JP2016167602A - Plasma processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a uniform plasma processing for a sample by adjusting an induced magnetic field distribution on an ICP plasma processing apparatus to correct a plasma distribution on the sample.SOLUTION: The ICP plasma processing apparatus is so configured that a conductor is disposed between an induction coil and a dielectric window, where the juxtaposed conductor is disposed along the induction coil and is located on at least a part of a circumferential direction of the induction coil. The conductor is disposed at a location where induced magnetic field strength from the induction coil is lowered, and at a position of satisfying relationship of Lp≥Lr, where Lr is a minimum distance from the induction coil to a surface of the conductor, and Lp is a minimum distance from the induction coil to plasma immediately below the dielectric window.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a plasma processing apparatus, and more particularly to a plasma processing apparatus suitable for an apparatus using an inductively coupled plasma source.

  In the field of semiconductor device manufacturing, inductively coupled plasma (ICP) plasma apparatuses are also used for etching and surface treatment of samples. As a conventional ICP plasma processing apparatus, as described in Patent Document 1, a vacuum processing chamber is provided that forms a part of a vacuum processing chamber and includes a processing gas blowing port, and covers the upper portion of the gas ring. Formed on the bell jar, an antenna for generating a plasma by supplying a high frequency electric field into the vacuum processing chamber, a mounting table for mounting a wafer in the vacuum processing chamber, and between the antenna and the bell jar. In addition, an ICP plasma processing apparatus including a Faraday shield to which a high frequency bias voltage is applied is known.

  In such an ICP plasma processing apparatus, as described in Patent Document 2, the entire plasma processing chamber is surrounded by a magnetic material and the magnetic field is shielded against plasma nonuniformity due to the influence of an external magnetic field. Techniques for improving uniformity are known.

JP 2007-158373 A Japanese Patent Laid-Open No. 2004-22988

  In general, in a plasma processing apparatus using an ICP plasma source, it is inevitable that the current distribution of the induction coil becomes nonuniform, and it is known that the plasma becomes nonuniform along the circumferential direction of the induction coil. Yes. As a result, plasma eccentricity occurs in which the central axis of the plasma diffused on the wafer is shifted from the central axis of the induction coil. In addition, the plasma distribution in the circumferential direction of the induction coil also becomes non-uniform in the power feeding portion of the induction coil. The eccentricity of the plasma on the wafer can also occur due to the eccentricity of the exhaust in the plasma processing chamber.

  The inventors have also experimentally confirmed that eccentricity occurs in the distribution of plasma diffused on the wafer. In the experiment, the eccentricity due to the magnetic field was simulated, and a plasma treatment was performed by installing a magnet of about 0.4 mT outside the plasma treatment chamber. As a result, it was found that the distribution of plasma diffused on the wafer greatly fluctuates due to the minute magnetic field of 0.4 mT that the magnet has. From this, it can be seen that the plasma may be affected even by a magnetic field as small as the geomagnetism. Furthermore, the same phenomenon may occur depending on the vacuum pressure gauge and motor magnetic field installed in the device. The eccentricity of the plasma diffused on the wafer described above is diffused obliquely by the action of a minute magnetic field when the plasma generated in the plasma processing chamber and in the vicinity of the induction coil diffuses downward in the plasma processing chamber. It was found that the plasma was eccentric. If etching is performed while plasma is decentered on the wafer, the uniformity of the etching process, the perpendicularity of the etching shape, and the like deteriorate. For this reason, while the demand for higher precision and higher speed of the etching process is increasing at present, the influence of the magnetic field cannot be ignored in order to perform a stable etching process.

  In addition, although the said patent document 2 discloses the means to solve the influence of a magnetic field, it cannot be said that sufficient consideration is given from the point of practicality, and there are three problems below. One is a performance problem. In the plasma processing chamber, openings such as a processing object transfer port and a processing gas exhaust port are required, and it is impossible to substantially shield the magnetic field. In addition, by enclosing with a magnetic material, the induction magnetic field generated from the induction coil causes an induction loss inside the magnetic material, and the plasma generation capability decreases. The second is an implementation problem. A significant design change is required to cover the magnetic material, and the chances of handling heavy objects increase during assembly, which increases the risk of work. The third is a cost issue. A magnetic material that covers the entire plasma processing chamber is required, which entails enormous costs. These three problems become very serious problems for mass production equipment.

