JP2009218485A - Plasma generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma generator improving an in-plane uniformity while keeping a high etching rate when used for plasma etching in a semiconductor manufacturing process. <P>SOLUTION: The plasma generator 100 includes a plate like ceramic plate 4 having a plurality of gas passing through-holes 5 passing through a thickness direction, a first electrode 1 disposed in the ceramic plate 4 and having a plurality of sets of linear electrodes 6 each having a linear discharge member 7, a plate like second electrode 2 disposed parallel such that a plane 2a and another plane 1a of the first electrode 1 face each other with a space between the first electrode 1 and the second electrode, and an electric power supply 3a and 3b having a plurality of pulse generating circuits each connected respectively to a plurality of linear electrodes 6 disposed in the first electrode 1 and capable of independently applying a nanopulse between each set of linear electrode 6 and the second electrodes 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a plasma generator, and more particularly to a plasma generator capable of improving in-plane uniformity while maintaining a high etching rate when used for plasma etching in a semiconductor manufacturing process.

2. Description of the Related Art Conventionally, a semiconductor manufacturing apparatus used for an etching process of a semiconductor process has a vacuum reaction container that can be sealed, and a semiconductor manufacturing apparatus such as an electrostatic chuck, a heater, or a susceptor on which a wafer (substrate) is placed in the reaction container. It has a member for use. For example, in a counter electrode type plasma generator, a buried electrode made of a metal plate in an electrostatic chuck is often used as a counter electrode for generating plasma. In addition, when a shower head is used as a reaction gas supply port facing the substrate, the shower head may be made of a conductive material and used as one of the counter electrodes (for example, Patent Document 1). reference).
JP 2004-296553 A

  In such a semiconductor manufacturing apparatus using a plasma generator, increasing the output of a high frequency power supply (RF power supply) in order to increase the etching rate and increase the productivity, the semiconductor substrate is greatly damaged, and the in-plane uniformity is increased. There was a problem that decreased. When a nano pulse power source is used instead of the RF power source, the semiconductor substrate is less damaged and the in-plane uniformity is improved, but the etching rate cannot be maintained as high as in the case of the RF power source. there were.

  The present invention has been made in view of the above-described problems, and a plasma generator capable of improving in-plane uniformity while maintaining a high etching rate when used for plasma etching in a semiconductor manufacturing process. The purpose is to provide.

  In order to achieve the above object, the present invention provides the following plasma generator.

[1] A plate-shaped ceramic plate having a plurality of gas-passing through holes penetrating in the thickness direction, and a plurality of sets of linear shapes each having a linear discharge portion disposed in the ceramic plate A plate-like second electrode disposed in parallel so that one surface and one surface of the first electrode face each other with a gap between the first electrode having electrodes and the first electrode And each of the plurality of sets of linear electrodes disposed on the first electrode, and a nano pulse voltage is applied independently between each of the sets of linear electrodes and the second electrode. And a power source having a plurality of pulse generation circuits.

[2] The plasma generation apparatus according to [1], wherein the power supply intermittently applies nanopulse voltages to the respective sets of linear electrodes with a time difference by the plurality of pulse generation circuits.

[3] When the plurality of sets of linear electrodes are projected onto a plane orthogonal to the thickness direction of the ceramic plate, the discharge portions of different sets of linear electrodes are arranged to be adjacent to each other [1]. Or the plasma generator as described in [2].

[4] The plasma generator according to any one of [1] to [3], wherein each of the plurality of sets of linear electrodes includes a plurality of the discharge units arranged at equal distances.

[5] The plasma generating apparatus according to [4], wherein each of the plurality of sets of linear electrodes has a linear discharge portion arranged in parallel with each other.

[6] The plasma generator according to [4], wherein the discharge portions of the plurality of sets of linear electrodes are each concentric.

[7] The plurality of sets of linear electrodes are arranged such that the discharge portions of each set of linear electrodes are arranged in order for each linear electrode, and the arrangement of the discharge portions is repeated [4]. -The plasma generator in any one of [6].

[8] The plasma generating apparatus according to any one of [1] to [3], wherein the discharge portions of the plurality of sets of linear electrodes each have a spiral shape centering on a central portion of the ceramic plate.

  According to the plasma generator of the present invention, each set is provided by a power source having a plurality of sets of linear electrodes each having a linear discharge portion in the first electrode and having a plurality of pulse generation circuits to which a nanopulse voltage can be applied. Since the nanopulse voltage can be independently applied to each pair between the linear electrode and the second electrode, in-plane uniformity can be improved while maintaining a high etching rate.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and the ordinary knowledge of those skilled in the art is within the scope of the present invention. Based on the above, it should be understood that design changes, improvements, and the like can be made as appropriate.

  As shown in FIG. 1, an embodiment of the plasma generator of the present invention (plasma generator 100) is a disk-shaped ceramic plate (ceramic) having a plurality of through holes 5 for gas passage penetrating in the thickness direction. A first electrode 1 having a plurality of sets (two sets) of linear electrodes 6 and 6 each having a linear discharge portion 7 disposed (embedded) inside the ceramic plate 4; A plate-like second electrode 2 arranged in parallel so that one surface 2a and one surface 1a of the first electrode 1 face each other with a space between the first electrode 1 and the first electrode 1 Are connected separately to each of a plurality (two sets) of linear electrodes 6, 6 arranged in 1, and a nanopulse voltage is independently applied between each pair of linear electrodes 6 and the second electrode 2. Power supply with multiple pulse generators that can be applied (nanopulse power supply) a, it is obtained by a 3b. Here, FIG. 1 is a schematic view showing a cross section of one embodiment of the plasma generator of the present invention. Note that the first electrode 1 shown in FIG. 1 corresponds to the A-A ′ cross section of the first electrode 1 shown in FIG. 2.

  As shown in FIG. 2, the first electrode 1 constituting the plasma generating apparatus 100 of the present embodiment has a plurality of (two sets) of linear electrodes 6 and 6 each having a plurality of discharges arranged at equal intervals. Part 7. And the discharge part 7 is linear form, and is mutually arrange | positioned in parallel. Each set of linear electrodes 6 has a comb-like structure in which a plurality of discharge portions 7 are connected by connecting portions 11 at their ends. Here, when referring to “a linear discharge portion”, as shown in FIGS. 1 and 2, the cross-sectional shape perpendicular to the longitudinal direction of the discharge portion may be a rectangular “strip shape”. The cross-sectional shape perpendicular to the longitudinal direction of the discharge part may be any shape other than a rectangle, such as a circle, an ellipse, a square, a triangle, and other polygons. Here, FIG. 2 is a plan view showing the first electrode 1 constituting one embodiment of the plasma generator of the present invention. Although the linear electrode is embedded in the ceramic plate and cannot be seen from the outside, FIG. 2 shows a state in which the linear electrode embedded in the ceramic plate is seen through for convenience of explanation. Yes.

  As shown in FIG. 1, the power supplies 3 a and 3 b are preferably connected to the connecting portion 11 of the linear electrode 6. The power supplies 3a and 3b may be connected to the discharge unit 7.

