JP2012222334A - Plasma processing apparatus and exhausting method of residual gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the safety by reliably exhausting residual gas from a chamber before the chamber of a plasma processing apparatus is opened.SOLUTION: Residual gas is exhausted from a load lock chamber 6a of a dry etching apparatus 1 by performing the following steps. A nitrogen gas valve 29a is opened to introduce nitrogen gas from a nitrogen gas source 28, and subsequently an exhaust valve 14a is opened to exhaust the nitrogen gas using a dry pump 12a; this step is repeated predetermined times. Then, an atmospheric air introduction valve 26a is opened to introduce atmospheric air, and subsequently the exhaust valve 14a is opened to exhaust the atmospheric air using the dry pump 12a; this step is repeated predetermined times. After that, both of the atmospheric air introduction valve 26a and a duct exhaust valve 24 are opened.

Description

  The present invention relates to a plasma processing apparatus such as a dry etching apparatus and a CVD apparatus, and a method for exhausting residual gas in the plasma processing apparatus.

  In the plasma processing apparatus, when the cassette containing the substrate is taken in and out of the load lock chamber, the load lock chamber is returned to atmospheric pressure and opened. Further, when maintenance is performed on the inside of a chamber such as a process chamber, a transfer chamber, or a load lock chamber, it is returned to atmospheric pressure and opened. In particular, in the case of a plasma processing apparatus using a dangerous gas such as a chlorine-based gas, it is necessary to ensure safety by exhausting the residual gas in the chamber without fail when the chamber is opened.

  Generally, when removing the residual gas when the chamber is opened, after the chamber is exhausted by an exhaust duct connected by an operator wearing a gas mask or the like, the operator uses a hand-held gas detector to detect residual gas in the chamber. Concentration is measured to confirm whether it is safe.

  On the other hand, Patent Document 1 describes that the door is opened in two stages to ensure safety when the process chamber is opened. Patent Document 2 describes a process chamber that does not include a load lock chamber or the like and removes residual gas through a case surrounding a gate valve when a substrate is loaded and unloaded.

JP-A-11-132356 JP 2010-263048 A

  The general residual gas removal operation when the chamber is opened cannot be performed in a state where the atmospheric gas in the chamber is sealed, and safety is not sufficient.

  On the other hand, even if the door is opened in two stages as in Patent Document 1, leakage of residual gas from the inside of the process chamber to the outside cannot be prevented. In Patent Document 2, no particular consideration is given to opening the chamber for maintenance or the like.

  An object of the present invention is to ensure the safety by reliably exhausting the gas remaining in the chamber when the chamber of the plasma processing apparatus is opened.

  According to a first aspect of the present invention, there is provided a plasma processing apparatus including an openable / closable chamber, wherein the chamber and the first exhaust equipment are connected, and a pump for exhaust and a first exhaust valve that is normally closed are provided. Is connected to the first exhaust path, the second exhaust path is connected to the second exhaust facility, and the normally exhausted second exhaust valve is connected to the atmosphere. An atmosphere path in which a normally closed atmosphere introduction valve is communicated and connected to the chamber and an inert gas source, and an inert gas path in which a normally closed inert gas introduction valve is interposed; A control device that controls the first exhaust valve, the second exhaust valve, the air introduction valve, the inert gas introduction valve, the inert gas source, and the pump. For opening the active gas valve The introduction of the inert gas from the inert gas source to the chamber and the subsequent exhaust of the chamber by the pump by opening the first exhaust valve are repeated a predetermined number of times, After the introduction of the atmosphere into the chamber by opening the introduction valve and the subsequent exhaust of the chamber by the pump by opening the first exhaust valve are repeated a predetermined number of times, the atmosphere introduction valve And a residual gas exhaust processing unit that opens both the second exhaust valve and the plasma processing apparatus.

  The introduction of the inert gas from the inert gas source to the chamber by opening the inert gas introduction valve and the forced exhaust of the chamber by the pump by opening the first exhaust valve are repeated a predetermined number of times. That is, the operation of replacing the gas in the chamber with the inert gas supplied from the inert gas source is repeated. Following the replacement with the inert gas, introduction of the atmosphere into the chamber by opening the atmosphere introduction valve and forced exhaust of the chamber by the pump by opening the first exhaust valve are repeated a predetermined number of times. That is, the operation of replacing the gas in the chamber with the atmosphere is repeated. In this way, the replacement with the inert gas and the subsequent replacement with the atmosphere are performed, and at that time, the gas in the chamber is surely exhausted by the pump provided in the first exhaust path, so that the chamber is exposed to the outside. The gas for plasma processing remaining in the chamber can be surely exhausted while maintaining the sealed state. As a result, it is possible to ensure safety when the chamber is opened until both the air introduction valve and the second exhaust valve are opened to return the inside of the chamber to atmospheric pressure.

  Preferably, further comprising: a releasable lock mechanism that locks the chamber in a closed state; and a gas detector that detects a concentration of gas exhausted by the second exhaust path, wherein the residual gas exhaust processing unit includes: After opening both the atmosphere introduction valve and the second exhaust valve, the detected value of the gas concentration of the gas detector is compared with a predetermined reference value, and the detected value is less than the reference value. If so, the lock by the lock mechanism is released.

  With this configuration, the chamber cannot be opened while being locked by the lock mechanism unless the gas concentration in the chamber drops below the reference value. As a result, the safety when the chamber is opened can be further improved.

  Preferably, each of the first exhaust valve, the second exhaust valve, and the atmosphere introduction valve includes a manual opening / closing mechanism.

  With this configuration, the first and second exhaust valves and the air introduction valve can be manually opened / closed by the manual opening / closing mechanism even when various valves are not normally operated due to the failure of the plasma processing apparatus itself. Thus, the gas in the chamber can be discharged while the chamber is kept sealed from the outside, and safety when the chamber is opened can be ensured.