  The object of the present invention has been made in view of these problems, and is capable of performing uniform plasma processing on a sample by adjusting the induced magnetic field distribution and correcting the plasma distribution on the sample. Is to provide a device.

  In order to solve the above-described problems, the present invention provides a vacuum processing chamber in which a sample is plasma-processed, a dielectric window that hermetically seals an upper portion of the vacuum processing chamber, and an induction disposed above the dielectric window. In the plasma processing apparatus, comprising: a coil; a high-frequency power source that supplies high-frequency power to the induction coil; and a Faraday shield that is disposed between the induction coil and the dielectric window and is capacitively coupled to plasma. A plurality of slits are arranged radially from the center, and the induction coil is a circular induction coil wound around the circumference so that the feed end and the end cross each other, and is arbitrarily closed in the plurality of slits The slit is arranged below a position where the feeding end and the end intersect.

  According to the present invention, since the induction magnetic field distribution by the induction coil can be adjusted, it is possible to correct the plasma distribution on the sample and obtain desired processing performance.

It is a longitudinal cross-sectional view which shows the plasma processing apparatus which is one Example of this invention. It is the top view which looked at FIG. 1 from A. It is an arrow line view which shows the detail of the induction coil which looked at FIG. 1 from B. It is a longitudinal cross-sectional view which shows the detail of the C section of FIG. It is a simulation figure which shows the induction magnetic field distribution by the position of a conductor ring. It is a figure which shows the spreading | diffusion of the plasma in a no magnetic field state. It is a figure which shows the spreading | diffusion of plasma when there exists magnetic fields other than an induction magnetic field. It is a figure which shows the spreading | diffusion of the plasma at the time of applying a conductor ring to the apparatus shown in FIG. It is a figure which shows the sample surface distribution of an etching rate. It is sectional drawing which shows the other Example of the attachment position of the conductor ring in the plasma processing apparatus of this invention. It is a figure which shows the other Example of the shape of the conductor ring in the plasma processing apparatus of this invention. It is a figure which shows an Example other than the shape of the Faraday shield in the plasma processing apparatus of this invention. It is a figure which shows the example of a combination of the induction coil and the Faraday shield in the plasma processing apparatus of this invention.

  An embodiment of the plasma processing apparatus of the present invention will be described below with reference to FIGS.

FIG. 1 is a longitudinal sectional view of an inductively coupled plasma processing apparatus. A dielectric window 1a, which is a top plate capable of keeping the inside airtight, is attached to the upper opening of the cylindrical processing container 1b, and constitutes a vacuum processing chamber 1. The dielectric window 1a is made of an insulating material capable of transmitting electromagnetic waves, for example, a non-conductive material such as alumina (Al ₂ O ₃ ) ceramic. An induction antenna is disposed above the dielectric window 1a which is the outer upper surface of the vacuum processing chamber 1. In this case, as shown in FIG. 2, the induction antenna is configured such that induction coils 4a to 4d having one turn with different inner diameters are arranged concentrically. Each of the induction coils 4a to 4d has power supply ends at both ends (both sides are power supply ends because the power supply is alternating current), and is wound longer than one turn starting from one power supply end, and partly overlaps. The other end is provided with a feeding end. This is to prevent the induction magnetic field from weakening due to a discontinuous portion of the coil on the circumference. As will be described in detail later, although a weak induction magnetic field cannot be strengthened, a strong induction magnetic field can be adjusted by providing an interference member, so that a partial overlap portion is provided to prevent the induction magnetic field from being weakened. In order to prevent contact at the overlapping portion, the induction coil 4 is covered with an insulating material including the rise of the feeding end as shown in FIG. The induction coil 4 is connected to a first high-frequency power source 8 via a matching unit 7. The first high frequency power supply 8 generates high frequency power of 13.56 MHz or 27.12 MHz, for example.

