JP4099181B2 - Ion beam etching method and ion beam etching apparatus - Google Patents

Description

  The present invention relates to an ion beam etching method and an ion beam etching apparatus.

An ion beam etching method for etching a workpiece by irradiating the surface of the workpiece with an ion beam is known (see, for example, Patent Document 1). Such an ion beam is obtained by extracting ions in the plasma generated in the discharge vessel of the ion source using extraction electrodes.
Japanese translation of PCT publication No. 2002-510428

  However, when a voltage is applied to the extraction electrode to extract the ion beam, the extraction electrode may be deformed by the heat of the plasma generated in the discharge vessel. For example, when using extraction electrodes made of three metal plates, the amounts of heat supplied from plasma to the metal plates are different from each other, and therefore the deformation amounts of the metal plates are different. Therefore, the center positions of the lead holes formed in each metal plate are shifted from each other. When an ion beam is extracted using such an extraction electrode, (1) since the ion beam emission direction is not constant, the radial distribution of the ion beam intensity is nonuniform, and (2) the ion beam extraction efficiency is reduced. Problem arises.

  Therefore, an object of the present invention is to provide an ion beam etching method and an ion beam etching apparatus that can suppress deformation of the extraction electrode due to heat.

  In order to solve the above-described problems, an ion beam etching method of the present invention includes an etching process for etching a workpiece using an ion beam extracted by an extraction electrode, and a cooling process for cooling the extraction electrode with an inert gas. Including. Here, the cooling step may be performed after the etching step, or may be performed before the etching step.

  In the ion beam etching method of the present invention, the deformation of the extraction electrode due to heat can be suppressed by performing the cooling step.

  For example, when the cooling step is performed before the etching step, deformation of the extraction electrode can be suppressed in advance in the cooling step. For this reason, in the etching process after the cooling process, the ion beam can be extracted using the extraction electrode in which the deformation is suppressed. For this reason, the radial distribution of the ion beam intensity can be made uniform, and the extraction efficiency of the ion beam can be improved.

  For example, when the cooling process is performed after the etching process, even if the temperature of the extraction electrode rises in the etching process, the deformation of the extraction electrode can be suppressed by performing the cooling process.

  Moreover, it is preferable to convey the said workpiece in the said cooling process. In addition, conveyance of a workpiece may be started before the cooling process, or conveyance of the workpiece may be continued after the cooling process.

  In this case, in the cooling process, the workpiece is conveyed in parallel with the cooling of the extraction electrode. Therefore, the processing time of all the steps of the ion beam etching method can be shortened.

  Preferably, the cooling step is performed before the etching step, and the ion beam etching method further includes a warming-up step of extracting an ion beam in advance using the extraction electrode before the cooling step.

  In this case, it is possible to confirm whether or not a desired ion beam can be obtained by the warm-up process. Even if the temperature of the extraction electrode rises in the warming-up process, deformation of the extraction electrode can be suppressed by performing the cooling process.

  The inert gas is preferably the same as an ion generating gas for generating ions in the ion beam in the etching step. Thereby, the extraction electrode can be easily cooled.

  In the cooling step, it is preferable that the flow rate of the inert gas is larger than the flow rate of the ion generating gas. Thereby, the extraction electrode can be efficiently cooled.

  The ion beam etching apparatus of the present invention includes an ion source, an extraction electrode for extracting an ion beam from the ion source, and a cooling means for cooling the extraction electrode.

  In the ion beam etching apparatus of the present invention, the deformation of the extraction electrode due to heat can be suppressed by the cooling means. For this reason, the radial distribution of the ion beam intensity is made uniform, and the ion beam extraction efficiency is improved.

  ADVANTAGE OF THE INVENTION According to this invention, the ion beam etching method and ion beam etching apparatus which can suppress the deformation | transformation by the heat | fever of an extraction electrode are provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same or equivalent elements, and duplicate descriptions are omitted.

  FIG. 1 is a drawing schematically showing a configuration of an ion beam etching apparatus (also referred to as an ion milling apparatus) according to an embodiment. FIG. 2 is a drawing schematically showing the configuration of the main part of the ion beam etching apparatus shown in FIG.

