JP2006313847A - Plasma emission measuring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma emission measuring system capable of precisely measuring a plasma emission distribution in a processing chamber. <P>SOLUTION: The plasma emission measuring system for measuring the plasma emission in the plasma processing device comprises a vaccum processing vessel, a gas introducing means 5 for introducing the processing gas into the vacuum processing vessel, a sample stand 6 for mounting and holding the sample in the processing chamber, and an electromagnetic energy applying means 2 for applying the electromagnetic energy to the processing gas introduced into the vacuum processing chamber to produce the plasma. The plasma emission measuring system further comprises a light receiving part 13 having an observation window and receiving the plasma emission entered in the observation window, a spectroscope 17 for separating the received plasma emission, and a computer 18 for storing or analysing the spectroscopic output of the spectroscope. The light receiving part 13 is rotatably arranged in the vacuum processing chamber, and its light receiving direction is adjustable at least in the range from a center of the sample stand to its periphery. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a plasma luminescence measurement system, and more particularly to a plasma luminescence measurement system capable of accurately measuring a plasma luminescence distribution in a processing vessel.

  In a plasma processing apparatus used in a semiconductor device manufacturing process, a processing gas introduced into a processing container is dissociated by plasma and becomes ions or radicals. A plasma CVD apparatus irradiates a wafer with these ions and radicals to deposit a thin film having a desired film quality on the wafer. In the plasma etching apparatus, ions are attracted to the wafer by applying a bias voltage to the wafer, and the wafer is etched by ions and radicals. In the case of etching processing, reaction products generated when the material on the wafer is removed diffuses and distributes on the wafer and re-enters the wafer, thereby affecting the processing shape.

  As described above, in these plasma processing apparatuses, the distribution of ions, radicals, reaction products, and the like inside the processing container in the processing container is the main factor that determines the film quality, the uniformity of the film thickness, or the uniformity of the processing shape. However, it is very difficult to measure the distribution of such plasma and radicals in the processing container.

For example, Patent Literature 1, Patent Literature 2, and Patent Literature 3 show a method in which a window is provided in a processing container and a plasma density distribution is measured by a CCD camera. Patent Document 4 discloses a method for measuring plasma distribution by receiving plasma light from a small observation window. In Patent Document 5, a large window is provided in the processing container, laser light is introduced into the processing container, laser induced light is observed from the side thereof, LIF (Laser Induced Fluorescence) is performed, and the processing container is longitudinally cut. A method for measuring the distribution of radicals in a plane is shown. Further, Non-Patent Document 1 applies a CT (Computed Tomography) technique by using a transparent quartz cylinder as a processing container and observing plasma emission from multiple directions using an automatically controlled robot that freely moves around it. It is shown that the radical distribution inside the processing vessel is measured.
JP-A-6-243991 JP-A-7-263178 JP 2002-38274 A JP 2000-269191 A JP-A-10-2859 Journal of Physics D, Vol.35, pp.454-461, 2002

  However, in the conventional method, it is necessary to look inside the processing container through the observation window. That is, all of these methods require a large window in the processing vessel. Since the plasma tends to interfere with the vessel wall, the installation of the window will affect the plasma distribution itself. For this reason, it is impossible to measure the plasma distribution in the original processing container in the state where there is no window.

  In addition, when using an observation window, the surface of the observation window exposed to plasma is unevenly shaved or roughened, or a non-uniform deposited film adheres to the window, and the light depends on the in-plane position of the observation window. The transmittance of is changed. Therefore, it cannot be distinguished whether the observed change in emission intensity is due to the plasma distribution or the transmittance distribution of the observation window.

  In the method disclosed in FIG. 9 of Patent Document 4, the inside of the processing container is looked into from a small window. For this reason, it is possible to avoid the observation window from affecting the state inside the processing container. However, since it is necessary to greatly move the optical system, it is difficult to increase the measurement accuracy. In addition, since the inside of the processing vessel is observed through the observation window, it is distinguished whether the observed emission intensity change is due to the plasma distribution or the transmittance distribution of the observation window in the same manner as described above. I can't do it. Further, when the observation window is small, the plasma density distribution greatly fluctuates at the boundary between the observation window and the processing container, so that the observation window is shaved and the deposited film is not uniform.