  Thus, since the plasma generator 100 of this embodiment can apply a nanopulse voltage independently with respect to multiple sets (2 sets) of linear electrodes 6 and 6 by the power supplies 3a and 3b. The power supplies 3a and 3b apply a nanopulse voltage intermittently to the linear electrodes 6 and 6 with a time difference (by time-sharing control in multiple parallels), so that the first electrode 1 and the second electrode 2 A high-density, high-energy plasma space (plasma field) having a time difference can be formed in the space between them. As in the present embodiment, the plasma generation electrode using an electrode structure in which a parallel line and a flat plate face each other is compared with the plasma generation electrode using an electrode structure in which a flat plate and a flat plate face each other. A larger electric field difference can be provided, and a strong plasma field can be created. In the plasma generator 100 of the present embodiment, since the linear electrode 6 is embedded in a ceramic plate having high insulation performance, the plasma does not interfere with each other even if the linear discharge portions 7 are arranged at a narrow interval. It is possible to increase the density. When the first electrode side is formed by arranging bare metal wires in parallel, there is a problem that dielectric breakdown occurs and plasma cannot be formed. Furthermore, by applying a phase difference (time difference) to multiple sets of linear electrodes and applying a nanopulse voltage, even if the distance between the electrodes is shortened, plasma can be generated without interfering with each other. It is possible to form a high-density space. Thus, by creating a strong plasma field with high density, it is possible to maintain a high etching rate and to maintain the plasma without increasing the electron temperature of the nanopulse plasma. Therefore, in-plane uniformity can be improved.

  In the plasma generator 100 of the present embodiment, the number of linear electrodes is not particularly limited as long as it is a plurality of sets.

  The arrangement range (area) of the plurality of sets of linear electrodes 6 and 6 in the ceramic plate is preferably 80% or more with respect to the area of the cross section perpendicular to the thickness direction of the ceramic plate. % Is more preferable, and 90 to 98% is particularly preferable. By disposing the linear electrode in such a range, it is possible to generate plasma over a wide range without being biased in the space between the first electrode and the second electrode. When the range is narrower than 80%, the plasma generation region becomes narrow, and it may be difficult to form a high-density and strong plasma field. Here, the term “arrangement range of a plurality of sets of linear electrodes in a ceramic plate” refers to a shape formed by connecting the outermost portions of each linear electrode on a disk-shaped ceramic plate. Is a range formed by connecting the outermost portions as a whole when all the linear electrodes are overlapped. In addition, when referring to “a shape formed by connecting the outermost portions of the linear electrode”, as shown in FIG. 3, in the case of a complicated structure such as a linear electrode having a linear discharge portion Is a shape formed by the outermost portion in the shape connecting the ends of each discharge portion and the connecting portion, and in FIG. 3, the shape indicated by a broken line corresponds to this. Here, FIG. 3 is a plan view showing a linear electrode that constitutes an embodiment of the plasma generator of the present invention, and an arrangement range of the linear electrode in the ceramic plate. As shown in FIGS. 7 and 8, when the discharge part is concentric, the arrangement range of the linear electrodes in the ceramic plate is the range of the discharge part forming the largest circle.

  The area of the arrangement range of the one linear electrode 6 in the ceramic plate is preferably 80% or more with respect to the area of the cross section perpendicular to the thickness direction of the ceramic plate, and is 80 to 99%. More preferably, it is particularly preferably 90 to 98%. By setting each linear electrode in such a range, plasma can be generated over a wide range without being biased in the space between the first electrode and the second electrode. .

  As shown in FIGS. 1 and 2, the plurality of sets of linear electrodes 6 in the plasma generating apparatus 100 of the present embodiment have different sets of linear electrodes when projected onto a plane orthogonal to the thickness direction of the ceramic plate 4. It is preferable that the six discharge parts 7 are arranged adjacent to each other. The first electrode 1 shown in FIGS. 1 and 2 is provided with two sets of linear electrodes 6, but the discharge portions constituting each linear electrode are adjacent to the discharge portions constituting other linear electrodes. The discharge portions are alternately arranged. In the first electrode 1 shown in FIGS. 1 and 2, the discharge portions 7 constituting the two sets of linear electrodes 6 and 6 are arranged on the same plane, but the discharge portions of one set of linear electrodes And the discharge portions of the other sets of linear electrodes may be arranged on different planes. Even in such a case, when the plurality of sets of linear electrodes 6 are projected onto a plane orthogonal to the thickness direction of the ceramic plate 4, the discharge portions 7 of the different sets of linear electrodes 6 are arranged adjacent to each other. Preferably it is. In this way, by disposing the discharge portions of the different sets of linear electrodes adjacent to each other, the discharge portions of the linear electrodes of each set are arranged evenly in the plane of the ceramic plate. . And when a nanopulse voltage is applied to each set of linear electrodes independently, even if a voltage is applied to any set of linear electrodes, similarly, there is no bias in the plane of the disk-shaped ceramic plate. It is possible to generate plasma over a wide range.

  In one linear electrode, when the distance between the first electrode and the second electrode is 10, the distance between adjacent discharge parts is preferably 15 or more, and more preferably 15-20. By setting the distance between adjacent discharge parts in such a range, it is possible to form a stronger plasma field. If the distance between adjacent discharge portions in one linear electrode is shorter than 15, discharge may be difficult to occur. Further, if the distance between adjacent discharge portions is shorter than the distance between the first electrode and the second electrode, interference may occur at adjacent parallel line intervals, and discharge may not occur.

  In the plasma generator 100 of the present embodiment, the discharge part 7 constituting the linear electrode 6 has a width perpendicular to the longitudinal direction in the plane perpendicular to the thickness direction of the ceramic plate is 0.01 to 1 mm. It is preferable that it is 0.01-0.5 mm, and it is especially preferable that it is 0.05-0.5 mm. If the width of the discharge part 7 is shorter than 0.01 mm, it is difficult to ensure the reliability of the conductor due to the narrow conductor width, and there is disconnection or fusing, and if it is longer than 1 mm, the electric field concentration becomes small and plasma generation becomes difficult. Sometimes. The length of the discharge part 7 in the thickness direction of the ceramic plate (thickness of the discharge part) is preferably 0.1 to 10 mm, more preferably 0.1 to 5 mm, and It is especially preferable that it is 5-5 mm. If the thickness of the discharge part 7 is less than 0.1 mm, dielectric breakdown may occur. If the thickness is more than 10 mm, the dielectric thickness increases, electric field concentration decreases, and plasma generation may become difficult.

  The discharge part 7 and the connection part 11 constituting the linear electrode 6 are arranged such that the discharge part 7 is arranged on the side close to the second electrode 2 and the connection part 11 is arranged on the side far from the second electrode 2. Preferably, it is arranged in a ceramic plate. As an example in which the discharge part and the connection part are located on different planes, the linear electrode 26 shown in FIGS. 6A and 6B can be cited. Further, the arrangement of the connecting portion 11 in the ceramic shower plate 4 is not particularly limited, but when the discharge portion is linear, it may be near the outer periphery of the ceramic shower plate 4 as shown in FIGS. preferable. On the other hand, when the discharge part is concentric, as shown in FIGS. 7 and 8, the discharge part is preferably arranged so as to extend in the radial direction from the vicinity of the center of the ceramic shower plate 4.

