Plasma processing apparatus and plasma processing method

Abstract

To determine the necessity of maintenance of a translucent member caused by dirt.SOLUTION: The plasma processing apparatus includes a chamber having an opening, a plasma generation unit configured to generate plasma within the chamber, a light transmitting member configured to block at least a part of the opening and configured to transmit infrared rays, a stage provided within the chamber and configured to place a substrate thereon, a sensor configured to receive infrared rays emitted from the stage or the substrate placed on the stage through the light transmitting member and configured to output a measurement value corresponding to an intensity of the received infrared rays, and a determination unit configured to determine whether maintenance of the light transmitting member is required based on the measurement value.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a plasma processing apparatus and a plasma processing method. [Background technology]

[0002] Conventionally, plasma processing apparatuses that perform plasma processing on a workpiece such as a substrate are known (for example, Patent Document 1). Patent Document 1 discloses "a plasma dicing apparatus comprising: a chamber; a substrate support for supporting a non-metallic substrate of a type having a dicing lane; a plasma generator for generating plasma in the chamber suitable for plasma etching the substrate along the dicing lane; an infrared detector for monitoring infrared radiation emitted from at least a portion of the dicing lane; and a condition detector configured to detect a condition related to a final stage of a plasma dicing process from the monitored infrared radiation." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-006758 Summary of the Invention [Problem to be solved by the invention]

[0004] Some plasma processing apparatuses are configured to allow infrared rays emitted from a substrate or the like to be incident on a sensor through a light-transmitting member (e.g., a window that transmits infrared rays). However, if by-products generated during plasma processing are deposited on the light-transmitting member, the light-transmitting member may block some of the infrared rays, making it difficult to accurately detect the temperature of the substrate using a sensor. When the light-transmitting member becomes contaminated with deposits beyond a certain level, maintenance is required (e.g., removing the contamination or replacing the light-transmitting member with a new one), and there is a need for a technology that can appropriately determine whether such maintenance is required. In this situation, one of the objectives of the present disclosure is to determine whether maintenance of the light-transmitting member due to contamination is required. [Means for solving the problem]

[0005] One aspect of the present disclosure relates to a plasma processing apparatus including: a chamber having an opening; a plasma generating unit configured to generate plasma in the chamber; a light-transmitting member configured to cover at least a portion of the opening and transmit infrared rays; a stage configured in the chamber and on which a substrate is placed; a sensor configured to receive infrared rays emitted from the stage or the substrate placed on the stage through the light-transmitting member and output a measurement value corresponding to the intensity of the received infrared rays; and a determination unit configured to determine whether maintenance of the light-transmitting member is required based on the measurement value.

[0006] Another aspect of the present disclosure relates to a plasma processing method, the plasma processing method being performed in a plasma processing apparatus including a chamber having an opening, a plasma generating unit that generates plasma in the chamber, a light-transmitting member that covers at least a portion of the opening and transmits infrared rays, a stage that is provided in the chamber and on which a substrate is placed, and a sensor that receives infrared rays radiated from the stage or the substrate placed on the stage through the light-transmitting member and outputs a measurement value corresponding to the intensity of the received infrared rays, and the plasma processing method further includes a determination step of determining whether maintenance of the light-transmitting member is required based on the measurement value. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to determine whether maintenance of a light-transmitting member due to dirt is required. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view schematically illustrating an example of a plasma processing apparatus according to the present disclosure. [Figure 2] 1 is a graph showing an example of sensor measurement values ​​before and after the start of plasma processing, in which the solid line shows the measurement values ​​when a new dielectric window is used, and the dashed line shows the measurement values ​​when a dirty dielectric window is used. [Figure 3] 1 is a flowchart of a plasma processing method according to the first embodiment. [Figure 4] 10 is a flowchart of a plasma processing method according to a second embodiment. [Figure 5] 1 is a graph showing an example of sensor measurement values ​​during plasma processing, in which the solid line indicates the measurement values ​​and the dashed line indicates the estimated values ​​assuming that no plasma is generated. [Figure 6] 10 is a flowchart of a plasma processing method according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiments of a plasma processing apparatus and a plasma processing method according to the present disclosure will be described below using examples. However, the present disclosure is not limited to the examples described below. While specific numerical values ​​and materials may be used in the following description, other numerical values ​​and materials may be used as long as the effects of the present disclosure are obtained.

[0010] (Plasma processing equipment) The plasma processing apparatus according to the present disclosure is an apparatus for plasma processing a substrate as a processing object. The plasma processing apparatus may be, for example, a plasma etching apparatus, a plasma dicer, a plasma ashing apparatus, or a plasma CVD apparatus. The plasma processing apparatus includes a chamber, a plasma generating unit, a light-transmitting member, a stage, a sensor, and a determining unit.

[0011] The chamber has an opening. The opening may be located at an upper portion of the chamber. The opening may be open upward. The chamber may be formed in a hollow cylindrical shape. The chamber may be made of metal and may be grounded.