  In addition, the method of observing the plasma inside the transparent tube that is easy to observe, as shown in Non-Patent Document 1, is actually difficult to apply to an opaque plasma processing apparatus. The present invention has been made in view of these problems, and provides a plasma emission measurement system capable of accurately measuring a plasma emission distribution in a processing container.

  In order to solve the above problems, the present invention employs the following means.

  Applying electromagnetic energy to a vacuum processing chamber, gas introduction means for introducing a processing gas into the vacuum processing chamber, a sample stage for placing a sample and holding it in the processing chamber, and a processing gas introduced into the vacuum processing chamber A plasma emission measurement system for measuring plasma emission in a plasma processing apparatus comprising an electromagnetic energy application means for generating plasma, a light receiving unit having an observation window and receiving plasma light incident on the observation window; A spectroscope for spectroscopically analyzing the received plasma light, and a computer for accumulating or analyzing the spectroscopic output of the spectroscope. It is configured to be adjustable in a range from the part to the one peripheral part.

  Since this invention is provided with the above structure, it can provide the plasma luminescence measuring system which can measure the plasma luminescence distribution in a processing container correctly.

  Hereinafter, the best embodiment will be described with reference to the accompanying drawings. FIG. 1 is a diagram for explaining a first embodiment of the present invention. A plasma processing apparatus that mainly processes a sample such as a semiconductor wafer with plasma includes a plasma emission measurement system that measures the emission of the plasma.

  In FIG. 1, the plasma processing apparatus includes a flow rate controller 4 and a gas supply pipe 3 that adjust the amount of processing gas supplied into the processing container 1. A processing gas having a flow rate determined according to the processing conditions is supplied by the flow rate controller 4, passes through the gas supply pipe 3, and is introduced into the processing container 1 through the gas introduction device 5.

  The gas introducing device 5 includes a quartz porous plate called a quartz shower plate, and the processing gas flows through a gap formed on the upper surface of the quartz porous plate, reaches a hole in the porous plate, and then jets into the processing vessel. To do. The plasma processing apparatus includes electromagnetic energy application means 2 for applying electromagnetic energy necessary for converting the processing gas into plasma. Further, a gas exhaust system 9 for exhausting the processing gas to keep the inside of the processing container 1 in a low pressure state, and a pressure adjusting valve 8 for adjusting the pressure in the processing container 1 are provided. The plasma processing apparatus also has a sample stage 6 on which the wafer 7 is placed.

  This plasma processing apparatus is provided with a plasma emission measurement system that measures the distribution of plasma and radicals based on plasma emission. This measurement system includes a motor 10, a rotation feedthrough 11, a rotation transmission shaft 12, a light receiving unit 13, an internal optical fiber 14, an optical feedthrough 15, an external optical fiber 16, a spectrometer 17, and a computer 18.

  The computer 18 instructs the motor 10 on a rotation angle necessary for directing the light receiving direction of the light receiving unit 13 to a desired observation direction. For this reason, a stepping motor may be used as the motor 10. When a stepping motor is used, the computer can accurately determine the rotational position based on the number of pulses instructed to the motor. In order to accurately determine the rotational position, it is preferable to provide an angle sensor on the rotation shaft of the motor and monitor the light receiving direction.

  The rotational driving force of the motor is introduced into the processing container 1 maintained at a low pressure through a rotation transmission shaft 12 having a rotation feedthrough 11. As a result, the light receiving direction of the light receiving unit 13 attached to the tip of the rotation transmission shaft 12 can be directed to a desired direction. In order to suppress unnecessary movement of the light receiving unit to a minimum, it is desirable that the rotating shaft pass through the light receiving unit as described later.

  The light receiving unit 13 receives light emitted by plasma in a predetermined direction directed by the rotation operation. The received plasma light is guided to the external optical fiber 16 through the internal optical fiber 14 and the optical feedthrough 15 and enters the spectroscope 17. The spectroscope 17 splits the incident plasma light, and the split plasma emission spectrum is sent to the computer 18.

