JP5877509B2 - Charged particle beam generation apparatus and charged particle beam generation method - Google Patents

Description

  The present invention relates to a charged particle beam generation apparatus and a charged particle beam generation method for generating a charged particle beam.

  Conventionally, plasma has been used in various processes such as plasma etching and plasma CVD. In such a process, a plasma generator for generating plasma is used. For example, the following Patent Document 1 discloses a high-frequency inductively coupled plasma generating apparatus including a discharge tube, a solenoid antenna, and a high-frequency power source. Patent Document 2 below includes a glass tube and a high-frequency coil wound around the tip portion thereof, Ar gas is introduced into the glass tube, and high-frequency power is applied by the high-frequency coil to generate inductively coupled plasma. A plasma generating apparatus for generating the above is disclosed.

JP 2010-109777 A

  However, in the conventional plasma generator described above, since inductively coupled plasma is used, there is a limit in stably generating a thin charged particle beam.

  Accordingly, the present invention has been made in view of such problems, and an object thereof is to provide a charged particle beam generation apparatus and a charged particle beam generation method capable of stably generating a thin charged particle beam. To do.

  In order to solve the above problems, a charged particle beam generating apparatus according to one aspect of the present invention includes a gas source that generates a gas flow, a tubular tube having a proximal end portion connected to the gas source and a distal end portion formed in a tapered shape. A member, a plate electrode provided so as to surround the side surface of the tubular member from the outside, a pulse voltage source that applies a pulse voltage to the plate electrode, and a negative DC bias applied to a target to be irradiated with a charged particle beam And one or more side holes are formed in the side surface of the tubular member, and the plate-like electrode and the side holes are arranged in this order from the proximal end portion to the distal end portion. Has been placed.

  Alternatively, the charged particle beam generation method according to one aspect of the present invention provides a tubular member having a distal end formed in a tapered shape and one or more side holes formed in a side surface between the proximal end and the distal end. Then, a gas flow is introduced from the gas source into the proximal end portion of the tubular member, and a pulse voltage is applied to the plate electrode provided so as to surround the space between the proximal end portion of the side surface of the tubular member and the side hole from the outside. Then, a negative DC bias is applied to the target to be irradiated with the charged particle beam.

  The "tapered shape" here is not limited to a cross-sectional shape that is linearly thinned, but a shape in which the inclination with respect to the central axis of the tubular member becomes steeper toward the tip (a shape with a rounded tip), It also includes a cross-sectional shape that becomes narrower in a curved shape such as a shape in which the inclination with respect to the central axis of the tubular member becomes gentler toward the tip (a shape with a sharp tip).

  According to the above aspect of the present invention, the gas flow is uniformly and stably formed from the proximal end portion toward the distal end portion inside the tubular member. Further, a pulse voltage is applied to the gas flow through the plate electrode and a negative DC bias is applied to the target, whereby an ion flow accompanying the displacement current is intermittently formed inside the tubular member. The ion flow is intermittently emitted toward the target as an ion beam. Thereby, the thin ion beam which goes to a target can be produced | generated stably. At the same time, the tubular member can be prevented from being damaged by appropriately adjusting the gas pressure at the tip of the tubular member.

  In the charged particle beam generating apparatus according to the above-described one aspect, the tubular member includes a linearly extending proximal end portion, a tapered distal end portion, and a relay portion that connects the proximal end portion and the distal end portion. It is preferable that the side hole is formed in the relay portion. If this structure is taken, the side hole in the tubular member can be easily processed.

  It is also preferable that the plate electrode has a curved plate shape surrounding the outer surface of the tubular member. According to the shape of the plate electrode, the uniformity of the ion flow formed inside the tubular member is improved, and the uniformity of the ion beam irradiated to the target can be further improved.

  Further, it is also preferable that two plate electrodes are provided side by side along the central axis of the tubular member, and the pulse voltage source is connected between the two plate electrodes. In this case, the ion beam can be stably irradiated toward the target without being influenced by the position of the target.

  Furthermore, it is preferable that a plurality of side holes are arranged so as to be arranged at equal intervals around the central axis of the tubular member. In this case, the fluctuation of the gas flow is reduced inside the tubular member, and the diameter of the ion beam toward the target can be further reduced. Furthermore, the gas pressure at the tip of the tubular member can be easily adjusted.