[0012] The plasma generating unit generates plasma in the chamber, and may include at least one induction coil and at least one high frequency power supply that supplies high frequency power to the at least one induction coil.

[0013] The light-transmitting member covers at least a portion of the opening of the chamber and transmits infrared rays. The light-transmitting member may transmit 90% or more of the incident infrared rays. The light-transmitting member may be made of, for example, a dielectric material. The shape of the light-transmitting member is not particularly limited and may be, for example, a disk shape.

[0014] The stage is provided in the chamber, and a substrate is placed on it. The stage may have a horizontal mounting surface on which the substrate is placed. The stage may have a flow path through which a coolant flows to cool the substrate during plasma processing. The stage may have an electrostatic chucking mechanism for attracting the substrate. The stage may have a lower electrode to which high-frequency power is applied. The substrate may be, for example, a semiconductor substrate to be singulated by plasma etching. The semiconductor substrate has a plurality of element regions and division regions that define the element regions. The element regions include, for example, a semiconductor layer and a wiring layer. Element chips having the semiconductor layer and the wiring layer are obtained by etching the division regions. The substrate may be placed on the stage while supported by a carrier. The carrier may be, for example, a resin sheet held at its outer periphery by a frame.

[0015] The sensor receives infrared rays emitted from the stage or a substrate placed on the stage through a light-transmitting member. The sensor outputs a measurement value corresponding to the intensity of the received infrared rays. The manner in which the measurement value is output is not particularly limited, and for example, a voltage having a magnitude corresponding to the intensity of the received infrared rays may be output. The intensity of the infrared rays emitted from the stage or substrate may increase as the temperature of the stage or substrate increases.

[0016] The determination unit determines whether maintenance of the light-transmitting member is necessary based on the measurement value output by the sensor. As described above, the sensor receives infrared rays through the light-transmitting member. Therefore, for example, if the light-transmitting member is contaminated beyond a certain level, the intensity of the infrared rays received by the sensor may change significantly compared to when the light-transmitting member is not very contaminated. As this change in intensity increases, it becomes more difficult to appropriately control the plasma processing apparatus based on the sensor measurement value. Therefore, for example, by comparing the sensor measurement value with a predetermined threshold, an excessively large change in the measurement value, i.e., the intensity of the infrared rays received by the sensor, may be detected. When such a detection is detected, it may be determined that maintenance of the light-transmitting member is necessary. By performing maintenance on the light-transmitting member in response to such a determination, appropriate plasma processing can be continued. As another example, it is possible to store information on the sensor measurement value when the light-transmitting member is not contaminated (hereinafter referred to as the first measurement value) in the determination unit, and determine that maintenance of the light-transmitting member is necessary when the difference between the first measurement value and the sensor measurement value exceeds a predetermined value. In this specification, "maintenance" includes at least removing dirt adhering to the light-transmitting member by any method and replacing the dirty light-transmitting member with a new light-transmitting member.

[0017] The determination unit may determine whether maintenance of the light-transmitting member is required based on a measurement value acquired when no plasma is generated in the chamber. Here, as a result of extensive research, it has been found that the measurement value output by the sensor changes more significantly due to contamination of the light-transmitting member in a low-temperature state (e.g., a state in which no plasma is generated in the chamber) than in a high-temperature state (e.g., a state in which plasma is generated in the chamber). Therefore, in this configuration, whether maintenance of the light-transmitting member is required is determined based on the measurement value in a state in which such a change in the measurement value is large, i.e., a state in which no plasma is generated in the chamber. This makes it even easier to determine whether maintenance of the light-transmitting member is required.

[0018] The determination unit may determine whether maintenance of the light-transmitting member is required based on a measurement value acquired when no substrate is placed on the stage. In other words, the determination unit may determine whether maintenance of the light-transmitting member is required based on a measurement value output by a sensor that receives infrared rays emitted from the stage. In this case, the determination of whether maintenance of the light-transmitting member is required can be easily performed by the plasma processing apparatus alone.

[0019] The determination unit may determine whether maintenance of the light-transmitting member is required based on measurement values ​​acquired when the substrate is placed on the stage. In other words, the determination unit may determine whether maintenance of the light-transmitting member is required based on measurement values ​​output by a sensor that receives infrared rays emitted from the substrate placed on the stage. In this case, for example, by preparing a substrate that is particularly suitable for determining whether maintenance of the light-transmitting member is required, the accuracy of the determination can be improved. Note that the substrate may be a substrate that is to be subjected to plasma processing, or may be a substrate that is not to be subjected to plasma processing.

[0020] The determination unit may determine whether maintenance of the light-transmitting member is required based on a measurement value acquired when a state in which plasma is not generated in the chamber continues for a predetermined time or longer. In this case, the determination of whether maintenance is required is performed when the chamber has reached a sufficiently low temperature (e.g., room temperature), allowing the determination to be made with high accuracy. The predetermined time may be, for example, 30 minutes or more and 1 hour or less.