  According to a second aspect of the present invention, there is provided a first chamber in which an openable / closable chamber is connected, the chamber and the first exhaust equipment are connected, and an exhaust pump and a normally closed first exhaust valve are interposed. An exhaust path, a second exhaust path connecting the chamber and the second exhaust facility, and a normally closed second exhaust valve interposed therebetween, and the chamber communicating with the atmosphere and the normally closed atmosphere Residual gas in a plasma processing apparatus comprising an atmospheric path provided with an introduction valve and an inert gas path connected with the chamber and an inert gas source and provided with a normally closed inert gas introduction valve. An exhaust method, wherein the inert gas source is introduced into the chamber from the inert gas source by opening the inert gas valve, and the chamber at the pump is subsequently opened by opening the first exhaust valve. Exhaust A first step that repeats a predetermined number of times, introduction of the atmosphere into the chamber by opening the atmosphere introduction valve, and subsequent exhaust of the chamber at the pump by opening the first exhaust valve A second step that repeats a predetermined number of times, and a third step that opens both the atmosphere introduction valve and the first exhaust valve after the first step and the second step. Provide an exhaust method.

  Preferably, a releasable lock mechanism that locks the chamber in a closed state and a gas detector that detects a concentration of gas exhausted from the second exhaust path are further provided, and during the third step, The detected value of the gas concentration of the gas detector is compared with a predetermined reference value, and if the detected value is equal to or less than the reference value, the lock mechanism releases the lock.

  According to the present invention, the replacement of the chamber with the inert gas and the subsequent replacement with the atmosphere are performed, and at that time, the gas in the chamber is surely exhausted by the pump provided in the first exhaust path. The gas for plasma processing remaining in the chamber can be surely exhausted while maintaining a hermetically sealed state, and the safety of the plasma processing apparatus when the chamber is opened can be ensured.

The schematic diagram of the plasma processing apparatus which concerns on embodiment of this invention. 1 is a block diagram of a plasma processing apparatus according to an embodiment of the present invention. The schematic diagram which shows the exhaust valve and the manual valve and automatic valve for opening and closing it. The flowchart for demonstrating operation | movement to the load-lock chamber opening | release at the time of normal of the residual gas automatic exhaust function of the plasma processing apparatus which concerns on embodiment of this invention. The flowchart for demonstrating operation | movement to the load-lock chamber opening | release at the time of abnormality of the residual gas automatic exhaust function of the plasma processing apparatus which concerns on embodiment of this invention.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  1 and 2 show a dry etching apparatus 1 according to an embodiment of the present invention. The dry etching apparatus 1 includes an openable / closable process chamber 3 including a processing chamber 3a in which dry etching is performed on the substrate 2 and an openable / closable opening provided adjacent to the process chamber 3 and including a transfer chamber 4a therein. A transfer chamber 4. Further, the dry etching apparatus 1 includes a load lock chamber 6 provided adjacent to the transfer chamber 4. A load lock chamber 6 a in the load lock chamber 6 can be opened and closed by a door 5. A gate valve 7a is provided at the communication port between the load lock chamber 6a and the transfer chamber 4a, and a gate valve 7b is also provided at the communication port between the transfer chamber 4a and the processing chamber 3a.

  A process gas supply unit 8 (shown only in FIG. 2) for supplying a process gas is connected to the processing chamber 3a of the process chamber 3. In the present embodiment, the process gas is a gas containing a chlorine-based gas. The processing chamber 3a is provided with plasma generating means 9 (shown only in FIG. 2). The method of the plasma generating means 9 is not particularly limited, and may be an ICP type or a parallel plate type.

  One end of an exhaust path (first exhaust path) 11 c is connected to the processing chamber 3 a of the process chamber 3. The other end of the exhaust path 11c is connected to an exhaust duct (first exhaust facility) 13A via a dry pump 12b. Further, an exhaust valve (first exhaust valve) 14c which is a normally closed and on / off type air drive valve is interposed in the exhaust path 11c. As will be described in detail later, the exhaust valve 14c is opened and closed by a command from the control unit 41 (shown only in FIG. 2) and can be opened and closed by manual operation.

  The process chamber 3 is provided with an exhaust chamber 3b communicating with the processing chamber 3a. A high vacuum pump 16, which is a turbo molecular pump, for example, is connected to the exhaust chamber 3 b via a pressure adjustment valve 15. The high vacuum pump 16 is connected to the exhaust path 11 c via the vacuum exhaust path 17. A vacuum exhaust valve 18 that is a normally closed and on / off type solenoid valve is interposed in the vacuum exhaust path 17.

  In the transfer chamber 4a of the transfer chamber 4, a transfer mechanism 19 (shown only in FIG. 2) of the substrate 2 is accommodated. The transport mechanism 19 takes out the unprocessed substrate 2 from the load lock chamber 6a and transports it to the processing chamber 3a. Further, the transport mechanism 19 takes out the substrate 2 that has been subjected to the above-described dry etching processing from the processing chamber 3a of the process chamber 3 and returns it to the load lock chamber 6a.

  In the load lock chamber 6a in the load lock chamber 6, for example, a plurality of substrates 2 housed in a cassette (not shown) are carried in via the communication port 6b with the outside. The substrate 2 that has been subjected to the dry etching process is returned to the cassette, and after the processing of all the substrates 2, the cassette is carried out from the communication port 6b. The door 5 is opened when the substrate 2 (cassette) is taken in and out, but otherwise the communication port 6b is closed. The load lock chamber 6 includes a lock device 21 that locks the door 5 in a state where the communication port 6b is closed. When the door 5 is opened and closed, the lock by the lock device 21 is released.

