Plasma processing apparatus and plasma processing method

Abstract

To improve the accuracy of anomaly detection.SOLUTION: A plasma processing device includes an electrostatic chucking mechanism having an electrostatic chucking electrode, a plasma generating unit that generates first and second plasmas, a control unit that controls the electrostatic chucking mechanism and the plasma generating unit such that a substrate is processed with the first or second plasma while the substrate chucks to the stage, and an abnormality detection unit that detects an abnormality on the basis of a plurality of parameters. The abnormality detection unit detects an abnormality during a predetermined period DT immediately after switching between the processing with the first plasma and the processing with the second plasma on the basis of a first parameter including monitoring information regarding a voltage V and / or a current I applied to the electrostatic chucking electrode but not including monitoring information regarding the pressure PR in a chamber while detecting an abnormality outside the predetermined period DT on the basis of a second parameter including monitoring information regarding the pressure PR in the chamber.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a plasma processing apparatus and a plasma processing method. BACKGROUND ART

[0002] Conventionally, a plasma processing apparatus for performing plasma processing on a substrate is known (for example, Patent Document 1). The plasma processing apparatus of Patent Document 1 includes a chamber, a stage on which the substrate is placed, an electrostatic adsorption mechanism having an electrostatic adsorption electrode for adsorbing the substrate to the stage, a plasma generation unit that generates first plasma and second plasma in the chamber, and a control unit that controls the electrostatic adsorption mechanism and the plasma generation unit. The control unit controls the plasma generation unit so as to switch between processing by the first plasma and processing by the second plasma. PRIOR ART DOCUMENTS PATENT DOCUMENTS

[0003] PATENT DOCUMENT 1 Japanese Unexamined Patent Publication No. 2018-78168 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] Incidentally, the plasma processing apparatus is configured to detect abnormalities such as abnormal discharge in order to avoid damage to the apparatus itself and the substrate. While this abnormality detection is performed based on various monitoring parameters measured by a sensor or the like provided in the plasma processing apparatus, a period during which abnormality detection based on the monitoring parameters is not performed (hereinafter also referred to as a ignore time) may be provided immediately after switching between the processing by the first plasma and the processing by the second plasma. Therefore, if an abnormality occurs during the ignore time, the processing continues without the abnormality being properly detected, which may damage the apparatus and the substrate. Under such circumstances, one of the objects of the present disclosure is to improve the accuracy of abnormality detection. MEANS FOR SOLVING THE PROBLEMS

[0005] One aspect of this disclosure relates to a plasma processing apparatus. The plasma processing apparatus comprises a chamber on which plasma processing is performed; a stage on which a substrate held by a transport carrier having an annular frame and a holding sheet is placed, provided in the chamber; an electrostatic adsorption mechanism disposed inside the stage and having electrostatic adsorption electrodes that adsorb the substrate to the stage when a voltage is applied; a plasma generation unit that generates a first plasma and a second plasma in the chamber by applying high-frequency power; a control unit that controls the electrostatic adsorption mechanism and the plasma generation unit so that the substrate is processed by the first plasma and the second plasma while the substrate is adsorbed to the stage; and an abnormality detection unit that detects abnormalities based on a plurality of parameters indicating the operating status of the electrostatic adsorption mechanism and the plasma generation unit. The abnormality detection unit detects abnormalities during a predetermined period immediately after switching between the first plasma processing and the second plasma processing based on a first parameter that includes monitoring information relating to at least one of the voltage and current applied to the electrostatic adsorption electrodes but does not include monitoring information relating to the pressure in the chamber, while detecting abnormalities outside the predetermined period based on a second parameter that includes monitoring information relating to the pressure in the chamber.

[0006] Another aspect of this disclosure relates to a plasma processing method. The plasma processing method uses a plasma processing apparatus comprising: a chamber on which plasma processing is performed; a stage on which a substrate held by a transport carrier having an annular frame and a holding sheet is placed, provided in the chamber; an electrostatic adsorption mechanism disposed inside the stage and having electrostatic adsorption electrodes that adsorb the substrate to the stage when a voltage is applied; and a plasma generation unit that generates a first plasma and a second plasma in the chamber by applying high-frequency power, wherein the substrate is treated with the first plasma and the second plasma while the substrate is adsorbed to the stage. The system includes a control step for controlling the electrostatic adsorption mechanism and the plasma generation unit, and an abnormality detection step for detecting abnormalities based on a plurality of parameters indicating the operating status of the electrostatic adsorption mechanism and the plasma generation unit. In the abnormality detection step, abnormalities during a predetermined period immediately after switching between processing with the first plasma and processing with the second plasma are detected based on a first parameter that includes monitoring information relating to at least one of the voltage and current applied to the electrostatic adsorption electrode, but does not include monitoring information relating to the pressure in the chamber, while abnormalities outside the predetermined period are detected based on a second parameter that includes monitoring information relating to the pressure in the chamber. [Effects of the Invention]

[0007] According to this disclosure, the accuracy of anomaly detection can be improved. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view showing an example of a plasma processing apparatus related to this disclosure. [Figure 2] This graph shows the relationship between each parameter and time when no abnormalities occur during the neglect period. [Figure 3] This graph shows the relationship between each parameter and time when an anomaly occurs at time te during the neglect period. [Figure 4]This is a flowchart of an example of the plasma processing method related to this disclosure. [Modes for carrying out the invention]

[0009] Embodiments of the plasma processing apparatus and plasma processing method relating to this disclosure will be described below with examples. However, this disclosure is not limited to the examples described below. In the following description, specific numerical values ​​and materials may be given as examples, but other numerical values ​​and materials may be applied as long as the effects of this disclosure are obtained.