[0021] The determination unit may calculate an estimated convergence value of the measured values ​​based on multiple measured values ​​acquired at different times while no plasma is generated in the chamber, and determine whether maintenance of the light-transmitting member is required based on the calculated estimated convergence value. Such an estimated convergence value is identical to or approximates a measured value acquired when no plasma is generated in the chamber for a predetermined period of time or longer. In other words, this configuration allows a pseudo-determination of whether maintenance is required when the chamber temperature has sufficiently cooled within a shorter period of time than the predetermined period, thereby improving the availability of the plasma processing apparatus. The number of measured values ​​used to calculate the estimated convergence value is not particularly limited and may be, for example, two or more and five or less. For example, the estimated convergence value may be calculated based on an approximate temperature curve obtained by plotting multiple measured values, or by experimentally or analytically determining the cooling characteristics of the plasma processing apparatus and applying multiple measured values ​​to the cooling characteristics.

[0022] (Plasma treatment method) The plasma processing method according to the present disclosure may be performed in the plasma processing apparatus described above, but can also be performed in a plasma processing apparatus that does not include a determination unit. The plasma processing method is a method performed in a plasma processing apparatus that includes the chamber described above, the plasma generation unit described above, the stage described above, and the sensor described above, and includes a determination step.

[0023] In the determination step, it is determined whether maintenance of the light-transmitting member is necessary based on the measurement value output by the sensor. If it is determined that maintenance of the light-transmitting member is necessary in this determination, maintenance of the light-transmitting member is performed, thereby enabling appropriate plasma processing to continue.

[0024] In the determination step, whether maintenance of the light-transmitting member is required may be determined based on measurements obtained when no plasma is generated in the chamber, which makes it even easier to determine whether maintenance of the light-transmitting member is required.

[0025] In the determination step, whether maintenance of the light-transmitting member is required may be determined based on measurements obtained when no substrate is placed on the stage, in which case the determination of whether maintenance of the light-transmitting member is required can be easily performed without carrying a substrate into the chamber.

[0026] In the determination step, whether maintenance of the light-transmitting member is required may be determined based on measurements obtained while the substrate is placed on the stage. In this case, for example, by preparing a substrate that is particularly suitable for determining whether maintenance of the light-transmitting member is required, the accuracy of the determination can be improved.

[0027] In the determination step, whether maintenance of the light-transmitting member is necessary may be determined based on a measurement value obtained when a state in which plasma is not generated in the chamber continues for a predetermined time or longer. In this case, the determination of whether maintenance is necessary is performed when the chamber has reached a sufficiently low temperature (e.g., room temperature), so that the determination can be made with high accuracy.

[0028] In the determination step, an estimated convergence value of the measurement values ​​may be calculated based on a plurality of measurement values ​​acquired at different times while the state in which plasma is not generated in the chamber continues, and whether maintenance of the light-transmitting member is required may be determined based on the estimated convergence value. In this configuration, the determination of whether maintenance is required when the chamber has reached a sufficiently low temperature can be performed in a simulated manner within a time shorter than the predetermined time, thereby improving the operating rate of the plasma processing apparatus.

[0029] As described above, according to the present disclosure, by using the measurement value output by the sensor, it is possible to determine whether maintenance of the light-transmitting member due to contamination is necessary. Furthermore, according to the present disclosure, by performing maintenance on the light-transmitting member at the appropriate time, it is possible to continue appropriate plasma processing.

[0030] An example of a plasma processing apparatus and a plasma processing method according to the present disclosure will be described in detail below with reference to the drawings. The above-described components and processes can be applied to the components and processes of the example plasma processing apparatus and plasma processing method described below. The components and processes of the example plasma processing apparatus and plasma processing method described below can be modified based on the above description. Furthermore, the matters described below may be applied to the above-described embodiment. Among the components and processes of the example plasma processing apparatus and plasma processing method described below, components and processes that are not essential to the plasma processing apparatus and plasma processing method according to the present disclosure may be omitted. Note that the diagrams shown below are schematic and do not accurately reflect the shapes and numbers of actual components.

[0031] First Embodiment First Embodiment A first embodiment of the present disclosure will be described. First, the configuration of a plasma processing apparatus 10 according to the present embodiment will be described, and then the plasma processing method according to the present embodiment will be described.

[0032] (Plasma processing equipment) The plasma processing apparatus 10 of this embodiment is an apparatus for plasma processing a substrate (e.g., a semiconductor substrate) as a processing object. The plasma processing apparatus 10 of this embodiment is a plasma dicer, but is not limited to this. As shown in FIG. 1, the plasma processing apparatus 10 includes a stage 11, a chamber 12, a first dielectric member 13, a cover 14, a second dielectric member 15, a first induction coil 16, a second induction coil 17, a first high-frequency power supply 18, a second high-frequency power supply 19, a sensor 23, a gas supply unit 24, and a determination unit 30.