  One end of an exhaust path (first exhaust path) 11a is connected to the load lock chamber 6a. The other end of the exhaust path 11a is connected to an exhaust duct (first exhaust facility) 13A via a dry pump 12a. An exhaust valve (first exhaust valve) 14a, which is an on / off type air drive valve, is interposed in the exhaust path 11a. Similarly, one end of an exhaust path (first exhaust path) 11b is connected to the transfer chamber 4a. The other end of the exhaust path 11b is connected to the exhaust path 11a on the dry pump 12a side of the exhaust valve 14a. An exhaust valve (first exhaust valve) 14b, which is an on / off type air drive valve, is interposed in the exhaust path 11b. As will be described in detail later, the exhaust valves 14a and 14b can be opened and closed by a command from the control unit 41 (shown only in FIG. 2) and can also be opened and closed by manual operation.

  Hereinafter, operations related to the processing of the substrate 2 of the dry etching apparatus 1 will be described.

  When the dry etching apparatus 1 is started, the gate valves 7a and 7b are both closed. The sealed transfer chamber 4a is evacuated to a certain degree of vacuum by the dry pump 12a. At this time, the exhaust valve 14b is opened, and the air in the transfer chamber 4a is discharged to the exhaust duct 13A through the exhaust path 11b. The sealed processing chamber 3a is evacuated to a certain degree of vacuum by the dry pump 12b. At this time, the exhaust valve 14c is opened, and the air in the processing chamber 3a is discharged to the exhaust duct 13A through the exhaust path 11c.

  After the unprocessed substrate 2 is carried into the load lock chamber 6a, the door 5 is closed and locked by the lock device 21. The sealed load lock chamber 6a is evacuated by the dry pump 12a to the same degree of vacuum as the transfer chamber 4a. At this time, the exhaust valve 14a is opened, and the air in the transfer chamber 4a is discharged to the exhaust duct 13A through the exhaust path 11a.

  Thereafter, the following operation is repeated until the dry etching process is completed for all the substrates 2 in the load lock chamber 6a.

  The gate valve 7a is opened, and the substrate 2 is unloaded from the load lock chamber 6a to the transfer chamber 4a by the transfer mechanism 19. When the substrate 2 is unloaded, the gate valve 7a is closed. Further, the gate valve 7b is opened, and the substrate 2 is carried into the processing chamber 3a from the transfer chamber 4a. When the substrate 2 is loaded, the gate valve 7b is closed.

  Next, the process gas is supplied from the process gas supply unit 8 to the processing chamber 3a and exhausted by the high vacuum pump 16 so that the inside of the processing chamber 3a is maintained at a predetermined high vacuum. In this state, the substrate 2 is etched by the plasma generated by the plasma generating means 9.

  The substrate 2 after the dry etching in the processing chamber 3a is returned from the processing chamber 3a to the load lock chamber 6a by the transport mechanism 19 through a path reverse to that at the time of loading.

  In the dry etching apparatus 1 in operation, not only the processing chamber 3a but also the transfer chamber 4a is in a negative pressure state, and the load lock chamber 6a is also in a negative pressure state except when the substrate is carried in and out. Further, process gas exists in the processing chamber 3a of the dry etching apparatus 1 in operation. The gate valve 7a between the transfer chamber 4a and the load lock chamber 6a is opened when the transfer mechanism 19 carries the substrate 2 into and out of the load lock chamber 6a, but it is closed. In addition, the second gate valve 7b between the transfer chamber 4a and the processing chamber 3a is opened when the transfer mechanism 19 carries the substrate 2 into and out of the processing chamber 3a, but is closed at other times. However, since it is difficult to completely eliminate process gas leakage from the processing chamber 3a to the transfer chamber 4a and the load lock chamber 6a, the process is also performed in the transfer chamber 4a and the load lock chamber 6a of the dry etching apparatus 1 in operation. Gas is present. The dry etching apparatus 1 according to the present embodiment is configured to exhaust the process gas remaining in these chambers when the load lock chamber 6, the transfer chamber 4, and the process chamber 3 are opened. In addition to the valves 14a to 14c and the dry pumps 7a and 7b, the following mechanisms are further provided.

  One ends of duct exhaust paths (second exhaust paths) 22a, 22b, and 22c are connected to the load lock chamber 6a, the transfer chamber 4a, and the processing chamber 3a, respectively. The other ends of the individual duct exhaust paths 22a to 22c are connected to a duct exhaust path 22d, and this duct exhaust path 22d is connected to an exhaust duct (second exhaust facility) 13B. A gas detector 23 for detecting the concentration of the process gas contained in the exhaust is provided in the duct exhaust path 22d. The gas detector 23 sends a detected value of the concentration of the process gas to residual gas exhaust processing units 53, 54, and 55 described later. Further, duct exhaust valves 22a to 22c are provided with duct exhaust valves (second exhaust valves) 24a, 24b, and 24c, which are normally closed and on / off type air drive valves. As will be described in detail later, the duct exhaust valves 24a to 24c are opened and closed by a command from the control unit 41 and can be opened and closed by manual operation.

  The exhaust duct (first exhaust equipment) 13A to which the exhaust paths (first exhaust paths) 11a, 11b, and 11c described above are connected is installed in a factory to exhaust harmful gases such as chlorine. Therefore, a detoxifying means 57 for detoxifying harmful gases is always provided. On the other hand, the exhaust duct (second exhaust equipment) 13B to which the duct exhaust path (second exhaust path) 22a to 22d is connected is installed in a factory to exhaust a relatively safe gas, Usually, no abatement means is provided. Any of the exhaust ducts 13A and 13B has an exhaust device provided in the factory, so that exhaust is performed without a special pump or the like, but a special dry pump 12a is provided in the exhaust path 13A. As will be described in detail, the harmful gas is surely exhausted, and at the same time, the replacement time of the gas in the chamber described in detail later is shortened.