  By extracting only light in a predetermined wavelength region of the plasma emission spectrum by the computer 18, the emission intensity of a desired radical can be known. For example, since the emission spectrum of silicon radicals in the gas phase has a peak at 288.16 nm, for example, the emission intensity of silicon radicals can be obtained by taking the average value of the spectrum intensity in the wavelength range of 287 nm to 289 nm. In this way, the user can observe the emission intensity of a desired radical in a desired direction set in the computer 18.

  The light receiving unit 13 and the rotation transmission shaft 12 are preferably made of an insulating material so as not to disturb the distribution of electromagnetic waves for generating plasma generated by the electromagnetic energy application means 2. For example, a quartz rod, a ceramic material, a polyimide material, a Teflon (registered trademark) material or the like may be used for the rotation transmission shaft 12. Moreover, since contamination of heavy metals often becomes a problem in semiconductor manufacturing apparatuses, it is desirable to use materials that do not contain such contaminants. Further, it is desirable to make the light receiving portion and the rotation transmission shaft as thin as possible so as not to disturb the gas flow. In addition, a method of installing the light receiving unit and the rotation transmission shaft outside the processing container and providing an observation window in the processing container is also conceivable. The reliability of the measured light emission intensity is lost because the transmittance of the observation window is different for each optical path due to the roughness unevenness and the film deposited on the inner surface of the observation window.

  FIG. 2 is a diagram illustrating the light receiving unit 13. The holder 36 which is the main body of the light receiving unit has an observation window 38 for taking in plasma emission, and the observation window is covered with a quartz plate 30 so that corrosive gas does not enter the holder from the observation window. The quartz plate 30 is fixed to the holder 36 with a holding screw 37, for example.

  Plasma light taken from the observation window 38 is taken out by the optical fiber 35. When an electromagnetic wave or a high frequency electric field is used to generate plasma, it is not preferable that the light receiving unit 13 inserted into the processing container is a conductor because the electromagnetic wave is disturbed. For this reason, the holder 36 is preferably made of an insulating material. Quartz or the like may be used as an insulating material, but quartz is difficult to process. Further, it is not preferable because plasma light from all directions enters without being able to block the plasma light. In addition, a material that can be easily processed such as a polyimide material may be selected, but it is not preferable as a material for incorporating an optical system because it is easily thermally expanded and its strength is not sufficient. For this reason, as the material of the holder 36, it is preferable to use an insulating material having a light shielding property and material strength such as polybenzimidazole.

  FIG. 3 is a diagram illustrating details of the light receiving unit 13. The light receiving unit 13 as shown in FIGS. 1 and 2 is required to have a function of bending incident plasma light by 90 degrees and extracting it through an optical fiber. For this purpose, the direction of the plasma light that has passed through the observation window 38 is bent 90 degrees by the reflection mirror 32 and directed in the direction of the rotation axis, introduced into the ferrule 34 via the collimation lens 33, and further connected to the ferrule 34. The optical fiber 35 is taken out.

  When the direction of the plasma light is bent in the same direction as the rotation axis, the optical fiber 35 can be directed in the same direction as the rotation axis (rotation transmission axis). Can be prevented from moving around. When a prism is used instead of the metal reflecting mirror 32, it is preferable to use no metal, but when plasma light is weak, it is preferable to use a mirror having good light reflectivity. Also, when the plasma light is sufficiently strong and a sufficient amount of light can be obtained even if the optical fiber is thin, the thin optical fiber can be bent 90 degrees so that the light can be bent in the direction of the rotation axis without using a mirror. it can.

  In general, since the light receiving angle of an optical fiber has a large angle range of about 20 degrees, it is important to use a collimation lens 33 to narrow the field of view into a beam and increase the spatial resolution of observation. If the optical system of the collimation lens 33 and the ferrule 34 is appropriately designed, the observation range at a position 500 mm away from the light receiving unit 13 can be suppressed to about 5 mm, and a high resolution spatial resolution can be obtained. Note that these optical systems may be gas-sealed by providing an O-ring 31 in the observation window 38 so that corrosive gas in the plasma does not enter.