  A Faraday shield 6 is disposed between the induction coil 4 and the dielectric window 1a. In this case, the Faraday shield 6 is attached to the upper surface of the dielectric window 1a. The Faraday shield 6 is made of a metal conductor, and is formed with a radial slit in the region between the central portion and the outer peripheral portion, as shown in FIG. ing. The dielectric window 1a, the Faraday shield 6, and the induction coil 4 are mounted concentrically and in parallel at a predetermined interval. Further, in this case, the upper surface of the Faraday shield 6, which is the opposite side of the Faraday shield 6 to the dielectric window 1 a side, is shifted and decentered from the center of the Faraday shield 6, that is, with respect to the center of the induction coil 4. An eccentric plate-like conductor ring 12 is attached. As will be described later, the conductor ring 12 is effective by being eccentric with respect to the induction coil 4.

  The conductor ring 12 has a ring shape shown in FIG. 2 and is made of a conductor such as aluminum or stainless steel. In this case, the width and thickness of the conductor ring 12 are 10 mm wide and 5 mm thick, but the effect of the present invention is not limited to this dimension. As shown in FIG. 4, the conductor ring 12 is provided in contact with the Faraday shield 6 so as to be electrically connected, and is disposed at a predetermined interval (Lr) from the induction coil 4.

  A processing gas supply path (not shown) is formed inside the dielectric window 1a in the vacuum processing chamber, and a gas supply device 9 is connected to the dielectric window 1a. In the vacuum processing chamber 1, a sample stage 3 is installed supported by a processing container 1b by a support member (not shown). A sample placement surface is formed on the upper surface of the sample stage 3, and the sample 2 is arranged by a transport device (not shown) so that the sample 2 can be held by electrostatic adsorption or the like. A second high-frequency power source 11 is connected to the sample 2 arranged on the upper surface of the sample stage 3 so that a bias voltage can be applied during the processing of the sample. The second high frequency power supply 11 generates high frequency power having a frequency lower than the frequency of the first high frequency power supply of 800 KHz or 4 MHz, for example. An exhaust device 10 for evacuating the inside of the vacuum processing chamber 1 is attached to the lower surface of the processing container 1b.

  In the plasma processing apparatus configured as described above, first, the inside of the vacuum processing chamber 1 is evacuated by the exhaust device 10 and the processing gas whose flow rate is controlled by the gas supply device 9 is supplied to the vacuum processing chamber 1 through the dielectric window 1a. The inside of the vacuum processing chamber 1 is set to a predetermined pressure. Next, high frequency power is supplied from the first high frequency power supply 8 to the induction coils 4 a to 4 d via the matching unit 7.

  As a result, plasma of the processing gas is generated in the vacuum processing chamber 1. The induction coils 4a to 4d can be adjusted in electric power supplied to the induction coils 4a to 4d based on the plasma distribution in the vacuum processing chamber 1 by a control device (not shown).

  The induction magnetic field radiated from the induction coil 4 is propagated into the vacuum processing chamber 1 through the dielectric window 1 a under the action of the conductor ring 12 and the Faraday shield 6. Although it is known that the Faraday shield 6 cuts off the electrostatic capacitance component by the induction coil 4, it is possible to adjust the plasma generation density distribution by making the Faraday shield 6 in electrical contact with the conductor ring 12. Become.

  That is, since the conductor ring 12 which is a ring-shaped electric conductor is located between the induction coil 4 and the Faraday shield 6, along the conductor ring 12 on the circumference of the conductor ring 12 as shown in FIG. 2. An induced current 13a flows in a direction to cancel the induced magnetic field generated from the induction coil 4. Furthermore, since the conductor ring 12 is electrically connected to the Faraday shield 6, an induced current 13 b similar to the induced current 13 a flows around each slit of the Faraday shield 6. Therefore, the plasma generation density distribution can be adjusted by arranging the conductor ring 12 so that the induced current 13a and the induced current 13b flow at a position where the induced magnetic field radiated from the induction coil 4 is desired to be weakened.

  Here, the effect | action which the conductor ring 12 exerts with reference to FIG. 3 and FIG. 5 is demonstrated. The conductor ring 12 is provided on the Faraday shield 6 as described above, and the shortest distance from the induction coil 4 to the surface of the conductor ring 12 is Lr. From the induction coil 4 to the plasma 5 generated immediately below the dielectric window 1a. If the shortest distance of Lp is Lp, the conductor ring 12 is installed at a position satisfying Lp ≧ Lr in a portion where the induction magnetic field strength is desired to be weakened. By setting the position of the conductor ring 12 to a position satisfying Lp ≧ Lr with respect to the induction coil 4, the mutual inductance between the induction coil 4 and the plasma can be locally changed.