[0010] (Plasma treatment device) The plasma processing apparatus according to this disclosure may be, for example, a plasma etching apparatus or a plasma dicer. The plasma processing apparatus according to this disclosure comprises a chamber, a stage, an electrostatic adsorption mechanism, a plasma generation unit, a control unit, and an abnormality detection unit.

[0011] The chamber is where the substrate is subjected to plasma treatment. Plasma treatment is a process in which the substrate is exposed to plasma, and the chemical and physical effects of the plasma are applied to the substrate. Plasma is generated by supplying process gas to a chamber under reduced pressure and generating high-frequency power in the plasma generation unit, allowing the substrate to be plasma treated.

[0012] The stage is provided within the chamber. A substrate is placed on the stage, held by a transport carrier having an annular frame and a holding sheet. The stage may have a horizontal mounting surface on which the substrate is placed. The stage may have a channel through which a coolant flows to cool the substrate and transport carrier during plasma processing. The stage may have a lower electrode to which high-frequency power is applied. The substrate may be, for example, a semiconductor substrate that is pieced by plasma etching. The semiconductor substrate comprises a plurality of element regions and dividing regions that define the element regions. The element regions comprise, for example, a semiconductor layer and a wiring layer. An element chip having a semiconductor layer and a wiring layer is obtained by etching the dividing regions.

[0013] The electrostatic adsorption mechanism has electrodes for electrostatic adsorption (hereinafter also referred to as ESC electrodes). The ESC electrodes are placed inside the stage, and the substrate is adsorbed to the stage when a voltage is applied. The electrostatic adsorption mechanism may further have a power supply unit for applying voltage to the ESC electrodes.

[0014] The plasma generation unit generates a first plasma and a second plasma in the chamber by applying high-frequency power. The first plasma may be a plasma for depositing a protective film on the surface of the substrate. The second plasma may be a plasma for etching the surface of the substrate. The process gas corresponding to the first plasma and the process gas corresponding to the second plasma may be different from each other. An example of the former process gas is a gas containing C4F8. An example of the latter process gas is a gas containing SF6. The plasma generation unit may have at least one coil that generates an alternating magnetic field when high-frequency power is applied.

[0015] The control unit controls the electrostatic adsorption mechanism and the plasma generation unit so that the substrate is treated with a first plasma and a second plasma while the substrate is adsorbed onto the stage. For example, the control unit may generate high-frequency power in the plasma generation unit while applying a voltage to the ESC electrode. The control unit may also have a computing unit and a memory device that stores a program executable by the computing unit.

[0016] The abnormality detection unit detects abnormalities (e.g., abnormal discharge during plasma processing) based on multiple parameters indicating the operating status of the electrostatic adsorption mechanism and the plasma generation unit. The abnormality detection unit may be integrated with the control unit or may be separate from the control unit. The multiple parameters include monitoring information such as the voltage and current applied to the ESC electrode, the pressure in the chamber, the high-frequency power applied to the plasma generation unit, and the capacitance value of the variable capacitor that controls the plasma impedance. The multiple parameters can be measured by sensors provided in the plasma processing unit. Examples of sensors provided in the plasma processing unit include voltmeters, ammeters, pressure gauges, and power meters.

[0017] The anomaly detection unit detects anomalies during a predetermined period (negligible time) immediately after switching between processing by the first plasma and processing by the second plasma based on a first parameter, while detecting anomalies outside the predetermined period based on a second parameter. The first parameter includes monitoring information regarding at least one of the voltage and current applied to the ESC electrode, but does not include monitoring information regarding the pressure in the chamber. The second parameter includes monitoring information regarding the pressure in the chamber. Both anomaly detection during the predetermined period and anomaly detection outside the predetermined period may be performed by determining that an anomaly has occurred when each parameter fluctuates beyond a predetermined threshold. The predetermined threshold may be, for example, the rate of fluctuation of each parameter relative to its set value, or an arbitrary absolute value. Examples of monitoring information regarding at least one of the voltage and current applied to the ESC electrode include measured values ​​of the voltage applied to the ESC electrode and measured values ​​of the current flowing through the ESC electrode. Examples of monitoring information regarding the pressure in the chamber include measured values ​​of the pressure in the chamber.