  In this way, by rotating the light receiving unit 13 around the rotation transmission shaft 12, the radical emission intensity distribution in a desired direction can be observed with one optical system. In this system, in order to observe the light receiving unit by moving it mechanically in a desired direction, the optical characteristics of the spectroscope and the optical fiber are more varied than when the light emission distribution is observed using a plurality of optical systems. Or the influence based on the difference in the light reception characteristic by the difference in the delicate setting of the optical system of a light-receiving part can be suppressed. Furthermore, since the radical emission intensity in a plurality of directions can be observed under the same conditions, the reliability of the emission intensity distribution can be improved. Further, even if the observation window 38 is shaved or the deposited film adheres and the light transmittance changes, the change in the transmittance can be ignored for all observations performed in a short time. . For this reason, there is no problem in obtaining the emission intensity distribution. In addition, since the observation direction is determined by the rotation angle, the number of observation points can be arbitrarily set. This is advantageous in observing the distribution of the emission intensity of radicals with high accuracy.

  FIG. 4 is a diagram illustrating a range in which light is received by rotational driving of the light receiving unit 13. According to the measurement system including the light receiving unit 13 described above, the emission intensity of a desired radical in an arbitrary direction can be observed. Therefore, by repeating this measurement operation, the radical emission intensity in a number of directions can be observed. For example, the distribution of radical emission intensity in the fan-shaped region as shown in FIG. 4 can be observed.

  Here, as shown in FIG. 4, an observation direction passing through the center of the wafer 7 is defined as a reference direction, and an angle 41 from the reference direction to the observation direction 40 is defined as θi. If the radical emission intensity observed in the direction of the angle θi is represented by Ii, the emission intensity I0, I1, I2, I3,.・ ・ IN can be obtained. The number N of observation points can be arbitrarily increased by reducing the increment of the rotation angle, but it is optimal to set the number of observation points to about 30 to 50 points from the performance of the collimator of the light receiving unit.

  Each emission intensity Ii is a line integral value of plasma emission from the observation direction θi, but when the plasma and radical are substantially axially symmetric, the radial distribution of radical emission intensity can be calculated using Abel transformation. .

  FIG. 5 is a diagram showing an example of radial distribution of emission intensity observed as a line integral value and radical emission intensity obtained by Abel transformation.

  In FIG. 5, the observed emission intensity is flat at the center and has a convex distribution. However, when the emission intensity at each radial position is obtained by Abel transformation, it has a peak at a radius of 100 mm. It can be seen that this is a donut-shaped distribution.

  Further, the emission intensity I of each radical is expressed by the following equation 1 by the electron density Ne, electron temperature Te, and radical density N in the plasma.

I = N × Ne × exp (−E / kTe) Equation 1
In Equation 1, E is an energy constant determined for each radical species, and k is a Boltzmann constant. Since the values of N and E are different for each radical species, the value obtained by averaging the emission of all radicals is approximately proportional to Ne, which is the invariant term of Equation 1, that is, the plasma density. Therefore, it is possible to observe only the intensity of the light received by the light receiving unit 13 without dispersing it, or to observe an amount substantially proportional to the plasma density by averaging the values of all wavelength regions of the dispersed light. it can. The amount obtained by Abel transforming the average value of all wavelengths is described as Ne ′ (r), and the amount obtained by Abel transformation of the emission intensity of each radical is described as I ′ (r). A distribution of the signal N ′ (r) proportional to the density N of radicals is obtained.

N ′ (r) = I ′ (r) / Ne ′ (r) Equation 2
The influence of the distribution of the plasma density Ne can be removed by the calculation of Equation 2, and the signal N ′ (r) is an amount that is approximately proportional to the radical density N. The signal as observed is a linear integral of radical emission in the visual field range as shown in FIG. 4, and Ne is different for each position on the line, so it is important to perform the division of Equation 2 after the Abel transformation. is there.

