JP6956696B2 - Particle generation suppression method and vacuum device - Google Patents

Description

The present invention relates to a particle generation suppressing method and a vacuum apparatus.

It is known that the amount of particles generated in the vacuum device correlates with the amount of water in the vacuum device. Therefore, in order to reduce the generation of particles during the process, the vacuum processing chamber is depressurized, an inert gas is introduced into the vacuum processing chamber, and then the vacuum processing chamber is depressurized again. A technique for reducing the amount of water in a vacuum has been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2008-305953

The present disclosure provides a technique for suppressing the generation of particles generated in a vacuum apparatus.

In order to solve the above problem, according to one aspect, it is a method of suppressing particle generation of a vacuum device having an alumite-treated component, in which the inside of the vacuum device is exhausted to reduce the pressure, and the pressure in the vacuum device is reduced. an exhaust step a of evacuating to 1.3 × ¹⁰ -1 Pa (1mTorr) below, after the evacuation step a, a boosting step which boosts the in the vacuum device to atmospheric pressure, after the boosting step, wherein Provided is a particle generation suppressing method comprising a moisture adhering step of adhering moisture to an alumite-treated component and an exhaust step B of exhausting the inside of the vacuum apparatus after the moisture adhering step.

According to one aspect, the generation of particles can be suppressed.

The figure which shows an example of the whole structure of the semiconductor manufacturing apparatus which concerns on one Embodiment. The cross-sectional view which shows an example of the structure of the substrate processing chamber which concerns on one Embodiment. The cross-sectional view which shows an example of the structure of the transport chamber which concerns on one Embodiment. The flowchart which shows an example of the particle generation suppression processing which concerns on one Embodiment. The figure which shows the relationship between the exhaust time and the change of an ion current which concerns on one Embodiment. The figure which shows the transition of the number of particles generated in the vacuum container which concerns on one Embodiment. The figure which shows the estimation model of the particle which concerns on one Embodiment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the present specification and the drawings, substantially the same configuration is designated by the same reference numerals to omit duplicate explanations.

[Introduction]
According to an experiment conducted by the present inventor, in a vacuum apparatus having an alumite-treated component (hereinafter, also referred to as "anodized component"), the generation of particles is suppressed by simply repeating depressurization and introduction of an inert gas. I got the finding that I can't. We also found that this is particularly noticeable in newly shipped vacuum equipment. Therefore, the present disclosure provides a technique for suppressing the generation of particles generated in the vacuum apparatus in consideration of the above findings.

[Overall configuration of semiconductor manufacturing equipment]
First, an example of the configuration of the vertical cross section of the semiconductor manufacturing apparatus 10 according to the embodiment of the present invention will be described with reference to FIG. The semiconductor manufacturing apparatus 10 shown in FIG. 1 is an apparatus having a cluster structure (multi-chamber type), and the transfer chamber VTM and the substrate processing chamber PM are examples of vacuum apparatus.

The semiconductor manufacturing apparatus 10 of FIG. 1 includes a substrate processing chamber PM (Process Module) 1 to PM6, a transfer chamber VTM (Vacuum Transfer Module), a load lock chamber LLM (Load Lock Module) 1, LLM2, and a loader module LM (Loader Module). It also has load ports LP (Load Port) 1 to LP3.

The semiconductor manufacturing apparatus 10 is controlled by the control unit 100, and performs a predetermined process on a semiconductor wafer W (hereinafter, also referred to as “wafer W”), which is an example of a substrate.

The substrate processing chambers PM1 to PM6 are arranged adjacent to the transport chamber VTM. The substrate processing chambers PM1 to PM6 are also collectively referred to as the substrate processing chamber PM. The substrate processing chambers PM1 to PM6 and the transport chamber VTM communicate with each other by opening and closing the gate valve GV. The substrate processing chambers PM1 to PM6 are depressurized to a predetermined vacuum atmosphere, and inside the wafer W, the wafer W is subjected to processing such as etching treatment, film formation treatment, cleaning treatment, and ashing treatment.

Inside the transfer chamber VTM, a transfer device VA for transporting the wafer W is arranged. The transport device VA has two robot arms AC and AD that are flexible and rotatable. Picks C and D are attached to the tips of the robot arms AC and AD, respectively. The transfer device VA can hold the wafer W in each of the picks C and D, and carries in and out the wafer W between the substrate processing chambers PM1 to PM6 and the transfer chamber VTM according to the opening and closing of the gate valve GV. .. Further, the transfer device VA carries in and out the wafer W between the transfer chamber VTM and the load lock chambers LLM1 and LLM2 according to the opening and closing of the gate valve GV.

The load lock chambers LLM1 and LLM2 are provided between the transport chamber VTM and the loader module LM. The load lock chambers LLM1 and LLM2 switch between an atmospheric atmosphere and a vacuum atmosphere to transport the wafer W from the loader module LM on the atmospheric side to the transport chamber VTM on the vacuum side, or from the transport chamber VTM on the vacuum side to the loader on the atmospheric side. Transport to module LM.