An ion beam etching apparatus 100 shown in FIG. 1 is suitably used for manufacturing a thin film magnetic head (for example, GMR head, TMR head) for HDD. In particular, it is suitably used for processing of an ABS surface or chamfer portion that defines the flying height of a thin film magnetic head. The ion beam etching apparatus 100 includes an ion source 40 and an extraction electrode E for extracting the ion beam IB from the ion source 40. The ion beam IB travels in the etching chamber 30 and etches the substrate W (workpiece) accommodated in the etching chamber 30. The extraction electrode E is made of, for example, molybdenum (Mo), and is disposed between the etching chamber 30 and the ion source 40. The substrate W is a silicon wafer, for example. The ion beam IB includes cations such as Ar ⁺ . The ion beam IB is not limited to positive ions.

A neutralizer 34 for neutralizing the ion beam IB is installed in the etching chamber 30. For example, when the ion beam IB is a positive ion such as Ar ^+, electrons e ⁻ are emitted from the neutralizer 34. The electrons e ⁻ can suppress, for example, filling of the space in the etching chamber 30 with positive charges and charging of the substrate W. As a result, the extraction efficiency of the ion beam IB can be improved, and the ion beam IB can be prevented from diverging in the radial direction.

  In addition, a shutter 32 that can block the ion beam IB as necessary is installed in the etching chamber 30. The shutter 32 is disposed between the substrate W and the extraction electrode E. As the shutter 32, for example, a mechanical shutter or an electrostatic shutter can be used. Further, a tray holder 36 for holding the substrate W in a predetermined position is installed in the etching chamber 30. The tray holder 36 is preferably cooled by cooling water cooled by a chiller (not shown).

  In the present embodiment, the transfer chamber 20 is connected to the etching chamber 30 via the connection portion 52. In addition, the load lock chamber 10 is connected to the transfer chamber 20 via a connection portion 50. The substrate W is introduced into the etching chamber 30 from the load lock chamber 10 via the transfer chamber 20.

  For example, a rotary pump RP and a turbo molecular pump TP are connected to the load lock chamber 10, the transfer chamber 20, and the etching chamber 30, respectively. A dry pump may be used instead of the rotary pump RP. The etching chamber 30 is maintained at a predetermined pressure (for example, 0.05 Pa) by the rotary pump RP and the turbo molecular pump TP.

  In the transfer chamber 20, for example, a robot arm 24 attached to the rotary shaft 22 is disposed. The tip of the robot arm 24 can hold a tray 26 for housing the substrate W. The tray 26 is preferably provided with a clamp portion (not shown). The substrate W is fixed to the tray 26 by the clamp portion. Note that a plurality of substrates W may be accommodated in the tray 26. The robot arm 24 is telescopic in the longitudinal direction. Therefore, the robot arm 24 can transfer the tray 26 set in the load lock chamber 10 into the etching chamber 30.

  The ion source 40 includes a discharge vessel 42 and a coil 44 that is provided outside the discharge vessel 42 and generates plasma P in the discharge vessel 42. The discharge vessel 42 is preferably made of a material mainly composed of a dielectric material such as quartz or aluminum oxide.

  A power supply device 48 is connected to one end of the coil 44 via, for example, an impedance matching unit 46. The other end of the coil 44 is grounded, for example. The power supply device 48 is, for example, a high frequency power supply or a high frequency amplifier. In this case, the frequency of the power supply device 48 is preferably several MHz to several tens of MHz (for example, 2 to 13.5 MHz). In one embodiment, the frequency of the power supply device 48 is 4 MHz, for example. The power supply device 48 preferably applies, for example, 200 to 2000 W of power to the coil 44 in accordance with the capacity and shape of the discharge vessel 42.