  The relationship between the distances Lp and Lr will be described below with reference to the installation position of the conductor ring 12 and the induced magnetic field strength distribution using simulation results. FIG. 5 is a diagram showing the contour of the induction magnetic field distribution generated from the induction coil 4 when a current of 10 A / m is constantly passed through the induction coil 4. The contour lines in FIG. 5 indicate that the portion with a lighter color has a weaker induced magnetic field strength (the portion with the weakest induced magnetic field strength is hatched), and conversely, the portion with a darker color has a higher induced magnetic field strength. Usually, the induction magnetic field generated from the induction coil 4 passes through the dielectric window 1 a while reaching the vacuum processing chamber 1 while spreading concentrically from the induction coil 4. The distribution is almost similar to the contour line of the induced magnetic field strength shown in FIG.

  FIG. 5A shows a simulation result when the conductor ring 12 is installed at a position satisfying Lp> Lr. At the position where the conductor ring 12 is installed, the induction magnetic field generated from the induction coil 4 is shielded by the conductor ring 12, and only the induction magnetic field inside the conductor ring 12, that is, on the side where the induction coil 4 exists is the dielectric window 1a. Reach the side. As described above, since the conductor ring 12 is disposed at a distance Lr closer to the induction coil 4 than the distance Lp to the plasma generation surface, an induction magnetic field used for plasma generation is generated in the conductor ring 12. This is because the induced magnetic field in the region near the conductor ring 12 is weakened by the action of the current.

  FIG. 5B shows a simulation result when the conductor ring 12 is installed at a position satisfying Lp = Lr. FIG. 5C shows a simulation result when the conductor ring 12 is installed at a position satisfying Lp <Lr. Also in FIGS. 5B and 5C, an induced current for shielding the induced magnetic field is generated at the position where the conductor ring 12 is installed, as in FIG. 5A. However, as shown in FIGS. 5B and 5C, it can be seen that as the conductor ring 12 is moved away from the induction coil 4, the region of the induction magnetic field that reaches the vacuum processing chamber 1 increases.

  From this, it can be seen that the generation density distribution of plasma formed in the vacuum processing chamber 1 varies depending on the mounting position of the conductor ring 12. In other words, the plasma generation density distribution can be adjusted by adjusting the position of the conductor ring 12. Further, when the position of the conductor ring 12 is in a relationship of Lp <Lr, although depending on the position of the outermost induction coil 4d of the induction coil 4, it is almost outside as in this embodiment (the inside diameter of the processing chamber). (Diameter D) −inductive coil diameter (diameter d) is less than about 2 Lp). For this reason, it is effective to install the induction coil 4 at a position satisfying Lp ≧ Lr, and the generation density distribution of the plasma generated immediately below the dielectric window 1a can be adjusted. The ring 12 is desirably installed at a position satisfying Lp ≧ Lr.

  Next, the plasma eccentric position correction of the present embodiment using the action of the conductor ring 12 will be described with reference to FIGS.

  FIG. 6 shows plasma diffusion when there is no influence by other magnetic fields other than the induction magnetic field generated from the induction coil 4. In this case, the plasma 5a generated immediately below the dielectric window 1a is diffused straight on the sample 2 based on the flow by the concentric exhaust device below the sample stage 3, and the eccentricity of the plasma is seen. Absent. On the other hand, as shown in FIG. 7, there is an external magnetic field (here, a horizontal magnetic field B (hereinafter referred to as “external DC magnetic field”) from the left to the right with respect to the paper surface) in addition to the induction magnetic field by the induction coil 4. Are affected by the external DC magnetic field.

  FIG. 7 shows the plasma diffusion in this case. The charged particles in the region where the horizontal magnetic field B acts in the vacuum processing chamber 1 spirally move with respect to the horizontal magnetic field by Lorentz force. For this reason, the plasma 5a generated immediately below the dielectric window 1a diffuses in an oblique direction (downward right direction in the drawing) by the horizontal magnetic field B. Therefore, the plasma diffused on the sample 2 is eccentric from the center of the sample 2.

