JP2008159931A - Substrate processing device, method for heating focus ring, and method for processing substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing device which accurately controls the temperature of a focus ring without causing abnormal discharge or backward flow of high-frequency power while high-frequency power is applied. <P>SOLUTION: A substrate processing device 10 includes: a circular focus ring 24 arranged to surround the peripheral border portion of a wafer W; and a focus ring temperature controller 26 which has a circular induction coil 36 that is located in opposition to the focus ring 24 to generate magnetic force lines upon receiving the power from a power supply rod 38. Resultant magnetic force lines intersect with an induction heating section 40, resulting in eddy current being generated in the induction heating section 40 because of magnetic field induction. Joule heat arising from the eddy current and electrical resistance of the induction heating section 40 heats the induction heating section 40, which leads to self-heating of the focus ring 24. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a substrate processing apparatus, a focus ring heating method, and a substrate processing method, and more particularly to a substrate processing apparatus that controls the temperature of a focus ring, a focus ring heating method, and a substrate processing method.

  When plasma processing, for example, etching processing is performed on a wafer as a substrate, the width and depth of grooves formed on the wafer surface by etching are affected by the temperature of the wafer. It is required to keep it uniform.

  A substrate processing apparatus that performs an etching process on a wafer includes a chamber that accommodates the wafer and a mounting table (hereinafter referred to as a “susceptor”) on which the wafer is placed during the etching process, and plasma is generated in the chamber. The plasma etches the wafer, and the susceptor has a temperature control mechanism and controls the temperature of the wafer. When the wafer is etched, the temperature of the wafer rises due to heat from the plasma. Therefore, the temperature control mechanism of the susceptor cools the wafer and keeps the temperature constant.

  In addition, an annular focus ring made of, for example, silicon is placed on the susceptor so as to surround the periphery of the wafer. The focus ring converges the plasma in the chamber onto the wafer, but the focus ring also receives heat from the plasma during the etching process, and the temperature rises to, for example, 300 ° C. to 400 ° C.

  During the etching process, most of the wafer is cooled by the temperature control mechanism of the susceptor, but the periphery of the wafer is affected by the radiant heat of the focus ring, so it is difficult to keep the temperature of the entire surface of the wafer uniform. It is. Therefore, it is necessary to control the temperature of the focus ring. In order to control the temperature of the focus ring, it is known to provide a heater inside the focus ring (see, for example, Patent Document 1).

  In addition, in a substrate processing apparatus, when a plurality of wafers are etched in a single wafer, in order to make the etching result of each wafer the same, it is necessary to make the time change of the focus ring temperature the same in the etching process of each wafer. is there.

  By the way, since the inside of the chamber is evacuated, the boundary between the focus ring and the susceptor forms a vacuum heat insulating layer. Therefore, since the heat is not transferred from the focus ring to the susceptor only by placing the focus ring on the susceptor, the temperature of the focus ring rises to, for example, 300 ° C. to 400 ° C. in the etching process of each wafer. In the etching process for the first wafer, since the focus ring is not heated before the etching process, the initial temperature is low and the temperature of the focus ring does not rise to 300 ° C. That is, since the initial temperature of the focus ring in the etching process of the first wafer is different from the initial temperature of the focus ring in the etching process of the second and subsequent wafers, the focus ring temperature in the etching process of the first wafer Is different from the time change of the focus ring temperature in the etching process of the second and subsequent wafers (see FIG. 7A). As a result, the etching result of the first wafer is different from the etching result of the second and subsequent wafers.

Correspondingly, the heat transfer efficiency of the focus ring and the susceptor is improved, and the focus ring is actively cooled by the susceptor temperature adjustment mechanism to adjust the temperature, thereby adjusting the time of the focus ring temperature in the etching process of each wafer. A technique for making the changes almost the same has been developed (see FIG. 7B). In this method, in order to improve the heat transfer efficiency of the focus ring and the susceptor, a heat transfer sheet is disposed between the focus ring and the susceptor, or the focus ring is electrostatically adsorbed to the susceptor.
JP 2005-353812 A

  However, in the method of improving the heat transfer efficiency of the focus ring and the susceptor, the temperature of the focus ring is kept relatively low in the etching process of each wafer. The type of etching process that cannot be performed is limited.

  In addition, when electrostatically attracting the focus ring, it is necessary to apply a DC voltage to the susceptor during the etching process, but since high-frequency power is also applied to the susceptor during the etching process, the DC voltage supply path An abnormal discharge may occur, and high-frequency power may flow back to the ground (ground) through the DC voltage supply path.

  Further, when a heat transfer sheet is disposed between the focus ring and the susceptor, a vacuum heat insulating layer may be formed between the focus ring and the heat transfer sheet, and the heat transfer sheet and the susceptor, respectively. It is difficult to control accurately.

  Among the problems described above, in order to solve the limitation on the types of etching process that can be performed, a technique for actively heating the focus ring during the etching process is being developed. Specifically, there are a method of irradiating and heating the focus ring with a lamp or a laser, a method of placing a heater on the focus ring mounting surface of the susceptor and heating with the heater, a method of providing a heater inside the focus ring, etc. Applicable.