  For example, an opening 43 for introducing an inert gas is formed in the discharge vessel 42. One end of the pipe P <b> 1 is connected to the opening 43. The other end of the pipe P1 is connected to the gas supply source G1 through the gas box GB. The gas supply source G <b> 1 supplies an inert gas into the discharge vessel 42. As the inert gas, for example, a rare gas such as Ar gas or He gas can be suitably used. He gas is preferably used from the viewpoint of heat transfer coefficient, and Ar gas is preferably used from the viewpoint of cost. The gas box GB has a valve V1, a mass flow controller MFC1, and a valve V2 in order from the upstream side. The flow rate of the inert gas supplied into the discharge vessel 42 can be adjusted by the mass flow controller MFC1.

  The inert gas supplied from the gas supply source G1 is preferably an ion generating gas for generating the plasma P in the discharge vessel 42 and a cooling gas for cooling the extraction electrode E. Thereby, the extraction electrode E can be easily cooled. The inert gas supplied from the gas supply source G1 may be a cooling gas, and the inert gas supplied from a gas supply source different from the gas supply source G1 may be an ion generation gas.

  Further, the tray holder 36 is formed with an opening 33 for supplying a substrate cooling gas for cooling the substrate W, for example. The opening 33 is preferably formed in the surface 36 a of the tray holder 36. The opening 33 can be formed on the side surface of the tray holder 36 by making the direction (angle) of the opening 33 oblique. As such a substrate cooling gas, a rare gas such as He gas can be suitably used. One end of the pipe P <b> 2 is connected to the opening 33. The other end of the pipe P2 is connected to the gas supply source G2 via the gas box GB. The gas box GB has a valve V3, a mass flow controller MFC2, and a valve V4 in this order from the upstream side. The flow rate of the substrate cooling gas can be adjusted by the mass flow controller MFC2. This substrate cooling gas can suppress an increase in the temperature of the substrate W during etching.

  Specifically, for example, a substrate cooling gas is applied to the tray 26 and the substrate W is cooled via the tray 26. The tray holder 36 and the tray 26 may have a structure in which the substrate cooling gas can be directly applied to the substrate W. As such a structure, for example, a structure in which a hole serving as a gas flow path is formed in the bottom surface portion of the tray 26, a substantially annular shape in which the surface 36 a of the tray holder 36 surrounds the periphery of the tray 26, and the center of the tray 26 is provided. For example, a structure in which the substrate cooling gas is supplied from the surface 36a can be given.

  The extraction electrode E preferably has a screen grid E1, an acceleration grid E2, and a deceleration grid E3. The extraction electrode E may not have the deceleration grid E3. The screen grid E1, the acceleration grid E2, and the deceleration grid E3 are sequentially arranged from the inside to the outside of the discharge vessel. The screen grid E1, the acceleration grid E2, and the deceleration grid E3 are, for example, metal plates each having a plurality of (for example, 10,000 or less) extraction holes. The center position of the drawing holes of the screen grid E1, the center position of the drawing holes of the acceleration grid E2, and the center position of the drawing holes of the deceleration grid E3 are preferably designed to overlap each other when viewed from the thickness direction of the metal plate.

  The screen grid E1 can separate the plasma P and the acceleration grid E2. For example, a power supply 60 for continuously applying a positive high voltage is connected to the screen grid E1. The voltage applied to the screen grid E1 is 2 kV, for example. The voltage applied to the screen grid E1 determines the ion beam energy of the ion beam IB.

  The acceleration grid E2 is also called a suppression electrode. For example, a power supply 62 for continuously applying a negative high voltage is connected to the acceleration grid E2. The voltage applied to the acceleration grid E2 is, for example, −600 to −800V. The deceleration grid E3 is also called a ground electrode and is grounded. By adjusting the potential difference between the acceleration grid E2 and the deceleration grid E3, the ion beam diameter of the ion beam IB can be controlled within a predetermined numerical range using the lens effect.

The ion beam IB is emitted from the ion source 40 as follows, for example. First, the inside of the discharge vessel 42 is reduced to a pressure of about 10 ⁻⁵ Pa, for example, and an inert gas such as Ar gas is introduced into the discharge vessel 42 from the gas supply source G1. Subsequently, plasma P is generated in the discharge vessel 42 by supplying power from the power supply device 48 to the coil 44. Ions such as Ar ⁺ in the plasma P are extracted as an ion beam IB by the extraction electrode E.

