JP2006278719A - Plasma processing apparatus and plasma processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma processing apparatus which can detect the terminal point of the plasma processing with sufficient accuracy, and to provide a plasma processing method which can raise the quality of the plasma processing. <P>SOLUTION: While impressing voltage to electrode members 12 and 13 disposed opposite to each other from a power supply 7, and generating plasma gas 4a by passing processing gas 4 between these electrodes, a plasma processing apparatus 1 which brings the plasma gas into contact with the surface of a glass substrate 2 as material to be processed so as to perform etching processing is provided with a laser displacement 20 which detects the boundary plane of the glass substrate 2 and a thin film 2a as a base level of the glass substrate 2. During the etching processing, the amount of displacement of a boundary plane is detected from an incidence light 21 and a reflection light 22 which are irradiated from this laser displacement meter, and a terminal point of etching processing is detected based on the variance of a detection value. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a plasma processing apparatus, a plasma processing method for detecting an end point of plasma processing, and ending the processing, and more particularly to a plasma processing apparatus for performing etching processing using plasma near atmospheric pressure, and a plasma processing method. .

  In recent years, with the development of flat panel displays such as liquid crystal display devices, plasma processing devices and the like are used in the display manufacturing stage. For example, an electrode pattern such as ITO is formed on a transparent substrate such as a glass substrate, and then a manufacturing process such as forming a polysilicon thin film transistor (“TFT”) with a built-in drive circuit is performed. However, since various thin films are formed on the electrode pattern, the thin film is finally removed and a part of the electrode pattern is used as a lead electrode. Therefore, manufacturing techniques such as a conventional wet etching method and a dry etching method are used. In this type of etching method, it is required that the thin film on the electrode pattern is completely removed and the electrode pattern is not damaged, and end point detection is important.

  Conventionally, as this type of plasma processing apparatus, the plasma etching apparatus described in Patent Document 1 has a plasma etching end point detection mechanism, and a detection unit that detects an etching end point of plasma etching by monitoring plasma emission intensity, There are means for monitoring the plasma impedance and determining the plasma impedance change time point as the etching end point, and means for determining the matching adjustment time point of the matching unit for matching the high frequency power source as the etching end point. Is used to detect an etching end point or abnormality in plasma etching.

  Further, the dry etching apparatus described in Patent Document 2 generates plasma between the first electrode and the second electrode by high-frequency power, guides the plasma light to the outside of the reaction chamber, and detects a light change of the plasma light. The end point of dry etching is determined based on the detection result, and the high frequency power is stopped.

Japanese Patent Laid-Open No. 7-169741 JP 2001-176851 A

  By the way, the end point detection mechanism of the above structure can be applied to the end point detection in the vacuum chamber or the reaction chamber, but in the etching end point processing under the pressure near the atmospheric pressure, the end point cannot be detected due to the change in plasma emission. There was a problem. If the processing is performed excessively using these end point detection methods, the base material such as glass is dissolved, and a residue is generated in the processing portion, and the surface of the processing surface to be exposed may be eroded.

  The present invention has been made in view of such problems, and the object of the present invention is to accurately detect the position and displacement of the material to be processed and accurately detect the end point of the plasma processing. The object is to provide a plasma processing apparatus which can be terminated. Another object of the present invention is to provide a plasma processing method for detecting the end point of plasma processing near atmospheric pressure and terminating the processing without using a vacuum chamber or reaction chamber. It is another object of the present invention to provide a plasma processing method capable of improving the quality of the etching process by detecting the end point of the etching process and performing the process for a predetermined time from the detected end point.