  Furthermore, it is also preferable that the plate electrode generates capacitively coupled plasma with the target. In this way, a uniform ion beam can be intermittently irradiated toward the target.

  According to the present invention, it is possible to provide a charged particle beam generation apparatus and a charged particle beam generation method capable of stably generating a thin charged particle beam.

1 is a schematic configuration diagram showing an ion beam generating apparatus 1 which is a preferred embodiment of the present invention. It is a side view which expands and shows the capillary tube 9 of FIG. FIG. 3 is a cross-sectional view taken along line III-III of the capillary tube 9 of FIG. 2. It is a graph which shows the waveform of the pulse voltage applied by the pulse voltage source 11 of FIG. 1, and the measurement result of the ion beam emitted from the front-end | tip 23 of the capillary tube 9 of FIG. It is a graph which expands and shows a part of FIG. It is a graph which shows the position dependence of the intensity | strength of the ion beam discharge | released from the front-end | tip 23 of the capillary tube 9 of FIG. It is a graph showing the relationship between the distance z and the ion transit times T _T from the tip 23 of the capillary tube 9 in Figure 1. It is a graph showing the relationship between the distance z and the ion transit times T _T from the tip 23 of the capillary tube 9 in Figure 1. It is a block diagram of the measurement system which measures the property of the particle | grains discharge | released from the front-end | tip 23 of the capillary tube 9 of FIG. Is a graph showing the dependency on the bias voltage V _B of the current I _P which is measured by the measurement system of FIG. It is a graph which shows the spectral characteristic of the emission spectrum observed in the capillary tube 9 of FIG. It is a figure which shows the picked-up image of the target T to which the etching process was given by the ion beam production | generation apparatus 1 of FIG. It is a figure which shows the surface image and cross-sectional image by the microscope of the target T which ashed by the ion beam production | generation apparatus 1 of FIG. It is a figure which shows the structure of the ion beam production | generation apparatus 1 for refinement | miniaturization of an ashing process. It is a figure which shows the surface image and cross-sectional image by the microscope of the target T which ashed by the ion beam production | generation apparatus 1 of the structure of FIG. It is a figure which shows the surface image at the time of performing a CVD process using the ion beam generating apparatus 1 of FIG. 1 with respect to the silicon substrate. It is a figure which shows the surface image at the time of performing a CVD process using the ion beam production | generation apparatus 1 of FIG. 1 with respect to a polycarbonate substrate. It is a figure which shows the image which observed the surface of the board | substrate with which the amino group modification process was given by the ion beam production | generation apparatus 1 of FIG. 1 with the fluorescence microscope. It is sectional drawing of the radial direction of the capillary tube 9 in the modification of this invention. It is a schematic block diagram which shows the ion beam generating apparatus 101 concerning the modification of this invention. It is a figure which shows the image which observed the surface of the board | substrate by which the amino group modification process was given by the ion beam production | generation apparatus 101 of FIG. 20 with the fluorescence microscope.

  Hereinafter, a charged particle beam generating apparatus and a charged particle beam generating method according to the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Each drawing is made for the purpose of explanation, and is drawn so as to particularly emphasize the target portion of the explanation. Therefore, the dimensional ratio of each member in the drawings does not necessarily match the actual one.

(Configuration of ion beam generator)
FIG. 1 is a schematic configuration diagram showing an ion beam generating apparatus 1 which is a preferred embodiment of the present invention. An ion beam generating apparatus 1 shown in the figure is an apparatus that irradiates an ion beam, which is a charged particle beam, toward a target T arranged outside by generating atmospheric pressure non-equilibrium plasma inside. The ion beam generating apparatus 1 includes, as main components, a gas source 7 including a gas cylinder 3, a regulator 4, and a flow rate control unit 5, and a capillary tube (tubular) that is supplied with gas from the gas source 7 and generates plasma therein. Member) 9, a pulse voltage source 11 connected to the capillary tube 9, and a bias voltage source 13 connected to a target T which is an irradiation target of the ion beam.