  However, when the focus ring is irradiated and heated by a lamp, not only the focus ring but also other components are heated. Therefore, it is impossible to accurately control the temperature of the focus ring by radiant heat from other heated components. Have difficulty.

  When the focus ring is irradiated and heated with a laser, the heating efficiency is not stable, and it is difficult to accurately control the temperature of the focus ring.

  When a heater is disposed on the focus ring mounting surface of the susceptor, it is difficult to accurately control the temperature of the focus ring because a vacuum heat insulating layer is formed between the focus ring and the heater.

  When a heater is provided inside the focus ring, it is necessary to supply an electrode to the heater, but it is necessary to connect wiring from the susceptor to the focus ring, which may cause abnormal discharge due to the presence of the wiring. There is also a possibility that the high frequency power flows back to the ground (ground) through the wiring.

  A first object of the present invention is to provide a substrate processing apparatus and a focus ring heating method capable of accurately controlling the temperature of the focus ring without causing abnormal discharge or reverse flow of the high frequency power during application of the high frequency power. It is to provide.

  A second object of the present invention is to provide a substrate processing method capable of making the results of plasma processing of each substrate the same without causing abnormal discharge or reverse flow of high frequency power during application of high frequency power. is there.

  In order to achieve the first object, a substrate processing apparatus according to a first aspect of the present invention is provided with a storage chamber for storing a substrate, a mounting table disposed in the storage chamber for mounting the substrate, and a mounting table. In the substrate processing apparatus, the focus chamber is depressurized and high frequency power is applied to the mounting table. The ring is characterized by self-heating.

  According to a second aspect of the present invention, there is provided the substrate processing apparatus according to the first aspect, further comprising a magnetic force line generator for generating magnetic force lines, wherein the magnetic force lines intersect with the focus ring.

  The substrate processing apparatus according to claim 3 is the substrate processing apparatus according to claim 2, wherein the magnetic field line generator is electrically connected to a power source via a power supply unit, and the high-frequency power is applied to the mounting table. In this case, the power supply unit is retracted from a region to which the high frequency power is applied.

  A substrate processing apparatus according to claim 4 is the substrate processing apparatus according to claim 2 or 3, wherein the focus ring has an induction heat generating portion therein, and the induction heat generating portion is iron, stainless steel, aluminum, silicon, silicon carbide. And at least one of carbon.

  The substrate processing apparatus according to claim 5 is the substrate processing apparatus according to any one of claims 2 to 4, wherein the line of magnetic force generator is an annular coil, and is disposed so as to face the focus ring. It is characterized by that.

  The substrate processing apparatus according to claim 6 is the substrate processing apparatus according to claim 5, wherein the coil is entirely covered with a heat insulating and insulating material, and is arranged between the focus ring and the mounting table. To do.

  In order to achieve the first object, a heating method for a focus ring according to claim 7, comprising: a storage chamber for storing a substrate; and a mounting table disposed in the storage chamber for mounting the substrate; In a substrate processing apparatus in which the accommodation chamber is depressurized and high frequency power is applied to the mounting table, heating of an annular focus ring mounted on the mounting table so as to surround a peripheral portion of the substrate mounted A method is characterized in that the method includes a magnetic field line crossing step in which magnetic field lines intersect the focus ring.

  The focus ring heating method according to claim 8 is the focus ring heating method according to claim 7, wherein the substrate processing apparatus includes a magnetic force line generating device that generates magnetic force lines, and ends the intersection of the magnetic force lines and the focus ring. It has a crossing end step and a high frequency power application step of applying the high frequency power to the mounting table after the crossing end step.

  The focus ring heating method according to claim 9 is the focus ring heating method according to claim 8, wherein the magnetic field line generator is electrically connected to a power source via a power supply unit, and before the high frequency power application step. The power supply unit includes a power supply unit evacuation step for evacuating from the region to which the high frequency power is applied.

  In order to achieve the second object, a substrate processing method according to a tenth aspect of the present invention includes a storage chamber for storing a substrate, a mounting table disposed in the storage chamber for mounting the substrate, Generated in the substrate processing apparatus to which the high frequency power is applied to the mounting table. A substrate processing method for performing plasma processing on each of a plurality of substrates using plasma, wherein the focus ring is heated to a predetermined temperature, and the focus ring is heated to the predetermined temperature. A first processing step for applying the plasma processing to the first substrate without supplying external heat or electric power to the focus ring when heated; And a second processing step of performing the plasma processing on each of the second and subsequent substrates without supplying heat and power from the second substrate, and the predetermined temperature is the second and subsequent substrates. It is the same as the initial temperature of the focus ring in the plasma treatment.

  The substrate processing method according to claim 11 is the substrate processing method according to claim 10, wherein the temperature raising step raises the focus ring to a temperature higher than the predetermined temperature and raises the focus to the high temperature. It is characterized by having a standing cooling step in which the ring is allowed to cool to the predetermined temperature.

  According to a twelfth aspect of the present invention, in the substrate processing method according to the tenth or eleventh aspect, in the temperature raising step, magnetic lines of force intersect with the focus ring.