  One ends of atmospheric paths 25a and 25b are connected to the load lock chamber 6a and the transfer chamber 4a, respectively. One end of an atmospheric passage 25c is also connected to the processing chamber 3a via the exhaust chamber 3b. The other ends of the individual atmospheric paths 25a to 25c are open to the atmosphere. Further, atmospheric introduction valves 26a, 26b, and 26c, which are normally closed and on / off type air drive valves, are interposed in the atmospheric passages 25a to 25c, respectively. As will be described in detail later, the air introduction valves 26a to 26c can be opened and closed by a command from the control unit 41 and can also be opened and closed by manual operation.

  One ends of nitrogen gas paths (inert gas paths) 27a and 27b are connected to the load lock chamber 6a and the transfer chamber 4a, respectively. One end of a nitrogen gas path 27c is also connected to the processing chamber 3a via the exhaust chamber 3b. The other ends of the individual nitrogen gas paths 27a to 27c are connected to a nitrogen gas path 27d, and this duct exhaust path 22d is a nitrogen gas source (non-reactor) that supplies nitrogen gas as an inert gas used for purging as described later. Active gas source) 28 is connected. Further, nitrogen gas introduction valves 29a to 29c, which are normally closed and on / off type solenoid valves, are interposed in the nitrogen gas paths 27a to 27c, respectively.

  Next, the opening / closing drive mechanism of the exhaust valves 14a to 14c (normally closed and on / off type air drive valves) will be described with reference to FIG. The duct exhaust valves 24a to 24c and the air introduction valves 26a to 26c are also normally closed and on / off type air drive valves, and are opened and closed by a mechanism similar to the open / close drive mechanism of the exhaust valves 14a to 14c described below. Is done.

  One end of a control air path 31 is connected to the exhaust valves 14a to 14c. The exhaust valves 14 a to 14 c are opened while compressed air is supplied via the control air path 31, but the closed state is maintained unless compressed air is supplied from the control air path 31. The other end of the control air path 31 is open to the atmosphere via a silencer 32. In the control air path 31, a manual valve 33 and an automatic valve 34 are provided in order from the exhaust valves 14a to 14c.

  The manual valve 33 is a 3-port 2-position type valve that can be manually operated by a lever 33d. The port 33a of the manual valve 33 is connected to the exhaust valves 14a to 14c, and the port 33b is connected to the automatic valve 34 (atmosphere side). Further, the port 33 c of the manual valve 33 is connected to the compressed air source 35. The manual valve 33 can be set at either the position A or A 'by the lever 33d. Manual valve 33 Once set to either position A or A ', it is held at that position unless lever 33d is operated. In the position A, the ports 33a and 33b are connected, while the port 33c is blocked from the other ports 33a and 33b. That is, if the manual valve 33 is at position A, the exhaust valves 14a to 14c are connected to the atmospheric pressure side. At the position A ', the port 33a and the port 33c are connected, while the port 33b is blocked from the other ports 33a and 33c. That is, if the manual valve is at position A ′, the exhaust valves 14 a to 14 c are connected to the compressed air source 35. The initial position of the manual valve 33 is position A, and is maintained at this position unless the lever 33d is operated.

  The automatic valve 34 is a 3-port 2-position type internal pilot type solenoid valve. In the automatic valve 34, the port 34a is connected to the manual valve 33 side (exhaust valves 14a to 14c side), the port 34b is connected to the atmosphere side, and the port 34c is connected to the compressed air source 35. Of the two positions B and B 'of the automatic valve 34, the port 34a and 34b are connected at the position B, while the port 34c is blocked from the other ports 34a and 34b. Therefore, when the automatic valve 34 is at the position B, the port 33b of the manual valve 33 is connected to the atmospheric pressure side. At the position B ', the ports 34a and 34c are connected, while the port 34b is blocked from the other ports 34a and 34c. Therefore, when the automatic valve 34 is at the position B ′, the port 33 b of the manual valve 33 is connected to the compressed air source 35. The initial position of the automatic valve 34 is position B and is maintained at this position unless power is supplied to the solenoid 34d. The automatic valve 34 that is supplying power to the solenoid 34d is at the position B '.

  When the manual valve 33 is at the initial position A, the exhaust valves 14a to 14c open and close according to whether the automatic valve 34 is set to the position B or B '. First, when the solenoid 34d of the automatic valve 34 is not supplied with power and the automatic valve 34 is at the position B, the exhaust valves 14a to 14c are connected to the atmosphere and are closed. On the other hand, when power is supplied to the solenoid 34d of the automatic valve 34 and the automatic valve 34 is at the position B ', the exhaust valves 14a to 14c are connected to the compressed air source 35 and open.

  Even if the automatic valve 34 is in the initial position B (corresponding to the closed state of the exhaust valves 14a to 14c), depending on whether the manual valve 33 is set to the position A or A ′ by operating the lever 33d, The exhaust valves 14a-14c open and close. First, when the manual valve 33 is at the initial position A, the exhaust valves 14a to 14c are connected to the atmosphere and are closed. On the other hand, when the manual valve 33 is at the position A ′, the exhaust valves 14 a to 14 c are connected to the compressed air source 35 and are in the open state.

  The control air path 31 is provided with a manual valve open / close state detection sensor 36 which is, for example, a pressure switch in order to detect the open / close state of the manual valve 33. The open / close state of the manual valve 33 output by the manual valve open / close state detection sensor 36 is transmitted to the control unit 41.