The gas cylinder 3 is connected to the base end 17 of the capillary tube 9 via the regulator 4, the flow rate controller 5, and the tube 15, and gas such as helium (He), methane (CH ₄ ), ammonia (NH ₃ ), etc. Is supplied into the capillary tube 9. The regulator 4 is an adjustment valve that adjusts the gas flow rate from the gas cylinder 3, and the flow rate control unit 5 is an apparatus that controls the regulator 4 to adjust the flow rate of the gas introduced from the gas cylinder 3 into the capillary tube 9. Yes, for example, a mass flow controller. The pulse voltage source 11 is a power source that is connected to a plate electrode 19 arranged outside the capillary tube 9 and applies a pulse voltage that is a periodic rectangular wave to the plate electrode 19. The bias voltage source 13 is a power source that is connected to the target T and applies a negative DC bias voltage to the target T.

  Next, the configuration of the capillary tube 9 will be described in detail with reference to FIGS. 2 and 3. 2 is an enlarged side view of the capillary tube 9 of FIG. 1, and FIG. 3 is a cross-sectional view of the capillary tube 9 of FIG. 2 taken along line III-III.

  The capillary tube 9 includes a base end portion 21 that is a glass tube linearly extending from the base end 17, a tip end portion 25 that is a glass capillary tube formed in a tapered shape toward the tip end 23, and a base end portion 21. It is comprised by the relay part 27 which is a resin-made tube which connects the front-end | tip part 25. FIG. Here, the material of the capillary tube 9 is not limited to glass, but may be other materials such as a resin typified by plastic. A cavity 29 that extends straight from the base end 17 to the tip 23 is formed inside the capillary tube 9 having such a configuration. It can guide in the cavity 29 connected to.

  Specifically, the distal end portion 25 is formed in a tapered shape such that the outer diameter and the inner diameter gradually decrease from the proximal end 31 connected to the relay portion 27 toward the distal end 23. Here, the outer end surface 33 of the distal end portion 25 is formed in a curved shape so that the diameter abruptly decreases from the proximal end 31 to the distal end 23 and the distal end 23 becomes very elongated. Regarding the size of the distal end portion 25, for example, the outer diameter of the proximal end 31 is about 1 mm, and the outer diameter of the distal end 23 is 100 nm to 1 μm. Such a tip portion 25 is produced, for example, by processing a glass tube having an outer diameter of about 1 mm and an inner diameter of 0.6 mm with a micropipette puller.

  The relay portion 27 is formed with two side holes 37 a and 37 b that penetrate from the outer surface 36 to the internal cavity 29. The two side holes 37a and 37b are formed around the central axis of the capillary tube 9 at equal intervals along the outer surface 36, that is, at positions facing each other in the direction perpendicular to the central axis of the capillary tube 9. ing.

  Further, a metal plate electrode 19 having a cylindrical shape as a whole is fixed to a central portion in the longitudinal direction of the outer side surface 35 of the base end portion 21. The plate electrode 19 is fixed along the outer surface 35 so as to surround the base end portion 21 from the outside. The plate electrode 19 may have a C-shaped cross-section in which a part of the cylindrical electrode is cut out or a curved plate shape having a semicircular cross-section.

  When a gas flow is supplied from the gas source 7 to the capillary tube 9 configured as described above, a gas flow is formed in the cavity 29 from the proximal end 31 to the distal end 23, and a part of the gas flow is formed in the side hole. It is discharged outside from 37a, 37b. Thereby, even when the tip 23 of the capillary tube 9 is thinned, a gas flow is stably formed in the cavity 29. Further, even if the tip 23 of the capillary tube 9 is thinned, an excessive gas pressure is prevented from being applied to the tip 23, and the durability of the capillary tube 9 is improved. In this way, in the state where the gas flow is formed in the capillary tube 9, the pulse voltage source 11 enables the pulse voltage to be applied to the plate-like electrode 19, and the extension of the center axis of the capillary tube 9 toward the tip 23 side. With the target T placed on the line, a DC bias voltage can be applied to the target T from the bias voltage source 13. As a result, the plate electrode 19 and the target T act as opposed electrodes, and capacitively coupled plasma at atmospheric pressure is intermittently generated in the cavity 29 of the capillary tube 9 in synchronization with the periodic pulse voltage. The Further, as a result, ions contained in the capacitively coupled plasma generated in the cavity 29 are accelerated toward the tip 23 by the action of the electric field in the cavity 29, and are emitted as an intermittent ion beam from the tip 23 to the outside. After that, it is further accelerated toward the target T to which a negative bias voltage is applied.