  According to the substrate processing apparatus of the first aspect, the focus ring self-heats. Thereby, it is not necessary to improve the heat transfer efficiency of the focus ring and the mounting table, and further, it is not necessary to provide an external heat or power supply device. Therefore, it is possible to prevent an abnormal discharge or a reverse flow of the high frequency power from occurring during the application of the high frequency power. Even if a vacuum heat insulating layer is formed between the focus ring and the mounting table, the temperature control of the focus ring is not affected, and other components of the substrate processing apparatus are not heated. Therefore, the temperature of the focus ring can be accurately controlled.

  According to the substrate processing apparatus of the second aspect, since the magnetic force lines generated from the magnetic force line generator intersect with the focus ring, the focus ring can be surely self-heated by induction heating.

  According to the substrate processing apparatus of the third aspect, when the high frequency power is applied to the mounting table, the power supply unit that electrically connects the magnetic force generation device and the power source retreats from the region to which the high frequency power is applied. . Therefore, the power supply unit does not function as an antenna for high frequency power, and it is possible to reliably prevent abnormal discharge and reverse flow of high frequency power.

  According to the substrate processing apparatus of claim 4, since the focus ring has an induction heating part made of at least one of iron, stainless steel, aluminum, silicon, silicon carbide, and carbon inside, the induction heating part is caused by the intersection with the magnetic field lines. An eddy current can be generated in the focus ring, and the focus ring can be surely self-heated by Joule heat caused by the eddy current.

  According to the substrate processing apparatus of the fifth aspect, since the magnetic force line generator is an annular coil and is disposed so as to face the annular focus ring, it is possible to evenly intersect the magnetic force lines generated from the coil with the focus ring. Thus, the focus ring can generate heat uniformly along the circumferential direction.

  According to the substrate processing apparatus of the sixth aspect, since the entire surface of the coil is covered with the heat insulating / insulating material, it is possible to prevent the high-frequency power from flowing back through the coil, and the entire surface is heat insulating / insulating. Since the coil covered with is disposed between the focus ring and the mounting table, the heat of the focus ring can be prevented from being transmitted to the mounting table.

  According to the heating method of the focus ring of the seventh aspect, since the magnetic field lines intersect with the focus ring, the focus ring self-heats by induction heating. Thereby, it is not necessary to improve the heat transfer efficiency of the focus ring and the mounting table, and further, it is not necessary to provide an external heat or power supply device. Therefore, it is possible to prevent an abnormal discharge or a reverse flow of the high frequency power from occurring during the application of the high frequency power. Even if a vacuum heat insulating layer is formed between the focus ring and the mounting table, the temperature control of the focus ring is not affected, and other components of the substrate processing apparatus are not heated. Therefore, the temperature of the focus ring can be accurately controlled.

  According to the heating method of the focus ring according to claim 8, since the high frequency power is applied to the mounting table after the intersection of the magnetic force lines and the focus ring is completed, the magnetic force lines are generated in the magnetic field generator during application of the high frequency power. It is possible to cut off the electric wires that supply the electric power. Therefore, it is possible to surely prevent the occurrence of abnormal discharge toward the electric wire or the like, and it is possible to reliably prevent the high-frequency power from flowing back through the electric wire or the like.

  According to the heating method of the focus ring according to claim 9, since the power supply unit retreats from the region where the high frequency power is applied before the high frequency power is applied, it is ensured that abnormal discharge occurs toward the power supply unit. In addition, it is possible to reliably prevent the high-frequency power from flowing back through the power supply unit.

  According to the substrate processing method of claim 10, when the focus ring is heated to the initial temperature of the focus ring in the plasma processing of the second and subsequent substrates, the first substrate is subjected to the plasma processing. Therefore, the initial temperature in the plasma processing of each substrate can be made the same, and the result of the plasma processing of each substrate can be made the same. In addition, plasma processing is performed on each substrate without supplying heat or power from the outside to the focus ring, so that the supply path for supplying heat and power from the outside is disconnected during application of high-frequency power. be able to. Therefore, it is possible to prevent abnormal discharge from occurring toward the supply path or the like during application of the high-frequency power, and it is possible to prevent the high-frequency power from flowing back through the supply path or the like.

  According to the substrate processing method of claim 11, after the focus ring is heated to a temperature higher than a predetermined temperature that is an initial temperature of the focus ring in the plasma processing of the second and subsequent substrates, the focus ring reaches the predetermined temperature. Allowed to cool. That is, since the focus ring is once heated to a temperature higher than the predetermined temperature, the entire focus ring can be reliably brought to the predetermined temperature.

  According to the substrate processing method of the twelfth aspect, since the magnetic lines of force generated from the magnetic line of force generator intersect with the focus ring, the focus ring can be self-heated by induction heating. As a result, it is possible to eliminate the need to improve the heat transfer efficiency of the focus ring and the mounting table, and it is also possible to eliminate the need for an external heat and power supply device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, a substrate processing apparatus according to an embodiment of the present invention will be described.