The loader module LM is provided with load ports LP1 to LP3. For example, a FOUP (Front Opening Unified Pod) containing 25 wafers W or an empty FOUP is placed on the load ports LP1 to LP3. The loader module LM carries the wafer W carried out from the FOUP in the load ports LP1 to LP3 into either the load lock chamber LLM1 or LLM2, and the wafer W carried out from either the load lock chamber LLM1 or LLM2 is FOUP. Carry in to.

The control unit 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, and an HDD (Hard Disk Drive) 104. The control unit 100 is not limited to the HDD 104, and may have another storage area such as an SSD (Solid State Drive). In the storage area of the HDD 104, the RAM 103, etc., a recipe in which the process procedure, the process condition, the transport condition, and the like are set is stored.

The CPU 101 controls the processing of the wafer W in the substrate processing chamber PM according to the recipe, and controls the transfer of the wafer W. Further, the CPU 101 controls process processing such as gas introduction and exhaust control according to the present embodiment, particle measurement, and the like. The HDD 104 or the RAM 103 may store, for example, a program for executing a substrate transfer process, a cleaning process, an exhaust control process, or the like. These programs may be stored in a storage medium and provided, or may be provided from an external device via a network.

The number of the substrate processing chamber PM, the load lock chamber LLM, and the load port LP is not limited to the number shown in this embodiment, and may be one or more.

[Structure of substrate processing room]
Next, an example of the configuration of the substrate processing chamber PM according to the embodiment of the present invention will be described with reference to FIG. Here, the substrate processing chamber PM is an apparatus that generates plasma in the vacuum vessel 11 and performs plasma processing such as etching processing on the wafer W by the action of the plasma.

The substrate processing chamber PM has a tubular vacuum container 11 whose inside can be sealed. The vacuum vessel 11 is connected to the ground potential. The vacuum vessel 11 may be made of aluminum and its surface may be anodized. Anodized parts having alumite-processed members or parts are used for a part of the substrate processing chamber PM and each component inside. The alumite component is a component that has been anodized on the surface of aluminum to form a film of _{aluminum oxide (Al 2} O _{3) on the surface of the member.} For example, an aluminum exhaust plate 14 or the like that has been anodized is given as an example of anodized parts. The vacuum vessel 11 is also an example of an alumite component when the inner wall of aluminum is anodized.

Further, the vacuum container 11 communicates with the transfer chamber VTM by opening and closing the gate valve GV. Inside the vacuum vessel 11, a mounting table 12 made of a conductive material such as aluminum is provided. The mounting table 12 is a columnar table on which the wafer W is placed, and also serves as a lower electrode. An exhaust passage 13 is formed between the side wall of the vacuum container 11 and the side surface of the mounting table 12 as a path for discharging the gas above the mounting table 12 to the outside of the vacuum container 11. An exhaust plate 14 is arranged in the middle of the exhaust passage 13. The exhaust plate 14 is a plate-shaped member having a large number of holes, and functions as a partition plate for partitioning the vacuum container 11 into an upper portion and a lower portion. The upper part of the vacuum vessel 11 partitioned by the exhaust plate 14 is a reaction chamber 17 in which plasma treatment is executed.

Further, an exhaust pipe 15 for discharging the gas in the vacuum container 11 is connected to the exhaust chamber (manifold) 18 below the vacuum container 11. An automatic pressure control (APC: Adaptive Pressure Control) valve 16 is connected to the exhaust pipe 15. The exhaust plate 14 captures or reflects the plasma generated in the reaction chamber 17 to prevent leakage to the exhaust chamber 18. A turbo molecular pump (TPP: Turbo Molecular Pump) 40 and a dry pump (DP: Dry Pump) 41 are connected to the exhaust pipe 15 via an APC valve 16, and these exhaust devices exhaust the inside of the vacuum vessel 11. And reduce the pressure.

Specifically, the dry pump 41 depressurizes the inside of the vacuum vessel 11 from atmospheric pressure to a medium vacuum state (for example, 1.3 × 10 Pa (0.1 Torr) or less). At that time, the valve 43 provided in the pipe (bypass route) connecting the dry pump 41 and the vacuum vessel 11 is opened, and the valve 42 provided in the pipe connecting the TMP 40 and the dry pump 41 is closed.

The TMP 40 cooperates with the dry pump 41 to create a high vacuum state (for example, 1.3 × 10 ^-3 Pa (1.0 × 10 ^-5 Torr) or less) in which the pressure inside the vacuum vessel 11 is lower than the medium vacuum state. ). At that time, the valve 43 is closed and the valve 42 is opened.

The first high-frequency power supply 19 is connected to the mounting table 12 via the matching unit 20, and supplies high-frequency power for biasing, for example, 400 kHz to 13.56 MHz to the mounting table 12. The matching device 20 suppresses reflection of high-frequency power from the mounting table 12 and maximizes the efficiency of supplying high-frequency power for bias to the mounting table 12.