Here, when ions such as Ar ⁺ in the plasma P collide with the extraction electrode E, the temperature of the extraction electrode E rises. Further, applying a voltage to the extraction electrode E also raises the temperature of the extraction electrode E. Therefore, when etching is performed, the temperature of the extraction electrode E rises.

  However, in the ion beam etching apparatus 100, the extraction electrode E can be cooled using an inert gas supplied from the gas supply source G1 and the gas box GB (cooling means). By cooling the extraction electrode E, the temperature rise of the extraction electrode E can be suppressed. As a result, deformation of the extraction electrode E due to heat can be suppressed. Thereby, the relative position shift of the center of each drawer hole of the screen grid E1, the acceleration grid E2, and the deceleration grid E3 can be suppressed within a predetermined range. Therefore, the radial distribution of the ion beam intensity can be made uniform, and the extraction efficiency of the ion beam IB can be improved. Note that the extraction electrode E may be cooled and the units such as the tray holder 36 may be simultaneously cooled.

  When the radial distribution of the ion beam intensity is made uniform, the in-plane distribution of the etching amount (etching depth) on the substrate W can be made uniform, so that etching with high accuracy and excellent reproducibility can be performed. it can. On the other hand, when the extraction efficiency of the ion beam IB is improved, the etching time can be shortened, and the variation with time of the power value supplied from the power supply device 48 to the coil 44 can be reduced.

  3 to 5 are flowcharts showing a procedure for carrying out the ion beam etching method according to the embodiment. 4 is a flowchart subsequent to FIG. 3, and FIG. 5 is a flowchart subsequent to FIG. The ion beam etching method according to the present embodiment is preferably carried out using the ion beam etching apparatus 100 described above.

  Hereinafter, the ion beam etching method according to the present embodiment will be described with reference to FIGS. The ion beam etching method according to this embodiment includes a cooling step S52 for cooling the extraction electrode E with an inert gas, and an etching step S54 for etching the substrate W using the ion beam IB extracted by the extraction electrode E. (See FIG. 4).

  In the present embodiment, the etching step S54 is performed after the cooling step S52. In addition, it is preferable to perform a warm-up step S50 in which the ion beam IB is extracted in advance using the extraction electrode E before the cooling step S52 (see FIG. 3). Whether or not a desired ion beam IB can be obtained can be confirmed by the warm-up step S50. Note that the warm-up step S50 may not be performed.

  More specifically, the ion beam etching method according to the present embodiment is preferably carried out by sequentially performing, for example, the following steps S1 to S29. Hereinafter, a case where, for example, Ar gas is used as the inert gas supplied to the discharge vessel 42 will be described. In this case, the Ar gas functions as an ion generating gas for generating the plasma P in the discharge vessel 42 and a cooling gas for cooling the extraction electrode E.

  In step S <b> 1, the tray 26 in which the substrate W is accommodated is put into the load lock chamber 10. At this time, the load lock chamber 10 is VENT (open to the atmosphere). The pressures in the transfer chamber 20 and the etching chamber 30 are set to a predetermined degree of vacuum.

In step S2, the load lock chamber 10 is evacuated using the rotary pump RP and the turbo molecular pump TP. Here, it is preferable to first perform roughing by the rotary pump RP, and switch to vacuuming by the turbo molecular pump TP when the pressure in the load lock chamber 10 reaches several Pa. Thereby, the inside of the load lock chamber 10 can be made into a high vacuum (for example, 1 × 10 ⁻⁵ to 1 × 10 ⁻⁴ Pa).

In step S <b> 3, it is determined whether or not the inside of the load lock chamber 10 has reached a predetermined degree of vacuum that can transport the tray 26. As a result, when it is determined that the predetermined degree of vacuum has been reached, Ar gas at a predetermined flow rate is introduced from the gas supply source G1 into the discharge vessel 42 in step S4. The flow rate of Ar gas is controlled by the gas box GB. At this time, it is preferable that electrons e ⁻ are emitted from the neutralizer 34 in the etching chamber 30. On the other hand, if it is determined that the predetermined degree of vacuum has not been reached, the process returns to step S2 to evacuate the load lock chamber 10.

