JP2010118290A - Ion milling apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ion milling apparatus capable of uniformly radiating a beam even when conditions of an ion source are changed. <P>SOLUTION: An ion beam 9 drawn out from a frequency power source is radiated to a substrate 12, thus the substrate is micromachined by the ion beam. A plurality of Faraday cups 20 are disposed in one line in the radial direction of a circular plate sample holder 11 with a plurality of sample substrates 12 thereon and measure ion beam current. A current integrator 16 temporally integrates a current value of each Faraday cup. A high-frequency power source 5 can supply a coil of the high-frequency ion source with high-frequency power and can vary the high-frequency power value thereof. A power conditioner 19 divides the plurality of Faraday cups into two groups of regions and adjusts the high-frequency power which is supplied from the high-frequency power source to the coil 4 based on a difference in integrated average values for each group. Integrated current values calculated by the current integrator are displayed on a display device 17. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ion milling apparatus, and more particularly to an ion milling apparatus suitable for use in an apparatus equipped with a high-frequency ion source as an ion source.

As an ion beam of an ion milling apparatus, an ion beam from a discharge gas such as CH ₄ (referred to as perfluorocarbon (PFC)), CHF ₃ , Cl ₂ (chlorine gas), or 0 ₂ (oxygen gas) is used in recent years. . As an ion source for that purpose, a high-frequency ion source that converts a gas into a plasma using high-frequency discharge and extracts an ion beam from the plasma is used (for example, Patent Document 1, Patent Document 2, Non-Patent Document 1, Non-Patent Document). Reference 2).

  On the other hand, in the ion milling apparatus, uniform irradiation of an ion beam is important in order to obtain uniform processing of a substrate when performing microfabrication of a sample substrate. By performing uniform processing, the yield of a plurality of elements formed on the substrate is improved.

  Therefore, it is known to adjust the interval between the porous extraction electrodes for extracting the ion beam and to change the size of the holes in order to perform uniform irradiation (see, for example, Patent Document 3).

Japanese Patent Publication No. 7-75152 JP-A-8-106996 JP-A-2005-174469 Review of Scientific Instruments, vol.69, No.2 (1998), V.Kanarov, pp.874-876 Review of Scientific Instruments, vol.71, No.2 (2000), VOIImer, pp.939-942

  However, in the conventional uniform beam irradiation by the porous extraction electrode, the condition of the uniform beam obtained by adjusting the electrode interval and the extraction hole diameter is satisfied for a specific plasma distribution, so that the ion beam current, the ion extraction voltage, etc. However, there was a problem that uniform irradiation could not be performed.

  An object of the present invention is to provide an ion milling apparatus capable of uniform beam irradiation even when the conditions of the ion source are changed.

(1) In order to achieve the above object, the present invention generates plasma by winding a coil for flowing a high-frequency current around the atmosphere side of a quartz tube that has been evacuated and flowing gas into the quartz chamber. In addition, a high-density plasma is generated by arranging multiple permanent magnets in the circumferential direction on the atmosphere side of the quartz cylindrical tube to generate a high-density plasma, and an ion beam is extracted from the plasma using a porous extraction electrode to which a voltage is applied. An ion mill and an ion milling device for performing microfabrication of a substrate by an ion beam by irradiating the substrate with an ion beam extracted from the high-frequency ion source, and a disk-like sample stage on which a plurality of sample substrates are placed A plurality of Faraday cups that measure the ion beam current, and a current accumulator that integrates the current values of each Faraday cup in time. , A display device that displays the current integrated value calculated by the current integrator, and a high-frequency power source that supplies high-frequency power to the coil of the high-frequency ion source and has a variable high-frequency power value. is there.
With this configuration, even when the ion source conditions are changed, uniform beam irradiation is possible.

  (2) In the above (1), preferably, the high-frequency ion source has a structure including a plasma expansion chamber in which permanent magnets are arranged in multiple poles in the circumferential direction and are arranged directly connected to the quartz cylindrical tube. The plasma generated in the quartz cylindrical tube is introduced into the plasma expansion chamber, and the extraction electrode is provided in the plasma expansion chamber to extract an ion beam.

  (3) In the above (1), preferably, the high-frequency ion source is provided with a quartz disk having a diameter slightly smaller than an inner diameter of the quartz cylinder at a discharge gas inlet into the quartz cylinder. It is.

  (4) In the above (1), preferably, the sample substrate is rotatable.

(5) Further, in order to achieve the above object, the present invention provides a plasma by winding a coil for flowing a high-frequency current around the atmosphere-side outer periphery of a quartz cylindrical tube that is evacuated, and flowing a gas into the quartz cylindrical chamber. A high-density plasma is generated by arranging multi-pole permanent magnets in the circumferential direction on the atmosphere side of the quartz cylindrical tube, and an ion beam is generated using a porous extraction electrode to which voltage is applied from this plasma. A high-frequency ion source to be extracted;
An ion milling apparatus that performs fine processing of a substrate by an ion beam by irradiating the substrate with an ion beam extracted from the high-frequency ion source, and is arranged in a radial direction of a disk-like sample stage on which a plurality of sample substrates are placed. A plurality of Faraday cups that are arranged in a line and measure the ion beam current, a current integrator that temporally integrates the current value of each Faraday cup, and a high-frequency power to the coil of the high-frequency ion source, A high-frequency power source having a variable high-frequency power value, and the high-frequency power supplied to the coil from the high-frequency power source based on the difference between the average values of the integrated values of the two groups divided into the two Faraday cups. It is made to provide the adjuster which adjusts.
With this configuration, even when the ion source conditions are changed, uniform beam irradiation is possible.