  Referring to FIG. 2, the control unit 41 is based on the input from various sensors including the gas detector 23 and the manual valve open / closed state detection sensor 36 in addition to the operator's command input from the operation / input unit 42. The operation of the entire dry etching apparatus 1 is controlled. In particular, the control unit 41 controls the transfer processing unit 51 that controls the transfer of the substrate 2 by the transfer mechanism 19, and the process that controls the dry etching process for the substrate 2 in the processing chamber 3 a by the plasma generation means 9 and the process gas supply unit 8. A processing unit 52 is provided. Further, after the dry etching apparatus 1 is stopped, the control unit 41 controls residual gas for automatically exhausting the process gas remaining in the load lock chamber 6a, the transfer chamber 4a, and the processing chamber 3a. Exhaust treatment units 53, 54 and 55 are provided. Further, the control unit 41 includes an apparatus activation processing unit 56 that controls the operation of the above-described dry etching apparatus 1 during activation.

  As shown in FIG. 2, the dry etching apparatus 1 includes a display unit 43 for displaying input from the operation / input unit 42 and information from the control unit 41. In addition, the dry etching apparatus 1 includes an informing unit 44 that generates a warning of occurrence of an abnormality, and an emergency stop for an operator to command the dry etching apparatus 1 to stop operation in an emergency such as when an alarm is generated by the informing unit 44 A switch 45 is provided.

  In the dry etching apparatus 1, when exhausting the process gas remaining in the load lock chamber 6a, the transfer chamber 4a, and the processing chamber 3a, it can be roughly classified into two types.

  The first method is to automatically exhaust residual gas from the load lock chamber 6a, the transfer chamber 4a, and the processing chamber 3a by the corresponding residual gas exhaust processing units 53, 54, and 55. This is the case when the exhaust process functions normally. Hereinafter, this case is referred to as normal time of the residual gas automatic exhaust function. For example, in the case of the processing chamber 3a (process chamber 3), if the automatic residual gas exhaust processing by the residual gas exhaust processing unit 55 can be normally executed even in a state where the dry etching process cannot be normally executed, the residual gas automatic exhaust is performed. When the function is normal. Similarly, in the case of the transfer chamber 4a (transfer chamber), even when the transfer mechanism 19 cannot normally transfer the substrate 2, the automatic residual gas exhaust processing by the residual gas exhaust processing unit 54 can be normally executed. When the residual gas automatic exhaust function is normal.

  Second, regardless of whether or not the operator operates the emergency stop switch 45 to stop the dry etching apparatus 1, the load lock chamber 6a, the transfer chamber 4a, and the processing chamber 3a remain. This is a case where the automatic residual gas exhaust processing by the corresponding residual gas exhaust processing units 53, 54, and 55 does not function normally for the one trying to exhaust the process gas. Hereinafter, this case is referred to as an abnormality of the residual gas automatic exhaust function. Possible causes of abnormalities in the residual gas automatic exhaust function include, for example, interruption of power supply, failure of the control unit 41, failure of the automatic opening / closing function of the exhaust valves 14a to 14c (problems of opening / closing due to the presence or absence of power supply to the automatic valve 34) ). Even when the residual gas automatic exhaust function is abnormal, as long as the exhaust ducts 13A and 13B function normally, the manual valve 33 is manually operated as will be described in detail later, and the exhaust valves 14a to 14c, duct By operating the exhaust valves 24a to 24c and the air introduction valves 26a to 26c, the process gas remaining in the load lock chamber 6a, the transfer chamber 4a, and the processing chamber 3a can be exhausted.

  The former, that is, when the residual gas automatic exhaust function is normal, is further divided into two types. The first is a case where the cassette (containing the substrate 2) in the load lock chamber 6a is replaced. Second, the operator designates the load lock chamber 6a, the transfer chamber 4a, and the processing chamber 3a by the operation / input unit 42, and the residual gas exhaust processing units 53, 54, and 55 perform the residual gas exhaust processing accordingly. This is the case.

  There are first and second modes of the residual gas exhausting process performed by the dry etching apparatus 1 when the cassette in the load lock chamber 6a is replaced.

  In the first mode, when the dry etching process is completed for all the substrates 2 in the cassette, the residual gas exhaust process is automatically performed for the load lock chamber 6a. When the exhaust of the residual gas is completed and the door 5 can be opened (unlocked), this is notified to the operator by the notification unit 44 and the like. Thereafter, the operator opens the door 5 and replaces the cassette in the load lock chamber 6a.

  In the second mode, when the dry etching process is completed for all the substrates 2 in the cassette, the fact is notified to the operator by the notification unit 44 or the like. Thereafter, when the operator instructs the operation / input unit 42, the residual gas exhausting process is executed. When the exhaust of the residual gas is completed and the door 5 can be opened (unlocked), this is notified to the operator by the notification unit 44 and the like. Thereafter, the operator opens the door 5 and replaces the cassette in the load lock chamber 6a.

  In this way, the first mode stops the operation of the dry etching apparatus 1 after the door 5 is unlocked and the operator is notified, whereas the second mode is dry etching when the load lock chamber 6a is still in a vacuum state. The operation of the apparatus 1 stops and the worker is notified. Switching between the first mode and the second mode can be set by the operation / input unit 42, and the dry etching apparatus 1 operates in either the first mode or the second mode according to the setting.

  Next, the process of exhausting the process gas when the residual gas automatic exhaust function is normal will be described by taking the load lock chamber 6a as an example. The following description is common to both the case where the cassette in the load lock chamber 6a is exchanged and the case where the operator designates residual gas exhaust in the load lock chamber 6a by the operation / input unit 42.

  The residual gas exhaust processing unit 53 of the control unit 41 controls the opening and closing of the exhaust valve 14a, the duct exhaust valve 24a, the air introduction valve 26a, and the nitrogen gas introduction valve 29a, thereby remaining in the load lock chamber 6a. Exhaust the gas.