An electrostatic chuck 22 having an electrostatic electrode plate 21 inside is arranged on the upper part of the mounting table 12. The electrostatic chuck 22 has a shape in which an upper disk-shaped member having a diameter smaller than that of the lower disk-shaped member is superposed on the lower disk-shaped member. The electrostatic chuck 22 is made of aluminum, and ceramic or the like is sprayed on the upper surface. When the wafer W is placed on the mounting table 12, the wafer W is placed on the upper disk-shaped member of the electrostatic chuck 22.

A DC power supply 23 is connected to the electrostatic electrode plate 21. When a positive DC voltage is applied to the electrostatic electrode plate 21, a negative potential is generated on the back surface of the wafer W (the surface on the electrostatic chuck 22 side), and a potential difference is generated between the electrostatic electrode plate 21 and the back surface of the wafer W. Occurs. The wafer W is electrostatically attracted and held on the upper disk-shaped member of the electrostatic chuck 22 by the Coulomb force caused by this potential difference.

Further, an annular focus ring 24 is placed on the electrostatic chuck 22 so as to surround the peripheral edge of the wafer W. The focus ring 24 is made of a conductive member, for example, silicon, and in the reaction chamber 17, the plasma is converged toward the surface of the wafer W to improve the efficiency of the etching process.

Further, inside the mounting table 12, for example, an annular refrigerant chamber 25 extending in the circumferential direction is provided. A low-temperature refrigerant such as cooling water or Galden (registered trademark) is circulated and supplied from the chiller unit to the refrigerant chamber 25 via the refrigerant pipe 26. The mounting table 12 cooled by the low-temperature refrigerant cools the wafer W and the focus ring 24 via the electrostatic chuck 22.

A plurality of heat transfer gas supply holes 27 are opened on the surface (adsorption surface) on the upper disk-shaped member of the electrostatic chuck 22 on which the wafer W is adsorbed. Heat transfer gas such as helium (He) gas is supplied to the plurality of heat transfer gas supply holes 27 via the heat transfer gas supply line 28. The heat transfer gas is supplied to the gap between the suction surface of the electrostatic chuck 22 and the back surface of the wafer W via the heat transfer gas supply hole 27. The heat transfer gas supplied to the gap transfers the heat of the wafer W to the electrostatic chuck 22.

A shower head 29 is arranged on the ceiling of the vacuum container 11 so as to face the mounting table 12. The second high-frequency power supply 31 is connected to the shower head 29 via the matching device 30, and supplies high-frequency power for plasma excitation of, for example, about 40 MHz to the shower head 29. That is, the shower head 29 functions as an upper electrode. The matching device 30 suppresses reflection of high-frequency power from the shower head 29 and maximizes the efficiency of supplying high-frequency power for plasma excitation to the mounting table 12.

The shower head 29 has a ceiling electrode plate 33 having a large number of gas holes 32, a cooling plate 34 for detachably supporting the ceiling electrode plate 33, and a lid 35 for covering the cooling plate 34. A buffer chamber 36 is provided inside the cooling plate 34, and a gas introduction pipe 37 is connected to the buffer chamber 36. The shower head 29 supplies the gas supplied from the gas introduction pipe 37 to the buffer chamber 36 into the reaction chamber 17 through a large number of gas holes 32.

A lid 38 that includes a shower head 29 and is removable from the vacuum container 11 is arranged above the vacuum container 11. A sealing member 39 such as an O-ring that seals the periphery is provided between the vacuum container 11 and the lid 38. If the lid 38 is separated from the vacuum container 11, the operator can directly touch the wall surface and the components of the vacuum container 11. As a result, the operator can clean the wall surface of the vacuum container 11 and the surface of the component parts, and can remove the deposits adhering to the wall surface of the vacuum container 11 and the like.

In the substrate processing chamber PM, the high frequency power for bias may or may not be applied. By applying at least high-frequency power for plasma generation into the reaction chamber 17, plasma is generated from the gas supplied from the shower head 29, and the wafer W is subjected to plasma treatment such as etching by the plasma.

The operation of each component of the substrate processing chamber PM may be controlled in cooperation with the control unit 100 and the control unit 200 that control the entire semiconductor manufacturing apparatus 10.

[Composition of transport room]
Next, an example of the configuration of the vertical cross section of the transport chamber VTM according to the embodiment of the present invention will be described with reference to FIG. Here, the transfer chamber VTM is an apparatus for transporting the wafer W between the substrate processing chambers PM1 to PM6 and the load lock chambers LLM1 and LLM2 using the transfer device VA.

The transport chamber VTM has a tubular vacuum container 51 whose inside can be sealed. The vacuum vessel 51 may be made of aluminum and its surface may be anodized. The vacuum vessel 51 communicates with the substrate processing chambers PM1 to PM6 by opening and closing the gate valve GV. Inside the vacuum container 51, a transfer device VA for transporting the wafer W is arranged. The transport device VA has two robot arms AC and AD that can bend and stretch and rotate, and picks C and D are attached to the tips of the robot arms AC and AD, respectively.