[0033] The stage 11 is an element on which a substrate (not shown) is placed. The stage 11 has a horizontal placement surface 11a on which the substrate is placed. The stage 11 has a flow path (not shown) through which a coolant flows to cool the substrate during plasma processing. The stage 11 has an electrostatic adsorption mechanism (not shown) for adsorbing the substrate. The stage 11 has a lower electrode (not shown) to which high-frequency power is applied.

[0034] The chamber 12 accommodates the stage 11 and has a first opening 12a at the top. The chamber 12 is formed in a hollow cylindrical shape, but is not limited to this. The first opening 12a opens upward. The chamber 12 is disposed on the outer periphery side of the stage 11 and has an exhaust port 12b for exhausting the source gas used in the plasma processing. An exhaust device (not shown) is connected to this exhaust port 12b. The chamber 12 is made of a conductive material (e.g., metal) and is grounded. The first opening 12a is an example of an opening.

[0035] The first dielectric member 13 forms a first space S1 inside the chamber 12 by covering most of the first opening 12a, and also has a second opening 13a. The first dielectric member 13 is formed in the shape of a horizontally extending plate. The first space S1 is a space in which the stage 11 is disposed. The second opening 13a penetrates the first dielectric member 13 from top to bottom. The second opening 13a is disposed in the center of the first dielectric member 13. The first dielectric member 13 has a recess 13b on its upper surface. The first dielectric member 13 is made of quartz, but is not limited to this.

[0036] Cover 14 is provided to cover the lower surface of first dielectric member 13. Cover 14 has first gas inlet passage 14b, which supplies source gas to a region of first space S1 facing first induction coil 16, and second gas inlet passage 14c, which supplies source gas to a region of first space S1 facing second induction coil 17. First gas inlet passage 14b and second gas inlet passage 14c are each formed as grooves or recesses on the upper surface of cover 14. First gas inlet passage 14b communicates with the outside of chamber 12 and communicates with first space S1 via first gas hole 14d. Second gas inlet passage 14c communicates with the outside of chamber 12 and communicates with first space S1 via second gas hole 14e. A plurality of first gas holes 14d and a plurality of second gas holes 14e are arranged at intervals in the circumferential direction. The first gas holes 14d and the second gas holes 14e are each arranged at intervals in the radial direction (left-right direction in FIG. 1). The first gas inlet passage 14b and the second gas inlet passage 14c are each formed between the cover 14 and the first dielectric member 13. A source gas is supplied to the first gas inlet passage 14b and the second gas inlet passage 14c from the gas supply unit 24. The cover 14 has a third opening 14a overlapping with the second opening 13a. The third opening 14a is located in the center of the cover 14. The cover 14 is made of aluminum nitride, but is not limited to this.

[0037] The second dielectric member 15 forms a second space S2 that communicates with the first space S1 via the second opening 13a and the third opening 14a and extends upward beyond the first dielectric member 13. The second dielectric member 15 fits into the second opening 13a and the third opening 14a. The second dielectric member 15 is formed in a cylindrical shape that extends vertically. The second dielectric member 15 is made of aluminum nitride, but is not limited to this.

[0038] The second dielectric member 15 has a dielectric window 15a at its top for optical measurement. The dielectric window 15a covers a portion of the central region of the first opening 12a. The dielectric window 15a transmits infrared rays and the like emitted from the stage 11 or a substrate placed on the stage 11. The dielectric window 15a may be integral with or separate from the cylindrical portion of the second dielectric member 15. The dielectric window 15a is made of calcium fluoride, but is not limited to this. The dielectric window 15a is an example of a light-transmitting member.

[0039] The first induction coil 16 extends from the center to the outer periphery of the first dielectric member 13 above the first dielectric member 13 and generates plasma for processing substrates. Each first induction coil 16 is composed of one or more conductors extending spirally in the circumferential direction. A portion of the outer periphery of the first induction coil 16 is disposed inside a recess 13b formed in the first dielectric member 13. The first induction coil 16 receives high-frequency power from the first high-frequency power supply 18 and generates a magnetic field. This magnetic field acts on the source gas in the first space S1 via the first dielectric member 13, generating plasma.

[0040] The second induction coil 17 is disposed to surround the second dielectric member 15 and generates plasma for processing the substrate. The second induction coil 17 has a portion that extends vertically along the second dielectric member 15 and a portion that extends horizontally along the first dielectric member 13. The former is configured as a spiral extending vertically, while the latter is configured as a whorl (spiral) extending horizontally. The second induction coil 17 is disposed on the inner circumferential side of the first induction coil 16. The second induction coil 17 receives high-frequency power from the second high-frequency power supply 19 and generates a magnetic field. This magnetic field acts on the source gas in the first space S1 and / or the second space S2 via the second dielectric member 15, generating plasma.