(Various measurement results)
Here, an evaluation result of the ion beam generated by the ion beam generating apparatus 1 will be described. 4 and 5 show the waveform of the pulse voltage applied by the pulse voltage source 11 and the measurement result of the ion beam emitted from the tip 23 of the capillary tube 9. FIG. 5 shows the measurement results in a part of the time range in FIG. Here, the front surface of the tip 23 of the capillary tube 9 is disposed an electrostatic probe is microelectrode instead of the target T, and the detection signal S _P1 of the current flowing through the electrostatic probe, plate electrodes 19 and the pulse voltage source 11 and a detection signal _{SP2 of a} current flowing between 11 were measured. The graph also shows the waveform _{SP0 of the} pulse voltage applied by the pulse voltage source 11. This detection signal S _P1 is considered to represent a change in the intensity of the ion beam, and the detection signal S _P2 is considered to represent the magnitude of the current flowing in the cavity 29 of the capillary tube 9. According to the result, at time T _I which is synchronized with the rise of the pulse voltage, the peak is observed in the detection signal S _P2, the displacement current is generated in the cavity 29 of the capillary tube 9. Capacitively coupled plasma in the cavity 29 by the generation of the displacement current is generated, the ion beam emitted from the capillary tube 9 with the plasma generation, immediately after time T _I at time T _P, the detection signal S _P1 It turns out that it is detected as a peak. From this, it is understood that when the pulse voltage source 11 applies a periodic pulse voltage, the ion beam generator 1 generates an intermittent pulsed ion beam.

Next, the velocity of the ion beam generated by the ion beam generator 1 was evaluated. FIG. 6 shows the position dependency of the measurement result of the ion beam emitted from the tip 23 of the capillary tube 9. Here, an electrostatic probe is arranged on the front surface of the tip 23 of the capillary tube 9, and the detection signal _{SP1 of the} current flowing through the electrostatic probe and a plate-like shape are varied while changing the distance z from the tip 23 of the electrostatic probe. A detection signal _{SP2 of a} current flowing between the electrode 19 and the pulse voltage source 11 was measured. From this measurement result, it was found that the timing of the detected ion beam gradually delayed as the distance from the tip 23 of the capillary tube 9 increased to z = 1.5 mm, 2.5 mm, 3.5 mm, and 4.5 mm. This indicates that an ion beam is emitted from the tip 23 along the longitudinal direction of the capillary tube 9. Then, by calculating the timing difference between the distance Z and the peak of the detection signal _SP1 , the progress speed of the ion beam generated by the ion beam generator 1 can be evaluated.

For example, in FIGS. 7 and 8 show the relationship between the distance z and the transport time T _T. Transit time _{T T} from the peak time _{T I} of the detection signal _{S P2,} the peak time _{T P} of the detection signal _{S P1} at respective distances z,
T _T = T _P −T _I
The ion transport time from the plate electrode 19 to the electrostatic probe is shown. FIG. 7 shows the case where helium is used as the gas, the outer diameter of the tip 23 of the capillary tube 9 is 1 μm, the magnitude of the pulse voltage is ± 5 kV, and the frequency of the pulse voltage is 5 kHz. It is a measurement result when the outer diameter of the tip 23 of the capillary tube 9 is 100 nm, the magnitude of the pulse voltage is ± 5 kV, and the frequency of the pulse voltage is 5 kHz. From the results shown in FIG. 7, when the distance z is in the range of about 1 mm to about 3.5 mm, the propagation speed of the ion beam is estimated to be about 1.1 × 10 ⁴ m / s, and in the range where the distance z is about 3.5 mm to about 6.0 mm. The propagation speed of the ion beam was estimated to be about 0.5 × 10 ⁴ m / s. Further, from the result of FIG. 8, when the distance z is in the range of 0 mm to about 0.7 mm, the ion beam propagation speed is estimated to be about 0.3 × 10 ⁴ m / s, and the distance z is in the range of about 0.7 mm to about 1.3 mm. The ion beam propagation speed was estimated to be about 530 m / s, and the ion beam propagation speed was estimated to be about 58 m / s when the distance z was in the range of about 1.3 mm to about 1.5 mm. From these results, it is understood that the velocity of the ion beam decreases as it travels through the atmosphere, and the charged particle groups in the ion beam initially maintain the ionization front, but as the ion beam travels through the atmosphere, the charged particle groups Are expected to recombine.