[0018] As a result of intensive studies, the inventor of the present application has found that among a plurality of parameters available for anomaly detection, there exist both parameters suitable for anomaly detection during the ignore time and parameters unsuitable for anomaly detection during the ignore time. According to this finding, parameters suitable for anomaly detection during the ignore time include monitoring information related to the voltage and current applied to the ESC electrode, while parameters unsuitable for anomaly detection during the ignore time include monitoring information related to the pressure inside the chamber. This is because during the ignore time, the former is unlikely to fluctuate significantly unless an anomaly occurs, while the latter is likely to fluctuate significantly even when no anomaly occurs (even during normal operation). Note that the pressure inside the chamber is a physical quantity that reflects the degree of decomposition of the source gas by plasma, so if the degree of decomposition of the source gas changes due to abnormal discharge, the pressure inside the chamber is also likely to change. For these reasons, it is desirable to use the monitoring information related to the pressure inside the chamber for anomaly detection in periods other than the ignore time. The anomaly detection unit of the present disclosure utilizes such findings, and is configured to perform anomaly detection based on the above-mentioned first parameter during the ignore time, and to perform anomaly detection based on the above-mentioned second parameter outside the ignore time. This makes it possible to appropriately detect anomalies without causing false detections during the ignore time.

[0019] The first parameter does not need to include monitoring information related to the high-frequency power applied to the plasma generation unit. Examples of the monitoring information related to the high-frequency power applied to the plasma generation unit may include a measured value of traveling wave power applied from the high-frequency power source to the plasma generation unit, and a measured value of reflected wave power from the plasma generation unit. The inventor of the present application has found that in addition to the monitoring information related to the pressure inside the chamber, the monitoring information related to the high-frequency power applied to the plasma generation unit may also be unsuitable for anomaly detection during the ignore time. Therefore, by not including the monitoring information related to the high-frequency power in the first parameter, the accuracy of anomaly detection can be further improved.

[0020] The second parameter may further include monitoring information related to at least one of the voltage and current applied to the ESC electrode. As a result, the accuracy of anomaly detection in periods other than the ignore time can be further improved.

[0021] The control unit does not need to change the set value of the voltage applied to the electrostatic adsorption electrode when switching between the processing by the first plasma and the processing by the second plasma. If the set value of the voltage applied to the ESC electrode is changed at the time of the switching, there is a risk that the monitoring information related to the voltage and current applied to the ESC electrode will fluctuate significantly accompanying the change even if no abnormality has occurred. In that case, depending on the magnitude relationship between the fluctuation amount and the threshold value, there is a risk of erroneously detecting an abnormality. In contrast, by not changing the set value of the voltage applied to the ESC electrode, it is possible to avoid erroneous detection of an abnormality caused by such a mechanism. In the present specification, "not changing the set value" includes not only strictly not changing the set value, but also slightly changing the set value (for example, a change of ±2% of the set value).

[0022] The first plasma may deposit a protective film on the surface of the substrate. The second plasma may etch the surface of the substrate. The control unit may control the plasma generation unit to alternately perform the processing by the first plasma and the processing by the second plasma. According to such control, a so-called Bosch process can be executed. In the Bosch process, the processing by the first plasma and the processing by the second plasma are switched at a relatively short cycle (for example, a cycle of several seconds), so the ratio of dead time to the processing time is high, and the effect of the abnormality detection unit of the present disclosure can be utilized particularly effectively.

[0023] (Plasma Processing Method) The plasma processing method according to the present disclosure may be executed, for example, using the plasma processing apparatus described above. The plasma processing method according to the present disclosure includes a control step and an abnormality detection step.

[0024] In the control step, the electrostatic adsorption mechanism and the plasma generation unit are controlled so that the processing by the first plasma and the processing by the second plasma are performed on the substrate in a state where the substrate is adsorbed to the stage. For example, in the control step, high-frequency power may be generated in the plasma generation unit while applying a voltage to the ESC electrode.

[0025] In the abnormality detection process, abnormalities (e.g., abnormal discharge during plasma processing) are detected based on multiple parameters indicating the operating status of the electrostatic adsorption mechanism and the plasma generation unit. These multiple parameters include monitoring information such as the voltage and current applied to the ESC electrode, the pressure in the chamber, the high-frequency power applied to the plasma generation unit, and the capacitance value of the variable capacitor that controls the plasma impedance. These multiple parameters are measured by sensors provided in the plasma processing unit. Examples of sensors provided in the plasma processing unit include voltmeters, ammeters, pressure gauges, and power meters.

[0026] In the anomaly detection process, anomalies are detected during a predetermined period (negligible time) immediately after switching between processing with the first plasma and processing with the second plasma, based on the first parameter, while anomalies outside of this predetermined period are detected based on the second parameter. The first parameter includes monitoring information regarding at least one of the voltage and current applied to the ESC electrode, but does not include monitoring information regarding the pressure inside the chamber. The second parameter includes monitoring information regarding the pressure inside the chamber.

[0027] In the anomaly detection process of this disclosure, the above-mentioned findings are utilized to perform anomaly detection during the neglect time based on a first parameter that includes monitoring information regarding at least one of the voltage and current applied to the ESC electrode, but does not include monitoring information regarding the pressure in the chamber. Outside of the neglect time, anomaly detection is performed based on a second parameter that includes monitoring information regarding the pressure in the chamber. This makes it possible to appropriately detect anomalies during the neglect time without false detections.