  FIG. 1 is a cross-sectional view schematically showing a configuration of a substrate processing apparatus according to the present embodiment. This substrate processing apparatus is configured to perform RIE (Reactive Ion Etching) processing on a semiconductor wafer W as a substrate.

  In FIG. 1, a substrate processing apparatus 10 has a cylindrical storage chamber 11, and the storage chamber 11 has a processing space PS on the upper side. Plasma to be described later is generated in the processing space PS. Further, in the storage chamber 11, for example, a cylindrical susceptor 12 is disposed as a mounting table on which a semiconductor wafer W having a diameter of 300 mm (hereinafter simply referred to as “wafer W”) is mounted. The inner wall surface of the storage chamber 11 is covered with a side wall member 13 made of an insulating material.

  In the substrate processing apparatus 10, an exhaust flow path 14 that functions as a flow path for discharging the gas above the susceptor 12 to the outside of the storage chamber 11 is formed by the inner wall of the storage chamber 11 and the side surface of the susceptor 12. An exhaust plate 15, which is a plate-like member having a large number of ventilation holes, is disposed in the exhaust flow path 14. The exhaust plate 15 partitions the exhaust flow path 14 and an exhaust space ES that is a lower space of the storage chamber 11. . Further, the roughing exhaust pipe 16 and the main exhaust pipe 17 are opened in the exhaust space ES. A DP (Dry Pump) (not shown) is connected to the roughing exhaust pipe 16, and a TMP (Turbo Molecular Pump) (not shown) is connected to the exhaust pipe 17.

  The roughing exhaust pipe 16, the main exhaust pipe 17, DP, TMP, and the like constitute an exhaust device, which exhausts the gas in the processing space PS to the outside of the storage chamber 11 through the exhaust passage 14 and the exhaust space ES. The process space PS is decompressed to a high vacuum state.

The susceptor 12 includes a high-frequency power plate 18 made of a conductive material, for example, aluminum, and a first high-frequency power source 19 is connected to the high-frequency power plate 18 via a first matcher 20. The first high frequency power supply 19 applies the first high frequency power to the high frequency power plate 18. The first matching unit 20 reduces the reflection of the high frequency power from the high frequency power plate 18 to maximize the supply efficiency of the first high frequency power to the high frequency power plate 18. Further, a second high frequency power source 32 is connected to the high frequency power plate 18 via a second matching unit 33, and the second high frequency power source 32 has a second frequency different from that of the first high frequency power. The high frequency power is applied to the high frequency power plate 18. The function of the second matching device 33 is the same as that of the first matching device 20. Thereby, the susceptor 12 functions as a lower high-frequency electrode, and applies the first and second high-frequency powers to the processing space PS. In the susceptor 12, a base 21 made of an insulating material, for example, alumina (Al ₂ O ₃ ) is disposed below the high frequency power plate 18.

  In the susceptor 12, an electrostatic chuck 23 is disposed above the high frequency power plate 18. The electrostatic chuck 23 has an electrode plate 22 to which a DC power supply 29 is electrically connected. When the susceptor 12 places the wafer W, the wafer W is placed on the electrostatic chuck 23. The wafer W placed on the electrostatic chuck 23 is attracted and held by a Coulomb force or a Johnson-Rahbek force caused by a DC voltage applied to the electrode plate 22.

On the susceptor 12, an annular focus ring 24 is placed so as to surround the periphery of the wafer W attracted and held on the upper surface of the susceptor 12. The focus ring 24 is made of silicon (Si), silica (SiO ₂ ), or silicon carbide (SiC), is exposed to the processing space PS, converges the plasma in the processing space PS toward the surface of the wafer W, and performs RIE processing. Improve the efficiency. An annular cover ring 25 made of quartz is disposed around the focus ring 24 to protect the side surface of the focus ring 24.

  The susceptor 12 is provided with a focus ring temperature control device 26 that controls the temperature of the focus ring 24. The configuration and operation of the focus ring temperature control device 26 will be described in detail later.

  A refrigerant chamber (not shown) to which a predetermined temperature of refrigerant is supplied is provided inside the susceptor 12, and the processing temperature of the wafer W adsorbed and held on the upper surface of the susceptor 12 is controlled by the temperature of the supplied refrigerant. Furthermore, a plurality of heat transfer gas supply holes (not shown) are opened in the portion of the upper surface of the susceptor 12 where the wafer W is adsorbed and held. The plurality of heat transfer gas supply holes improve the heat transfer efficiency of the wafer W and the susceptor 12 by supplying helium (He) gas as a heat transfer gas to the gap between the susceptor 12 and the back surface of the wafer W.

  A gas introduction shower head 27 is disposed on the ceiling of the storage chamber 11 so as to face the susceptor 12. The gas introduction shower head 27 includes an electrode plate support 30 having a buffer chamber 28 formed therein, and an upper electrode plate 31 supported by the electrode plate support 30. The upper electrode plate 31 is a disk-shaped member made of a conductive material, for example, silicon, and the electrode plate support 30 is also made of a conductive material. Further, an insulating ring 30 a made of an insulating material is interposed between the ceiling portion of the storage chamber 11 and the electrode plate support 30. The insulating ring 30 a insulates the electrode plate support 30 from the ceiling portion of the storage chamber 11. The electrode plate support 30 is grounded.