Furthermore, the measurement result regarding the property of the particle | grains discharge | released from the front-end | tip 23 of the capillary tube 9 of the ion beam generating apparatus 1 is shown. At this time, as shown in FIG. 9, an electrostatic probe 39 is arranged on the front surface of the capillary tube 9, and a bias power supply 41 is connected to the electrostatic probe 39 to apply a variable bias voltage V _B. The current I _P flowing through 39 was measured using a series resistor 43 connected to the electrostatic probe 39 and an oscilloscope 45 connected to both ends of the series resistor 43. Figure 10 shows a dependence on the bias voltage V _B of the current I _P which is measured by such a measurement system. From this result, current I _P becomes large in the case of applying a negative bias voltage V _B, be changed bias voltage V _B is a saturated state hardly changed, in case of applying a positive bias voltage V _B it can be seen that the decreasing current I _P according to the bias voltage V _B increases. This indicates that most of the particles emitted from the tip 23 of the capillary tube 9 are positive ions such as nitrogen ions and helium ions.

  Next, the measurement result about the component of the plasma which generate | occur | produces in the capillary tube 9 of the ion beam generating apparatus 1 is shown. FIG. 11 shows the spectral characteristics of the emission spectrum observed in the capillary tube 9. In this figure, the spectral characteristics in the vicinity of the plate electrode 19 of the capillary tube 9, the spectral characteristics in the vicinity of the relay portion 27 of the capillary tube 9, and the spectral characteristics in the vicinity of the tip 23 of the capillary tube 9 are shown in order from the top. Show. In this case, helium was used as the feed gas. From this measurement result, helium emission spectrum (587.6 nm, 706.5 nm), OH molecule emission spectrum (308.9 nm) and oxygen (O) emission spectrum (777.2 nm) are observed. Thereby, it turns out that the ion beam generating apparatus 1 can be applied to various processes such as resist film etching.

(Application examples)
Examples of applications of the ion beam generator 1 include various processes such as etching, ashing, CVD, and surface modification.

  For example, by preparing a semiconductor substrate with a photoresist film formed on the surface as the target T and irradiating the surface of the target T with an ion beam using the ion beam generating apparatus 1, the etching process can be realized. In FIG. 12, the image which image | photographed the target T etched with the ion beam production | generation apparatus 1 with the CCD camera is shown. In this case, as the target T, a silicon substrate coated with an acrylic resin having a film thickness of 650 nm and an average surface roughness Ra of 1 to 3 nm as a photoresist film is used, and the outer diameter of the tip 23 of the capillary tube 9 is set. Set to 100 nm. At this time, the size of the fine pattern formed on the target T by the ion beam generator 1 is about 100 nm in width at the bottom, 500 to 700 nm in width on the surface of the photoresist film, and 30 to 50 nm in depth. confirmed. Thus, according to the ion beam generator 1, nanoscale patterning is realized by the ultrafine atmospheric pressure ion beam.

  Further, ashing can also be realized by irradiating the surface of the target T with an ion beam using the ion beam generating apparatus 1 for a semiconductor substrate on which a photoresist film is formed as the target T. FIG. 13 shows a surface image and a cross-sectional image of the target T that has been subjected to the ashing process by the ion beam generating apparatus 1. In this case, the target T is a substrate coated with acrylic resin as a photoresist film, the outer diameter of the tip 23 of the capillary tube 9 is set to 100 nm, and the distance between the tip 23 and the target T is 500 μm. Set as follows. In this case, the size of the removal pattern formed on the target T was evaluated to be 4.0 μm. Further, when it is desired to make the removal pattern formed on the target T finer, a magnet may be arranged with the target T sandwiched between the front surfaces of the tips of the capillary tubes 9 as shown in FIG. In FIG. 14, a magnet 49 such as a neodymium magnet that generates a magnetic field along the central axis of the capillary tube 9 on the surface of the target T is disposed between the target T and the XY stage 47 that moves the target T. The FIG. 15 shows a surface image and a cross-sectional image of a target T that has been subjected to ashing by the ion beam generating apparatus 1 configured as shown in FIG. In this case, the size of the removal pattern formed on the target T was evaluated as 1.75 μm. As described above, according to the ion beam generating apparatus 1, the ashing process can be miniaturized by the ultrafine atmospheric pressure ion beam.