Anodized parts are used as a part of each component of the transport chamber VTM. For example, aluminum robot arms AC, AD, and the like of the transfer device VA are alumite parts. The vacuum vessel 51 is also an example of an alumite component when the inner wall of aluminum is anodized.

Further, an exhaust pipe 52 for discharging the gas in the vacuum container 51 is connected to the lower part of the vacuum container 51. A dry pump (DP) 53 is connected to the exhaust pipe 52, and the dry pump 53 exhausts the inside of the vacuum vessel 51 to reduce the pressure. Specifically, the dry pump 53 depressurizes the inside of the vacuum vessel 51 from atmospheric pressure to a medium vacuum state (for example, 1.3 × 10 Pa (0.1 Torr) or less).

On the side wall of the vacuum container 51, a dry gas supply line 54 for supplying dry gas to the inside of the vacuum container 51 and a valve 55 for opening and closing the dry gas supply line 54 are provided, and the dry gas is evacuated by opening and closing the valve 55. It can be supplied to the inside of the container 51. As the dry gas, a dry gas such as dry air or _{an inert gas such as nitrogen (N 2} ) gas or a rare gas can be used. Similarly, the vacuum vessel 11 may be provided with a dry gas supply line and a valve so that dry gas such as dry air can be supplied to the inside of the vacuum vessel 11.

Further, on the ceiling of the vacuum container 51, an aluminum surface is anodized, and a lid 57 for closing the opening 56 provided in the vacuum container 51 is arranged. Further, a sealing member 58 such as an O-ring that seals the periphery of the opening 56 is provided between the vacuum container 51 and the lid 57.

The lid 57 is removable from the vacuum container 51, and if the lid 57 is opened, the operator can directly touch the wall surface and the components of the vacuum container 51. As a result, the operator can clean the wall surface of the vacuum container 51 and the surface of the component parts, and can remove the deposits adhering to the wall surface of the vacuum container 51 and the like.

Further, inside the vacuum vessel 51, a quadrupole mass spectrometer (QMS: Quadrupole Mass Spectrometer) 59 is attached in order to monitor the amount of water in the vacuum vessel 51. The QMS 59 is an example of a mass spectrometer that separates and detects ions derived from a sample to be analyzed according to a mass-to-charge ratio by using a quadrupole mass filter.

This makes it possible to confirm the amount of molecules present in the space to be measured. Here, the QMS 59 outputs an ion current proportional to the amount of water in the detected vacuum vessel 51. Any device such as an infrared absorption / emission spectrometer or an ICP mass spectrometer may be used as long as the amount of water in the vacuum vessel 51 can be detected. Similarly, a QMS or the like may be attached to the vacuum container 11.

The operation of each component of the transfer chamber VTM may be controlled in cooperation with the control unit 100 and the control unit 300 that control the entire semiconductor manufacturing apparatus 10.

[Particle generation suppression method]
Next, the particle generation suppression method according to the present embodiment will be described with reference to FIG. FIG. 4 is a flowchart showing an example of the particle generation suppression process according to the present embodiment. In the present embodiment, the suppression of particle generation in the vacuum container 51 of the transport chamber VTM will be described, but the same applies to the suppression of particle generation in the vacuum container 11 of the substrate processing chamber PM. The particle generation suppression process according to the present embodiment is mainly executed by the control unit 100, but may be executed by the control unit 300 of the transport chamber VTM or in cooperation with the control unit 100.

First, the control unit 100 starts exhausting the vacuum vessel 51 of the transport chamber VTM installed in the clean room by the dry pump 53 (step S11), and changes the pressure in the vacuum vessel 51 from atmospheric pressure to medium vacuum (for example, 1). Reduce the pressure to about 3 x 10 Pa (0.1 Torr)).

Subsequently, the control unit 100 opens the gate valve GV between the transfer chamber VTM and the substrate processing chamber PM (step S12). Next, the control unit 100 exhausts the vacuum vessel 51 of the transport chamber VTM by the TMP 40 of the substrate processing chamber PM, and the pressure in the vacuum vessel 51 of the transport chamber VTM becomes 1.3 × 10 ^-1 Pa (1 mTorr) or less. (Step S13).

Here, the ^{reason why the value is} 1.3 × 10 -1 Pa (1 mTorr) or less is that the TMP40 of the substrate processing chamber PM is used for the transport chamber VTM in order to sufficiently remove the water contained in the alumite parts in the vacuum vessel 51. The degree of vacuum that can be reached by evacuating the inside of the vacuum vessel 51 is set as a degree of vacuum that cannot be reached only by the dry pump 53 of the transport chamber VTM.

Subsequently, the control unit 100 waits until the first set time elapses (step S14), and then closes the gate valve GV between the transfer chamber VTM and the substrate processing chamber PM (step S16). ). The first set time is the time when the dry gas is exhausted by the TMP 40 before being introduced into the vacuum vessel.