  In addition, it is desirable that the observation range be as wide as possible in order to perform the Abel transformation with high accuracy. For this reason, it is desirable that the light receiving unit 13 can be rotated so as to have a visual field range covering from one peripheral part of the sample stage 6 to the other peripheral part.

  There are many data acquisition procedures to which the Abel transform can be applied in addition to the above-described methods. For example, in FIG. 4, only the left half region in the processing container is the object of observation, but the remaining right half region is also observed with plasma light in the same procedure as described above, and subjected to abelian conversion to generate radical emission intensity distribution. Can be requested. If the radical distribution is perfectly axisymmetric, the radial distribution of the same radical emission intensity can be obtained in the left and right halves, but the observation data in the right and left halves are averaged to reduce the noise in the observation data. Abel conversion may be used. Furthermore, when the radicals are biased and have an asymmetric distribution, it is possible to grasp the degree of radical bias by comparing the results of separate Abel transformations on the right and left halves.

  FIG. 11 is a diagram showing a result of calculating a distribution by generating asymmetric plasma by adjusting the processing conditions, and performing abel transform on the left and right separately. In the case of an asymmetric distribution, the calculation of the Abel transform is not correct, but it is suitable for the purpose of confirming the symmetry of the plasma because it is a guide for knowing the degree of asymmetry as shown in FIG.

  In the description so far, the description has been made on the assumption that the light receiving unit is stationary while observing plasma light in a predetermined direction. However, the light receiving portion does not necessarily have to be stationary. For example, in FIG. 4, it is assumed that the integration time of the plasma light in the spectroscope in one direction takes m seconds, and N + 1 points are observed from the angles θ0 to θN. In this case, the radical emission intensity I′0 is obtained by continuously rotating the motor at a constant speed of (θN−θ0) / {(N + 1) m} degrees per second and capturing plasma light every m seconds during the rotation of the motor. , I′1, I′2, I′3,... I′N can be obtained, and the radial distribution of the radical emission intensity can be calculated by applying an Abel transformation to this observed value.

  According to this method, since it is not necessary to stop the motor each time plasma light is taken in, a series of plasma light acquisition can be completed in a short time. For example, when the accumulated time of light emission is set to 0.5 seconds, the method of stationary each time using a typical servo motor takes 30 seconds to scan once on the wafer, but continuously rotates. In the method, scanning is completed in 4 seconds. If the scan time can be performed in a few seconds, each scan is less susceptible to plasma aging. In addition, it becomes easy to obtain a temporal change in plasma emission distribution by repeating scanning during plasma processing.

  FIG. 6 is a diagram for explaining a second embodiment of the present invention. In the example shown in FIG. 1, the rotation transmission shaft 12 for rotationally driving the light receiving unit 13 is directly connected to the drive shaft of the motor 10, and the drive shaft is inserted from below the processing container 1.

  However, in the existing plasma processing apparatus, as described above, it is often difficult to install a measurement system such as a motor below the processing container. However, a maintenance port or the like is often prepared on the lower side surface of the plasma processing apparatus. In such a case, the measurement system can be attached using the lid of the maintenance port. For this purpose, the motor 10 is provided on the side of the processing container, and the rotational drive shaft 20 of the motor is inserted from the side of the processing container through the rotary feedthrough 11 to transmit the driving force to the rotation transmission shaft 12. At this time, the rotational driving force introduced into the processing container is transmitted to the rotational transmission shaft 12 via the rotational direction converter 21 such as a bevel gear, and rotationally drives the light receiving unit 13.

  FIG. 7 is a diagram for explaining a third embodiment of the present invention. In the above example, the light receiving unit 13 and the rotation transmission shaft 12 constituting the measurement system are installed so as to be exposed to plasma. For this reason, there is a concern that contaminants and the like are released from these parts.

  Therefore, as shown in FIG. 7, a storage section 48 is provided in the lower part of the processing container 1, and the light receiving section 45 'is stored therein. The light receiving unit is stored in the storage unit 48 when not in use. The motor 10 is connected to the up-and-down operation unit 47, and the up-and-down operation unit 47 drives the motor 10 and the rotation transmission shaft 12 and the light-receiving unit 45 up and down using the up-and-down movement guide shaft 46 as a guide shaft. Can do. When the measurement system is used, the light receiving unit 45 is lifted to a desired height by the vertical operation unit 47, and the light emission unit 45 can be observed in the desired direction by the motor 10 to observe the emission of plasma.