  The processing executed by the residual gas exhaust processing unit 53 is shown in FIG. In this figure, the exhaust valve 14a, the duct exhaust valve 24a, and the air introduction valve 26a are opened and closed by switching between power supply and non-power supply to the solenoid 34d of the automatic valve 34.

  First, the nitrogen gas introduction valve 29a is opened, and nitrogen gas is introduced from the nitrogen gas source 28 through the nitrogen gas paths 27d and 27a into the load lock chamber 6a (step S4-1). Next, the nitrogen gas introduction valve 29a is closed, and the introduction of nitrogen gas from the nitrogen gas source 28 to the load lock chamber 6a is stopped (step S4-2). Thereafter, the exhaust valve 14a is opened, and the gas (including process gas and nitrogen gas) in the load lock chamber 6a is exhausted by suction by the dry pump 12a (step S4-3). Specifically, the gas in the load lock chamber 6a is exhausted from the exhaust path 11a to the exhaust duct 13A through the dry pump 12a. At this time, a process of detoxifying the gas exhausted by the abatement means 57 provided in the exhaust duct 13A is performed. Next, the exhaust valve 14a is closed, and the exhaust of the gas in the load lock chamber 6a is stopped (step S4-4).

  Steps S4-1 to S4-4 are repeated a predetermined number of times. That is, introduction of nitrogen gas from the nitrogen gas source 28 to the load lock chamber 6a by opening the nitrogen gas introduction valve 29a and forced exhaust of the load lock chamber 6a by the dry pump 12a by opening the exhaust valve 14a. Repeated a predetermined number of times. In other words, the purge operation for replacing the gas in the load lock chamber 6a with the nitrogen gas supplied from the nitrogen gas source 28 is repeated.

  After steps S4-1 to S4-4 are repeated a predetermined number of times, the atmosphere introduction valve 26a is opened, and the atmosphere is introduced into the load lock chamber 6a through the atmosphere path 25a (step S4-5). Next, the atmosphere introduction valve 26a is closed, and introduction of the atmosphere into the load lock chamber 6a is stopped (step S4-6). Thereafter, the exhaust valve 14a is opened, and the gas in the load lock chamber 6a is exhausted by suction by the dry pump 12a (step S4-7). Specifically, the gas in the load lock chamber 6a is exhausted from the exhaust path 11a to the exhaust duct 13A through the dry pump 12a. At this time, a process of detoxifying the gas exhausted by the abatement means 57 provided in the exhaust duct 13A is performed. Next, the exhaust valve 14a is closed, and the exhaust of the gas in the load lock chamber 6a is stopped (step S4-8).

  Steps S4-5 to S4-8 are repeated a predetermined number of times. That is, the introduction of the atmosphere into the load lock chamber 6a by opening the atmosphere introduction valve 26a and the forced exhaust in the load lock chamber 6a by the dry pump 12a by opening the exhaust valve 14a are repeated a predetermined number of times. In other words, the purge operation for replacing the gas in the load lock chamber 6a with the atmosphere is repeated.

  After steps S4-5 to S4-8 are repeated a predetermined number of times, the air introduction valve 26a is opened (step S4-9), and the duct exhaust valve 24a is also opened (step S4-10). By opening the atmosphere introduction valve 26a and the duct exhaust valve 24a, the load lock chamber 6a communicates with the atmosphere via both the exhaust path 11a and the duct exhaust path 22a, and the pressure in the load lock chamber 6a returns to approximately atmospheric pressure.

  Next, the concentration of the process gas (residual gas) remaining in the gas in the load lock chamber 6a is detected by the gas detector 23 (S4-11). If the detected concentration of residual gas is below the reference value (step S4-12), the lock of the door 5 by the lock device 21 is released (step S4-13), and the door 5 can be opened (step S4). -14). On the other hand, when the concentration of the detected residual gas exceeds the reference value (step S4-12), a purge operation (steps S4-1 to S4-4) for replacing the gas in the load lock chamber 6a with nitrogen gas, and the load The operation (steps S4-5 to S4-8) of replacing the gas in the lock chamber 6a with the atmosphere is repeated again. When the concentration of the residual gas detected by the gas detector 23 exceeds the reference value, a purge operation (steps S4-1 to S4-4) for replacing the gas in the load lock chamber 6a with nitrogen gas, and the load lock Only one of the operations (steps S4-5 to S4-8) for replacing the gas in the chamber 6a with the atmosphere may be repeated.

  Introduction of nitrogen gas from the nitrogen gas source 28 and forced exhaustion by the dry pump 12a are repeated a predetermined number of times, that is, operations for replacing the gas in the load lock chamber 6a with nitrogen gas are repeated (steps S4-1 to S4). -4). Subsequent to the replacement with nitrogen gas, the introduction of the atmosphere and the forced exhaust by the dry pump 12a are repeated a predetermined number of times, that is, the operation of replacing the gas in the load lock chamber 6a with the atmosphere is repeated. In this way, replacement with nitrogen gas and subsequent replacement with air are performed. Further, the gas in the load lock chamber 6a is surely exhausted by the dry pump 12 provided in the exhaust path 11c at the time of replacement with nitrogen gas or air. That is, even if the exhaust path 22c connected to the load lock chamber 6a (connected to the exhaust duct 13B) is used, the exhaust can be exhausted by the exhaust apparatus provided in the factory, but the exhaust path 11c ( By exhausting through the exhaust duct 13A), the residual gas in the load lock chamber 6a is exhausted efficiently and reliably. The residual gas in the load lock chamber 6a exhausted by the dry pump 12a is rendered harmless by the abatement means 57, so that no harmful gas is exhausted to the outside via the exhaust duct 13A. As described above, the process gas remaining in the load lock chamber 6a can be reliably exhausted while the load lock chamber 6a is kept sealed from the outside. As a result, it is possible to ensure safety when the door 5 is opened before both the air introduction valve 26a and the duct exhaust valve 24a are opened to return the load lock chamber 6a to atmospheric pressure.