  The discharge part 7 which comprises the linear electrode 6 may be one, and multiple may be sufficient as it. In the case of a plurality, the number is not particularly limited.

  The material of the discharge part and the connection part constituting the linear electrode is a metal, for example, iron, chromium, nickel, cobalt, tungsten, molybdenum, titanium, aluminum, gold, silver, copper, platinum, or these metal and ceramic component The cermet material etc. which mixed are preferable. It is more preferable to combine the base ceramic and a material having a small difference in thermal expansion. For example, when a ceramic member having a small thermal expansion such as aluminum nitride, silicon nitride, cordierite or the like is selected as the base material, tungsten, molybdenum, or a cermet material thereof is suitable. On the other hand, when aluminum oxide having a relatively high coefficient of thermal expansion is used as the base material, iron-based alloys, platinum, titanium, and the like can be used in addition to tungsten and molybdenum. The materials of the discharge part and the connection part may be the same or different.

  In the plasma generating apparatus 100 of the present embodiment, the ceramic plate (ceramic shower plate) 4 constituting the first electrode 1 has a plurality of through holes for gas passage that penetrate in the thickness direction as shown in FIGS. 5 is a disk-shaped plate having 5; By providing the through hole in this way, a gas necessary for etching can be allowed to flow from the through hole into the space between the first electrode and the second electrode. The shape of the ceramic plate 4 is preferably a disc shape (circular shape), but may be any shape such as a polygon such as a quadrangle, an ellipse, or a racetrack shape. The shape, size, arrangement position, and number of arrangement of the through holes are not particularly limited, and can be known conditions suitable for target etching conditions. Further, the thickness and size of the ceramic shower plate are not particularly limited, and may be known conditions suitable for target etching conditions. For example, in the case of a disk shape, those having a thickness of about 0.1 to 10 mm and a diameter of about 50 to 500 mm can be suitably used.

  The material of the ceramic shower plate 4 is preferably at least one selected from oxides, nitrides, and borides. By using such a material, there is an advantage of a highly insulating electrode. The material of the ceramic shower plate 4 may be an amorphous material, or a composite of at least one selected from oxide, nitride, and boride and glass.

  The plasma generator of the present invention is provided with a “power source having a plurality of pulse generation circuits”. This is because among the whole of one or a plurality of power sources provided in the plasma generator, “a plurality of pulses” is used. This means that there is a “generator circuit”, and there may be a plurality of “power supplies” having a “single pulse generator circuit”, or a single “power source” having a “plurality of pulse generator circuits”. Alternatively, a plurality of “power supplies” having one or a plurality of “pulse generation circuits” may be provided. In any case, it is preferable that the “plurality of pulse generation circuits” operate in synchronization. The plasma generation apparatus 100 of this embodiment includes a plurality of “power supplies” 3a and 3b each having one “pulse generation circuit”.

  The power supplies 3a and 3b preferably have a nano pulse generation circuit capable of applying a nano pulse voltage having a half width of 50 μsec or less. Furthermore, it is more preferable that the power supplies 3a and 3b can apply a nanopulse voltage with a half width of 1 μsec or less, and can apply a nanopulse voltage with a half width of 0.05 to 0.5 μsec. Particularly preferred. When the half-value width of the nanopulse voltage exceeds 50 μsec, when the multi-parallel time-division control is performed, the voltage becomes 10 Hz or less, and it may be difficult to generate plasma. Furthermore, when the half-value width of the nanopulse voltage is 1 μsec or less, highly efficient plasma can be generated without converting input energy into heat. Here, the nano-pulse power source refers to a power source that generates a pulse with a half-value width smaller than 1 μsec, and the nano-pulse voltage refers to a voltage pulse with a half-value width smaller than 1 μsec. The frequency of the nanopulse voltage is preferably 100 Hz to 100,000 Hz, more preferably 1000 Hz to 10,000 Hz. The phase difference between the nanopulse voltage from the power source 3a and the nanopulse voltage from the power source 3b is preferably 180 degrees.

  As the power supplies 3a and 3b, in order to apply a nano-pulse voltage, an inductive energy storage method using an open switch, a capacitive energy storage method using a short-circuit switch, a pulse forming network method, a magnetic compression method, and a combination thereof Nanopulse generator circuit can be used. Among these, it is preferable to use an inductive energy storage system using an open switch as a small and highly efficient power source capable of forming a nanopulse voltage having a half width of 1 μsec or less. As the open switch, a semiconductor switch such as an electrostatic induction (SI) thyristor, IGBT, or MOS-FET can be used. When using a high current and voltage, it is more preferable to use an SI thyristor as an open switch.

  In the plasma generating apparatus 100 of the present embodiment, as shown in FIG. 1, a power source 3a having one pulse generating circuit is connected to one set of linear electrodes 6 and a conductive plate electrode 8 to generate one pulse. A power source 3 b having a circuit is connected to another set of linear electrodes 6 and conductive plate electrodes 8. Wirings connected to the conductive plate electrode 8 of the power supplies 3 a and 3 b are connected to the earth 10. In this way, different power sources (3a and 3b) are connected to one set of linear electrodes 6 and the other set of linear electrodes 6, respectively. A nanopulse voltage can be applied to the pair of linear electrodes 6 with a time difference. Thus, the effect of increasing the density of radicals generated by plasma is achieved by applying nanopulse voltages from different power sources to different linear electrodes.

  In the plasma generator 100 of the present embodiment, the plate-like second electrode 2 has a conductor plate electrode 8, and the conductor plate electrode 8 constituting the second electrode 2 is embedded in a disk-like ceramic plate 9. ing. The conductive plate electrode 8 may be formed by embedding a circular metal plate in ceramics, or by cutting out a metal mesh into a circular shape and embedding in ceramics. Alternatively, a conductive paste may be printed in a circle on the tape-formed flat plate by a screen printing method or the like, laminated with the same ceramic, and integrated. It is preferable that the conductive plate electrode 8 is embedded in the ceramic plate 9 because the insulation design is easy and a stable and uniform plasma field can be formed without causing abnormal discharge even when a high pulse voltage is applied. In the semiconductor manufacturing apparatus, when the plasma generator of this embodiment is used, the second electrode is disposed on the lower side in the vertical direction (the first electrode is disposed on the upper side in the vertical direction), and the second electrode is disposed on the wafer (substrate). It is preferable to use it as an electrostatic chuck to be placed. As shown in FIG. 1, the first electrode and the second electrode are arranged so that one surface 1 a of the first electrode and one surface 2 a of the second electrode face each other. It is preferable that one surface 1a of the first electrode and one surface 2a of the second electrode are parallel. The shape of the conductive plate electrode is preferably circular, but may be any shape such as a polygon such as a quadrangle, an ellipse, or a racetrack. The shape of the ceramic plate in which the conductive plate electrode is embedded is preferably a disc shape (circular shape), but may be any shape such as a polygon such as a quadrangle, an ellipse, or a racetrack shape. When the second electrode is disk-shaped, the size (thickness and diameter) is preferably the same as that of the first electrode. Moreover, when the conductor flat plate electrode 8 is circular, the thickness is preferably 0.1 to 10 mm, and the diameter is preferably 50 to 500 mm.

