency power supplied to the electrode, pressure in the processing container, gas type, or gas flow rate. The integrating means integrates the values related to the processing conditions of the plasma processing according to the composition of the gas introduced into the processing container,
3. The integrated value corresponding to the electrode replacement time and the electrode replacement time is recorded according to the composition of the gas introduced into the processing vessel with respect to the value related to the processing conditions of the plasma processing. The replacement time determination device described. The replacement time determination apparatus according to any one of claims 1 to 3, wherein the plasma processing includes an etching process for a thin film on the substrate. In a replacement time determination method for determining a replacement time of an electrode constituting a plasma processing apparatus for plasma processing a thin film on a substrate,
Accumulating values related to processing conditions for plasma treatment of the thin film,
The replacement time determination method, wherein the electrode replacement time is determined based on the integrated value corresponding to the electrode replacement time recorded in the recording means with respect to the integrated integrated value and the value related to the plasma processing conditions. . In a plasma processing system comprising: a plasma processing apparatus for plasma processing a thin film on a substrate; and a replacement time determination device for determining a replacement time of an electrode constituting the plasma processing apparatus,
The replacement time determination device is:
Integrating means for integrating values related to processing conditions for plasma processing the thin film;
Recording means in which the integrated value corresponding to the electrode replacement time and the electrode replacement time with respect to the value relating to the processing conditions of the plasma processing is recorded,
A plasma processing system comprising: a determination unit that determines an exchange time of the electrode based on the integrated value integrated by the integrating unit and the integrated value recorded in the recording unit.

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