[0028] The first parameter does not necessarily have to include monitoring information regarding the high-frequency power applied to the plasma generation unit. Examples of monitoring information regarding the high-frequency power applied to the plasma generation unit include measured values ​​of the traveling wave power applied from the high-frequency power supply to the plasma generation unit and measured values ​​of the reflected wave power from the plasma generation unit. By not including such monitoring information regarding high-frequency power in the first parameter, the accuracy of anomaly detection can be further improved.

[0029] The second parameter may further include monitoring information regarding at least one of the voltage and current applied to the ESC electrode. This can further improve the accuracy of anomaly detection outside of the neglect time.

[0030] In the control process, when switching between processing with the first plasma and processing with the second plasma, it is not necessary to change the set value of the voltage applied to the electrostatic adsorption electrode. By not changing the set value of the voltage applied to the ESC electrode, it is possible to avoid false detection of abnormalities caused by fluctuations in the voltage and current applied to the ESC electrode, which may occur if the set value is changed.

[0031] The first plasma may deposit a protective film on the substrate surface. The second plasma may etch the substrate surface. In the control step, the plasma generation unit may be controlled to alternate between processing with the first plasma and processing with the second plasma. In a Bosch process performed by such control, the processing with the first plasma and processing with the second plasma are switched at relatively short cycles (e.g., cycles of a few seconds), so the proportion of negligible time in the processing time is high, and the effects of the anomaly detection step of this disclosure can be particularly effectively utilized.

[0032] As described above, this disclosure makes it possible to improve the accuracy of anomaly detection by suppressing false detections of anomalies during the ignore time.

[0033] Hereinafter, an example of a plasma processing apparatus and plasma processing method according to this disclosure will be specifically described with reference to the drawings. The components and processes described above 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 embodiments. 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 this disclosure may be omitted. Note that the figures shown below are schematic and do not accurately reflect the actual shape and number of components.

[0034] (Plasma treatment device) The plasma processing apparatus 10 in this embodiment is a plasma dicer, but is not limited to this. As shown in Figure 1, the plasma processing apparatus 10 comprises a chamber 11, a stage 16, a cover 26, an electrostatic adsorption mechanism 33, a plasma generation unit 34, a control unit 35, and an abnormality detection unit 36.

[0035] Chamber 11 is formed in a generally cylindrical shape with an open top, and the top opening is closed by a dielectric member 12 which is a lid. Examples of materials that make up Chamber 11 include aluminum, stainless steel (SUS), and aluminum with anodized surface treatment. Examples of materials that make up Dielectric member 12 include yttrium oxide (Y2O3), aluminum nitride (AlN), alumina (Al2O3), and quartz (SiO2).

[0036] A gas inlet 11a is connected to the chamber 11. A process gas source 13 and an ashing gas source 14, which are the supply sources for plasma generation gas (process gas), are connected to the gas inlet 11a by piping. The chamber 11 is also provided with an exhaust port 11b. A depressurization mechanism 15, including a vacuum pump for exhausting the gas inside the chamber 11 and reducing the pressure, is connected to the exhaust port 11b.

[0037] Stage 16 is located at the bottom of Chamber 11. Stage 16 is on which a substrate 40, held by a transport carrier 50 having an annular frame 51 and a retaining sheet 52, is placed. The transport carrier 50 is placed on Stage 16 such that the side of the retaining sheet 52 that holds the substrate 40 faces upward. Stage 16 is large enough to accommodate the entire transport carrier 50.

[0038] The stage 16 has a substantially circular electrode layer 17, a metal layer 19, a base 22 that supports the electrode layer 17 and the metal layer 19, and an outer periphery 23 that surrounds the electrode layer 17, the metal layer 19, and the base 22. The outer periphery 23 is made of a metal that is conductive and etch-resistant and protects the electrode layer 17, the metal layer 19, and the base 22 from plasma. An annular outer ring 24 is placed on the upper surface of the outer periphery 23. The outer ring 24 serves to protect the upper surface of the outer periphery 23 from plasma. The electrode layer 17 and the outer ring 24 are made of, for example, the dielectric material described above. Inside the electrode layer 17, a lower electrode 18 is placed that is electrically connected to the second high-frequency power supply 29.

[0039] The metal layer 19 is made of, for example, aluminum with an anodized coating on its surface. A refrigerant channel 21 is formed within the metal layer 19. The stage 16 can be cooled by the refrigerant flowing through the refrigerant channel 21. As the stage 16 is cooled, the holding sheet 52 placed on the stage 16 is cooled, as is the cover 26, which is partially in contact with the stage 16. This prevents the substrate 40 and the holding sheet 52 from being damaged by heating during plasma processing. The refrigerant in the refrigerant channel 21 is circulated by a refrigerant circulation device 31.

[0040] Multiple support sections 25 are positioned near the outer periphery of the stage 16, penetrating the stage 16. The support sections 25 support the frame 51 of the transport carrier 50. The support sections 25 are driven to move up and down by a lifting mechanism 32A. When the transport carrier 50 is transported into the chamber 11, it is handed over to the support sections 25, which have risen to a predetermined position. As the upper end surface of the support sections 25 is lowered to the same level as or below the stage 16, the transport carrier 50 is placed in a predetermined position on the stage 16.