  In order to achieve the above object, the present inventors have conducted extensive research on detecting the end point of plasma processing such as etching processing, and as a result, accurately detected the reference surface of the substrate on which the thin film to be removed has been accurately detected. The inventors have found that the processing end point can be detected well, and have completed the present invention having the following characteristics. That is, the plasma processing apparatus according to the present invention applies a voltage to opposing electrodes, causes a processing gas to flow between the electrodes, generates a plasma gas, and makes the plasma gas contact the surface of the material to be processed. This apparatus is equipped with a laser displacement meter that detects the reference surface of the material to be processed. During the etching process, the laser displacement meter is used to detect the reference surface, and fluctuations in the detected value are detected. The end point of the etching process is detected based on the above. The etching process is dry etching, and the voltage is preferably a high frequency voltage.

  The plasma processing apparatus of the present invention configured as described above uses a laser displacement meter to detect the reference surface of the material to be etched and to detect that the thin film to be removed has been removed reliably, for example. Since the detection is performed based on the displacement amount of the reference surface output from the meter, the etching end point can be detected with high accuracy. In this way, the end point of the etching process can be accurately detected without contact, and the quality of the plasma process can be improved. The end point of the etching process can be detected near atmospheric pressure. As the reference surface, a boundary surface between the substrate and the thin film, the surface of the thin film, and the like are preferable.

  As a preferred specific aspect of the plasma processing apparatus according to the present invention, the laser displacement meter is arranged at a position not in contact with the plasma gas. According to this configuration, since the laser displacement meter that detects the end point of the treatment can be prevented from touching the activated processing gas (plasma gas), the function of the laser displacement meter can be stabilized and the laser displacement can be prevented. The durability of the meter can be improved.

  Furthermore, as another preferable specific embodiment of the plasma processing apparatus according to the present invention, the material to be processed is a transparent substrate, and a laser displacement meter is installed inside a gantry on which the transparent substrate is placed and fixed. A transparent window through which the total laser beam can pass is opened on the mounting surface of the gantry. According to this configuration, a transparent substrate such as glass is fixed to the mounting surface of the gantry, and the laser beam for measurement of the laser displacement meter is processed from the inside of the gantry through the transparent window opened on the mounting surface of the gantry. Since the material is irradiated, the plasma displacement does not hit the laser displacement meter, and the etching processing portion on the upper surface of the transparent substrate can be detected accurately without contact through the transparent window and the transparent substrate.

  In the plasma processing method according to the present invention, an electric field is applied to opposing electrodes, a processing gas is caused to flow between the electrodes to generate a plasma gas, and the plasma gas is brought into contact with the surface of the processing material to be processed. A plasma processing method that removes a thin film formed on the surface by etching, and a laser displacement meter is focused on the interface between the surface of the material to be processed and the thin film, and the amount of displacement of the interface as the etching process proceeds , And the end point of the plasma processing is detected using the fact that the amount of displacement of the laser displacement meter varies when the thin film is removed.

  The plasma processing end point detection method configured as described above can accurately detect the end point of the etching process under a pressure in the vicinity of the atmospheric pressure, and can improve the quality of the plasma processing. In addition, even when processing is performed using water vapor plasma or when moisture in the atmosphere adheres to the processing portion during processing, it is possible to detect displacement fluctuations at the boundary surface without being affected by the liquid phase formed on the processing surface. Therefore, the detection accuracy of the end point of the etching process can be increased. For example, the operator can confirm the displacement variation of the laser displacement meter on the monitor, and can finish the work at that time. Alternatively, the peak of displacement fluctuation may be detected and the etching operation may be terminated by the controller.

  In the plasma processing method according to the present invention, an electric field is applied to opposing electrodes, a processing gas is caused to flow between the electrodes to generate a plasma gas, and the plasma gas is brought into contact with the surface of the processing material to be processed. A plasma processing method that removes the thin film formed on the surface by etching. The laser displacement meter is focused on the interface between the surface of the workpiece and the thin film, and the displacement of the interface as the etching process progresses is detected. Then, after confirming the removal of the thin film using the fact that the displacement amount of the laser displacement meter fluctuates, an etching process is further performed for a predetermined time, and the process is terminated. The etching process using the plasma gas is preferably performed under atmospheric pressure.