  The distance between the first electrode and the second electrode is preferably 10 to 150 mm, more preferably 20 to 100 mm, and particularly preferably 30 to 50 mm. If it is shorter than 10 mm, the discharge may not spread and the in-plane distribution may be deteriorated. If it is longer than 150 mm, the discharge may be difficult.

  The material of the conductive plate electrode 8 constituting the second electrode 2 is not particularly limited, and tungsten, molybdenum, iron, chromium, nickel, titanium, zirconium, manganese, gold, silver, copper, platinum, and alloys thereof or these The cermet containing these metals can be mentioned. The material of the ceramic plate 9 constituting the second electrode 2 is not particularly limited, and examples thereof include silicon nitride, aluminum nitride, aluminum oxide, silicon oxide, cordierite, and yttria. About the 2nd electrode 2, what is used for the electrostatic chuck in the existing semiconductor manufacturing apparatus etc. can be used.

  FIG. 4 is a schematic view showing a cross section of another embodiment (plasma generator 200) of the plasma generator of the present invention, and FIG. 5 is a first view showing another embodiment of the plasma generator of the present invention. 3 is a plan view showing an electrode 21. FIG. The first electrode 21 shown in FIG. 4 corresponds to the B-B ′ cross section of the first electrode 21 shown in FIG. 5. Further, in FIG. 5, the linear electrode 26 embedded in the ceramic plate 24 is shown in a transparent state for convenience. In the plasma generator 200 of the present embodiment, four sets of linear electrodes 26 are used. The plasma generator 200 of the present embodiment is arranged in a disk-shaped ceramic plate (ceramic shower plate) 24 having a plurality of gas passage through holes 25 penetrating in the thickness direction, and the ceramic plate 24. A first electrode 21 having a plurality of sets (four sets) of linear electrodes 26 each having a linear discharge portion 27, and one surface 22a with a space between the first electrode 21 and the first electrode 21; A second electrode 22 having a disk-shaped conductive plate electrode 28 disposed so as to face one surface 21a of the first electrode 1, and a plurality of sets (four sets) arranged on the first electrode 21. A plurality of (four) power supplies 23 a, 23 b, 23 c, which are separately connected to each of the linear electrodes 26 and can independently apply a nanopulse voltage between each pair of the linear electrodes 26 and the second electrode 22, and With 23d Those were.

  In the plasma generator 200 of the present embodiment, as shown in FIG. 4, a power source 23 a having one pulse generation circuit is connected to one set of linear electrode 26 and conductor plate electrode 28, A power source 23b having a pulse generation circuit is connected to another set of linear electrodes 26 and conductive plate electrodes 28, and a power source 23c having one pulse generation circuit is further connected to another set of linear electrodes 26 and conductive plate electrodes. A power source 23d having one pulse generating circuit is connected to another set of linear electrodes 26 and conductive plate electrodes 28. Thus, since different power sources (23a, 23b, 23c, and 23d) are connected to each set of linear electrodes 26, a nanopulse voltage is applied with a time difference for each set of linear electrodes 26. can do. Wirings connected to the conductive plate electrode 28 of the power supplies 23 a, 23 b, 23 c and 23 d are connected to the ground 30. Further, the disk-shaped conductor flat plate electrode 28 constituting the second electrode 22 is embedded in a disk-shaped ceramic plate 29. The conductive plate electrode 28 may be formed by embedding a circular metal plate in ceramics, or by cutting a metal mesh into a circular shape and embedding it in ceramics. Alternatively, a conductive paste may be printed in a circle on the tape-formed flat plate by a screen printing method or the like, laminated with the same ceramic, and integrated. Further, the second electrode may not be a structure in which the conductive flat plate electrode is embedded in the ceramic plate, but may be configured by only the conductive flat plate electrode made of a metal flat plate without the ceramic plate.

  As shown in FIG. 5, the first electrode 21 constituting the plasma generating apparatus 200 of the present embodiment includes a plurality of discharge portions 27 in which a plurality of sets (four sets) of linear electrodes 26 are arranged at equidistant intervals. Have And the discharge part 27 is linear form, and is mutually arrange | positioned in parallel. Each set of linear electrodes 26 has a comb-like structure in which a plurality of discharge portions 27 are connected by connecting portions 31 at their end portions.

  In the plasma generating apparatus 200 of the present embodiment, four sets of linear electrodes 26 are embedded in the ceramic shower plate 24 in this way, and therefore, as shown in FIGS. 6A and 6B, the discharge portions 27 of the linear electrodes 26 and The connecting portion 31 is formed so as not to be located in the same plane but in different planes. Here, FIG. 6A is a perspective view schematically showing two of the four sets of linear electrodes 26 shown in FIG. 5, and FIG. 6B is one of the four sets of linear electrodes 26 shown in FIG. It is a perspective view which shows typically the remaining 2 sets of. Thus, since the discharge part 27 of the linear electrode 26 and the connection part 31 were formed so that it might be located in a different plane, as shown to FIG. 6A, two sets of linear electrodes 26 are made into one group. The comb-like discharge portions 27 of the other linear electrode 26 are arranged so as to enter the gap between the comb-like discharge portions 27 of the other set of linear electrodes 26, and the other two sets as shown in FIG. 6B. The linear electrodes 26 are also arranged in the same manner as in the case of the linear electrodes 26 shown in FIG. 6A, and the discharge portions of these two sets of linear electrodes and the discharge portions of the other two sets of linear electrodes. Can be arranged so that the entire discharge portion is arranged in parallel on the same plane as shown in FIG. That is, when the linear electrode 26 is embedded in the ceramic shower plate 24, all the discharge parts are arranged on the same plane, the discharge part and the connection part are arranged on different planes, and the connection part 31 is also The connecting portions of the two sets of linear electrodes are arranged on the same plane, and the connecting portions of the remaining two sets of linear electrodes are flush with and inside the connecting portions of the two sets of linear electrodes. Can be placed. By arranging in this manner, the discharge portions of all the linear electrodes are arranged in parallel on the same plane in the ceramic shower plate 24 without the connection portions 31 of each set becoming an obstacle to the arrangement. It becomes possible to do. The discharge part 27 of the linear electrode 26 shown in FIG. 6A is formed in an L shape, and the discharge part 27 of the linear electrode 26 shown in FIG. 6B is formed in a T shape. When “the discharge part is a straight line”, the shape of each of the L-shaped and T-shaped discharge parts 27 is parallel to the surface of the ceramic shower plate 24 (perpendicular to the thickness direction of the ceramic shower plate 24). Means that the portion parallel to the plane to be straight is straight, and does not include the portion orthogonal to the surface. Moreover, the connection part 31 of the linear electrode 26 shown to FIG. 6B is smaller than the connection part 31 of the linear electrode 26 shown to FIG. 6A, and is arrange | positioned inside the connection part 31 of the linear electrode 26 shown to FIG. 6A. Is preferred.