  A processing gas introduction pipe 34 from a processing gas supply unit (not shown) is connected to the buffer chamber 28 of the gas introduction shower head 27. In addition, the gas introduction shower head 27 has a plurality of gas holes 35 that allow the buffer chamber 28 to conduct to the processing space PS. The gas introduction shower head 27 supplies the processing gas supplied from the processing gas introduction pipe 34 to the buffer chamber 28 to the processing space PS via the gas hole 35.

  In the storage chamber 11 of the substrate processing apparatus 10, as described above, the susceptor 12 applies the first and second high-frequency power to the processing space PS that is a space between the susceptor 12 and the upper electrode plate 31. In the processing space PS, the processing gas supplied from the gas introduction shower head 27 is made into high-density plasma to generate cations and radicals, and the wafer W is subjected to RIE processing by the generated cations and radicals.

  FIG. 2 is a cross-sectional view showing the configuration of the focus ring temperature control apparatus in FIG.

  Usually, as shown in FIG. 2, the peripheral edge of the wafer W placed on the susceptor 12 covers the inner peripheral edge 24 a of the focus ring 24. Therefore, the peripheral edge of the wafer W is affected by the radiant heat from the focus ring 24. Correspondingly, the focus ring temperature control device 26 controls the temperature of the focus ring 24 to minimize the influence of the radiant heat from the focus ring 24 received by the peripheral portion of the wafer W.

  The focus ring temperature control device 26 includes an annular induction coil 36 (magnetic field generator), a heat insulating / insulating part 37a that covers the entire surface of the induction coil 36, and a power supply rod 38 (power supply part) that contacts the induction coil 36. And a heat insulating / insulating portion 37b that covers the power supply rod 38 and a lifting device 39 that lifts and lowers the power supply rod 38 in the vertical direction in the figure.

  On the other hand, the focus ring 24 has an induction heat generating portion 40 that is an annular plate member inside the inner peripheral edge portion 24a. The induction heating unit 40 is made of a conductor or a semiconductor, and is made of, for example, at least one of iron, stainless steel, aluminum, silicon, silicon carbide, and carbon.

  The induction coil 36 has a diameter substantially equal to the diameter of the inner peripheral edge 24 a of the focus ring 24, and is arranged so that the central axis of the focus ring 24 coincides with the central axis of the induction coil 36. Therefore, the induction coil 36 faces the inner peripheral edge 24 a of the focus ring 24. Further, since the induction coil 36 is disposed on the electrostatic chuck 23, it is interposed between the electrostatic chuck 23 and the focus ring 24.

  The induction coil 36 generates lines of magnetic force when supplied with power from the power supply rod 38. Since the induction coil 36 faces the inner peripheral edge 24 a, the generated magnetic field lines intersect with the induction heating part 40. When the magnetic field lines intersect with the induction heating unit 40, an eddy current is generated in the induction heating unit 40 due to magnetic field induction, and the induction heating unit 40 generates heat due to Joule heat caused by the eddy current and the electrical resistance of the induction heating unit 40. To do. Thereby, the focus ring 24 self-heats.

  The heat insulation / insulation section 37 a insulates the focus ring 24 and the electrostatic chuck 23 and insulates the induction coil 36 and the high-frequency power plate 18. The material constituting the heat insulating / insulating portion 37a is preferably a low dielectric constant material. For example, the dielectric constant is preferably 12 or less, and the heat transfer coefficient is 30 W / m · K or less. preferable.

  The power supply bar 38 electrically connects a power source (not shown) and the induction coil 36 and supplies power to the induction coil 36. The power supply rod 38 protrudes from the substrate 41 disposed below the base 21 of the susceptor 12 and penetrates the base 21, the high-frequency power plate 18, the electrostatic chuck 23 and the heat insulating / insulating portion 37 a to the induction coil 36. To reach.

  When the substrate processing apparatus 10 performs the RIE process on the wafer W, the first and second high frequency powers are applied to the high frequency power plate 18. At this time, the first and second high frequency power applied to the high frequency power plate 18 is also applied to the electrostatic chuck 23. Therefore, when the power supply rod 38 protrudes to the same height as the high-frequency power plate 18 and the electrostatic chuck 23 in FIG. 2, the power supply rod 38 functions as an antenna for the first and second high-frequency powers. There is a possibility that the first and second high-frequency power applied to the power plate 18 and the like flow backward to the power source or the like. On the other hand, since the base 21 is made of alumina, the first and second high frequency powers are cut off. As a result, the first and second high frequency powers are not applied to the substrate 41.

  In the substrate processing apparatus 10, when the first and second high frequency powers are applied to the high frequency power plate 18, as shown in FIG. 3, the lifting and lowering device 39 lowers the power supply rod 38, so that the first and first The tip of the power supply rod 38 is lowered to the substrate 41 by retracting from the vicinity of the high frequency power plate 18 and the electrostatic chuck 23, which is the region where the high frequency power of 2 is applied. This prevents the power supply rod 38 from functioning as an antenna.