  FIG. 8 is a diagram for explaining a fourth embodiment of the present invention. In this example, the light receiving unit 13 can move up and down as well as rotate. Thereby, the light-receiving part 13 can be moved to a desired height position on the wafer, and the radical emission distribution at the height position can be measured. Further, by combining scanning in the rotation angle direction and the height direction, the radical emission distribution in the entire processing container can be measured.

  In the example shown in FIG. 8, the example in which the mechanism for moving up and down and rotating is housed in the sub-chamber 60 installed on the side surface of the processing container is shown.

  The rotational driving force of the motor 71 is transmitted into the sub-chamber 60 through the rotational transmission shaft 68, rotates the rotational pulley 67 through the driving steel belt 65, and passes through the rotational transmission shaft 12 coupled to the rotational pulley 67 to receive the light receiving unit 13. Can be rotated. The rotating pulley 67 is installed on a support arm 66, and the support arm 66 is coupled to an arm guide 64. The arm guide 64 is coupled to the vertical movement guide 63 by a connector 72, and the vertical movement guide 63 can move up and down with the vertical movement guide shaft 61 and the rotary shaft 62 as guides. The vertical movement unit 70 moves the vertical movement guide 63 up and down through the vertical movement transmission shaft 69, and this operation moves the light receiving unit 13 up and down. Therefore, the light receiving unit 13 can be directed at a desired height and in a desired direction by the drive system shown in FIG.

  If the light emission distribution in the height direction can be measured, the distribution in the longitudinal section can also be calculated. Therefore, the radial distribution of plasma emission can be calculated by the above-mentioned Abel transformation at a plurality of different height positions, and the plasma emission distribution of the longitudinal section can be plotted from the radial distribution data at each height position. In addition, the plasma emission distribution in the entire processing container can be displayed three-dimensionally. A special use case for this function is to identify the source of metal contamination. In the processing of semiconductor devices, device characteristics deteriorate when a wafer is contaminated with metal generated from somewhere in the processing container during processing. For this reason, in the plasma processing apparatus, when metal contamination occurs, it may be necessary to examine where in the processing container the metal as the contamination source is released. For example, aluminum Al can monitor the emission peak with either Al itself or the metal compound AlCl of aluminum. For this reason, the metal contamination source can be identified by observing the distribution of the metal or the metal compound in the processing container with a monitor and following the place where the intensity is strong.

  FIG. 9 is a diagram for explaining a fifth embodiment of the present invention. 9A is a front view, and FIG. 9B is a front view with the quartz plate 30 'removed. In the example of this figure, information in the height direction is acquired by using a plurality of optical systems. For this reason, as shown in FIG. 9, a plurality of observation windows are provided in the height direction of the light receiving unit so that plasma light at a plurality of height positions can be observed without driving the light receiving unit up and down.

  In the example shown in FIG. 9, in order to place a plurality of optical systems inside the thin holder 36, the optical systems of the reflection mirror 32, the collimation lens 33, and the ferrule 34 are alternately tilted, and the optical fiber 35 is wired to receive light. Part. When a plurality of optical systems are used in this manner, there is a variation in light reception sensitivity between the optical systems. Therefore, when comparing the light emission intensities detected by optical systems with different height positions, the variation in the light reception sensitivity. Need to be corrected. Note that, if the light received by the plurality of optical fibers 35 is separated by different spectroscopes, it is affected by the individual difference of the spectroscopes. Therefore, it is preferable to use one spectroscope while switching it using an optical switch or the like.

  10A and 10B are diagrams for explaining a sixth embodiment of the present invention. FIG. 10A is a diagram showing an example in which the light receiving portions are arranged close to each other, and FIG. It is a figure which shows the example to arrange | position.