  FIG. 8 shows the diffusion of plasma when an external DC magnetic field other than the induction magnetic field of the induction coil 4 shown in FIG. 7 is applied and the conductor ring 12 of this embodiment is provided. In the case of FIG. 7 without the conductor ring 12, the plasma diffused on the sample 2 by the horizontal magnetic field B is eccentric on the right side of the drawing. On the other hand, as shown in FIG. 8, the conductor ring 12 is installed to be shifted to the left from the center axis of the drawing, whereby the effect of the circulating current (inductive current 13 a) generated in the conductor ring 12 with respect to the induced magnetic field of the induction coil 4. Thus, the induction magnetic field generated from the induction coil 4 on the right side of the drawing, that is, the induction magnetic field from the induction coil 4 in the region close to the conductor ring 12 is weakened. Therefore, only a low density plasma is generated on the right side of the drawing immediately below the dielectric window 1a, and a high density plasma is generated that is substantially eccentric to the left side of the drawing with respect to the center of the dielectric window 1a. When there is an influence of the horizontal magnetic field B, the diffusion of the plasma with a small density on the right side of the drawing immediately below the dielectric window 1a diffuses to the sample 2 while gradually moving the low density plasma region to the right side of the drawing. . Thereby, even when a horizontal magnetic field acts on the sample 2, the eccentricity of the high-density plasma can be offset.

  Thus, by providing means (inductive magnetic field attenuating means) through which an induced current flows opposite to the induced magnetic field from the induction coil 4, the strength of the induced magnetic field from the induction coil 4 can be attenuated, and the dielectric window The distribution of the induced magnetic field transmitted through 1a can be adjusted. Installation of the induction magnetic field attenuating means is not limited to the upper part of the dielectric window 1a, but may be formed in the dielectric window 1a or on the lower surface of the dielectric window 1a. That is, it may be disposed between the induction coil 4 and the plasma generation surface.

The result of confirming the action in FIGS. 6 to 8 described above by the etching rate will be described with reference to FIG. The etching rate was measured by using an inductively coupled plasma etching apparatus for φ200 mm in which plasma eccentricity was observed, and using a thin film sample of alumina (Al ₂ O ₃ ) as a chlorine-based gas (mixed gas of Cl ₂ gas and BCl ₃ gas). Etched and measured. FIG. 9 shows the in-plane distribution of the etching rate at that time. Note that the in-plane distribution of the etching rate is obtained by measuring a specified point on the sample before and after processing using a film thickness measuring machine, and showing the in-plane distribution of the etching rate by contour lines. The contour lines indicate that the lighter the color portion, the faster the etching rate, and the darker portion, the slower the etching rate. In addition, the effect of this example was confirmed by calculating the average value of each point of the etching rate within the sample surface, the uniformity of the etching rate within the sample surface, and the eccentricity. The eccentricity is an index representing the degree of eccentricity of the plasma diffused on the sample 2, and the smaller the eccentricity, the less the eccentricity.

  First, in the plasma processing apparatus in which the conductor ring 12 is not applied and the forced external DC magnetic field is not provided, the sample in-plane distribution of the etching rate has a high rate rate at the lower right of the figure as shown in FIG. This is considered to be because the plasma is eccentric to the lower right due to the influence of some DC magnetic field (for example, geomagnetism) other than the induction magnetic field. Next, FIG. 9B shows the in-plane distribution of the etching rate when the magnet is installed on the outer periphery of the plasma processing apparatus without applying the conductor ring 12. S pole and N pole magnets (0.4 mT) were installed at the upper left and lower right positions in the figure, respectively. As a result of measuring the etching rate, the portion with the higher etching rate moved to the upper right. This is because a DC magnetic field was applied to the plasma by forcibly installing the magnet. Further, as described above, even when a DC magnetic field other than the induction magnetic field is generated at any location, the eccentric position of the plasma diffused on the sample 2 can be estimated from the result of the in-plane distribution of the etching rate.

  From this result, the eccentricity of the plasma diffused on the sample 2 can be improved by installing the conductor ring 12 based on the estimation result of the eccentric position in FIG. 9A. Next, the result of the in-sample distribution of the etching rate when the conductor ring 12 of this example is applied is shown in FIG. According to this, the in-plane distribution of the almost uniform etching rate was obtained over the entire surface of the sample 2, and the eccentricity ratio was improved from 8.6% in FIG. 9A to 2.7%. Along with this improvement, the uniformity of the etching rate within the sample surface could be improved from 8.3% in FIG. 9A to 5.8%.