  According to the substrate processing apparatus 10 described above, the magnetic field lines generated from the induction coil 36 intersect with the induction heat generating part 40 in the inner peripheral edge 24a of the focus ring 24, so that the focus ring 24 self-heats. Thereby, it is not necessary to improve the heat transfer efficiency of the focus ring 24 and the susceptor 12, and further, it is not necessary to provide a heat or power supply device to the focus ring 24 from the outside. Therefore, during the application of the first and second high-frequency power, it is possible to prevent occurrence of abnormal discharge or reverse flow of the high-frequency power mediated by the heat or power supply device. Moreover, since it is not necessary to improve the adhesion degree of the focus ring 24 and the susceptor 12, the surface state of the focus ring 24 and the susceptor 12 can be arbitrarily set. Furthermore, since the processing space PS is depressurized, there is a possibility that a vacuum heat insulating layer is formed between the focus ring 24 and the susceptor 12. However, since the focus ring 24 is self-heating, even if a vacuum heat insulating layer is formed. The temperature control of the focus ring 24 is not affected, and the temperature of other components of the substrate processing apparatus 10 is not increased. Therefore, the focus ring 24 is hardly affected by radiant heat from other components. . Therefore, the temperature of the focus ring 24 can be accurately controlled.

  In the substrate processing apparatus 10 described above, the power supply rod 38 is retracted from the vicinity of the high frequency power plate 18 or the electrostatic chuck 23 when the first and second high frequency power is applied to the high frequency power plate 18. Therefore, the power supply rod 38 does not function as an antenna for the first and second high-frequency powers, and it is possible to reliably prevent abnormal discharge and reverse flow of the high-frequency power.

  In the substrate processing apparatus 10 described above, since the annular induction coil 36 faces the inner peripheral edge 24 a of the focus ring 24, the magnetic field lines generated from the induction coil 36 are moved along the circumferential direction of the annular induction heating part 40. Therefore, the focus ring 24 can be heated uniformly along the circumferential direction.

  In the substrate processing apparatus 10 described above, since the entire surface of the induction coil 36 is covered with the heat insulating / insulating portion 37a, high-frequency power can be prevented from flowing back through the induction coil 36. Since it is interposed between the electrostatic chuck 23 and the focus ring 24, the heat of the focus ring 24 can be prevented from being transmitted to the susceptor 12 by the heat insulating / insulating portion 37 a.

  In the substrate processing apparatus 10 described above, the inner peripheral edge 24a of the focus ring 24 is heated. However, since the heat transfer coefficient of the material constituting the focus ring 24 is large, any part of the focus ring 24 may be heated. For example, the induction coil 36 of the focus ring temperature control device 26 may be disposed so as to face the outer peripheral edge of the focus ring 24, and the outer peripheral edge of the focus ring 24 may be heated. The temperature can be easily controlled.

  Further, since the focus ring 24 self-heats when the lines of magnetic force intersect with the induction heating part 40 in the inner peripheral edge 24a, the induction coil 36 is electrostatic as long as the line of magnetic force from the induction coil 36 intersects with the induction heating part 40. It may be arranged on the chuck 23 or may be built in the electrostatic chuck 23.

  Next, a heating method and a substrate processing method of the focus ring according to the present embodiment will be described.

  FIG. 4 is a graph showing the temporal change of the focus ring temperature in the focus ring heating method and the substrate processing method according to the present embodiment.

  In the focus ring heating method and the substrate processing method according to the present embodiment, first, magnetic lines of force are generated from the induction coil 36 of the focus ring temperature control device 26, and the magnetic lines of force intersect with the induction heating unit 40 in the focus ring 24 ( The magnetic force line crossing step) causes the focus ring 24 to self-heat and raises the temperature of the focus ring 24 from the temperature of the susceptor 12 maintained at about 60 ° C. by the temperature of the refrigerant in the refrigerant chamber to T ° C. (predetermined temperature). (Temperature raising step) (FIG. 4 (1)). Here, T.degree. C. is the same temperature as the initial temperature of the focus ring 24 in the RIE process for each of the second and subsequent wafers.

  Thereafter, the supply of power to the induction coil 36 is stopped, the intersection of the magnetic lines of force and the induction heat generating unit 40 is ended (intersection end step), and the temperature rise of the focus ring 24 is stopped. At this time, the power supply bar 38 is lowered by the elevating device 39 and is retracted from the vicinity of the high-frequency power plate 18 or the electrostatic chuck 23 (power supply unit retracting step). In the following, no power is supplied to the induction coil 36, and no heat or power is supplied to the focus ring 24 itself from the outside.

  Next, first and second high-frequency power are applied to the high-frequency power plate 18 (high-frequency power application step) to generate cations and radicals in the processing space PS, and the first wafer W is subjected to RIE processing ( (First processing step) (FIG. 4 (2)) Subsequently, the second and subsequent wafers W are subjected to RIE processing for each wafer (second processing step) (FIG. 4 (3)).