  In the above description, an example in which only one light receiving unit is installed in the processing container has been described. However, as shown in FIG. 10, it is possible to install light receiving portions at a plurality of locations. When the distribution of radicals is almost axisymmetric, the radial distribution of radicals can be calculated by using an Abel transformation at one location. However, when the radical distribution has a strong asymmetry, an asymmetric radical distribution can be calculated by applying a computed tomography (CT) technique using observation results from a plurality of locations.

  FIG. 10A shows an example in which the light receiving portions are arranged relatively close to the three locations 50, 51, and 52. However, in order to apply CT, it is preferable that the distance between the light receiving portions be as far as possible as shown in FIG. 10B because it is less susceptible to errors due to light emission noise or the like. However, in the case of plasma, since the attenuation rate by which plasma blocks the plasma light emitted by the plasma itself is very low, it is not necessary to observe from all directions as in a CT scan used in medical treatment. For this reason, as shown in FIG. 10A, the radical distribution can be obtained by combining the observation data scanned by the light receiving units installed at a plurality of locations (50, 51, 52) on one side and performing inverse two-dimensional Fourier transform. it can.

  In the above description, the example in which the light received by the light receiving unit is bent by 90 degrees has been described. However, the bending angle may not be 90 degrees. Further, the mechanism for rotating the light receiving unit can be implemented using a mechanism other than the above. In addition, plasma light spectroscopy can be carried out using a monochromator having a different detection wavelength without using a spectroscope. In addition, the internal state of the plasma can be monitored by using an imaging fiber for light transmission from the light receiving unit. At this time, a fish-eye lens or the like may be used to adjust the viewing direction of the imaging fiber.

  As described above, according to the present embodiment, it is possible to measure plasma emission at an arbitrary location in the processing container without being affected by the observation window by rotating or vertically moving the light receiving unit with a narrow viewing angle. Therefore, it is possible to measure the line integral data of plasma emission particularly suitable for Abel conversion, and to measure the spatial distribution of plasma emission and radical emission obtained by spectroscopically analyzing it.

  In addition, it is possible to measure plasma emission at any location inside the processing vessel without providing an observation window in the processing vessel. In particular, plasma processing conditions are improved while measuring the plasma emission distribution in the processing vessel, and plasma processing is performed. Can improve the uniformity.

It is a figure explaining the 1st Embodiment of this invention. It is a figure explaining the light-receiving part. It is a figure explaining the detail of the light-receiving part. It is a figure explaining the range received by the rotational drive of the light-receiving part. It is a figure which shows the example of radial direction distribution of the emitted light intensity observed as a line integral value, and the radical emitted light intensity obtained by Abel transformation. It is a figure explaining the 2nd Embodiment of this invention. It is a figure explaining the 3rd Embodiment of this invention. It is a figure explaining the 4th Embodiment of this invention. It is a figure explaining the 5th Embodiment of this invention. It is a figure explaining the 6th Embodiment of this invention. It is a figure which shows the result of having adjusted processing conditions, producing | generating asymmetrical plasma, and calculating the distribution by carrying out the Abel transform of this separately on either side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing container 2 Electromagnetic energy application means 3 Gas supply pipe 4 Flow rate controller 5 Gas introduction device 6 Sample stand 7 Wafer 8 Pressure adjustment valve 9 Gas exhaust system 10 Motor 11 Rotation feedthrough 12 Rotation transmission shaft 13 Light receiving part 14 Internal optical fiber 15 Optical feedthrough 16 External optical fiber 17 Spectrometer 18 Computer 20 Rotation drive shaft 21 Rotation direction changer 30, 30 'Quartz plate 31 O-ring 32 Reflection mirror 33 Collimation lens 34 Ferrule 35 Optical fiber 36 Holder 37 Holding screw 38 Observation window 40 Observation direction 41 Observation angle 45 Light receiving part (when retracted)
45 'light receiving unit (when used)
46 Vertical movement guide shaft 47 Vertical movement part 48 Storage part 50, 51, 52 Position of light receiving part 60 Subchamber 61 Vertical movement guide shaft 62 Rotating shaft 63 Vertical movement guide 64 Arm guide 65 Driving steel belt 66 Support arm 67 Rotating pulley 68 Rotation transmission shaft 69 Vertical motion transmission shaft 70 Vertical motion part 71 Motor 72 Connector