Next, the control unit 100 opens the valve 55 that opens and closes the dry gas supply line 54 to introduce the dry gas into the vacuum vessel 51 of the transport chamber VTM, and brings the inside of the vacuum vessel 51 of the transport chamber VTM to atmospheric pressure. (Step S17). As a result, the lid 57 can be opened. Therefore, next, the lid 57 of the transport chamber VTM is opened (step S18). When the lid 57 is opened, the inside of the vacuum vessel 51 is exposed to the atmosphere.

Subsequently, the lid 57 of the transport chamber VTM is closed (step S19). Next, the control unit 100 starts exhausting the transport chamber VTM by the dry pump 53 (step S20). Next, the control unit 100 carries the wafer W into the transport chamber VTM in a state where the transport chamber VTM is exhausted by the dry pump 53. The wafer W is left to stand (sitting) for a certain period of time while being held by the pick in the transfer chamber VTM, and then transferred to the FOUP (step S21). Subsequently, the control unit 100 opens the gate valve GV between the transfer chamber VTM and the substrate processing chamber PM (step S22).

Next, the control unit 100 exhausts the vacuum vessel 51 of the transport chamber VTM by the TMP 40 of the substrate processing chamber PM, and the pressure in the vacuum vessel 51 of the transport chamber VTM becomes 1.3 × 10 ^-1 Pa (1 mTorr) or less. (Step S23).

Subsequently, the control unit 100 waits until the second set time elapses (step S24), and then closes the gate valve GV between the transfer chamber VTM and the substrate processing chamber PM (step S25). ).

Next, the control unit 100 sits the wafer W in the transfer chamber VTM in a state where the transfer chamber VTM is exhausted by the dry pump 53, and then conveys the sitting wafer W to the FOUP (step S26). Subsequently, the FOUP is set in the particle measuring device, and the number of particles on the wafer W sitting in the transfer chamber VTM in steps S21 and S26 is measured (step S27). Next, it is determined whether the measured number of particles has fallen below the threshold value (step S28). The number of particles on the wafer W can be counted using a detector that detects scattered light by the particles.

When the measured number of particles falls below the threshold value, it is determined that the inside of the transport chamber VTM has been exhausted to the extent that the generation of particles can be suppressed, and this process is terminated. On the other hand, if the measured number of particles does not fall below the threshold value, the process returns to step S12, vacuuming in the transport chamber VTM is started again, and the processes after step S12 are performed. The processes of steps S12 to S28 are repeated until it is determined that the measured number of particles has fallen below the threshold value. The determination in step S28 may be performed by the operator based on the measurement result of the particle measuring instrument, or may be performed by the control unit 100.

As described above, in the particle generation suppressing method according to the present embodiment, the TMP40 is used to evacuate for the first set time, and the pressure in the vacuum vessel 51 of the transport chamber VTM is 1.3 × 10 ^-1 Pa (1 mTorr) or less. In the evacuation step of evacuating to, the moisture contained in the alumite component in the vacuum vessel 51 is sufficiently removed. After that, a pressure-boosting step is performed in which the drying gas is introduced into the vacuum vessel 51 to boost the pressure inside the vacuum vessel 51 to atmospheric pressure. Then, after the pressurizing step, the lid 57 of the vacuum vessel 51 is opened, and the exposure step of exposing the inside of the vacuum vessel 51 to the atmosphere is performed. As a result, it is possible to suppress the generation of particles from the alumite parts in the vacuum container 51 of the transport chamber VTM.

Further, in the particle generation suppressing method according to the present embodiment, after the exposure step, the number of particles is measured based on a predetermined condition, and it is determined whether or not the number of particles is below the threshold value. That is, the exhaust step, the boosting step, and the exposure step are repeated until the measured number of particles falls below the threshold value. As a result, the generation of particles in the vacuum vessel 51 can be reliably suppressed. However, sitting and the accompanying particle measurement do not necessarily have to be performed.

The predetermined conditions for measuring the number of particles in the vacuum vessel 51 after the exposure step based on the predetermined conditions include a condition for evacuation after the exposure step and a condition for measuring the number of particles in the vacuum vessel 51. As an example of the condition related to evacuation, the time of evacuation (second set time) and the like can be mentioned as an example, and as a condition related to the measurement of the number of particles, the time of sitting the wafer W in the vacuum container 51 and the like can be mentioned as an example. ..

Here, an example of the result of the particle generation suppression method according to the present embodiment will be described with reference to FIG. In the exhaust step, the inside of the vacuum vessel 51 was exhausted by the dry pump 53, and then exhausted by the TMP 40 for 72 hours. After that, in the pressurizing step, a dry gas was introduced into the vacuum vessel 51 to bring the inside of the vacuum vessel 51 to atmospheric pressure. After that, the lid 57 was opened and closed, the inside of the vacuum vessel 51 was exhausted by the dry pump 53, and then the amount of water in the vacuum vessel 51 was measured when exhausted by the TMP 40 for 110 hours. The exhaust time of the exhaust process shown in FIG. 5 is an example of the first set time. The exhaust time performed after opening the lid is an example of the second set time. The degree of decrease in the amount of water in the vacuum vessel 51 at this time is indirectly indicated by the ion current on the vertical axis of FIG.