  In the plasma processing method configured in this way, after the end point of the etching process is accurately detected, the etching process is continued for a predetermined time and then the process is terminated. The probability that the power part remains is extremely reduced, and the processing quality can be improved. In particular, when a thin film formed on a pattern such as an electrode is removed by an etching process in a process near atmospheric pressure, the thin film on the electrode can be reliably removed.

  Since the plasma processing apparatus and the plasma processing method of the present invention can accurately detect the end point of the etching process, the quality of the etching process can be improved under a pressure near atmospheric pressure without using a vacuum chamber or the like. In another aspect of the plasma processing method of the present invention, the quality of plasma processing can be improved by accurately detecting the end point of the etching processing and continuing the processing for a predetermined time.

  Hereinafter, an embodiment of a plasma processing apparatus according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a main part configuration diagram schematically showing the plasma processing apparatus according to the present embodiment, and FIG. 2 is a perspective view of the main part configuration for detecting the end point of the plasma processing of FIG.

1 and 2, a plasma processing apparatus 1 is a remote type including a plasma source 10 as a processing head for spraying a plasma processing gas onto a glass substrate 2 (material to be processed) that is a transparent substrate for performing an etching process. This is a (down flow type) processing apparatus. The plasma source 10 includes a discharge processing unit 11 into which the processing gas 4 is introduced from the processing gas supply source 3. The plasma processing apparatus 1 according to the present embodiment is an apparatus that removes dry processing by bringing sprayed processing gas into contact with a SiO ₂ thin film of a material to be processed in which a SiO ₂ thin film 2a is formed on the surface of a glass substrate 2. It is.

  The plasma processing apparatus 1 also includes a gantry 5 on which the glass substrate 2 is placed and fixed. The glass substrate 2 fixed to the gantry 5 located below the plasma source 10 is etched below the discharge processing unit 11. It becomes the composition which is done. The plasma processing apparatus 1 includes two opposing electrode members 12 and 13 in the discharge processing unit 11, and supplies, for example, a pulsed high-frequency voltage from the power source 7 to one of them, and the other is grounded to the GND 8. With this configuration, plasma processing gas (plasma gas) 4 a is sprayed on the glass substrate 2 fixed to the gantry 5 to perform dry etching processing of the thin film formed on the glass substrate 2. The glass substrate 2 is preferably configured to be adsorbed by, for example, a decompression unit (not shown).

  The two opposing electrode members 12 and 13 of the discharge processing unit 11 have a long shape or a long bar shape, and are arranged in parallel along the width direction of the etching processing of the glass substrate 2. The two electrode members are opposed to each other with a center gap 14 having a predetermined width. When the voltage from the power source 7 is applied to each electrode member, the center gap 14 generates glow discharge and becomes a discharge space. An etching process gas 4 is supplied into the discharge space and activated to generate a plasma gas 4a. Each of the electrode members 12 and 13 is composed of a single metal such as copper or aluminum, an alloy such as stainless steel or brass, an intermetallic compound, or the like.

  The electrode members 12 and 13 have at least an electrode facing surface covered with a solid dielectric coating layer (not shown), and the thickness of the coating layer is preferably about 0.01 to 4 mm. As the solid dielectric, in addition to alumina, for example, plastics such as polytetrafluoroethylene and polyethylene terephthalate, metal oxides such as glass, silicon dioxide, zirconium dioxide, and titanium dioxide, double oxides such as barium titanate, and the like Various types such as a multilayered structure can be used. In order to perform a stable glow discharge at the center gap 14, the outer peripheral surface of the electrode member may be covered with a plate-like material such as ceramics or resin, a sheet-like material, or a film-like material. Further, it is preferable to round at least the corners of the electrode member on the center gap side, and it is preferable to round the four corners as shown.