[0041] The cover 26 is positioned above the stage 16 within the chamber 11. The cover 26 has a window 26W for exposing at least a portion of the substrate 40. A pressing member 27 is positioned on the cover 26 for pressing the frame 51 when the frame 51 is placed on the stage 16. The pressing member 27 is preferably a material that can make point contact with the frame 51 (for example, a coil spring or an elastic resin). This allows for the correction of distortion of the frame 51 while suppressing the mutual influence of heat between the frame 51 and the cover 26.

[0042] Multiple lifting rods 28 for raising and lowering the cover 26 are connected to the end of the cover 26. The lifting rods 28 are driven to move up and down by a lifting mechanism 32B. The lifting and lowering operation of the cover 26 by the lifting mechanism 32B can be performed independently of the lifting and lowering operation of the support part 25 by the lifting mechanism 32.

[0043] The electrostatic adsorption mechanism 33 includes an electrostatic adsorption electrode 33a (ESC electrode 33A) disposed inside the electrode layer 17, and a DC power supply 33b electrically connected to the ESC electrode 33A. The ESC electrode 33A attracts the substrate 40 (or an assembly including the substrate 40 and the transport carrier 50) to the stage 16 when a voltage is applied from the DC power supply 33b.

[0044] The plasma generation unit 34 is positioned above the dielectric member 12. The plasma generation unit 34 includes a coil 34a as an upper electrode and a first high-frequency power supply 34b electrically connected to the coil 34a. The plasma generation unit 34 generates a first plasma and a second plasma in the chamber 11 by applying high-frequency power from the first high-frequency power supply 34b to the coil 34a while a process gas is supplied to the chamber 11 under reduced pressure.

[0045] The control unit 35 controls the electrostatic adsorption mechanism 33 (specifically, the DC power supply 33b) and the plasma generation unit 34 (specifically, the first high-frequency power supply 34b) so that the substrate 40 is treated with the first plasma and the second plasma while the substrate 40 is adsorbed onto the stage 16. The control unit 35 does not change the set value of the voltage V applied to the ESC electrode 33A when switching between the first plasma treatment and the second plasma treatment. Disposal The plasma generation unit 34 is controlled to perform the first plasma and the second plasma alternately multiple times. Here, the first plasma deposits a protective film (not shown) on the surface of the substrate 40, while the second plasma etches the surface of the substrate 40.

[0046] In addition to the above-described control, the control unit 35 controls the operation of the components of the plasma processing apparatus 10, including the second high-frequency power supply 29, process gas source 13, ashing gas source 14, pressure reducing mechanism 15, refrigerant circulation device 31, lifting mechanism 32A, and lifting mechanism 32B.

[0047] The abnormality detection unit 36 ​​detects abnormalities in the plasma processing apparatus 10 based on a plurality of parameters indicating the operating status of the electrostatic adsorption mechanism 33 and the plasma generation unit 34. The abnormality detection unit 36 ​​detects abnormalities during a predetermined period DT (neglect time DT) immediately after switching between processing with the first plasma and processing with the second plasma based on the first parameter, while detecting abnormalities outside the predetermined period DT based on the second parameter. The first parameter includes monitoring information regarding both the voltage V and current I applied to the ESC electrode 33A, but does not include monitoring information regarding the pressure PR in the chamber 11 or monitoring information regarding the high-frequency power PW of the plasma generation unit 34. The second parameter includes monitoring information regarding both the voltage V and current I applied to the ESC electrode 33A, as well as monitoring information regarding the pressure PR in the chamber 11. In this embodiment, the abnormality detection unit 36 ​​is integrated with the control unit 35, but is not limited to this configuration.

[0048] Figure 2 is a graph showing the relationship between each parameter and time when the plasma processing is performed normally during the neglected time DT immediately after switching from processing with the first plasma to processing with the second plasma. Figure 3 is a graph showing the relationship between each parameter and time when an abnormality occurs at time te during the neglected time DT immediately after switching from processing with the first plasma to processing with the second plasma. As shown in Figures 2 and 3, the voltage V and current I applied to the ESC electrode 33A do not fluctuate beyond the first threshold TH1 during the neglected time DT if the plasma processing is performed normally, but they fluctuate beyond the first threshold TH1 if an abnormality occurs during the plasma processing. In contrast, the monitoring information regarding the pressure PR in the chamber 11, specifically the rate of change D from the set value of the pressure PR, may fluctuate beyond the second threshold TH2 during the neglected time DT even if the plasma processing is performed normally. Here, the rate of change D is calculated using the measured value M of the pressure PR and the set value S as D = (MS) / S. This is because, normally, the pressure PR in the chamber 11 of the plasma processing apparatus 10 is controlled by adjusting the opening of an exhaust valve provided between the chamber 11 and the vacuum pump that exhausts the chamber 11. Therefore, when switching from processing with a first plasma, where the conditions such as pressure, flow rate, and gas composition are different, to processing with a second plasma, a time delay occurs between the time immediately after the switch and the time it takes for the pressure to stabilize. In this embodiment, the abnormality detection unit 36 ​​takes into account the characteristics of each of these parameters and uses a first parameter suitable for detecting abnormalities during the neglect time DT.