[0041] First high frequency power supply 18 supplies high frequency power (e.g., AC power of 3 to 30 MHz) to first induction coil 16. First high frequency power supply 18 is connected to one end of first induction coil 16 via first matching box 21 such as a variable capacitor. The other end of first induction coil 16 is grounded via conductive chamber 12.

[0042] Second high frequency power supply 19 supplies high frequency power (e.g., AC power of 3 to 30 MHz) to second induction coil 17. Second high frequency power supply 19 is connected to one end of second induction coil 17 via second matching box 22 such as a variable capacitor. The other end of second induction coil 17 is grounded via conductive chamber 12.

[0043] The frequency of the power from first high frequency power supply 18 (power applied to first induction coil 16) and the frequency of the power from second high frequency power supply 19 (power applied to second induction coil 17) are different from each other. However, both frequencies may be the same. Alternatively, instead of first high frequency power supply 18 and second high frequency power supply 19, a single high frequency power supply may be provided and its power may be distributed to first induction coil 16 and second induction coil 17.

[0044] The first induction coil 16, the second induction coil 17, the first high frequency power supply 18, and the second high frequency power supply 19 constitute a plasma generating unit of this embodiment.

[0045] Sensor 23 is provided above dielectric window 15a and receives infrared rays emitted from stage 11 or a substrate placed on stage 11. Sensor 23 outputs a measurement value (hereinafter simply referred to as a measurement value) corresponding to the intensity of the received infrared rays. Information regarding the measurement value is sent to determination unit 30 via wired or wireless communication.

[0046] The gas supply unit 24 supplies a plasma raw material gas into the chamber 12. The gas supply unit 24 is connected to the first gas inlet path 14b and the second gas inlet path 14c via gas piping (not shown). The gas supply unit 24 is configured to be able to switch the type of raw material gas to be supplied, thereby making it possible to switch the type of plasma generated in the chamber 12.

[0047] The determination unit 30 includes a calculation device and a storage device storing a program executable by the calculation device (for example, a program for executing the plasma processing method of the present embodiment). The determination unit 30 determines whether maintenance of the dielectric window 15a is required based on the measurement value T output by the sensor 23.

[0048] The determination unit 30 of this embodiment determines whether maintenance of the dielectric window 15a is required based on the measurement value T obtained when no plasma is generated in the chamber 12. The determination unit 30 also determines whether maintenance of the dielectric window 15a is required based on the measurement value T obtained when a substrate is placed on the stage 11.

[0049] FIG. 2 is a graph showing an example of the measured values ​​T of the sensor 23 before and after the start of plasma processing. In this graph, the horizontal axis represents processing time, and the vertical axis represents the measured value T. The solid line represents the measured value T when a new (or clean) dielectric window 15a is used, and the dashed line represents the measured value T' when a contaminated dielectric window 15a is used. This graph shows the transition of the measured values ​​T and T' when plasma processing (specifically, substrate adsorption processing and the subsequent etching processing) is started at time t1. As can be seen from this graph, the difference between the measured value T corresponding to the new dielectric window 15a and the measured value T' corresponding to the contaminated dielectric window 15a is larger before the start of plasma processing than during the plasma processing (especially after the plasma processing has progressed to a certain extent). The determination unit 30 of this embodiment compares the measured value T with a predetermined threshold value Th before the start of plasma processing, and determines that maintenance of the dielectric window 15a is required if the measured value T exceeds the threshold value Th. On the other hand, if the measured value T is equal to or less than the threshold value Th before the start of plasma processing, the determining unit 30 may determine that maintenance of the dielectric window 15a is not required.

[0050] (Plasma treatment method) The plasma processing method of this embodiment can be performed, for example, in the plasma processing apparatus 10 of this embodiment, and includes a transport process ST11, a measurement process ST12, a determination process ST13, a plasma processing process ST14, and a notification process ST15, as shown in FIG. 3.

[0051] In the transfer step ST11, the substrate is transferred into the chamber 12 and placed on the stage 11. This transfer and placement may be performed by, for example, a robot equipped with an end effector capable of holding the substrate.

[0052] In the measurement step ST12, the sensor 23 receives infrared rays emitted from the substrate placed on the stage 11 through the dielectric window 15a, and outputs a measurement value T corresponding to the intensity of the received infrared rays.

[0053] In the determination step ST13, the determination unit 30 determines whether maintenance of the dielectric window 15a is required based on the measurement value T. If it is determined that maintenance of the dielectric window 15a is not required (if "No" in the determination step ST13), the process proceeds to the plasma treatment step ST14. On the other hand, if it is determined that maintenance of the dielectric window 15a is required (if "Yes" in the determination step ST13), the process proceeds to the notification step ST15.

[0054] In the plasma processing step ST14, the substrate is subjected to plasma processing, and the plasma processing method of this embodiment is completed.