  As shown in FIGS. 4 and 5, the four sets of linear electrodes constituting the plasma generating apparatus 200 of the present embodiment are arranged in order, one discharge portion of each set of linear electrodes for each linear electrode. The arrangement of the discharge portions is repeated. In the linear electrodes shown in FIGS. 4 and 5, the discharge portions of the four sets of linear electrodes are formed one by one in order, “the discharge portions of the different sets of linear electrodes are arranged one by one. The “four rows” are repeated four times.

  The other configuration of the plasma generator 200 of the present embodiment is preferably the same as that of the above-described embodiment of the plasma generator of the present invention (plasma generator 100).

  FIG. 7 is a plan view schematically showing linear electrodes 41a and 41b constituting still another embodiment of the plasma generator of the present invention. The configuration of the plasma generator of the present embodiment is preferably the same as that of the plasma generator of the present invention (plasma generator 100) except that the structure of the linear electrode is different.

  In the plural sets (two sets) of linear electrodes 41a and 41b constituting the plasma generator of the present embodiment, the discharge portions 42a and 42b are concentric. And the discharge part 42a of the linear electrode 41a is connected to the linear connection part 43a, and the discharge part 42b of the linear electrode 41b is connected to the linear connection part 43b. Furthermore, the discharge part 42a and the discharge part 42b are located in a line at equal intervals. Thus, even if it makes the discharge part of a linear electrode concentric, the effect similar to the case of one Embodiment (plasma generator 100) of the said plasma generator of this invention can be acquired.

  In the present embodiment, the discharge part and the connection part are arranged in the same plane. Therefore, the concentric discharge portions 42a of one set of linear electrodes 41a are not connected to the connecting portions 43b of other sets of linear electrodes 41b so as not to contact the connecting portions 43b of other sets of linear electrodes 41b. The overlapping part is cut out.

  When the discharge part is concentric as in this embodiment, the distance between adjacent discharge parts in one linear electrode is preferably 1 to 100 mm, more preferably 2 to 100 mm, and particularly preferably 2 to 50 mm. . By setting the distance between adjacent discharge parts in such a range, it is possible to form a stronger plasma field. If the distance between adjacent discharge portions in one linear electrode is shorter than 1 mm, discharge may be difficult to occur. Further, if the distance between adjacent discharge portions is shorter than the distance between the first electrode and the second electrode, interference may occur at adjacent parallel line intervals, and discharge may not occur. Further, if the distance between the discharge parts is longer than 100 mm, a strong plasma field may not be obtained.

  As in this embodiment, when the discharge part is concentric, in the plurality of sets of linear electrodes arranged on the first electrode, the distance between adjacent discharge parts is preferably 0.5 to 50 mm, 50 mm is more preferable, and 1 to 10 mm is particularly preferable. If the distance between adjacent discharge parts in the plurality of sets of linear electrodes arranged on the first electrode is shorter than 0.5 mm, dielectric breakdown may occur. Moreover, when the distance between the discharge parts is longer than 50 mm, the discharge may not occur.

  The width and thickness of the discharge part constituting the linear electrode are preferably the same as those in the embodiment of the plasma generator of the present invention (plasma generator 100).

  FIG. 8 is a plan view schematically showing linear electrodes 51a, 51b, 51c and 51d constituting still another embodiment of the plasma generator of the present invention. The configuration of the plasma generator of the present embodiment is preferably the same as that of the plasma generator of the present invention (plasma generator 100) except that the structure of the linear electrode is different.

  In the plural sets (four sets) of linear electrodes 51a, 51b, 51c and 51d constituting the plasma generator of the present embodiment, the discharge portions 52a, 52b, 52c and 52d are concentric. And the discharge part 52a of the linear electrode 51a is connected to the linear connection part 53a, the discharge part 52b of the linear electrode 51b is connected to the linear connection part 53b, and the discharge part 52c of the linear electrode 51c is a straight line. The discharge part 52d of the linear electrode 51d is connected to the linear connection part 53d. Furthermore, the discharge parts 52a-52d are arranged in order so that adjacent discharge parts may be equidistant. As described above, even when the discharge portions of the four sets of linear electrodes are concentric, the same effect as that of the embodiment of the plasma generator of the present invention (plasma generator 100) can be obtained.

  The width and thickness of the discharge part constituting the linear electrode are preferably the same as those in the embodiment of the plasma generator of the present invention (plasma generator 100).

  As shown in FIG. 9, the connecting portion that connects the discharge portions of the respective linear electrodes is arranged on a plane different from the plane on which the linear electrodes are arranged. Here, FIG. 9 is a schematic view showing a C-C ′ cross section of FIG. 8. As shown in FIG. 9, in each of the linear electrodes, for example, the discharge part 52b of the linear electrode 51b has a connecting part 53b arranged in parallel to a plane on which the discharging part 52b is arranged, and the concentric part and two connecting parts 53b. The discharge section 52b is connected. The discharge part 52d of the linear electrode 51d has a connecting part 53d arranged in parallel to the plane on which the discharging part 52d is arranged, and the connecting part 53d and two concentric discharge parts 52d are connected. The linear electrodes 51a and 51c shown in FIG. 8 have the same structure. Thus, since the discharge part of a linear electrode and the connection part are arrange | positioned on a different plane within a ceramic shower plate, the concentric discharge part of one set of linear electrodes is connected to the other In order to avoid the connection part of a set of linear electrodes, the discharge part of four sets of linear electrodes can be arrange | positioned on the same plane, without cutting out near a connection part.

  FIG. 10 is a plan view schematically showing linear electrodes 61a, 61b and 61c constituting still another embodiment of the plasma generator of the present invention. The configuration of the plasma generator of the present embodiment is preferably the same as that of the plasma generator of the present invention (plasma generator 100) except that the structure of the linear electrode is different.

  In the plural sets (three sets) of linear electrodes 61a, 61b, and 61c constituting the plasma generator of the present embodiment, the discharge portions 62a, 62b, and 62c are respectively spiral. The spiral linear electrodes are preferably disposed in the ceramic shower plate 4 so that the center thereof is located at the center of the ceramic shower plate 4. Since the linear electrode which comprises the plasma generator of this embodiment has one spiral discharge part for every linear electrode, it does not have a connection part.