  According to the substrate processing method according to the present embodiment, when the focus ring 24 is heated up to the initial temperature (T ° C.) of the focus ring 24 in the RIE processing of the second and subsequent wafers W, Since the first wafer W is subjected to the RIE process, the initial temperature in the RIE process of each wafer W can be made the same, and the result of the RIE process of each wafer W can be made the same. Further, since the RIE process is performed on each wafer W for each wafer without supplying heat or power from the outside to the focus ring 24 itself, for example, the substrate processing apparatus 10 supplies heat or power to the focus ring 24 from the outside. Even if a supply path or the like is provided, the supply path or the like can be disconnected during application of the first and second high-frequency powers. Therefore, it is possible to prevent abnormal discharge from occurring toward the supply path or the like during application of the first and second high-frequency power, and to prevent the high-frequency power from flowing back through the supply path or the like. Can do.

  Further, in the substrate processing method described above, since it is not necessary to actively control the temperature of the focus ring 24 in the RIE processing of each wafer W, disturbance elements of the RIE processing can be reduced, and thus each wafer W can be reduced. The RIE process can be performed stably.

  In the substrate processing method according to the present embodiment described above, the RIE process is performed on the first wafer W only by raising the temperature of the focus ring 24 from the temperature of the susceptor 12 to T ° C. In some cases, it is difficult to raise the temperature of the entire focus ring 24 to T ° C. only by raising the temperature.

  Accordingly, in response to this, first, the temperature of the focus ring 24 is raised to a temperature higher than T ° C. (FIG. 5A), and then the temperature of the focus ring 24 is maintained at a high temperature for a predetermined time. (FIG. 5 (2)), the supply of power to the induction coil 36 is stopped, the intersection of the magnetic lines of force and the induction heating unit 40 is terminated, and the focus ring 24 is left to cool (FIG. 5 (3)). When the temperature of the focus ring 24 that has been left to cool reaches T ° C., the first and second high-frequency powers may be applied to the high-frequency power plate 18 to perform the RIE process on the first wafer W. Thus, since the focus ring 24 is once heated to a temperature higher than T ° C., the entire focus ring 24 can be reliably raised to T ° C. when the RIE processing of the first wafer W is started.

  In addition, according to the heating method of the focus ring according to the present embodiment, the first and second high frequency powers are applied to the high frequency power plate 18 after the intersection of the magnetic field lines and the induction heating unit 40 is completed. In addition, it is not necessary to connect the power supply rod 38 to the induction coil 36 during the application of the second high-frequency power, whereby the power supply rod 38 is connected to the high-frequency power plate 18 or It can be retracted from the vicinity of the electrostatic chuck 23. Therefore, it is possible to reliably prevent abnormal discharge from occurring toward the power supply rod 38 and reliably prevent high-frequency power from flowing back through the power supply rod 38.

  In the substrate processing apparatus 10 described above, the power supply rod 38 is lifted and lowered by the lifting device 39, but the power supply rod 38 may remain connected to the induction coil 36 without being lifted or lowered. In this case, as shown in FIG. 6, a control unit that controls connection / disconnection of the power supply rod 38, for example, a vacuum filter 42 is provided in the middle of the power supply rod 38. The vacuum filter 42 is provided in the vicinity of the base 21. When the first and second high frequency powers are applied to the high frequency power plate 18, the vacuum filter 42 disconnects the power supply rod 38. At this time, since the tip of the lower portion of the disconnected power supply rod 38 does not exist in the vicinity of the high frequency power plate 18 or the electrostatic chuck 23, the lower portion of the power supply rod 38 does not function as an antenna. Thereby, it is possible to reliably prevent the occurrence of abnormal discharge and reverse flow of high-frequency power.

  In the substrate processing apparatus 10 described above, the focus ring 24 has the induction heating unit 40. However, the focus ring 24 is a semiconductor made of silicon or the like, and the magnetic field induction occurs when the focus ring 24 intersects the magnetic field lines from the induction coil 36. Therefore, the focus ring 24 does not have to have the induction heat generating portion 40.

  In addition, the first and second objects of the present invention are to supply a computer or an external server with a storage medium that records software program codes for realizing the functions of the above-described embodiments, and a CPU such as the computer stores the storage medium. It is also achieved by reading out and executing the program code stored in.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code and the storage medium storing the program code constitute the present invention.

  Examples of the storage medium for supplying the program code include RAM, NV-RAM, floppy (registered trademark) disk, hard disk, magneto-optical disk, CD-ROM, CD-R, CD-RW, DVD (DVD). -ROM, DVD-RAM, DVD-RW, DVD + RW) and other optical disks, magnetic tapes, non-volatile memory cards, other ROMs, etc., as long as they can store the program code. Alternatively, the program code may be supplied to a computer or the like by downloading from another computer or database (not shown) connected to the Internet, a commercial network, a local area network, or the like.

  Further, by executing the program code read by the computer or the like, not only the functions of the above embodiments are realized, but also an OS (operating system) running on the CPU based on the instruction of the program code. Includes a case where part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.