[0049] The processing time (times t1-t3) for the first plasma may be, for example, 0.5 seconds or more and 5 seconds or less. The negligible time DT (times t1-t2) for the first plasma may be, for example, 0.5 seconds or more and 2 seconds or less. The processing time (times t3-t5) for the second plasma may be, for example, 0.5 seconds or more and 15 seconds or less. The negligible time DT (times t3-t4) for the second plasma may be, for example, 0.5 seconds or more and 3 seconds or less.

[0050] (Plasma treatment method) Next, a plasma processing method that can be performed using the plasma processing apparatus 10 described above will be explained with reference to Figure 4. The plasma processing method of this embodiment comprises a first step ST1 to a tenth step ST10.

[0051] In the first step ST1, processing with the first plasma (for example, protective film deposition) is started. Specifically, in the first step ST1, the electrostatic adsorption mechanism 33 (specifically, the DC power supply 33b) and the plasma generation unit (specifically, the first high-frequency power supply 34b) are controlled while supplying a process gas corresponding to the first plasma to the chamber 11 under reduced pressure, so that the substrate 40 is treated with the first plasma while the substrate 40 is adsorbed onto the stage 16. The first step ST1 is an example of a control step. The process then proceeds to the second step ST2.

[0052] In the second step ST2, an abnormality in the plasma processing apparatus 10 is detected based on the first parameter. The first parameter includes monitoring information regarding at least one of the voltage V and current I applied to the ESC electrode 33A, but does not include monitoring information regarding the pressure PR in the chamber 11 or monitoring information regarding the high-frequency power PW of the plasma generation unit 34. For example, in the second step ST2, it may be determined that an abnormality has occurred in the plasma processing apparatus 10 if the voltage V or current I applied to the ESC electrode 33A fluctuates above the first threshold TH1. The second step ST2 is an example of an abnormality detection step. The process then proceeds to the third step ST3.

[0053] In the third step, ST3, it is determined whether a predetermined period DT has elapsed since the start of processing with the first plasma. If it has elapsed (Yes), the process returns to the second step, ST2. On the other hand, if it has not elapsed (No), the process proceeds to the fourth step, ST4.

[0054] In the fourth step ST4, an anomaly in the plasma processing apparatus 10 is detected based on the second parameter. The second parameter includes monitoring information regarding at least one of the voltage V and current I applied to the ESC electrode 33A, as well as monitoring information regarding the pressure PR in the chamber 11. For example, in the fourth step ST4, if the monitoring information regarding the pressure PR in the chamber 11 fluctuates beyond the second threshold TH2, it may be determined that an anomaly has occurred in the plasma processing apparatus 10. An example of monitoring information regarding the pressure PR in the chamber 11 is the rate of fluctuation D from the set value of the pressure PR. The rate of fluctuation D is calculated using the measured value M of the pressure PR and the set value S as D = (MS) / S. The fourth step ST4 is an example of an anomaly detection step. The process then proceeds to the fifth step ST5.

[0055] In the fifth step, ST5, it is determined whether or not the processing time for the first plasma treatment is still within the specified time. If it is within the processing time (Yes), the process returns to the fourth step, ST4. On the other hand, if it is not within the processing time (No), the process proceeds to the sixth step, ST6.

[0056] In the sixth step, ST6, processing with the second plasma (for example, etching) is started. Specifically, in the sixth step, ST6, the electrostatic adsorption mechanism 33 (specifically, the DC power supply 33b) and the plasma generation unit (specifically, the first high-frequency power supply 34b) are controlled while supplying a process gas corresponding to the second plasma to the chamber 11 under reduced pressure, so that the substrate 40 is treated with the second plasma while the substrate 40 is adsorbed onto the stage 16. The sixth step, ST6, is an example of a control step. The process then proceeds to the seventh step, ST7.

[0057] In the seventh step, ST7, an abnormality in the plasma processing apparatus 10 is detected based on the first parameter. For example, in the seventh step, ST7, it may be determined that an abnormality has occurred in the plasma processing apparatus 10 if the voltage V or current I applied to the ESC electrode 33A fluctuates above the first threshold TH1. The seventh step, ST7, is an example of an abnormality detection step. The process then proceeds to the eighth step, ST8.

[0058] In step 8, ST8, it is determined whether a predetermined period DT has elapsed since the start of processing with the second plasma. If it has elapsed (Yes), the process returns to step 7, ST7. On the other hand, if it has not elapsed (No), the process proceeds to step 9, ST9.

[0059] In the ninth step, ST9, abnormalities in the plasma processing apparatus 10 are detected based on the second parameter. For example, in the ninth step, ST9, if the monitoring information regarding the pressure PR in the chamber 11 fluctuates beyond the second threshold TH2, it may be determined that an abnormality has occurred in the plasma processing apparatus 10. An example of the monitoring information regarding the pressure PR in the chamber 11 is the rate of fluctuation D from the set value of the pressure PR. The rate of fluctuation D is calculated using the measured value M of the pressure PR and the set value S as D = (MS) / S. The ninth step, ST9, is an example of an abnormality detection process. Next, the process proceeds to the tenth step, ST10.