[0055] In the notification step ST15, the determining unit 30 notifies the operator of the plasma processing apparatus 10 that maintenance of the dielectric window 15a is necessary, and the plasma processing method of this embodiment is terminated. Note that the manner of the notification is not particularly limited, and may be, for example, visual via a monitor or a lamp, or audible via a speaker.

[0056] Second Embodiment A second embodiment of the present disclosure will be described. The plasma processing apparatus 10 and plasma processing method of this embodiment differ from the first embodiment in that infrared rays emitted from the stage 11 are used to determine whether maintenance is required. The following mainly describes the differences from the first embodiment.

[0057] (Plasma processing equipment) The determination unit 30 of the plasma processing apparatus 10 of this embodiment determines whether maintenance of the dielectric window 15a is required based on the measurement value T obtained when no substrate is placed on the stage 11. The determination unit 30 also determines whether maintenance of the dielectric window 15a is required based on the measurement value T obtained when a state in which no plasma is generated in the chamber 12 continues for a predetermined time or longer.

[0058] (Plasma treatment method) As shown in FIG. 4, the plasma processing method of this embodiment includes a waiting step ST21, a measuring step ST22, a determining step ST23, a transporting step ST24, a plasma processing step ST25, and a notifying step ST26.

[0059] In the standby step ST21, it is determined whether a predetermined time has elapsed since the end of the most recent plasma processing. If the determination result is "Yes," the process proceeds to the measurement step ST22, whereas if the determination result is "No," the standby step ST21 is repeated.

[0060] In the measurement step ST22, the sensor 23 receives the infrared rays emitted from the stage 11 through the dielectric window 15a, and outputs a measurement value T corresponding to the intensity of the received infrared rays.

[0061] In the determination step ST23, the determination unit 30 determines whether or not maintenance of the dielectric window 15a is required based on the measurement value T. If it is determined that maintenance of the dielectric window 15a is not required (if "No" in the determination step ST23), the process proceeds to the transfer step ST24. On the other hand, if it is determined that maintenance of the dielectric window 15a is required (if "Yes" in the determination step ST23), the process proceeds to the notification step ST26.

[0062] In the transfer step ST24, the substrate is transferred into the chamber 12 and placed on the stage 11. This transfer and placement may be performed by, for example, a robot equipped with an end effector capable of holding the substrate.

[0063] In the plasma processing step ST25, the substrate is subjected to plasma processing, and the plasma processing method of this embodiment is completed.

[0064] In the notification step ST26, the determination unit 30 notifies the operator of the plasma processing apparatus 10 that maintenance of the dielectric window 15a is required, and the plasma processing method of this embodiment is terminated. Note that the manner of the notification is not particularly limited, and may be, for example, visual via a monitor or a lamp, or audible via a speaker.

[0065] Third Embodiment A third embodiment of the present disclosure will be described. The plasma processing apparatus 10 and plasma processing method of this embodiment differ from the first embodiment in that an estimated convergence value Te calculated from a plurality of measurement values ​​T is used to determine whether maintenance is required. The following mainly describes the differences from the first embodiment.

[0066] (Plasma processing equipment) The judgment unit 30 of the plasma processing apparatus 10 of this embodiment calculates an estimated convergence value Te of the measurement value T based on multiple measurement values ​​T obtained at different times while a state in which plasma is not generated in the chamber 12 continues, and judges whether maintenance of the dielectric window 15a is necessary based on the calculated estimated convergence value Te.

[0067] FIG. 5 is a graph showing an example of the measured value T of the sensor 23 during plasma processing. In this graph, the horizontal axis represents processing time, and the vertical axis represents the measured value T. The solid line represents the measured value, and the dashed line represents the estimated value assuming that no plasma is generated. In this graph, the solid line represents the change in the measured value T when plasma is generated in the chamber 12 from time t1, the plasma generation is stopped at time t2, and the plasma is generated again at time t3, and the same process is repeated. On the other hand, the dashed line represents the estimated value assuming that the plasma processing is terminated without generating plasma again at time t3. As shown in the graph, this estimated value asymptotically approaches an estimated convergence value Te, which can be calculated by any appropriate method based on multiple measured values ​​T (shown by dots in FIG. 5 ) acquired at different times between time t2 and time t3. The determination unit 30 of this embodiment is configured to determine whether maintenance of the dielectric window 15a is required by comparing the estimated convergence value Te with the predetermined threshold value Th.

[0068] (Plasma treatment method) As shown in FIG. 6, the plasma processing method of this embodiment includes a first plasma generation step ST31, a first plasma extinguishing step ST32, a measurement step ST33, an estimation step ST34, a determination step ST35, a second plasma processing step ST36, and a notification step ST37.