  The width of the center gap 14 is appropriately determined in consideration of the thickness of the solid dielectric covering the electrode members 12 and 13, the magnitude of the applied voltage, the purpose of using plasma, and the like, but is 1 to 3 mm. Is preferred. If it is less than 1 mm, it may not be sufficient to install with a gap between the electrodes. If it exceeds 3 mm, it is difficult to generate uniform discharge plasma. The gantry 5 may be configured to be movable in the direction orthogonal to the longitudinal direction of the electrode members 12 and 13 by the conveying means 6 so as to widen the etching processing width.

  The power source 7 applies a pulsed high-frequency voltage to the two electrode members 12 and 13 in the discharge processing unit 11, applies a pulsed voltage to one electrode member, and grounds the other electrode member facing each other. Thus, a discharge is generated in the central gap 14 between the electrodes. The pulse voltage preferably has, for example, a rise time and a fall time of 10 μs or less, a pulse duration of 200 μs or less, an electric field strength of 1 to 1000 kV / cm, and a frequency of 0.5 kHz or more.

  If the electric field strength is less than 1 kV / cm, the process takes too much time, and if it exceeds 1000 kV / cm, arc discharge tends to occur. If it is less than 0.5 kHz, the plasma density is low, and the process takes too much time. The upper limit is not particularly limited, but it may be a high frequency band such as 13.56 MHz that is commonly used and 500 MHz that is used experimentally. In consideration of ease of matching with the load and handleability, 500 kHz or less is preferable. By applying such a high-frequency pulse voltage, the processing speed can be greatly improved.

  The voltage applied to the electrode members 12 and 13 is not limited to the pulse voltage, and may be a continuous wave voltage. As the pulse voltage waveform, an appropriate waveform such as a square wave type, a modulation type, or a combination of the above waveforms can be used in addition to the impulse type. Further, the voltage waveform may be a so-called one-wave waveform in which a voltage is applied to either the positive or negative polarity side, in addition to the voltage application repeating positive and negative. A bipolar waveform may also be used. Of course, an AC waveform that is a general sine wave may be used.

In the plasma processing apparatus 1 of the present embodiment, the etching process is performed under a pressure near atmospheric pressure. The pressure near atmospheric pressure is a pressure of 100 to 800 Torr (about 1.333 × 10 ^{4 to} 10.664 × 10 ⁴ Pa), and is actually easy to adjust the pressure and used for the discharge plasma treatment. A pressure of 700 to 780 Torr (about 9.331 × 10 ^{4 to} 10.9797 × 10 ⁴ Pa), which makes the apparatus simple, is preferable. The processing gas 4 is activated by glow discharge, and the thin film 2a and the like on the surface of the glass substrate 2 are removed by etching.

  Plasma etching is performed using a processing gas that can dry-etch a wafer or the like, for example, mainly a halogen-based gas, but basically any processing gas can be used as long as it can separate halogen in plasma. There may be. Specific examples of the halogen-based gas as a processing gas used for etching include chlorine gas, bromine gas, fluorine gas, and the like, and halogen compound gas containing halogen and carbon or halogen and hydrogen is also included.

Examples of the halogen compound gas include CF ₄ and CHF ₃ . In addition, reactive gases such as oxygen may act directly or catalytically on the etching that occurs from halogen-based gases to enhance the effect, so they are diluted with a general-purpose gas such as oxygen or air. May be. In the etching process, the halogen-based gas may be used as it is, or a rare gas such as neon, argon, or xenon, nitrogen gas, or the like may be mixed. These may be used alone or in admixture of two or more.

  The plasma processing apparatus 1 of the present embodiment includes a laser displacement meter 20 as means for detecting the end point of the etching process as a characteristic configuration. This laser displacement meter is provided with laser light generating means (not shown) built in the main body, and irradiates incident light 21 onto an object to be measured (glass substrate 2) and reflects the reflected light 22 inside an CCD sensor (not shown). And the displacement of the glass substrate 2 and the displacement of the reference plane are detected. It can measure with a high sampling time of about 50 Hz and has a high resolution of about 0.05 μm.