  Next, the manufacturing method of one embodiment (plasma generator 100) of the plasma generator of the present invention will be described. The plasma generating electrode 100 is produced by forming the first electrode 1 and the second electrode 2, arranging the first electrode 1 and the second electrode 2 so that one surfaces thereof face each other, and arranging the first electrode 1 and the second electrode 2 on the first electrode 1. Each set of linear electrodes may be connected to a separate predetermined nanopulse power source, and the other wiring of the nanopulse power source may be connected to the second electrode and ground. The manufacturing method of the first electrode constituting the plasma generating apparatus 100 is not particularly limited, and a hot plate method in which a linear electrode is embedded in a ceramic plate by hot pressing to form the first electrode, and a tape-like green sheet A tape forming method is preferable in which a predetermined linear electrode is disposed by printing or the like and fired to form the first electrode. Hereinafter, the hot press method and the tape forming method will be described.

(Hot press method)
(1) Raw material powder preparation process:
The raw material powder and the additive are mixed at a predetermined ratio and mixed using a trommel or the like. Examples of the raw material powder include oxides, nitrides, borides, and the like. Among these, nitrides and oxides are preferable, and aluminum nitride, silicon nitride, aluminum oxide, silicon oxide, cordierite are preferable. preferable. Examples of the additive include yttrium oxide, other rare earth oxides, alkaline earth metal oxides, and the like. When aluminum nitride is used as the raw material powder, the additive is preferably yttrium oxide. When silicon nitride is used as the raw material powder, the additive is preferably an alkaline earth metal oxide or rare earth oxide. Particularly preferred are magnesium oxide and yttrium oxide. Mixing may be either wet or dry. For example, when wet is used, the mixture is dried using SD (spray dryer) or the like to obtain a raw material mixed powder. When aluminum nitride is used as the raw material powder, the aluminum nitride used may be one produced by a production method such as a direct nitridation method, a reduction nitridation method, or a vapor phase synthesis method. In this case, the purity of aluminum nitride is preferably 99% by mass or more, and more preferably 99.9% by mass or more. The blending amount of yttrium oxide and other rare earth oxides is preferably 0.1 to 10% by mass in terms of oxide with respect to the raw material mixed powder. Further, a blackening agent may be added as an additive in order to suppress uneven color of the product and obtain a good appearance. Examples of the blackening agent include transition metal elements (metal alone) such as Ti, Zr, and Cr, or metal compounds such as oxides, nitrides, carbides, sulfates, nitrates, and organometallic compounds of these metals. be able to. It is preferable that the addition amount of a blackening agent is 0.1-5 mass% with respect to raw material mixed powder.

(2) Molding process:
A plate-shaped ceramic molded body (unfired) is formed using the raw material mixed powder containing the aluminum nitride raw material powder obtained in the blending step as it is or granulated by adding a binder. The molding method is not particularly limited, and examples thereof include a mold molding method, a CIP (Cold Isostatic Pressing) method, and a slip casting method. Examples of the binder include PVA and PEG. Moreover, it does not specifically limit as a method of adding a binder to raw material mixed powder, and granulating, A method, such as spray drying, can be mentioned. The linear electrode is preferably embedded when the ceramic shower plate is formed. For example, a ceramic molded body is molded, and a linear electrode that has been processed and welded into a predetermined shape is placed on the ceramic molded body. This is then placed in a mold, and the mixed raw material powder is then placed in the mold so as to cover the linear electrode. It is preferable to perform molding again to produce an integrated ceramic molded body in which linear electrodes are embedded.

(3) Firing step:
The obtained ceramic molded body is fired. A hot press firing method is used as the firing method. The obtained ceramic compact is housed in a graphite mold for firing, and fired at a press pressure of 1.96 × 10 ⁷ Pa (200 kgf / cm ² ) and a maximum firing temperature of 1680 to 1900 ° C. The firing atmosphere is a vacuum from room temperature to 1000 ° C., and a nitrogen gas atmosphere from a temperature exceeding 1000 ° C. to the maximum firing temperature. In order to make the resistance within a crystal grain as high as 10 ¹⁴ Ωcm or higher, the maximum firing temperature is preferably 1720 to 1870 ° C, and more preferably 1720 to 1800 ° C. When oxides such as aluminum oxide and cordierite are used for the ceramic substrate, the firing temperature is preferably set to 1500 to 1700 ° C. for the former and 1300 to 1450 ° C. for the latter.

(4) Processing process:
About the aluminum nitride sintered compact obtained by baking, it grinds so that it may become a predetermined shape, The 1st electrode of the plasma generator of this embodiment can be obtained. The thickness of the ceramic shower plate is adjusted to be 0.1 to 5 mm. Further, if necessary, an opening for drawing out the terminal of the electrode is formed, and the terminal is pulled out.

(Tape molding method)
(1) Raw material powder preparation process:
The raw material powder and the additive are mixed at a predetermined ratio and mixed using a trommel or the like. Examples of the raw material powder include oxides, nitrides, borides, and the like. Among these, nitrides and oxides are preferable, and aluminum nitride, silicon nitride, aluminum oxide, silicon oxide, cordierite are preferable. preferable. Examples of the additive include yttrium oxide, other rare earth oxides, alkaline earth metal oxides, and the like. When aluminum nitride is used as the raw material powder, the additive is preferably yttrium oxide. When silicon nitride is used as the raw material powder, the additive is preferably an alkaline earth metal oxide or rare earth oxide. In particular, magnesium oxide and yttrium oxide are preferable. Mixing may be either wet or dry. For example, when wet is used, the mixture is dried using SD (spray dryer) or the like to obtain a raw material mixed powder. When aluminum nitride is used as the raw material powder, the aluminum nitride used may be one produced by a production method such as a direct nitridation method, a reduction nitridation method, or a vapor phase synthesis method. In this case, the purity of aluminum nitride is preferably 99% by mass or more, and more preferably 99.9% by mass or more. The blending amount of yttrium oxide and other rare earth oxides is preferably 0.1 to 10% by mass in terms of oxide with respect to the raw material mixed powder. Further, a blackening agent may be added as an additive in order to suppress uneven color of the product and obtain a good appearance. Examples of the blackening agent include transition metal elements (metal alone) such as Ti, Zr, and Cr, or metal compounds such as oxides, nitrides, carbides, sulfates, nitrates, and organometallic compounds of these metals. be able to. It is preferable that the addition amount of a blackening agent is 0.1-5 mass% with respect to raw material mixed powder.

  It is preferable to mix other raw material components with the raw material mixed powder to form a slurry-like forming raw material. As said other component, it is preferable to use solvents, such as a binder, a plasticizer, a dispersing agent, water, and an organic solvent.

  The binder is not particularly limited, and either an aqueous binder or a non-aqueous binder may be used. As the aqueous binder, methyl cellulose, polyvinyl alcohol, polyethylene oxide or the like can be suitably used, and as the non-aqueous binder, polyvinyl butyral, Acrylic resins, polyethylene, polypropylene, and the like can be suitably used. Examples of the acrylic resin include (meth) acrylic resin, (meth) acrylic acid ester copolymer, acrylic acid ester-methacrylic acid ester copolymer, and the like.