[0069] Note that, before the first plasma generating step ST31, a loading step may be performed in which a substrate is transported into chamber 12 and placed on stage 11. When the loading step is performed, a carrying-out step in which the substrate is removed from chamber 12 may be performed after first plasma extinguishing step ST32. This carrying-in, placing, and carrying-out may be performed, for example, by a robot equipped with an end effector capable of holding the substrate. The substrate carried in the loading step may be a production substrate or a dummy substrate such as silicon.

[0070] In the first plasma generation step ST31, the plasma generation unit generates a first plasma in the chamber 12. The first plasma may be, for example, a cleaning plasma for cleaning the inside of the chamber 12 before the start of production. The first plasma may also be, for example, a seasoning plasma for seasoning to stabilize the atmosphere inside the chamber 12. The first plasma may also be, for example, a second plasma for plasma processing of production substrates, which will be described later.

[0071] In the first plasma extinguishing step ST32, the plasma generating unit extinguishes the first plasma (or stops the generation of the first plasma).

[0072] In the measurement process ST33, while no plasma is generated in the chamber 12, the sensor 23 receives infrared rays emitted from the stage 11 or from a substrate placed on the stage 11 through the dielectric window 15a, and outputs a measurement value T corresponding to the intensity of the received infrared rays multiple times at different times.

[0073] In the estimation step ST34, the determination unit 30 determines an estimated convergence value Te of the measurement values ​​T based on a plurality of measurement values ​​T using any appropriate method.

[0074] In the determination step ST35, the determination unit 30 determines whether maintenance of the dielectric window 15a is required based on the calculated estimated convergence value Te. If it is determined that maintenance of the dielectric window 15a is not required (if "No" in the determination step ST35), the process proceeds to the second plasma treatment step ST36. On the other hand, if it is determined that maintenance of the dielectric window 15a is required (if "Yes" in the determination step ST35), the process proceeds to the notification step ST37.

[0075] In the second plasma treatment step ST36, the production substrate is carried into chamber 12, and then the plasma generating unit generates a second plasma in chamber 12 to perform plasma treatment on the production substrate. The second plasma may be, for example, an etching processing plasma for etching the production substrate.

[0076] In the notification step ST37, the determining unit 30 notifies the operator of the plasma processing apparatus 10 that maintenance of the dielectric window 15a is required, and the plasma processing method of this embodiment is terminated. Note that the manner of the notification is not particularly limited, and may be, for example, visual via a monitor or a lamp, or audible via a speaker.

[0077] <<Notes>> The above description of the embodiments discloses the following techniques. (Technology 1) a chamber having an opening; a plasma generating unit that generates plasma in the chamber; a translucent member that covers at least a portion of the opening and transmits infrared light; a stage provided in the chamber and on which a substrate is placed; a sensor that receives infrared rays radiated from the stage or the substrate placed on the stage through the light-transmitting member and outputs a measurement value corresponding to the intensity of the received infrared rays; a determination unit that determines whether maintenance of the light-transmitting member is required based on the measurement value; and A plasma processing apparatus comprising: (Technology 2) The plasma processing apparatus according to Technology 1, wherein the determining unit determines whether maintenance of the light-transmitting member is required based on the measurement value obtained when no plasma is generated in the chamber. (Technology 3) The plasma processing apparatus according to technique 2, wherein the determining unit determines whether maintenance of the light-transmitting member is required based on the measurement value obtained when the substrate is not placed on the stage. (Technology 4) The plasma processing apparatus according to technique 2, wherein the determining unit determines whether maintenance of the light-transmitting member is required based on the measurement value obtained when the substrate is placed on the stage. (Technology 5) The plasma processing apparatus according to Technology 3 or 4, wherein the determination unit determines whether maintenance of the light-transmitting member is required based on the measurement value obtained when a state in which plasma is not generated in the chamber continues for a predetermined time or more. (Technology 6) The plasma processing apparatus according to Technology 3 or 4, wherein the determination unit calculates an estimated convergence value of the measurement values ​​based on a plurality of the measurement values ​​acquired at different timings while a state in which plasma is not generated in the chamber continues, and determines whether maintenance of the light-transmitting member is required based on the calculated estimated convergence value. (Technology 7) a chamber having an opening; a plasma generating unit that generates plasma in the chamber; a translucent member that covers at least a portion of the opening and transmits infrared light; a stage provided in the chamber and on which a substrate is placed; a sensor that receives infrared rays radiated from the stage or the substrate placed on the stage through the light-transmitting member and outputs a measurement value corresponding to the intensity of the received infrared rays; A plasma processing method performed in a plasma processing apparatus, comprising: The plasma processing method further comprises a determining step of determining whether maintenance of the light-transmitting member is required based on the measured value. (Technology 8) The plasma processing method according to technique 7, wherein the determining step determines whether maintenance of the light-transmitting member is required based on the measurement value obtained when no plasma is generated in the chamber. (Technology 9) The plasma processing method according to technique 8, wherein the determining step determines whether maintenance of the light-transmitting member is required based on the measurement values ​​obtained when the substrate is not placed on the stage. (Technology 10) The plasma processing method according to technique 8, wherein the determining step determines whether maintenance of the light-transmitting member is required based on the measurement values ​​acquired while the substrate is placed on the stage. (Technology 11) The plasma processing method according to technique 9 or 10, wherein the determining step determines whether maintenance of the light-transmitting member is required based on the measurement value obtained when a state in which plasma is not generated in the chamber continues for a predetermined time or longer. (Technology 12) The plasma processing method according to Technology 9 or Technology 10, wherein in the determining step, an estimated convergence value of the measurement values ​​is calculated based on a plurality of the measurement values ​​acquired at different timings while a state in which plasma is not generated in the chamber continues, and whether maintenance of the light-transmitting member is required is determined based on the estimated convergence value calculated. [Industrial Applicability]