  The laser displacement meter 20 is installed inside the gantry 5 of the plasma processing apparatus 1 on which the glass substrate 2 is placed and fixed, and a transparent window such as a glass plate through which incident light 21 and reflected light 22 can be transmitted on the upper surface of the gantry. 5a is fitted. Incident light 21 for measurement is irradiated upward and is installed so that the reference surface of the glass substrate 2 can be measured through the transparent window 5a. Thus, since the laser displacement meter 20 is installed inside the gantry 5, it is configured not to be exposed to the processing gas during the plasma etching process.

  The operation of the plasma processing apparatus 1 of the present embodiment configured as described above will be described below with reference to FIGS. A pulsed high frequency voltage is applied from the power source 7 to the electrode members 12 and 13 of the discharge processing unit 11 and glow discharge is caused in the opposed central gap 14 to form a discharge space. A processing gas 4 for etching is supplied from the processing gas supply source 3 to the discharge space, activated to be a plasma etching gas 4a, and sprayed on the surface of the glass substrate 2. The etching process is usually performed at normal temperature and normal pressure, but may be performed in a high temperature environment, for example. Further, a resist film may be formed in a portion other than the removal range of the thin film to be etched.

  As shown in FIG. 3a, the incident light 21 of the laser displacement meter 20 is focused on the boundary surface between the transparent glass substrate 2 and the thin film 2a, and the reflected light 22 from the boundary surface is reflected in the main body. It is detected by CCD. In the present embodiment, the boundary surface between the glass substrate and the thin film is used as the reference surface. That is, the focal position is detected with a resolution of 0.05 μm in a predetermined sampling time, and the position of the boundary surface is detected as the reference plane of the glass substrate 2. Although not shown in the figure, the exhaust gas after the etching process is sucked by an intake device or the like, and then processed in a harmless state by the processing device and discarded.

When the plasma processing etching gas 4a is sprayed under atmospheric pressure from the state of FIG. 3a to contact the surface of the SiO ₂ thin film 2a and the etching process is performed, the SiO ₂ thin film 2a on the glass substrate 2 is dry-etched, and FIG. The film thickness of the sprayed portion is reduced as shown in FIG. However, the incident light 21 for measurement irradiated from the laser displacement meter 20 is focused on the boundary surface between the glass substrate 2 and the SiO ₂ thin film 2a, and the position of the boundary surface does not change. As shown, the amount of displacement fluctuates within a range of about ± 1 μm. This displacement shake is noise or the like.

The etching depth increases with the lapse of processing time for spraying the plasma etching gas 4a and bringing it into contact with the SiO ₂ thin film 2a. Then, as shown in FIG. 3c, when the SiO ₂ thin film 2a is removed and the boundary surface is exposed, the incident light 21 does not have the SiO ₂ thin film 2a, so the displacement amount is as shown in period B of FIG. Shows a large displacement fluctuation in the range of 4 to 5 μm. That is, as shown in the period B of FIG. 4, it is possible to detect when the amount of displacement has changed greatly and detect that the etching process has been completed.

  As described above, the displacement amount of the boundary surface is detected by the laser displacement meter 20 during the etching process, and the end point of the etching process can be easily detected with high accuracy in a short time based on the fluctuation of the detected value. Quality can be improved. Further, since the laser displacement meter 20 does not contact the plasma gas 4a inside the gantry 5 during the etching process, corrosion does not occur, durability can be improved, and output can be stably detected with high accuracy. Become. For example, the operator can confirm the displacement variation with a monitor or the like, and can finish the etching operation at an optimal timing.