In FIG. 5, it can be seen that the amount of water in the vacuum vessel 51 is continuously reduced by continuously evacuating the inside of the vacuum vessel 51 for 72 hours with the TMP 40. Therefore, the generation of particles from the alumite component can be suppressed by sufficiently removing the water content in the vacuum container 51 of the TM by the exhaust step and the boosting step.

The vacuuming (exhaust step) by the TMP40 of the substrate processing chamber PM is continued until the amount of decrease in the ion current becomes flat (that is, a state in which the decrease cannot be expected even if the decrease is continued). Particle measurement by sitting may be performed during the exhaust process, and the result may be used for judgment. Further, the first set time may be set in advance from these results. After that, a dry gas is introduced to increase the pressure to atmospheric pressure (pressurization step), and then the lid is opened (exposure step).

Although the amount of water (ion current amount) temporarily increases due to the opening of the lid, the amount of water (ion current amount) that had leveled off before the exposure process is further reduced due to the subsequent evacuation by the dry pump 53 and TMP40. You can see that it is doing.

After the exposure step described above, a third exhaust step of exhausting the inside of the vacuum container 51 by a dry pump 53 provided in the vacuum container 51 of the transfer chamber VTM is performed. Further, after the third exhaust step, the inside of the vacuum vessel 51 is opened by the opening step of opening the gate valve GV provided between the substrate processing chamber PM and the transfer chamber VTM and the TMP40 provided in the substrate processing chamber PM. A fourth exhaust step of exhausting is performed.

[Number of particles generated in the vacuum vessel]
Next, an example of the result of measuring the number of particles under the set predetermined conditions (evacuation condition, sitting time) before and after the exposure step will be described with reference to FIG. 5 and 6 are the results of separately executing the particle generation suppressing method according to the present embodiment.

Here, after the inside of the vacuum vessel 51 was evacuated by the dry pump 53, the number of particles generated in the vacuum vessel 51 was intermittently measured while the inside of the vacuum vessel 51 was evacuated by the TMP 40. The transition of the number of particles at this time is shown in FIG. The horizontal axis of FIG. 6 shows time, and the vertical axis shows the transition of the number of particles in logarithmic display. For example, the number of particles when exhausted by the dry pump DP, which is the first exhaust process, after 1 hour, 24 hours, 48 hours, and 96 hours have passed since the start of exhaust by the TMP40, which is the second exhaust process. Was measured intermittently.

In FIG. 6, after the inside of the vacuum container 51 is evacuated by the dry pump 53, the inside of the vacuum container 51 of the transfer chamber VTM is evacuated by the TMP 40. That is, the exhaust steps include a first exhaust step of exhausting the vacuum vessel 51 by a dry pump 53, which is an example of the first pump provided in the vacuum vessel 51 of the transfer chamber VTM, and a substrate processing chamber PM and a transport chamber VTM. Includes an opening step of opening the gate valve GV provided between the two, and a second exhaust step of exhausting the inside of the transport chamber VTM by TPM40, which is an example of the second pump provided in the substrate processing chamber PM. ..

At this time, the second exhaust step is preferably performed for 1 hour or more. As a result, in DP to TMP (1h) shown in FIG. 6, it can be seen that the number of particles increases in the process of removing the water contained in the alumite component, and the generation of particles is promoted. Further, it can be seen that in TMP (1h) to TMP (24h), the water content contained in the alumite component is removed, and the generation of particles is further promoted.

After that, by continuing the evacuation in the vacuum vessel 51 by the TMP 40, the amount of water contained in the alumite component is reduced, the number of particles generated in TMP (24h) to TMP (96h) is reduced, and the particles are generated. Can be seen to be suppressed.

Subsequently, a drying gas was introduced into the vacuum vessel 51 to return the inside of the vacuum vessel 51 to atmospheric pressure, and the inside of the vacuum vessel 51 was evacuated with DP and TMP40 (1h) without opening and closing the lid 57. It can be seen that the number of particles was further reduced by vacuuming with TMP40 for 1 hour, but not significantly.

Subsequently, a dry gas is introduced into the vacuum vessel 51 to return the inside of the vacuum vessel 51 to atmospheric pressure, the lid 57 is opened and closed (exposure step), and the inside of the vacuum vessel 51 is depressurized by DP (third exhaust step). ), Further evacuated with TMP40 (1h) (fourth exhaust step). It can be seen that the number of particles is reduced by an order of magnitude or more from the number of particles one hour after the start of exhaust by TMP40 in the boosting process by opening and closing the lid 57 as well as returning to atmospheric pressure. ..

In the example of FIG. 6, it was determined that the measured value of the number of particles was below a predetermined threshold value by evacuation after opening and closing the lid 57. On the other hand, when it is determined that the measured value exceeds a predetermined threshold value, the process returns to the exhaust step, and the exhaust step, the boosting step, and the exposure step are repeated until the measured value falls below the threshold value. As a result, the amount of water in the vacuum vessel 51 can be sufficiently reduced, and the generation of particles from the alumite component can be more reliably avoided.