[0078] The present disclosure can be used in a plasma processing apparatus and a plasma processing method. [Explanation of symbols]

[0079] 10: Plasma processing equipment 11: Stage 11a: Placement surface 12: Chamber 12a: 1st opening (opening) 12b: Exhaust port 13: First dielectric member 13a: 2nd opening 13b: Recess 14: Cover 14a: Third opening 14b: First gas inlet 14c: Second gas inlet 14d: First gas hole 14e: Second gas hole 15: Second dielectric member 15a: Dielectric window (light-transmitting member) 16: First induction coil (plasma generation section) 17: Second induction coil (plasma generation section) 18: First high frequency power supply (plasma generation part) 19: Second high frequency power supply (plasma generation part) 21: 1st matching box 22:Second matching box 23: Sensor 24: Gas supply unit 30: Judgment section S1: 1st space S2:Second space T: Measurement value T': Measured value when the dielectric window is dirty Te: Estimated convergence value Th: Threshold

Claims

1. a chamber having an opening; a plasma generating unit that generates plasma in the chamber; a translucent member that covers at least a portion of the opening and transmits infrared light; a stage provided in the chamber and on which a substrate is placed; a sensor that receives infrared rays radiated from the stage or the substrate placed on the stage through the light-transmitting member and outputs a measurement value corresponding to the intensity of the received infrared rays; a determination unit that determines whether maintenance of the light-transmitting member is required based on the measurement value; and A plasma processing apparatus comprising:

2. The plasma processing apparatus according to claim 1 , wherein the determining unit determines whether maintenance of the light-transmitting member is required based on the measurement value obtained when no plasma is generated in the chamber.

3. The plasma processing apparatus according to claim 2 , wherein the determining unit determines whether maintenance of the light-transmitting member is required based on the measurement value obtained when the substrate is not placed on the stage.

4. The plasma processing apparatus according to claim 2 , wherein the determining unit determines whether maintenance of the light-transmitting member is required based on the measurement value obtained while the substrate is placed on the stage.

5. 5. The plasma processing apparatus according to claim 3, wherein the determining unit determines whether maintenance of the light-transmitting member is required based on the measurement value acquired when a state in which plasma is not generated in the chamber continues for a predetermined time or more.

6. 5. The plasma processing apparatus according to claim 3, wherein the determination unit calculates an estimated convergence value of the measurement values ​​based on a plurality of the measurement values ​​acquired at different times while a state in which plasma is not generated in the chamber continues, and determines whether maintenance of the translucent member is required based on the estimated convergence value.

7. a chamber having an opening; a plasma generating unit that generates plasma in the chamber; a translucent member that covers at least a portion of the opening and transmits infrared light; a stage provided in the chamber and on which a substrate is placed; a sensor that receives infrared rays radiated from the stage or the substrate placed on the stage through the light-transmitting member and outputs a measurement value corresponding to the intensity of the received infrared rays; A plasma processing method performed in a plasma processing apparatus, comprising: The plasma processing method further comprises a determining step of determining whether maintenance of the light-transmitting member is required based on the measured value.

8. 8. The plasma processing method according to claim 7, wherein in the determining step, it is determined whether maintenance of the light-transmitting member is required based on the measurement value obtained when no plasma is generated in the chamber.

9. 9. The plasma processing method according to claim 8, wherein in the determining step, it is determined whether maintenance of the light-transmitting member is required based on the measurement value acquired when the substrate is not placed on the stage.

10. 9. The plasma processing method according to claim 8, wherein the determining step determines whether maintenance of the light-transmitting member is required based on the measurement value obtained while the substrate is placed on the stage.

11. 11. The plasma processing method according to claim 9, wherein the determining step determines whether maintenance of the light-transmitting member is required based on the measurement value obtained when a state in which plasma is not generated in the chamber continues for a predetermined time or more.

12. 11. The plasma processing method according to claim 9, wherein the determining step calculates an estimated convergence value of the measurement values ​​based on a plurality of the measurement values ​​acquired at different timings while a state in which plasma is not generated in the chamber continues, and determines whether maintenance of the light-transmitting member is required based on the estimated convergence value.

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