Furthermore, the CVD process can be realized by using a mixed gas of helium and methane as a supply gas in the ion beam generating apparatus 1. In FIG. 16, the surface image at the time of performing 3 points | pieces of CVD process using the ion beam production | generation apparatus 1 with respect to a silicon substrate is shown. In this case, the outer diameter of the tip 23 of the capillary tube 9 was set to 100 nm. In addition, FIG.
The surface image at the time of performing a CVD process on a polycarbonate substrate is shown. Thus, it was found that microfabrication is possible in the range of diameter 6-9 μm and film thickness 300-400 nm. It has also been found that deposition on thermoplastic substrates such as polycarbonate is possible.

  In addition, the surface modification process can be realized by using helium, oxygen, or ammonia as the supply gas in the ion beam generating apparatus 1. For example, when ammonia is used, amino group modification can be realized. As an example of processing conditions, as preprocessing, helium is supplied from the gas source 7 in the ion beam generating apparatus 1 to irradiate the target T with the ion beam. In this case, the outer diameter of the tip 23 of the capillary tube 9 is 1 μm, the magnitude of the applied pulse voltage is ± 6.5 kV, the frequency of the voltage is 5 kHz, the duty ratio is 50%, the magnitude of the DC bias voltage is −500 V, The distance between the tip 23 and the target T is set to 250 μm, and the processing time is set to 0.01 seconds to 0.1 seconds. Thereafter, as post-processing, the ion beam generator 1 supplies a mixed gas of helium and ammonia from the gas source 7 to irradiate the target T with the ion beam. In this case, the conditions are the same as those in the preprocessing except that the processing time is set to 3.0 seconds. FIG. 18 shows an image obtained by observing the surface of the substrate on which the amino group modification processing has been performed by the ion beam generating apparatus 1 with a fluorescence microscope. FIG. 18A shows a case where the pretreatment time is set to 0.1 second. , (B) shows a case where the pre-processing time is set to 0.01 seconds. From these evaluation results, it was found that fine surface modification processing was realized by the ion beam generator 1.

  According to the ion beam generation apparatus 1 and the ion beam generation method using the ion beam generation apparatus 1 described above, a gas flow is uniformly and stably formed from the proximal end portion 21 toward the distal end portion 25 in the cavity 29 of the capillary tube 9. The In other words, the linear velocity in the cavity 29 can be increased by providing a flow path extending from the base end portion 21 to the side holes 37a and 37b. Further, a pulse voltage is applied to the gas flow with the increased linear velocity via the plate electrode 19 and a negative DC bias is applied to the target T, whereby a displacement current flows into the cavity 29 of the capillary tube 9. Accordingly, an ion flow is intermittently formed, and the ion flow is intermittently emitted toward the target T as an ion beam. Thereby, the thin ion beam which goes to the target T can be produced | generated stably. At the same time, the capillary tube 9 can be prevented from being damaged by appropriately adjusting the gas pressure at the tip 25 of the capillary tube 9.

  In the ion beam generating apparatus 1, the two side holes 37 a and 37 b are arranged so as to be arranged at equal intervals around the central axis of the capillary tube 9. As a result, fluctuations in the gas flow inside the capillary tube 9 are reduced, and the diameter of the ion beam toward the target T can be made smaller. Furthermore, the gas pressure at the tip 25 of the capillary tube 9 can be easily adjusted.

  The capillary tube 9 has a relay portion 27 that connects the base end portion 21 and the distal end portion 25, and the two side holes 37 a and 37 b are formed in the relay portion 27. The holes 37a and 37b can be easily processed.

  Further, since the plate electrode 19 has a cylindrical shape surrounding the outer surface 35 of the capillary tube 9, the uniformity of the ion flow formed in the cavity 29 of the capillary tube 9 is improved and the target T is irradiated. The ion beam uniformity can be further improved.