In FIG. 4, the processes of steps S12 to S28 are repeated until it is determined that the measured number of particles has fallen below the threshold value. In this case, the third exhaust step corresponds to the first exhaust step, and the fourth exhaust step corresponds to the second exhaust step.

[Estimation model of particles generated from alumite parts]
Next, an estimation model of particles generated from the alumite component will be described with reference to FIG. 7. 7 (a) to 7 (e) are diagrams showing an estimation model of particles according to the present embodiment. The alumite component 300 contains water and fine foreign matter in the micropores 202 formed on the surface of the alumite layer (FIG. 7A).

When the moisture pressure in the vacuum vessel 51 is lowered by evacuating the vacuum vessel 51 of the transport chamber VTM with a turbo molecular pump, the moisture contained in the micropores 202 is vaporized and released into the vacuum vessel 51. At this time, fine foreign matter is discharged together with the moisture contained in the fine pores 202, and particles P are generated (FIG. 7 (b)). Therefore, in the initial stage of evacuation (after 1 hour and 24 hours have passed from the start of exhaust in FIG. 6), the number of particles P increases. It has been confirmed that the main component of the particles P generated here is aluminum (Al). Therefore, it is considered that the foreign matter contained in the micropores 202 is generated from the fragile layer 201 formed on the surface of the alumite layer.

Further, when the vacuum vessel 51 is continuously evacuated with a turbo molecular pump (48 hours and 96 hours after the start of exhaust in FIG. 6), the water content in the micropores 202 is further removed (FIG. 7). (C)). Therefore, the amount of foreign matter discharged together with the water is reduced, and the number of particles is reduced. However, since the foreign matter continues to be discharged due to the vibration of the vacuum vessel 51 or the like, some particles are generated. Here, a dry gas is introduced into the vacuum vessel 51 to increase the pressure in the vacuum vessel 51 to atmospheric pressure and open the lid. As a result, the atmosphere outside the vacuum vessel 51 flows in, and the moisture contained in the atmosphere is re-adsorbed to the micropores 202 formed on the surface of the alumite layer (FIG. 7 (d)).

By evacuating the vacuum vessel 51 in this state, fine foreign matter is discharged together with water contained in the fine hole 202, and the fine foreign matter contained in the fine hole 202 is sufficiently removed (FIG. 7 (e)). .. As a result, it is considered that the particles P generated from the fine pores 202 on the surface of the alumite layer are significantly reduced.

The particle generation suppressing method according to the present embodiment may be applied to an unused vacuum device before new shipment or a vacuum device after replacing an internal alumite component. According to this, before the first wafer processing is performed using a new vacuum device or a new alumite component, moisture is removed from the alumite component installed in the vacuum device, and the process of removing the moisture is performed in advance. Can generate particles in the vacuum. As a result, even an unused vacuum device can be used in a stable state in which particles are unlikely to be generated, as in the case of a vacuum device after use. As a result, it is possible to prevent a decrease in yield and improve productivity.

Although the particle generation suppression method has been described above by the above embodiment, the particle generation suppression method according to the present invention is not limited to the above embodiment, and various modifications and improvements can be made within the scope of the present invention. be. The matters described in the plurality of embodiments can be combined within a consistent range.

The particle generation suppression method according to the above embodiment is applicable not only to the particle generation suppression method in the vacuum container 51 of the transport chamber VTM but also to the substrate processing chamber PM. This makes it possible to reduce the number of particles generated from the alumite components used in the substrate processing chamber PM.

Further, in the above embodiment, the lid is opened and the moisture is re-adsorbed by the exposure step of introducing the atmosphere containing moisture. However, the means for re-adsorbing water is not limited to opening the lid. For example, since the relative humidity in a clean room is usually 40 to 50%, a gas containing 40 to 50% of water corresponding to the humidity of the clean room is supplied into the vacuum device to remove the water without opening the lid. It may be re-adsorbed. Further, in order to re-adsorb water more efficiently and in a short time, even if a gas having a high humidity of 50 to 100% is supplied into the vacuum device or the inner wall surface of the vacuum device is directly wiped with water to re-adsorb. good. Further, when the pressure inside the vacuum apparatus is increased to atmospheric pressure, a gas containing these waters may be introduced. Further, the introduction of the gas containing these waters may be controlled by the control unit 100. These are examples of the moisture adhesion step, and the exposure step is also an example of the moisture adhesion step.

Further, not only the alumite parts used in the transport chamber VTM or the substrate processing chamber PM, but also the alumite parts before assembly and the alumite parts used for other purposes, for example, the particle generation suppressing method according to the above embodiment can be applied. Applicable. As a result, particles generated from the alumite component can be reduced. For example, the particle generation suppressing method according to the above embodiment may be executed on the alumite component before assembly in an arbitrary vacuum device to reduce the particles generated from the alumite component, and then the device may be assembled.