  Unless the concentration of the residual gas in the load lock chamber 6a detected by the gas detector 23 falls below the reference value, the door 5 of the load lock chamber 6a cannot be opened while being locked by the lock mechanism 21 ( Step S4-12). As a result, the safety when the door 5 is opened can be further enhanced.

  For the transfer chamber 4a, the residual gas exhaust processing unit 54 of the control unit 41 executes the processing of FIG. 4 and exhausts the process gas remaining even after the dry etching apparatus 1 is stopped. In this case, the residual gas exhaust processing unit 54 controls the opening and closing of the exhaust valve 14b, the duct exhaust valve 24b, the air introduction valve 26b, and the nitrogen gas introduction valve 29b. Similarly, in the plasma processing chamber 3a, the residual gas exhaust processing unit 55 of the control unit 41 executes the processing of FIG. 4 and exhausts the remaining process gas even after the dry etching apparatus 1 is stopped. In this case, the residual gas exhaust processing unit 55 controls opening and closing of the exhaust valve 14c, the duct exhaust valve 24c, the air introduction valve 26c, and the nitrogen gas introduction valve 29c.

  Next, a process for exhausting the remaining process gas when the residual gas automatic exhaust function is abnormal will be described using the load lock chamber 6a as an example. The factory equipment itself including the exhaust devices of the exhaust ducts 13A and 13B is operating normally. In this case, the exhaust valve 14a, the duct exhaust valve 24a, and the air introduction valve 26a are manually operated. The exhaust valve 14a, the duct exhaust valve 24a, and the air introduction valve 26b are opened and closed by operating the lever 33d and setting the manual valve 33 to either position A or A 'as described above. That is, the exhaust valve 14a, the duct exhaust valve 24a, and the air introduction valve 26b are closed when the manual valve 33 is at the position A and opened when the manual valve 33 is at the position A '.

  FIG. 5 shows a procedure for exhausting the load lock chamber 6a in this case. First, the atmosphere introduction valve 26a is manually opened to introduce the atmosphere into the load lock chamber 6a via the atmosphere path 25a (step S5-1). The air introduction valve 26a is manually opened by operating the lever 33a of the manual valve 33 for the air introduction valve 26a. Further, the exhaust valve 14a is manually opened while the atmosphere introduction valve 26a is maintained in the open state to introduce the atmosphere into the load lock chamber 6a (step S5-2). When the exhaust valve 14a is opened, the dry pump 12a is stopped, but the gas in the load lock chamber 6a is exhausted from the exhaust path 11c through the exhaust duct 13A by the exhaust device of the exhaust duct 13A. As a result, the gas in the load lock chamber 6a is replaced with the atmosphere. The station for replacing the gas in the load lock chamber 6a with the atmosphere is continued for a predetermined time (step S5-3). The manual opening of the exhaust valve 14a is performed by operating the lever 33a of the manual valve 33 for the exhaust valve 14a.

  After a predetermined time has elapsed, the exhaust valve 14a is manually closed (step S5-4). The manual closing of the exhaust valve 14a is performed by operating the lever 33a of the manual valve 33 for the exhaust valve 14a. Next, the duct exhaust valve 24a is manually opened (step S5-5). The manual opening of the duct exhaust valve 24a is performed by operating the lever 33a of the manual valve 33 for the duct exhaust valve 24a. When the duct exhaust valve 24a is opened, the gas in the load lock chamber 6a is exhausted from the duct exhaust path 22a through the exhaust duct 23B by the exhaust device of the exhaust duct 13B.

  Next, the concentration of the residual gas in the load lock chamber 6a is detected by the gas detector 23 (S5-6). If the detected concentration of the residual gas is equal to or lower than the reference value (step S5-7), the lock of the door 5 by the lock device 21 is released (step S5-8), and the door 5 can be opened (step S5). -9). On the other hand, when the concentration of the detected residual gas exceeds the reference value (step S5-7), the operations of steps S5-1 to S5-6 are repeated again. The detection value of the gas detector 23 is displayed on the display unit 43, for example. The operator can confirm that the detection value of the gas detector 23 exceeds the reference value from the display on the display unit 43 and repeat the operation procedure of steps S5-1 to S5-6.

  As described above, when the residual gas automatic exhaust function is abnormal, the atmosphere is introduced into the load lock chamber 6a by manually opening the atmosphere introduction valve 29a. Further, the load lock chamber 6a is forcibly exhausted by manually opening the exhaust valve 14a. That is, the gas in the load lock chamber 6a is replaced with the atmosphere, and this state continues for a predetermined time. By the replacement with the atmosphere, the load lock chamber 6a is kept sealed with respect to the outside, and the minimum apparatus (in this example, the atmosphere introduction valve 29a, the exhaust valve 14a, and the exhaust valve 14a) is effectively used. Gas for plasma processing remaining in the chamber can be discharged, and safety when the chamber is opened can be secured.

  Further, as long as the concentration of the residual gas in the load lock chamber 6a detected by the gas detector 23 does not drop below the reference value, the door 5 of the load lock chamber 6a is kept locked by the lock mechanism 21 and opened. Not possible (step S5-8). As a result, the safety when the door 5 is opened can be further enhanced.

  Also for the transfer chamber 4a, the remaining process gas can be exhausted manually after the dry etching apparatus 1 is stopped by performing the operation procedure of FIG. In this case, the exhaust valve 14b, the duct exhaust valve 24b, and the air introduction valve 26b are manually operated. Further, also for the processing chamber 3a, by performing the operation procedure of FIG. 5, after the dry etching apparatus 1 is stopped in an emergency, the remaining process gas can be exhausted manually. In this case, the exhaust valve 14c, the duct exhaust valve 24c, and the air introduction valve 26c are manually operated.