In the plasma processing method of this embodiment, after the end point of the etching process is detected by the laser displacement meter 20 as described above, the etching process is further continued for a predetermined time, and the SiO ₂ thin film 2a is reliably removed, which is a base material. This continues until the glass substrate 2 is slightly over-etched. After detecting the end point, the output of the laser displacement meter 20 fluctuates within a range of about ± 1 μm as shown in a period C in FIG. In this way, by performing over-etching for a predetermined time after the end point is detected, the thin film to be removed can be surely removed. For example, when there is an electrode pattern such as ITO under the thin film, contact of the exposed electrode pattern Resistance can be reduced.

FIG. 3 shows a state in which the environment of the etching process is atmospheric air, moisture in the air adheres along with the etching process, and the liquid phase W adheres to the surface of the SiO ₂ thin film 2a. Further, during the etching process, water vapor may be positively supplied to form water vapor plasma to perform the etching process. In this case as well, the liquid phase W may be formed due to moisture adhering to the etched portion, but the detection state of the laser displacement meter 20 does not change depending on the liquid phase. That is, even if the liquid phase W is formed in the etching processing portion 2b, the end point of the etching processing can be similarly detected with high accuracy because the reference surface is the boundary surface between the glass substrate 2 and the SiO ₂ thin film 2a. The formed liquid phase such as water vapor is vaporized after completion of the treatment, but may be removed by a process such as heating.

  Note that the focus of the incident light 21 output from the laser displacement meter 20 is not limited to the example in which the incident light 21 is aligned with the boundary surface between the glass substrate 2 and the thin film 2a, but may be focused so as to detect the position of the upper surface of the thin film. Good. As described above, when the position of the upper surface of the thin film to be etched is detected as a reference plane by the laser displacement meter, a decrease in film thickness due to the etching process is output from the laser displacement meter 20, so the processing end point is determined from this displacement amount. It can be detected with high accuracy.

In the plasma processing method of the present invention, as shown in FIG. 3c, after the end point of the etching process is detected, the etching process is further continued for a predetermined time, and then the process is terminated. That is, after the SiO ₂ thin film 2a is removed, an etching process is further performed. As a result, as shown in FIG. 3d, the etched portion 2b is over-etched, and the surface of the glass substrate 2 as a base material is slightly eroded. In FIG. 4, after the period B at the end of the process, the process is continued for about 80 seconds as shown in the period C, but this process time can be appropriately set depending on the material of the material to be processed. .

As described above, in the plasma processing method of the present embodiment, which is slightly over-etched after detection of the processing end point, for example, a transparent electrode pattern such as ITO is formed on the surface of the glass substrate 2, and the SiO ₂ thin film 2a is formed thereon. Is suitable for removing the SiO ₂ thin film 2a by an etching process. That is, the contact resistance of the transparent electrode pattern can be reduced by over-etching the surface of the glass substrate 2 within a range where no damage remains on the surface of the transparent electrode pattern.

A SiO ₂ thin film 2a was formed on the glass substrate 2 to a thickness of 10 μm. When the etching rate of the SiO ₂ thin film 2a in the etching process is set to 3 μm / min, the time for removing the 10 μm thickness by etching is about 200 seconds in calculation. Actually, as shown in FIG. 4, the output displacement amount of the laser displacement meter 20 suddenly fluctuated in 200 to 210 seconds, which coincided with the calculation time. At the time indicated by period B in FIG. 4, the SiO ₂ thin film 2a has been removed as shown in FIG. 3c, and the glass is exposed in the etched portion 2b. Did not occur.

  The plasma processing apparatus 1 according to the present invention can be controlled so that the etching process is terminated when a change (peak) in the detection value of the laser displacement meter 20 is detected. It is also possible to perform control so that the process is terminated after a predetermined time has elapsed after detecting the peak at the end of the process. As described above, in the plasma processing apparatus and the end point detection method of the present invention, since the processing end can be accurately detected using the laser displacement meter, the plasma processing such as etching can be easily controlled and the processing quality can be improved.

  Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention described in the claims. Design changes can be made. For example, in the above-described embodiment, an example of a remote type in which a processing gas is converted into plasma between two opposed electrodes and this plasma gas is sprayed on the surface of the material to be processed for etching is shown. Alternatively, a direct-type plasma processing apparatus may be used in which a material to be processed is positioned and plasma is generated between the electrodes to perform an etching process.

  In addition, an example of a nozzle head having parallel plate-type electrodes facing each other was shown as the nozzle head for performing the etching process, but plasma gas is generated by discharging between the center electrode and the cylindrical electrode located on the outer periphery thereof. An appropriate electrode such as a processing head to be used can be used. Although the configuration in which the substrate, which is the object to be processed, is conveyed with respect to the nozzle head, it is needless to say that the nozzle head may be moved in the opposite direction.

The plasma processing apparatus, the plasma processing end point detection method, and the application example of the plasma processing method of the present invention can be applied to general atmospheric pressure plasma processing in semiconductor manufacturing processes, LCD manufacturing processes, and the like. The substrate to be processed is not limited to a glass substrate but may be any material such as a silicon substrate. Of course, the thin film removed by the etching process may be a film other than the SiO ₂ film.

The principal part block diagram which shows typically one Embodiment of the plasma processing apparatus which concerns on this invention. The perspective view of the principal part structure which detects the end point of the plasma processing of FIG. The principal part sectional drawing which shows operation | movement description of the plasma processing apparatus of FIG. The graph which shows the displacement amount of the laser displacement meter in operation | movement description shown in FIG.

Explanation of symbols

1: plasma processing apparatus 2: a glass substrate (object to be processed), 2a: SiO ₂ thin film (thin film) 2b: etched portion, 4: process gas, 4a: plasma etching gas (plasma gas), 5: frame 5a: Transparent window, 7: Power supply, 8: GND, 10: Plasma source (processing head), 11: Discharge processing section, 12, 13: Electrode member, 14: Center gap (discharge space), 20: Laser displacement meter , 21: incident light, 22: reflected light, B: detected end point

Claims (6)

A plasma processing apparatus that applies a voltage to opposing electrodes and generates a plasma gas by flowing a processing gas between the electrodes, and performs an etching process by bringing the plasma gas into contact with the surface of a material to be processed,
The apparatus includes a laser displacement meter that detects a reference surface of the workpiece.
A plasma processing apparatus, wherein the reference plane is detected using the laser displacement meter during an etching process, and an end point of the etching process is detected based on a change in the detected value.   The plasma processing apparatus according to claim 1, wherein the laser displacement meter is disposed at a position not in contact with the plasma gas.   The material to be treated is a transparent substrate, the laser displacement meter is installed inside a gantry on which the transparent substrate is placed and fixed, and a transparent window through which the laser light of the laser displacement meter can pass is opened on the placement surface of the gantry. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus is provided. An electric field is applied to the opposing electrodes, a processing gas is flowed between the electrodes to generate plasma gas, and the plasma gas is brought into contact with the surface of the material to be processed to etch the thin film formed on the surface of the material to be processed. A plasma processing method for removing at
Focus the laser displacement meter on the interface between the surface of the material to be processed and the thin film,
Detecting the amount of displacement of the boundary surface as the etching process proceeds,
A plasma processing method for detecting an end point of plasma processing by using a change amount of the laser displacement meter when the thin film is removed. An electric field is applied to the opposing electrodes, a processing gas is flowed between the electrodes to generate plasma gas, and the plasma gas is brought into contact with the surface of the material to be processed to etch the thin film formed on the surface of the material to be processed. A plasma processing method for removing at
Focus the laser displacement meter on the interface between the surface of the material to be processed and the thin film,
Detecting the amount of displacement of the boundary surface as the etching process proceeds,
A plasma processing method comprising: performing an etching process for a predetermined time after the removal of the thin film is confirmed by using a change amount of a displacement of the laser displacement meter, and ending the process.   The plasma processing method according to claim 4, wherein the etching process is performed near atmospheric pressure.

Images