  As described above, according to the present embodiment, the conductor ring is shifted from the induction coil at a predetermined position that is shorter than the distance between the induction coil and the plasma generation surface, so that the induction magnetic field directly below the dielectric window 1a is provided. There is an effect that a desired etching performance can be obtained by adjusting the distribution to correct the eccentricity of the diffusion plasma on the upper surface of the sample 2. That is, since the plasma processing apparatus of the present embodiment can generate the plasma 5b that corrects the eccentricity of the plasma diffused on the sample 2, the eccentricity of the plasma diffused on the sample 2 can be improved (note that The plasma in which the eccentricity of the plasma diffused on the sample 2 is corrected is a plasma in which the eccentricity can be corrected in advance so that the plasma on the sample 2 is not eccentric when diffused obliquely. .)

  In the above-described embodiment, the conductor ring 12 is disposed on the Faraday shield 6 between the induction coil 4 and the Faraday shield 6. However, the conductor ring 12 is not necessarily provided between the induction coil 4 and the Faraday shield 6. Instead, as shown in FIG. 10A, the conductor ring 12 may be installed between the Faraday shield 6 and the dielectric window 1a. In this embodiment, the conductor ring 12 is electrically connected to the Faraday shield 6. However, since the current normally flows in a closed circuit, it is sufficient that the conductor ring 12 is electrically connected to a circuit that can form a closed circuit for the induced current to flow. . For this reason, for example, it may be conducted with the processing container 1b, the cover of the matching unit 7, and the like. Moreover, if a closed circuit can be formed only by the conductor ring 12, it is not essential to conduct with the above-described one.

  Further, when the action of the Faraday shield 6 is not required, the Faraday shield may be eliminated as shown in FIG. 10B, and the conductor ring 12 may be simply installed on the upper surface of the dielectric window 1a. That is, if the conductor ring 12 is installed between the induction coil 4 and the dielectric window 1a, the distribution of the induction magnetic field generated from the induction coil 4 can be corrected. Here, the conductor ring 12 does not necessarily need to be electrically connected to a grounded apparatus main body, for example, the processing vessel 1b, as long as a closed circuit for flowing an induced current can be formed. That is, it may be electrically floating.

  Further, the shape of the conductor ring 12 is not limited to the shape shown in FIG. 2 (FIG. 11A), and may be, for example, a comb-shaped conductor ring as shown in FIG. An elliptical ring or a ring having a different width on the circumference may be used, that is, it may be deformed into a shape that provides a desired induced magnetic field distribution. Moreover, since the conductor ring 12 of the present embodiment is electrically connected to the Faraday shield 6, it does not necessarily have a ring shape. That is, the feature of the present invention is that the induced magnetic field distribution generated from the induction coil 4 is locally corrected by the circulating current generated locally. Therefore, if the ring-shaped conductor ring as shown in FIG. 11C is provided in contact with the Faraday shield 6, for example, an arc-shaped conductor plate obtained by dividing the ring into quarters may be used.

  Also, a plurality or multiple types of conductor rings may be used simultaneously. In addition, the conductor ring 12 can be independently arranged so as to correspond to any eccentric position of the plasma distribution. Thereby, installation of only a conductor ring becomes easy and the adjustment according to the machine difference between plasma processing apparatuses is attained.

  Furthermore, although the Faraday shield 6 and the conductor ring 12 are separately provided in this embodiment, they may be integrated with the functions of the Faraday shield and the conductor ring. For example, the Faraday shield having the radial slits shown in FIG. 12 (e) is formed by changing the shape of the conductor portion by forming a deformed slit having a different radial length as shown in FIGS. 12 (a) to 12 (d). But it ’s okay.