Further, in the above embodiment, if the TMP40 is operated and then the cryopump or heating is performed, the water removal may be accelerated, and as a result, the particles may be reduced quickly. By using a cryopump or the above method, the partial pressure of water in the vacuum vessel 51 can be reduced, and the continuous evacuation time of the vacuum vessel 51 may be shortened.

Further, the substrate processing chamber PM and the transport chamber VTM are examples of a vacuum apparatus provided with alumite-treated parts, and the particle generation suppressing method according to the present invention is an exhaust system capable of holding the inside of the vacuum apparatus at 1 mTorr or less. Can be used for.

When the vacuum apparatus according to the present invention is applied to the substrate processing chamber PM, the substrate processing chamber includes a capacitively coupled plasma (CCP) apparatus, an inductively coupled plasma (ICP), and a radial. It may be a plasma processing device using a line slot antenna, a helicon wave excitation type plasma (HWP: Helicon Wave Plasma) device, an electron cyclotron resonance plasma (ECR: Electron Cyclotron Resonance Plasma) device, or the like. Further, it may be a plasmaless device that performs etching and film formation processing by using a reactive gas and heat.

Further, in this specification, a wafer has been described as an example of a substrate, but various substrates used for LCD (Liquid Crystal Display), FPD (Flat Panel Display), etc., photomasks, CD substrates, printed circuit boards, etc. May be good.

10: Semiconductor manufacturing equipment 11: Vacuum container 38: Lid 51: Vacuum container 57: Lid 59: QMS
300: Alumite parts PM: Substrate processing room VTM: Conveyance room

Claims (14)

A method for suppressing particle generation in a vacuum device that has alumite-treated parts.
Exhaust step A in which the inside of the vacuum device is evacuated to reduce the pressure, and the pressure in the vacuum device is evacuated to 1.3 × 10 ^-1 Pa (1 mTorr) or less.
After the exhaust step A , a boosting step of boosting the inside of the vacuum device to atmospheric pressure,
After the pressurizing step, a moisture adhering step of adhering moisture to the alumite-treated part, and
After the moisture adhesion step, the exhaust step B for exhausting the inside of the vacuum device and
A method for suppressing particle generation. The vacuum device is a transfer chamber of a semiconductor manufacturing device.
A first exhaust step of exhausting the transport chamber by a first pump provided in the transport chamber, and
An opening process for opening the gate valve provided between the substrate processing chamber and the transport chamber, and
Look including a second exhaust step of exhausting the transfer chamber by a second pump provided in said substrate processing chamber,
The particle generation suppressing method according to claim 1, wherein the exhaust step A includes the first exhaust step and the second exhaust step. The particle generation suppressing method according to claim 2, wherein the second exhaust step is performed for at least one hour or more. The particle generation suppressing method according to claim 2 or 3, wherein the first pump is a dry pump and the second pump is a turbo molecular pump. The exhaust step B is any one of claims 2 to 4, which includes a third exhaust step of exhausting the transport chamber by the first pump provided in the transport chamber after the moisture adhesion step. The method for suppressing particle generation according to item 1. After the third exhaust step, there is an opening step of opening a gate valve provided between the substrate processing chamber and the transport chamber.
The exhaust step B, particle generation suppression method according to claim 5 including a fourth exhaust step of exhausting the transfer chamber by the second pump provided in the substrate processing chamber. The particle generation suppressing method according to any one of claims 1 to 6, wherein the moisture adhesion step is performed by opening the lid of the vacuum device and exposing the inside of the vacuum device to the atmosphere. The particle generation suppressing method according to any one of claims 1 to 6, wherein the moisture adhering step is performed by introducing a gas containing moisture into the vacuum apparatus. The pressurizing step is performed by introducing a dry gas, and the dry gas is either dry air, nitrogen gas or a rare gas.
The particle generation suppressing method according to any one of claims 1 to 8. The vacuum device is an unused vacuum device before shipment or the vacuum device after replacing the alumite-treated parts.
The particle generation suppressing method according to any one of claims 1 to 9. The particle generation suppressing method according to any one of claims 1 to 10, wherein the alumite-treated part is an inner wall of the vacuum apparatus. A vacuum device having anodized parts and a control unit.
The control unit
The inside of the vacuum device is evacuated to reduce the pressure, and the pressure inside the vacuum device is evacuated to 1.3 × 10 ^-1 Pa (1 mTorr) or less.
After the evacuation, the pressure inside the vacuum device is increased to atmospheric pressure.
After the pressure is increased, moisture is attached to the alumite-treated component to allow it to adhere to the alumite-treated component.
After the moisture is attached, the inside of the vacuum device is exhausted.
A vacuum device that controls the process including that. The control unit
A gas containing water is introduced into the vacuum device to control the inside of the vacuum device so as to boost the pressure to atmospheric pressure.
The vacuum apparatus according to claim 12. The control unit
A drying gas is introduced into the vacuum device to control the inside of the vacuum device so as to boost the pressure to atmospheric pressure.
After the pressure is increased, the lid of the vacuum device is controlled to be opened.
The vacuum apparatus according to claim 12.

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