[0060] In the 10th step ST10, it is determined whether or not it is within the processing time for the second plasma treatment. If it is within the processing time (Yes), the process returns to the 9th step ST9. On the other hand, if it is not within the processing time (No), the series of processes ends (or the process returns to the 1st step ST1). By repeatedly executing the above steps 1 ST1 to 10 ST10, the processing with the first plasma and the processing with the second plasma can be performed alternately multiple times. Note that the set value of the voltage V applied to the ESC electrode 33A may remain constant throughout steps 1 ST1 to 10 ST10.

[0061] [Note] The above description of embodiments discloses the following technologies. (Technology 1) A chamber in which plasma processing is performed, A stage is provided within the chamber on which a substrate, held by a transport carrier having an annular frame and a holding sheet, is placed. An electrostatic adsorption mechanism having electrostatic adsorption electrodes arranged inside the stage and which adsorb the substrate onto the stage when a voltage is applied, A plasma generation unit that generates a first plasma and a second plasma in the chamber by applying high-frequency power, A control unit controls the electrostatic adsorption mechanism and the plasma generation unit so that the substrate is treated with the first plasma and the second plasma while it is adsorbed onto the stage. An abnormality detection unit that detects abnormalities based on a plurality of parameters indicating the operating status of the electrostatic adsorption mechanism and the plasma generation unit, Equipped with, The plasma processing apparatus comprises an abnormality detection unit which detects abnormalities during a predetermined period immediately after switching between processing with the first plasma and processing with the second plasma based on a first parameter that includes monitoring information relating to at least one of the voltage and current applied to the electrostatic adsorption electrode, but does not include monitoring information relating to the pressure in the chamber, and which detects abnormalities outside the predetermined period based on a second parameter that includes monitoring information relating to the pressure in the chamber. (Technology 2) The plasma processing apparatus according to Art 1, wherein the first parameter does not include monitoring information regarding the high-frequency power applied to the plasma generation unit. (Technology 3) The plasma processing apparatus according to Art 1 or 2, wherein the second parameter further includes monitoring information relating to at least one of the voltage and current applied to the electrostatic adsorption electrode. (Technology 4) The plasma processing apparatus according to any one of the technologies 1 to 3, wherein the control unit does not change the set value of the voltage applied to the electrostatic adsorption electrode when switching between processing with the first plasma and processing with the second plasma. (Technology 5) The first plasma deposits a protective film on the surface of the substrate. The second plasma etches the surface of the substrate, The plasma processing apparatus according to any one of technologies 1 to 4, wherein the control unit controls the plasma generation unit to alternately perform processing with the first plasma and processing with the second plasma. (Technology 6) A chamber in which plasma processing is performed, A stage is provided within the chamber on which a substrate, held by a transport carrier having an annular frame and a holding sheet, is placed. An electrostatic adsorption mechanism having electrostatic adsorption electrodes arranged inside the stage and which adsorb the substrate onto the stage when a voltage is applied, A plasma generation unit that generates a first plasma and a second plasma in the chamber by applying high-frequency power, A plasma processing method using a plasma processing apparatus comprising, A control step for controlling the electrostatic adsorption mechanism and the plasma generation unit so that the substrate is treated with the first plasma and the second plasma while the substrate is adsorbed onto the stage, An abnormality detection step for detecting an abnormality based on a plurality of parameters indicating the operating status of the electrostatic adsorption mechanism and the plasma generation unit, Equipped with, Plasma processing method wherein, in the abnormality detection step, abnormalities during a predetermined period immediately after switching between processing with the first plasma and processing with the second plasma are detected based on a first parameter that includes monitoring information relating to at least one of the voltage and current applied to the electrostatic adsorption electrode, but does not include monitoring information relating to the pressure in the chamber, while abnormalities outside the predetermined period are detected based on a second parameter that includes monitoring information relating to the pressure in the chamber. (Technology 7) The plasma processing method according to Technical Reference 6, wherein the first parameter does not include monitoring information regarding the high-frequency power applied to the plasma generation unit. (Technology 8) The plasma processing method according to Art 6 or 7, wherein the second parameter further includes monitoring information relating to at least one of the voltage and current applied to the electrostatic adsorption electrode. (Technology 9) The plasma processing method according to any one of technologies 6 to 8, wherein the control step does not change the set value of the voltage applied to the electrostatic adsorption electrode when switching between processing with the first plasma and processing with the second plasma. (Technology 10) The first plasma deposits a protective film on the surface of the substrate. The second plasma etches the surface of the substrate, The plasma processing method according to any one of technologies 6 to 9, wherein the control step involves controlling the plasma generation unit to alternately perform processing with the first plasma and processing with the second plasma. [Industrial applicability]

[0062] This disclosure can be used in plasma processing apparatus and plasma processing methods. [Explanation of symbols]