  In addition, this invention is not limited to embodiment mentioned above. For example, the number of side holes formed in the relay portion 27 is not limited to a specific number as long as it is 1 or more. For example, as shown in FIG. 19, four side holes 37 a to 37 d may be formed so as to be arranged at equal intervals around the central axis of the capillary tube 9. However, the side holes are not necessarily arranged at regular intervals. By increasing the number of side holes in this way, fluctuation of the ion beam emitted from the capillary tube 9 can be suppressed, and the diameter of the beam irradiated to the target T can be reduced.

  The pulse voltage applied to the plate electrode 19 is not limited to a rectangular wave, and may be a sine pulse voltage. Also in this case, an ion flow accompanying the displacement current is intermittently formed in the cavity 29 of the capillary tube 9.

  Further, like the ion beam generating apparatus 101 which is a modified example of the present invention shown in FIG. 20, two plate electrodes 19 a and 19 b having the same shape as the plate electrode 19 are connected to the center of the proximal end portion 21 of the capillary tube 9. The pulse voltage source 11 may be fixed so as to be aligned along the axis, and the two plate electrodes 19a and 19b may be connected. Even with such a configuration, a pulse voltage is applied between the two plate electrodes 19 a and 19 b by the pulse voltage source 11, whereby an ion flow accompanying the displacement current is intermittently generated in the cavity 29 of the capillary tube 9. Formed. FIG. 21 shows an image obtained by observing, with a fluorescence microscope, the surface of the substrate that has been subjected to the amino group modification by the ion beam generator 101. In this case, the processing conditions were set the same as when the observation result shown in FIG. 18B was obtained. From this result, it was found that if the ion beam generating apparatus 101 is used, further refinement of the surface modification process can be realized.

  DESCRIPTION OF SYMBOLS 1,101 ... Ion beam generator, 7 ... Gas source, 9 ... Capillary tube (tubular member), 11 ... Pulse voltage source, 13 ... Bias voltage source, 17 ... Base end, 19, 19a, 19b ... Plate electrode, 21 ... Base end part, 23 ... Tip, 25 ... Tip part, 27 ... Relay part, 29 ... Cavity, 33, 35, 36 ... Outer surface, 37a-37d ... Side hole.

Claims (7)

A gas source for generating a gas flow;
A tubular member having a proximal end connected to the gas source and a distal end formed in a tapered shape;
A plate-like electrode provided so as to surround the side surface of the tubular member from the outside;
A pulse voltage source for applying a pulse voltage to the plate electrode;
A bias voltage source that applies a negative DC bias to a target to be irradiated with the charged particle beam,
The side surface of the tubular member is configured to discharge a part of the gas flow formed inside the tubular member to the outside of the tubular member, and adjusts the gas pressure at the tip of the tubular member. is 1 or more side holes of formation and,
In the tubular member, the plate electrode and the side hole are arranged in this order from the base end portion to the tip end portion.
A charged particle beam generator characterized by that. The tubular member includes the base end portion extending linearly, the tip portion formed in a taper shape, and a relay portion connecting the base end portion and the tip portion,
The side hole is formed in the relay portion,
The charged particle beam generating apparatus according to claim 1. The plate electrode has a curved plate shape surrounding the outer surface of the tubular member,
The charged particle beam generation apparatus according to claim 1, wherein The plate electrode is provided in two along the central axis of the tubular member,
The pulse voltage source is connected between the two plate electrodes.
The charged particle beam generating apparatus according to claim 1, wherein A plurality of the side holes are arranged so as to be arranged at equal intervals around the central axis of the tubular member.
The charged particle beam generation apparatus according to any one of claims 1 to 4, wherein The plate electrode generates capacitively coupled plasma with the target;
The charged particle beam generating apparatus according to claim 1, wherein A tubular member having a distal end formed in a tapered shape and one or more side holes formed on a side surface between the proximal end and the distal end is prepared, and a gas is supplied from a gas source to the proximal end of the tubular member. Flow in,
Adjusting the gas pressure at the tip of the tubular member by discharging a part of the gas flow formed inside the tubular member to the outside of the tubular member from the one or more side holes;
Applying a pulse voltage to a plate-like electrode provided so as to surround between the base end portion of the side surface of the tubular member and the side hole from the outside,
Apply a negative DC bias to the target to be irradiated with the charged particle beam,
The charged particle beam generation method characterized by the above-mentioned.