After step S4, a warm-up step S50 is performed. The warming up step S50 preferably includes a step S5, a step S6, and a step S7. In step S <b> 5, RF power is supplied to the coil 44 using the power supply device 48. As a result, plasma P containing active species such as Ar ⁺ , electrons, and neutral Ar atoms is generated in the discharge vessel 42. Here, it is preferable to gradually increase the value of the RF power. The discharge vessel 42 and the extraction electrode E are heated by the collision of the active species, and the inner surface of the discharge vessel 42 is cleaned. In particular, the screen grid E1 has a larger temperature rise than the acceleration grid E2 and the deceleration grid E3.

  In step S <b> 6, a voltage is applied to the extraction electrode E using the power sources 60 and 62. Thereby, the ion beam IB is emitted from the extraction electrode E. At this time, since the shutter 32 is in a closed state, the ion beam IB is blocked by the shutter 32.

  In step S7, it is determined whether or not warming up of the ion beam IB is completed. As a result, when it is determined that the warm-up has been completed, the voltage applied to the extraction electrode E is turned off in step S8. The irradiation time of the ion beam IB is, for example, about 5 minutes. When the warming up is completed, the irradiation of the ion beam IB is stabilized. On the other hand, if it is determined that the warm-up has not been completed, the process returns to step S5 and continues to supply RF power to the coil 44.

In step S9, the RF power supplied to the coil 44 is turned off. Thereby, the irradiation of the ion beam IB is stopped. Thereafter, emission of electrons e ⁻ from the neutralizer 34 is stopped. In step S10, the shutter 32 is opened.

  After step S10, a cooling step S52 is performed. The cooling step S52 preferably includes a step S11, a step S12, and a step S13. In step S11, the flow rate of Ar gas supplied from the gas supply source G1 into the discharge vessel 42 is preferably larger than the flow rate of Ar gas in step S4, and more preferably (for example, 300 sccm). At this time, it is preferable that the pressure in the etching chamber 30 is 100 times or more that during warm-up. The flow rate of Ar gas is controlled by the gas box GB.

  In step S12, the tray 26 is conveyed. The tray 26 is conveyed from the load lock chamber 10 to the origin position on the surface 36a of the tray holder 36 in the etching chamber 30 by the robot arm 24, and is fixed at the origin position. The substrate W is transported together with the tray 26.

  In step S13, the tray 26 is set at a predetermined position by rotating and tilting the tray holder 36. Thereby, the incident angle of the ion beam IB with respect to the substrate W is adjusted.

In step S14, the supply of Ar gas is stopped. In step S15, the etching chamber 30 is evacuated. In step S16, it is determined whether or not a predetermined degree of vacuum has been reached. As a result, if it is determined that the predetermined degree of vacuum has been reached, a predetermined flow rate of Ar gas is introduced from the gas supply source G1 into the discharge vessel 42 in step S17, as in step S4. On the other hand, if it is determined that the predetermined degree of vacuum has not been reached, the process returns to step S15, and the etching chamber 30 is evacuated. At this time, it is preferable that electrons e ⁻ are emitted from the neutralizer 34 in the etching chamber 30. In addition, since the etching chamber 30 and the discharge vessel 42 are connected by the hole of the extraction electrode E, when the evacuation in the etching chamber 30 is performed, the inside of the discharge vessel 42 has the same degree of vacuum as that in the etching chamber 30.

  After step S17, an etching step S54 is performed. Etching step S54 preferably includes step S18, step S19 and step S20. In step S18, RF power is supplied from the power supply device 48 to the coil 44 in the same manner as in step S5. Thereby, plasma P is generated in the discharge vessel 42. Here, it is preferable to gradually increase the RF power value. The discharge vessel 42 and the extraction electrode E are heated by the plasma P. In order to prevent the temperature of the substrate W from rising during etching, it is preferable to flow He gas exchanged with cooling water cooled by a chiller between the substrate W and the tray 26. In step S19, as in step S6, a voltage is applied to the extraction electrode E using the power sources 60 and 62. Thereby, the ion beam IB is emitted from the extraction electrode E, and the etching is started by applying the ion beam IB to the substrate W.