[0063] 10: Plasma processing equipment 11: Chamber 11a: Gas inlet 11b: Exhaust vent 12: Dielectric material 13: Process gas source 14: Ashing gas source 15: Pressure reduction mechanism 16: Stage 17: Electrode layer 18: Lower electrode 19: Metal layer 21: Refrigerant flow path 22: Base 23: Outer perimeter 24: Outer ring 25: Support part 26: Cover 26W: Window section 27: Retaining member 28: Lifting rod 29:Second high frequency power supply 31: Refrigerant circulation device 32A: Lifting mechanism 32B: Lifting mechanism 33: Electrostatic adsorption mechanism 33a: Electrostatic adsorption electrode (ESC electrode) 33b: DC power supply 34: Plasma generation unit 34a: Coil 34b: 1st high frequency power supply 35: Control Unit 36: Anomaly detection unit 40: Circuit board 50: Transport Carrier 51: Frame 52: Retaining sheet D: Fluctuation rate DT: Designated period (neglect time) I: Current applied to the ESC electrode PR: Pressure inside the chamber PW: High-frequency power of the plasma generation unit TH1: First threshold TH2: Second threshold V: Voltage applied to the ESC electrode

Claims

1. A chamber in which plasma processing is performed, A stage is provided within the chamber on which a substrate, held by a transport carrier having an annular frame and a holding sheet, is placed. An electrostatic adsorption mechanism having electrostatic adsorption electrodes arranged inside the stage and which adsorb the substrate onto the stage when a voltage is applied, A plasma generation unit that generates a first plasma and a second plasma in the chamber by applying high-frequency power, A control unit controls the electrostatic adsorption mechanism and the plasma generation unit so that the substrate is treated with the first plasma and the second plasma while it is adsorbed onto the stage. An abnormality detection unit that detects abnormalities based on a plurality of parameters indicating the operating status of the electrostatic adsorption mechanism and the plasma generation unit, Equipped with, The abnormality detection unit detects abnormalities during a predetermined period immediately following the switching between the processing by the first plasma and the processing by the second plasma based on a first parameter that includes monitoring information relating to at least one of the voltage and current applied to the electrostatic adsorption electrode, but does not include monitoring information relating to the pressure in the chamber. On the other hand, it detects abnormalities outside of the predetermined period based on a second parameter that includes monitoring information relating to the pressure in the chamber. Plasma processing apparatus, wherein the abnormality detection unit determines that an abnormality has occurred if the voltage or current applied to the electrostatic adsorption electrode fluctuates above a first threshold during a predetermined period, and determines that an abnormality has occurred if the monitoring information regarding the pressure in the chamber fluctuates above a second threshold outside of the predetermined period.

2. The plasma processing apparatus according to claim 1, wherein the first parameter does not include monitoring information relating to the high-frequency power applied to the plasma generation unit.

3. The plasma processing apparatus according to claim 1 or 2, wherein the second parameter further includes monitoring information relating to at least one of the voltage and current applied to the electrostatic adsorption electrode.

4. The plasma processing apparatus according to claim 1 or 2, wherein the control unit does not change the set value of the voltage applied to the electrostatic adsorption electrode when switching between processing with the first plasma and processing with the second plasma.

5. The first plasma deposits a protective film on the surface of the substrate. The second plasma etches the surface of the substrate, The plasma processing apparatus according to claim 1 or 2, wherein the control unit controls the plasma generation unit to alternately perform processing with the first plasma and processing with the second plasma.

6. A chamber in which plasma processing is performed, A stage is provided within the chamber on which a substrate, held by a transport carrier having an annular frame and a holding sheet, is placed. An electrostatic adsorption mechanism having electrostatic adsorption electrodes arranged inside the stage and which adsorb the substrate onto the stage when a voltage is applied, A plasma generation unit that generates a first plasma and a second plasma in the chamber by applying high-frequency power, A plasma processing method using a plasma processing apparatus comprising: A control step for controlling the electrostatic adsorption mechanism and the plasma generation unit so that the substrate is treated with the first plasma and the second plasma while the substrate is adsorbed onto the stage, An abnormality detection step that detects an abnormality based on a plurality of parameters indicating the operating status of the electrostatic adsorption mechanism and the plasma generation unit, Equipped with, In the abnormality detection step, abnormalities during a predetermined period immediately following the switching between the processing with the first plasma and the processing with the second plasma are detected based on a first parameter that includes monitoring information relating to at least one of the voltage and current applied to the electrostatic adsorption electrode, but does not include monitoring information relating to the pressure in the chamber; while abnormalities outside the predetermined period are detected based on a second parameter that includes monitoring information relating to the pressure in the chamber. Plasma processing method, wherein the abnormality detection step determines that an abnormality has occurred if the voltage or current applied to the electrostatic adsorption electrode fluctuates above a first threshold during the predetermined period, and determines that an abnormality has occurred if the monitoring information regarding the pressure in the chamber fluctuates above a second threshold outside of the predetermined period.

7. The plasma processing method according to claim 6, wherein the first parameter does not include monitoring information relating to the high-frequency power applied to the plasma generation unit.

8. The plasma processing method according to claim 6 or 7, wherein the second parameter further includes monitoring information relating to at least one of the voltage and current applied to the electrostatic adsorption electrode.

9. The plasma processing method according to claim 6 or 7, wherein the control step does not change the set value of the voltage applied to the electrostatic adsorption electrode when switching between processing with the first plasma and processing with the second plasma.

10. The first plasma deposits a protective film on the surface of the substrate. The second plasma etches the surface of the substrate, The plasma processing method according to claim 6 or 7, wherein the control step involves controlling the plasma generation unit to alternately perform processing with the first plasma and processing with the second plasma.

Images