  The addition amount of the binder is preferably 3 to 20 parts by mass, and more preferably 6 to 17 parts by mass with respect to 100 parts by mass of the raw material mixed powder. By setting it as such binder content, it becomes possible to prevent generation | occurrence | production of a crack etc., when shape | molding a slurry-like shaping | molding raw material and shape | molding a green sheet, and when drying and baking.

  As the plasticizer, glycerin, polyethylene glycol, dibutyl phthalate, di-2-ethylhexyl phthalate, diisononyl phthalate, or the like can be used.

  The addition amount of the plasticizer is preferably 30 to 70 parts by mass and more preferably 45 to 55 parts by mass with respect to 100 parts by mass of the binder. When the amount is more than 70 parts by mass, the green sheet becomes too soft and may be easily deformed in the process of processing the sheet. When the amount is less than 30 parts by mass, the green sheet becomes too hard and cracks are generated only by bending. Handling characteristics may deteriorate.

  As the dispersant, an anionic surfactant, a wax emulsion, pyridine, or the like can be used in an aqueous system, and a fatty acid, a phosphate ester, a synthetic surfactant, or the like can be used in a non-aqueous system.

  It is preferable that a dispersing agent is 0.5-3 mass parts with respect to 100 mass parts of raw material mixed powder, and it is still more preferable that it is 1-2 mass parts. When the amount is less than 0.5 parts by mass, the dispersibility of the raw material mixed powder may be reduced, and a crack or the like may occur in the green sheet. When the amount is more than 3 parts by mass, the dispersibility of the raw material mixed powder is not changed, and impurities during firing are increased.

  Examples of the organic solvent used for the solvent include xylene and butanol. An organic solvent may be used individually by 1 type, and may mix and use multiple. The solvent is preferably 50 to 200 parts by mass, and more preferably 75 to 150 parts by mass with respect to 100 parts by mass of the raw material mixed powder.

  The above raw materials are sufficiently mixed using an alumina pot and alumina cobblestone to produce a slurry-like forming raw material for producing a green sheet. Further, these materials may be manufactured by ball mill mixing with a monoball.

  Next, the resulting green sheet-forming slurry-like forming raw material is stirred and degassed under reduced pressure, and further prepared to have a predetermined viscosity. The viscosity of the slurry-like molding material obtained in the preparation of the molding material is preferably 2.0 to 6.0 Pa · s, more preferably 3.0 to 5.0 Pa · s, 3.5 It is especially preferable that it is -4.5 Pa.s. It is preferable to adjust the viscosity range in this manner because the slurry can be easily formed into a sheet shape. If the slurry viscosity is too high or too low, molding may be difficult. The viscosity of the slurry is a value measured at 25 ° C. with a B-type viscometer.

(2) Molding process:
Next, the slurry-like forming raw material obtained by the above method is formed into a sheet shape to form a green sheet. The forming method is not particularly limited as long as the forming raw material can be formed into a sheet shape to form a green sheet, and a known method such as a doctor blade method, a press forming method, a rolling method, or a calendar roll method is used. Can do.

  The thickness of the green sheet to be produced is preferably 1 μm to 1 mm.

(3) Printing process:
Each set of linear electrodes and wiring is disposed on the surface of the obtained green sheet. For example, when the first electrode 1 as shown in FIGS. 1 and 2 is manufactured, the green electrodes are arranged so that each set of linear electrodes and wirings (not shown) are arranged at predetermined positions. It is preferable to print each set of linear electrodes and wirings at corresponding positions on the sheet. A conductor paste for forming each set of linear electrodes and wiring to be arranged is prepared. This conductor paste is obtained by adding a solvent such as binder and terpineol to a powder containing at least one selected from the group consisting of gold, silver, copper, platinum, nickel, titanium, zirconia, manganese, molybdenum, and tungsten, for example. It can be prepared by sufficiently kneading using a tri-roll mill or the like. The conductor paste thus formed is printed on the surface of the green sheet using screen printing or the like to form each set of linear electrodes and wirings having a predetermined shape.

(4) Lamination process:
Next, a green sheet is laminated. When laminating, each set of linear electrodes is arranged as shown in FIGS. Lamination is preferably performed while applying pressure.

(5) Firing step:
The obtained green sheet laminate is dried at 60 to 150 ° C. and fired at 1200 to 1600 ° C. to produce a first electrode. When a green sheet contains an organic binder, it is preferable to degrease at 400-800 degreeC before baking.

  The second electrode of the plasma generator of this embodiment can also be manufactured by the hot press method or the tape forming method in which the first electrode 1 is manufactured. Then, the plasma generator of the present embodiment can be obtained by connecting a predetermined nanopulse generating circuit to each set of linear electrodes, the second electrode, and the ground. The nanopulse power source to be used is preferably a nanopulse power source similar to that in the embodiment of the plasma generator of the present invention (plasma generator 100).

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1
The first electrode 1 shown in FIGS. 1 and 2 is manufactured, and the manufactured first electrode and a predetermined nanopulse power source are incorporated into an existing semiconductor manufacturing apparatus (Applied Materials Co., Ltd.) and incorporated into the semiconductor manufacturing apparatus. A plasma generator in a state of the above was produced.

Production of the first electrode:
Yttrium oxide (Y ₂ O ₃ ) (manufactured by Shin-Etsu Chemical Co., Ltd.) having a purity of 99.9% by mass and an average particle diameter of 1 μm is added to aluminum nitride powder (manufactured by Tokuyama Corporation) having a purity of 99.9% by mass and nitrided. Aluminum raw material mixed powder was prepared. The blending amount of yttrium oxide was 5% by mass of the entire raw material mixed powder, and the blending amount of aluminum nitride powder was 95% by mass of the entire raw material mixed powder. Isopropyl alcohol was added as a solvent to the obtained aluminum nitride raw material mixed powder and mixed for 4 hours using a nylon pot and cobblestone to prepare a slurry. The obtained slurry was dried at 110 ° C. using a dryer to obtain a dry powder. Furthermore, the obtained dry powder was heat-treated at 450 ° C. for 5 hours in the air atmosphere to burn off the organic components mixed during the wet mixing, thereby producing aluminum nitride granulated granules.

The obtained aluminum nitride granulated granules were filled in a mold and press-molded at a pressure of 1.96 × 10 ⁷ Pa (200 kgf / cm ² ). Further, two sets of comb-like electrodes (linear electrodes) in which discharge parts (Mo wire materials) were arranged at a pitch of 10 mm were prepared using a molybdenum (Mo) wire material having a width of 1 mm. With the press-molded aluminum nitride in the mold, the comb-like electrodes are placed on the press-molded aluminum nitride so that the electrode pitch (interval between the discharge parts) is 5 mm. Set in the same arrangement. Then, from above the comb-like electrode, the aluminum nitride granule was filled into the mold, and press molded at a pressure of 1.96 × 10 ⁷ Pa (200 kgf / cm ² ) to obtain a molded body. .

The obtained molded body was housed in a graphite mold and subjected to hot press firing to obtain a sintered body. The hot press firing was performed at a press pressure of 1.96 × 10 ⁷ Pa (200 kgf / cm ² ), fired at 1850 ° C., held for 2 hours, and then cooled to room temperature at 400 ° C./hour.