  In step S20, it is determined whether a predetermined etching time has elapsed. As a result, when it is determined that a predetermined etching time has elapsed, the voltage applied to the extraction electrode E is turned off in step S21. On the other hand, if it is determined that the predetermined etching time has not elapsed, the process returns to step S18 to continue supplying RF power to the coil 44.

In step S22, the RF power supplied to the coil 44 is turned off. Thereby, the irradiation of the ion beam IB is stopped. Thereafter, emission of electrons e ⁻ from the neutralizer 34 is stopped.

  In step S23, the supply of Ar gas is stopped. In step S24, the shutter 32 is closed. In step S25, the tray 26 is returned to the original position by rotating and tilting the tray holder 36. In step S26, the tray 26 is conveyed. The tray 26 is transported into the load lock chamber 10 from the origin position on the surface 36 a of the tray holder 36 by the robot arm 24.

  In step S27, VENT of the load lock chamber 10 is performed. In step S28, it is determined whether or not VENT is completed. As a result, when it is determined that the VENT is completed, the tray 26 is taken out from the load lock chamber 10. On the other hand, if it is determined that VENT has not been completed, the process returns to step S27 and VENT of the load lock chamber 10 is performed.

  As described above, since the ion beam etching method according to this embodiment includes the cooling step S52, deformation of the extraction electrode E due to heat can be suppressed. Specifically, for example, even if the temperature of the extraction electrode E rises in the warm-up step S50, the temperature of the extraction electrode E can be lowered by performing the cooling step S52. Therefore, deformation of the extraction electrode E due to heat can be suppressed.

  Further, since the deformation of the extraction electrode E is alleviated in the cooling step S52 in advance, in the etching step S54 after the cooling step S52, the ion beam IB can be extracted using the extraction electrode E whose deformation has been alleviated. For this reason, the radial distribution of the ion beam intensity in the etching step S54 can be made uniform, and the extraction efficiency of the ion beam IB can be improved.

FIG. 6 is a graph schematically showing the relationship between the value of the RF power supplied from the power supply device 48 to the coil 44 and time. As shown in the graph, etching starts at time t ₁ and stops at time t ₂ . In this case, the temperature of the extraction electrode E rises from time t ₁ to time t ₂ . When the temperature of the extraction electrode E rises, the extraction efficiency of the ion beam IB tends to decrease. Therefore, in order to maintain the extraction efficiency, it is necessary to increase the value of the RF power. In the ion beam etching method according to the present embodiment, the extraction electrode E is cooled by turning off the RF power from time t ₂ to time t ₃ . Thereby, the deformation | transformation by the heat | fever of the extraction electrode E is relieve | moderated.

Then, the following etching starts at time t _3, to stop the etching at the time t _4. Since the extraction electrode E the time t _{2 ~} time t ₃ is cooled, thermal deformation of the extraction electrode E at time t ₃ is suppressed. Therefore, RF power similar to that at time t ₁ to time t ₂ can be applied also at time t ₃ to time t ₄ . Accordingly, by cooling the extraction electrode E from time t ₂ to time t ₃ , it is possible to suppress the value of the RF power from fluctuating with time. Therefore, highly accurate and reproducible etching can be performed.

  In the present embodiment, since the substrate W is transported in the cooling step S52, the substrate W is transported in parallel with the cooling of the extraction electrode E. Therefore, the processing time of all the steps of the ion beam etching method is shortened. Moreover, it is preferable that the flow rate of Ar gas in step S11 is larger than the flow rate of Ar gas in steps S4 and S17. Thereby, the extraction electrode E can be efficiently cooled. In particular, it is preferable to maximize the flow rate of Ar gas in step S11.