Claims (9)

Applying electromagnetic energy to a vacuum processing chamber, gas introduction means for introducing a processing gas into the vacuum processing chamber, a sample stage for placing a sample and holding it in the processing chamber, and a processing gas introduced into the vacuum processing chamber A plasma emission measurement system for measuring plasma emission in a plasma processing apparatus comprising electromagnetic energy application means for generating plasma,
A light receiving unit that has an observation window and receives plasma light incident on the observation window;
A spectroscope that separates the received plasma light;
A computer for accumulating or analyzing the spectral output of the spectrometer;
The plasma light emission measuring system, wherein the light receiving part is rotatably arranged in a vacuum processing chamber, and the light receiving direction is adjustable at least in the range from the central part of the sample stage to one peripheral part thereof. Applying electromagnetic energy to a vacuum processing chamber, gas introduction means for introducing a processing gas into the vacuum processing chamber, a sample stage for placing a sample and holding it in the processing chamber, and a processing gas introduced into the vacuum processing chamber A plasma emission measurement system for measuring plasma emission in a plasma processing apparatus comprising electromagnetic energy application means for generating plasma,
A light receiving portion having a transparent observation window and receiving plasma light incident on the observation window;
A spectroscope that separates the received plasma light;
A computer for accumulating or analyzing the spectral output of the spectrometer;
The light receiving unit is rotatably arranged in the vacuum processing chamber, and reflects a traveling direction of light incident on the light receiving unit in a direction coinciding with the rotation axis of the light receiving unit, and a light collecting unit that collects reflected light from the mirror. A plasma comprising an optical lens and an optical fiber for deriving condensed light, wherein the light receiving direction of the light receiving part is adjustable at least in the range from the central part of the sample stage to one peripheral part thereof. Luminescence measurement system. The plasma emission measurement system according to claim 1 or 2,
The light emission direction of the light receiving part can be adjusted in a range from one peripheral part to the other peripheral part of the sample stage. The plasma emission measurement system according to claim 1 or 2,
The said computer calculates the radial distribution of radical luminescence by abel transforming the observation data of plasma light, The plasma luminescence measuring system characterized by the above-mentioned. The plasma emission measurement system according to claim 1 or 2,
The light receiving unit has a rotation axis in a direction orthogonal to the sample placement surface of the sample stage, and a rotation direction converter that drives the rotation axis by a rotation axis parallel to the sample placement surface of the sample stage. A characteristic plasma emission measurement system. The plasma emission measurement system according to claim 1 or 2,
The plasma light emission measuring system, wherein the light receiving unit has a rotation axis in a direction orthogonal to a sample mounting surface of a sample stage, and the light receiving unit includes a drive mechanism that drives up and down along the rotation axis. . The plasma emission measurement system according to claim 1 or 2,
The light-receiving unit has a rotation axis in a direction orthogonal to a sample mounting surface of a sample stage, and includes a plurality of observation windows for observing plasma emission along the rotation axis. . The plasma emission measurement system according to claim 1 or 2,
A plasma light emission measuring system comprising a plurality of the light receiving parts around a plasma generating part in a vacuum processing container. Applying electromagnetic energy to a vacuum processing chamber, gas introduction means for introducing a processing gas into the vacuum processing chamber, a sample stage for placing a sample and holding it in the processing chamber, and a processing gas introduced into the vacuum processing chamber A plasma processing apparatus comprising electromagnetic energy applying means for generating plasma,
A light receiving unit that has an observation window and receives plasma light incident on the observation window;
A spectroscope that separates the received plasma light; and
A computer for accumulating or analyzing the spectral output of the spectrometer;
The light receiving portion is rotatably arranged in the vacuum processing chamber, and the light receiving direction thereof can be adjusted at least in the range from the central portion of the sample stage to one peripheral portion thereof, and the light receiving portion is stored when not in use. A plasma processing apparatus comprising a storage unit.

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