  FIG. 12A shows a Faraday shield in which at least one slit is divided in the radial direction and an intermediate region is a conductor. FIG. 12B shows a Faraday shield having a shape in which at least one slit is not provided at an arbitrary position. FIG. 12C shows a Faraday shield in which at least one slit is changed in length in the radial direction, the center side is shortened, and the area of the conductor on the center side is widened. FIG. 12D is a Faraday shield in which the area of the outer conductor is expanded in the reverse of FIG. By changing the length in the radial direction, in other words, using a Faraday shield that blocks any area of the slit and selecting it appropriately according to the induced magnetic field distribution, the conductor plate is arranged in the direction intersecting with the plurality of slits. The induced magnetic field distribution can be corrected.

  FIG. 13 illustrates an example of attaching an integrated Faraday shield that enables correction of the induction magnetic field distribution at the feeding end of the induction coil 4 of this embodiment. Since the feeding end portion of the induction coil 4 in this embodiment is partially overlapped, it is a location where the strength of the induced magnetic field is strongest in the circumferential direction. Here, although the weak induction magnetic field cannot be strengthened, it is possible to weaken the strong magnetic field strength by forming the local circulating current described in this embodiment. As shown in FIG. 13, by closing the slit at the location facing the power feeding portion of the induction coil, it is possible to block the strong magnetic field strength of the power feeding portion and improve the plasma non-uniformity in the circumferential direction of the induction coil. In this embodiment, a one-turn induction coil is used. However, a plurality of induction coils may be used.

  As described above, according to the present embodiment, the induced magnetic field distribution generated from the induction coil can be corrected. Therefore, the non-uniformity of the diffused plasma on the upper surface of the sample, that is, the influence of the DC magnetic field other than the induced magnetic field or It is possible to improve the eccentricity of the plasma diffused on the sample due to the eccentricity of the exhaust gas in the plasma processing chamber, or the nonuniformity of the plasma in the circumferential direction of the induction coil caused by the induction coil power supply unit.

DESCRIPTION OF SYMBOLS 1 Vacuum processing chamber 1a Dielectric window 1b Processing container 2 Sample 3 Sample stand 4, 4a, 4b, 4c, 4d Inductive coil 5 Plasma 6 Faraday shield 7 Matching device 8 First high frequency power supply 9 Gas supply device 10 Exhaust device 11 First Second high frequency power source 12 Conductor rings 13a and 13b Inductive current

Claims (6)

A vacuum processing chamber in which a sample is plasma-processed, a dielectric window that hermetically seals the upper portion of the vacuum processing chamber, an induction coil disposed above the dielectric window, and high-frequency power to the induction coil A plasma processing apparatus comprising: a high-frequency power source; and a Faraday shield that is disposed between the induction coil and the dielectric window and is capacitively coupled to the plasma.
The Faraday shield has a plurality of slits arranged radially from the center,
The slit comprises a first slit and a number of second slits less than the number of the first slit,
Each longitudinal direction of the first slit extends from the apex to the outer periphery,
Each of said 2nd slits is a slit of the shape where a part of longitudinal direction of the slit of the same shape as said 1st slit was block | closed in the circumferential direction, The plasma processing apparatus characterized by the above-mentioned. The plasma processing apparatus according to claim 1,
The range of the closed region in the longitudinal direction of each of the second slits is a range from the first position to the second position in the longitudinal direction of each of the second slits,
The first position is different from each vertex of the second slit,
The plasma processing apparatus characterized in that the second position is a position away from the first position of the second slit from the first position and is different from the outer periphery of the second slit. The plasma processing apparatus according to claim 1,
The range of the closed region in the longitudinal direction of each of the second slits is a range from the first position to the second position in the longitudinal direction of each of the second slits,
The first position is the apex of each of the second slits;
Said 2nd position is located between each vertex of said 2nd slit, and outer periphery, The plasma processing apparatus characterized by the above-mentioned. The plasma processing apparatus according to claim 1,
The range of the closed region in the longitudinal direction of each of the second slits is a range from the first position to the second position in the longitudinal direction of each of the second slits,
The first position is located between each vertex of the second slit and the outer periphery,
Said 2nd position is each outer periphery of said 2nd slit, The plasma processing apparatus characterized by the above-mentioned. In the plasma processing apparatus according to any one of claims 1 to 4,
The plasma processing apparatus, wherein the induction coil is a circular induction coil that is wound around so that a power supply end and a terminal end intersect each other. In the plasma processing apparatus according to any one of claims 1 to 4,
The plasma processing apparatus, wherein the first slit and the second slit are plural.

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