  In addition, the ion beam etching method according to the present embodiment can be suitably used when performing deep etching, but is particularly effective when performing shallow etching. For example, when processing the ABS surface of a thin film magnetic head, shallow etching is called shallow etching, and deep etching is called cavity etching.

  As mentioned above, although preferred embodiment of this invention was described in detail, this invention is not limited to the said embodiment.

  For example, the cooling step S52 may be performed after the etching step S54. In this case, even if the extraction electrode E is deformed by heat in the etching step S54, the deformation of the extraction electrode E is suppressed by performing the cooling step S52.

  Further, the substrate W may not be transferred in the cooling step S52. For example, the substrate W may be transported between the warming up step S50 and the cooling step S52.

  Further, an inert gas different from the ion generating gas for generating the plasma P in the discharge vessel 42 may be used as the inert gas for cooling the extraction electrode E. For example, the extraction electrode E may be cooled using He gas, and Ar gas may be used as the ion generation gas.

It is drawing which shows typically the structure of the ion beam etching apparatus which concerns on embodiment. It is drawing which shows typically the structure of the principal part of the ion beam etching apparatus shown by FIG. It is a flowchart which shows the procedure for enforcing the ion beam etching method which concerns on embodiment. It is a flowchart which shows the procedure for enforcing the ion beam etching method which concerns on embodiment. It is a flowchart which shows the procedure for enforcing the ion beam etching method which concerns on embodiment. It is a graph which shows typically the relation between the value of RF power supplied to a coil from a power supply device, and time.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 40 ... Ion source, 100 ... Ion beam etching apparatus, E ... Extraction electrode, IB ... Ion beam, G1 ... Gas supply source (cooling means), GB ... Gas box (cooling means), W ... Substrate (workpiece).

Claims (11)

An etching process for etching a workpiece using an ion beam extracted by an extraction electrode;
A cooling step of cooling by the inert gas the extraction electrode by supplying an inert gas to be in contact with the extraction electrode,
An ion beam etching method.   The workpiece is held by holding means,
  The lead electrode is provided with a lead hole,
  2. The cooling step according to claim 1, wherein in the cooling step, the holding means is cooled by the passing gas by bringing the passing gas that has passed through the drawing hole out of the inert gas in contact with the drawing electrode into contact with the holding means. The ion beam etching method as described. Wherein the cooling step, conveying the workpiece, ion beam etching method according to claim 1 or 2. The cooling process is performed before the etching process,
The ion beam etching method according to any one of claims 1 to 3 , further comprising a warming-up step of previously extracting an ion beam using the extraction electrode before the cooling step. The ion beam etching method according to any one of claims 1 to 4 , wherein the inert gas is the same as an ion generation gas for generating ions in the ion beam in the etching step. The ion beam etching method according to claim 5 , wherein in the cooling step, the flow rate of the inert gas is made larger than the flow rate of the ion generating gas.   An etching process for etching a workpiece using an ion beam extracted by an extraction electrode;
  A cooling step of cooling the extraction electrode with an inert gas;
Including
  The ion beam etching method, wherein the inert gas is the same as an ion generation gas for generating ions in the ion beam in the etching step.   The ion beam etching method according to claim 7, wherein in the cooling step, the flow rate of the inert gas is made larger than the flow rate of the ion generating gas. An ion source;
An extraction electrode for extracting an ion beam from the ion source;
Cooling means for cooling the extraction electrode with an inert gas ;
Equipped with a,
The ion beam etching apparatus, wherein the cooling means supplies the inert gas so as to be in contact with the extraction electrode .   Further comprising holding means for holding the workpiece;
  The extraction electrode is disposed between the cooling means and the holding means;
  The ion beam etching apparatus according to claim 9, wherein the extraction electrode is provided with an extraction hole through which at least a part of the cooling gas in contact with the cooling unit can pass toward the holding unit.   An ion source;
  An extraction electrode for extracting an ion beam from the ion source;
  Cooling means for cooling the extraction electrode with an inert gas;
With
  The ion beam etching apparatus, wherein the inert gas is the same as an ion generation gas for generating ions in the ion beam extracted from the ion source.

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