  Further, after the program code read from the storage medium is written in a memory provided in a function expansion board inserted in a computer or the like or a function expansion unit connected to the computer or the like, the program code is read based on the instruction of the program code. A case where the CPU of the function expansion board or the function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing is also included.

  The form of the program code may include an object code, a program code executed by an interpreter, script data supplied to the OS, and the like.

It is sectional drawing which shows schematically the structure of the substrate processing apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the focus ring temperature control apparatus in FIG. It is a figure which shows the case where the electric power supply rod descend | falls in the focus ring temperature control apparatus of FIG. It is a graph which shows the time change of the focus ring temperature in the heating method of a focus ring and the substrate processing method concerning an embodiment of the invention. It is a graph which shows the time change of the focus ring temperature in the modification of the heating method of a focus ring which concerns on embodiment of this invention, and a substrate processing method. It is a figure which shows the modification of the focus ring temperature control apparatus of FIG. FIGS. 7A and 7B are graphs showing temporal changes in the focus ring temperature in the conventional etching process for each wafer. FIG. 7A shows a case where the focus ring is simply placed on a susceptor, and FIG. The case where the time change of the focus ring temperature in the etching process of each wafer is made substantially the same by positively cooling and adjusting the temperature is shown.

Explanation of symbols

W Wafer PS Processing space 10 Substrate processing apparatus 11 Storage chamber 12 Susceptor 18 High frequency power plate 19 First high frequency power supply 23 Electrostatic chuck 24 Focus ring 24a Inner peripheral edge 26 Focus ring temperature control device 32 Second high frequency power supply 36 Inductive coil 37a, 37b Heat insulation / insulation section 38 Power supply rod 39 Lifting device 40 Induction heating section

Claims (12)

A storage chamber for storing a substrate, a mounting table disposed in the storage chamber for mounting the substrate, and an annular focus ring mounted on the mounting table so as to surround a peripheral edge of the previously mounted substrate In the substrate processing apparatus in which the storage chamber is depressurized and high frequency power is applied to the mounting table,
The substrate processing apparatus, wherein the focus ring self-heats. It has a magnetic field generator that generates magnetic field lines,
The substrate processing apparatus according to claim 1, wherein the magnetic field lines intersect with the focus ring.   The magnetic field generator is electrically connected to a power source through a power supply unit, and when the high frequency power is applied to the mounting table, the power supply unit is retracted from a region to which the high frequency power is applied. The substrate processing apparatus according to claim 2.   4. The substrate processing according to claim 2, wherein the focus ring has an induction heating portion therein, and the induction heating portion is made of at least one of iron, stainless steel, aluminum, silicon, silicon carbide, and carbon. apparatus.   5. The substrate processing apparatus according to claim 2, wherein the magnetic field line generator is an annular coil and is disposed so as to face the focus ring. 6.   6. The substrate processing apparatus according to claim 5, wherein the entire surface of the coil is covered with a heat insulating / insulating material, and is arranged between the focus ring and the mounting table. In a substrate processing apparatus comprising: a storage chamber for storing a substrate; and a mounting table disposed in the storage chamber for mounting the substrate, wherein the storage chamber is decompressed, and high-frequency power is applied to the mounting table. A heating method for an annular focus ring mounted on the mounting table so as to surround a peripheral portion of the substrate mounted previously,
A heating method comprising a magnetic field line crossing step in which magnetic field lines intersect the focus ring. The substrate processing apparatus includes a magnetic force line generator that generates magnetic force lines,
An intersection end step for ending the intersection of the magnetic field lines and the focus ring;
The focus ring heating method according to claim 7, further comprising a high frequency power application step of applying the high frequency power to the mounting table after the crossing end step. The magnetic field line generator is electrically connected to a power source through a power supply unit,
9. The focus ring heating method according to claim 8, wherein the power supply unit includes a power supply unit retracting step for retracting from the region to which the high-frequency power is applied before the high-frequency power applying step. A storage chamber for storing a substrate, a mounting table disposed in the storage chamber for mounting the substrate, and an annular focus ring mounted on the mounting table so as to surround a peripheral edge of the previously mounted substrate In the substrate processing apparatus in which high-frequency power is applied to the mounting table, a substrate processing method of performing plasma processing on each of the plurality of substrates using plasma generated due to the high-frequency power. There,
A temperature raising step for raising the temperature of the focus ring to a predetermined temperature;
A first processing step of performing the plasma processing on the first substrate without supplying external heat or electric power to the focus ring when the focus ring is heated to the predetermined temperature; ,
A second processing step of applying the plasma processing to each of the second and subsequent substrates without supplying heat or power from the outside to the focus ring;
The substrate processing method, wherein the predetermined temperature is the same as an initial temperature of the focus ring in the plasma processing of the second and subsequent substrates. In the heating step, the focus ring is heated to a temperature higher than the predetermined temperature,
The substrate processing method according to claim 10, further comprising a standing cooling step in which the focus ring heated to the high temperature is left to cool to the predetermined temperature.   The substrate processing method according to claim 10, wherein in the temperature raising step, the magnetic field lines intersect with the focus ring.

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