  Next, the surface of the sintered body is ground so that it becomes a ceramic shower plate having a thickness of 0.5 mm on the side of the comb-tooth electrode, and a through-hole having a diameter of 1.8 mm for gas passage is formed in a comb-like shape. A first electrode (linear electrode embedded type) was obtained at a pitch of 5 mm at a position where no electrode was disposed.

Production of plasma generator:
The obtained first electrode (linear electrode embedded type) was replaced with a metal shower plate of the upper electrode of the semiconductor manufacturing apparatus (Applied Materials) to obtain a plasma generator incorporated in the semiconductor manufacturing apparatus. It was. The second electrode was an electrostatic chuck constituting the semiconductor manufacturing apparatus, and each circuit of the power supply having two nanopulse generation circuits was connected to each set of linear electrodes (comb-like electrodes). The nanopulse power supply used was an energy storage type pulse power supply, and an SI thyristor that could be controlled to a nanopulse width of 100 to 500 nm was used as an open switch.

  Using the obtained plasma generator (semiconductor manufacturing apparatus), an etching test was performed by the following method to measure an etching rate and in-plane uniformity. The obtained results are shown in Table 1.

(Etching test)
The etching test was performed under the conditions of a nano-pulse power supply of 500 w, a pulse half-width of 200 ns, a pulse voltage of 20 kV, a frequency of 5 kHz, and two pulse voltage time differences of 100 ms.

(Etching rate)
The etching depth was measured with a stylus type step measuring instrument, and the etching rate per unit time was calculated from the processing time.

(In-plane uniformity)
The etching depth was measured with a stylus type step measuring instrument, and the in-plane uniformity was measured.

(Comparative Example 1)
A plasma generator (semiconductor manufacturing apparatus) was manufactured as an energy storage type pulse power source using “SI thyristor” as a power source of a semiconductor manufacturing apparatus (Applied Materials Co., Ltd.) (Comparative Example 1). In addition, the metal shower plate currently used with the said semiconductor manufacturing apparatus was used for the 1st electrode as it was.The etching test was performed using the obtained plasma generator (semiconductor manufacturing apparatus), and an etching rate and in-plane uniformity were used. The results obtained are shown in Table 1.

(Comparative Example 2)
A semiconductor generator (Applied Materials) was used as it was to obtain a plasma generator (semiconductor manufacturing apparatus) (Comparative Example 1). In addition, the metal shower plate used with the said semiconductor manufacturing apparatus was used for the 1st electrode as it was, and the RF power source used with the said semiconductor manufacturing apparatus was used for the power supply as it was. An etching test was performed using the plasma generator (semiconductor manufacturing apparatus), and the etching rate and in-plane uniformity were measured. The obtained results are shown in Table 1.

  From Table 1, the plasma generator of Example 1 uses a linear electrode embedded type electrode in which a linear electrode is embedded in a ceramic shower plate as a first electrode, and a nanopulse power source using an SI thyristor as a power source. Therefore, it can be seen that both the etching rate and the in-plane uniformity are excellent. On the other hand, it can be seen that the plasma generator of Comparative Example 1 is inferior in etching rate because the metal shower plate is used as the first electrode. Moreover, since the plasma generator of the comparative example 2 used the metal shower plate as a 1st electrode and used RF power supply as a power supply, it turns out that it is inferior to in-plane uniformity.

  It can be suitably used for an etching process in a semiconductor process.

It is a schematic diagram which shows the cross section of one Embodiment of the plasma generator of this invention. It is a top view which shows the 1st electrode which comprises one Embodiment of the plasma generator of this invention. It is a top view which shows the linear electrode which comprises one Embodiment of the plasma generator of this invention, and the arrangement | positioning range in the ceramic plate of the linear electrode. It is a schematic diagram which shows the cross section of other embodiment of the plasma generator of this invention. It is a top view which shows the 1st electrode which comprises other embodiment of the plasma generator of this invention. FIG. 6 is a perspective view schematically showing two sets of the four sets of linear electrodes shown in FIG. 5. FIG. 6 is a perspective view schematically showing the remaining two sets of the four sets of linear electrodes shown in FIG. 5. It is a top view which shows typically the linear electrode which comprises other embodiment of the plasma generator of this invention. It is a top view which shows typically the linear electrode which comprises other embodiment of the plasma generator of this invention. It is a schematic diagram which shows the C-C 'cross section of FIG. It is a top view which shows typically the linear electrode which comprises other embodiment of the plasma generator of this invention.

Explanation of symbols

1, 2: 1st electrode, 1a, 21a: one surface, 2, 22: second electrode, 2a, 22a: one surface, 3a, 3b, 23a, 23b, 23c, 23d: power supply, 4, 24: Ceramic plates (ceramic shower plates), 5, 25: through holes, 6, 26, 41a, 41b, 51a, 51b, 51c, 51d, 61a, 61b, 61c: linear electrodes, 7, 27, 42a, 42b, 52a , 52b, 52c, 52d, 62a, 62b, 62c: discharge part, 8, 28: conductor plate electrode, 9, 29: ceramic plate, 10, 30: ground, 11, 31, 43a, 43b, 53a, 53b, 53c , 53d: connecting portion, 100, 200: plasma generator.

Claims (8)

A plate-shaped ceramic plate having a plurality of gas-passing through holes penetrating in the thickness direction, and a plurality of sets of linear electrodes each having a linear discharge portion disposed inside the ceramic plate A first electrode;
A plate-like second electrode disposed in parallel so that one surface and one surface of the first electrode face each other with a gap between the first electrode and the first electrode;
A plurality of linear electrodes that are separately connected to each of the plurality of sets of linear electrodes disposed on the first electrode and that can independently apply a nanopulse voltage between each of the sets of linear electrodes and the second electrode. And a power source having a pulse generation circuit.   2. The plasma generator according to claim 1, wherein the power supply intermittently applies a nanopulse voltage to the respective sets of linear electrodes with a time difference by the plurality of pulse generation circuits.   3. The discharge electrode of the different sets of linear electrodes are arranged adjacent to each other when the plurality of sets of linear electrodes are projected onto a plane orthogonal to the thickness direction of the ceramic plate. The plasma generator described.   The plasma generator according to any one of claims 1 to 3, wherein each of the plurality of sets of linear electrodes includes a plurality of the discharge units arranged at equal distances.   The plasma generating apparatus according to claim 4, wherein each of the plurality of sets of linear electrodes has linear discharge portions arranged in parallel to each other.   The plasma generating apparatus according to claim 4, wherein discharge portions of the plurality of sets of linear electrodes are each concentric.   The plurality of sets of linear electrodes are arranged so that the discharge portions of each set of linear electrodes are arranged one by one for each linear electrode, and the arrangement of the discharge portions is repeated. The plasma generator according to any one of the above.   The plasma generator according to any one of claims 1 to 3, wherein each of the plurality of sets of linear electrodes has a spiral shape centered on a central portion of the ceramic plate.

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