  The present invention is not limited to the above-described embodiment, and various modifications are possible as exemplified below.

  The specific mechanisms of the exhaust valves 14a to 14c, the duct exhaust valves 24a to 24c, the air introduction valves 26a to 26c, and the nitrogen introduction valves 29a to 29c are not particularly limited as long as the same or equivalent functions can be realized. Further, the specific configurations of the exhaust paths 11a to 11c, the vacuum exhaust path 17, the duct exhaust paths 22a to 22d, and the nitrogen gas paths 27a to 27d are not particularly limited as long as the same or equivalent functions can be realized.

  The inert gas for purging is not limited to nitrogen gas (nitrogen gas source 28), and an inert gas corresponding to the type of process gas may be used.

  The present invention is not limited to a dry etching apparatus, but can be applied to other plasma processing apparatuses such as a CVD apparatus.

DESCRIPTION OF SYMBOLS 1 Dry etching apparatus 2 Substrate 3 Process chamber 3a Processing chamber 3b Exhaust chamber 4 Transfer chamber 4a Transfer chamber 5 Door 6 Load lock chamber 6a Load lock chamber 6b Communication port 7a, 7b Kate valve 8 Process gas supply part 9 Plasma generating means 11a, 11b, 11c Exhaust path 12a, 12b Dry pump 13A, 13B Exhaust duct 14a, 14b, 14c Exhaust valve 15 Pressure adjustment valve 16 High vacuum pump 17 Vacuum exhaust path 18 Vacuum exhaust valve 19 Transport mechanism 21 Lock device 22a, 22b, 22c, 22d Duct exhaust path 23 Gas detector 24a, 24b, 24c Duct exhaust valve 25a, 25b, 25c Atmospheric path 26a, 26b, 26c Atmospheric introduction valve 27a, 27b, 27c, 27d Nitrogen gas path 28 Nitrogen gas Sources 29a, 29, 29c Nitrogen gas introduction valve 31 Control air path 32 Silencer 33 Manual valve 33a, 33b, 33c Port 33d Lever 34 Automatic valve 35 Compressed air source 36 Manual valve open / closed state detection sensor 41 Control unit 42 Operation / input unit 43 Display unit 44 Notification unit 45 Emergency stop switch 51 Transfer processing unit 52 Process processing unit 53, 54, 55 Residual gas exhaust processing unit 56 Device activation processing unit 57 Detoxifying means

Claims (5)

A plasma processing apparatus comprising a chamber that can be opened and closed,
A first exhaust path connecting the chamber and the first exhaust facility and interposing an exhaust pump and a normally closed first exhaust valve;
A second exhaust path that connects the chamber and the second exhaust facility and is provided with a normally closed second exhaust valve;
An atmospheric path in which the chamber communicates with the atmosphere and a normally-closed atmospheric introduction valve is interposed;
An inert gas path that connects the chamber and an inert gas source and is provided with a normally closed inert gas introduction valve;
A control device for controlling the first exhaust valve, the second exhaust valve, the air introduction valve, the inert gas introduction valve, the inert gas source, and the pump;
The controller is
Introducing the inert gas from the inert gas source into the chamber by opening the inert gas valve and subsequently evacuating the chamber at the pump by opening the first exhaust valve are predetermined. Repeated as many times as
After repeating the introduction of the atmosphere into the chamber by opening the atmosphere introduction valve and the exhaust of the chamber by the pump by opening the first exhaust valve, followed by a predetermined number of times,
A plasma processing apparatus comprising a residual gas exhaust processing unit that opens both the atmosphere introduction valve and the second exhaust valve. A releasable locking mechanism for locking the chamber in a closed state;
A gas detector for detecting the concentration of the gas exhausted by the second exhaust path;
The residual gas exhaust processing unit, after opening both the atmosphere introduction valve and the second exhaust valve, compares the detected value of the gas concentration of the gas detector with a predetermined reference value, The plasma processing apparatus according to claim 1, wherein when the detected value is equal to or less than the reference value, the lock by the lock mechanism is released.   The plasma processing apparatus according to claim 1, wherein each of the first exhaust valve, the second exhaust valve, and the atmosphere introduction valve includes a manual opening / closing mechanism. A chamber that can be opened and closed; a first exhaust path that connects the chamber and the first exhaust facility and is provided with a pump for exhaust and a first exhaust valve that is normally closed; A second exhaust path connected to the two exhaust facilities and provided with a normally closed second exhaust valve; and an atmospheric path provided with a normally closed atmosphere introduction valve connected to the chamber and the atmosphere. And a method of exhausting residual gas in a plasma processing apparatus comprising an inert gas path that connects the chamber and an inert gas source and is provided with a normally closed inert gas introduction valve,
Introducing the inert gas from the inert gas source into the chamber by opening the inert gas valve and subsequently evacuating the chamber at the pump by opening the first exhaust valve are predetermined. A first step that is repeated a number of times,
A second step of repeating the introduction of the atmosphere into the chamber by opening the atmosphere introduction valve and the subsequent exhaust of the chamber by the pump by opening the first exhaust valve;
After the first step and the second step, a residual gas exhausting method including a third step of opening both the atmosphere introduction valve and the first exhaust valve. A releasable locking mechanism that locks the chamber in a closed state, and a gas detector that detects a concentration of gas exhausted from the second exhaust path;
During the third step, the detection value of the gas concentration of the gas detector is compared with a predetermined reference value, and if the detection value is equal to or less than the reference value, the lock by the lock mechanism is released. The method for exhausting residual gas according to claim 4.

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