  (6) In the above (5), preferably, a stop controller is provided to turn off the high-frequency power source when all the integrated current average values of the plurality of Faraday cups are set to a predicted integrated current value. It is a thing.

  (7) In the above (5), preferably, the high-frequency ion source has a structure including a plasma expansion chamber in which permanent magnets are arranged in multiple poles in the circumferential direction and are arranged directly connected to the quartz cylindrical tube. The plasma generated in the quartz cylindrical tube is introduced into the plasma expansion chamber, and the extraction electrode is provided in the plasma expansion chamber to extract an ion beam.

  (8) In the above (5), preferably, the high-frequency ion source includes a quartz disk having a diameter slightly smaller than an inner diameter of the quartz cylinder at a discharge gas inlet into the quartz cylinder. It is.

  (9) In the above (5), preferably, the sample substrate is rotatable.

  According to the present invention, uniform beam irradiation is possible even when the conditions of the ion source are changed.

Hereinafter, the configuration and operation of the ion milling apparatus according to the first embodiment of the present invention will be described with reference to FIGS.
First, the overall configuration of the ion milling apparatus according to the present embodiment will be described with reference to FIGS. 1 and 2.
FIG. 1 is an overall configuration diagram of an ion milling apparatus according to a first embodiment of the present invention. 2 is a cross-sectional view taken along the line CC ′ of FIG.

  First, the basic configuration of the ion milling apparatus according to the present embodiment will be described.

  The plasma chamber of the radio frequency ion source includes a radio frequency (RF) plasma chamber 1 and a plasma expansion chamber 3 directly connected thereto. In the radio frequency (RF) plasma chamber 1, a coil 4 is wound around an outer periphery of a quartz cylindrical tube 2 that is evacuated. A discharge gas is supplied to the radio frequency (RF) plasma chamber 1 from the outside. The flow rate of the discharge gas supplied to the radio frequency (RF) plasma chamber 1 is adjusted by a gas flow rate regulator 6. The coil 4 is supplied with high frequency power from a high frequency power source 5. The frequency of the high frequency power is 2 MHz, for example. The high frequency power supplied from the high frequency power source 5 to the coil 4 is variable. In the radio frequency (RF) plasma chamber 1 having the above-described configuration, a plasma is generated by discharging a gas by supplying a high frequency current to the coil 4. For example, argon is used as the gas. As shown in FIG. 2, a multipolar permanent magnet 7 is disposed on the outer periphery of the expansion chamber 3.

  An ion beam 9 is extracted from the expansion chamber 3 using the porous extraction electrode 8 and guided to the processing chamber 14. The extraction electrode 8 is an acceleration-deceleration type three-electrode, and is composed of first, second, and third electrodes. Each electrode is provided with a large number of small holes in the disk. The material of the electrode is molybdenum. An acceleration power source is connected to the first electrode. A deceleration power supply is connected to the second electrode. The third electrode is applied with a voltage of less than −100 V with respect to the ground or the ground. The extraction voltage (acceleration voltage) is 500 to 2000V, and the deceleration voltage is between 1100 and 1500V.

  A microwave plasma neutralizer 15 is disposed downstream of the extraction electrode 8. The microwave plasma neutralizer 15 generates plasma by microwave discharge downstream of the extraction electrode 8. This plasma is used as an electron supply source for preventing the ion beam 9 from hitting the sample 12 and being charged.

  The processing chamber 14 is evacuated by the evacuation apparatus 10. A disk-shaped sample holder 11 is rotatably installed in the processing chamber 14. The sample holder 11 can also be used in a stationary state. A plurality of samples 12 are mounted on the sample holder 11.

  Furthermore, in the present embodiment, the sample holder 14 is provided with a plurality of small-hole Faraday cups 20 for measuring the ion beam current in a line along the radial direction.

Here, the configuration of the Faraday cup 20 disposed in the ion milling apparatus according to the present embodiment will be described with reference to FIG.
FIG. 3 is a cross-sectional view showing a configuration of a Faraday cup arranged in the ion milling apparatus according to the first embodiment of the present invention. 3, the same reference numerals as those in FIG. 1 denote the same parts.

  A plurality of holes are formed in the sample holder 11. A plurality of Faraday cups 20 are arranged on the back side of the sample holder 11 (on the back side when viewed from the ion source 1), corresponding to the positions of the holes. A suppressor electrode 21 having a small hole is disposed between the sample holder 11 and the Faraday cup 20. A negative voltage is applied to the suppressor electrode 21. Here, the microwave neutralizer 15 is generally applied with a negative voltage that efficiently flows the plasma electrons from the neutralizer 15 to prevent the sample substrate from being charged. In this case, the neutralizer 15 may be electrically connected to the above-described third electrode so that a negative voltage having the same potential as that of the third electrode is applied. The negative voltage applied to the suppressor electrode 21 is a negative voltage (preferably 120V to 1100V) greater than the negative voltage applied to the neutralizer 15. As a result, plasma electrons do not enter the Faraday cup 20 and only the ion beam flows, so that correct current measurement can be performed.

  The outer periphery of the Faraday cup 20 is covered with a cover 23. Further, the current detection signal from the Faraday cup 20 is connected to the current integrator 16 from the rotating shaft of the sample holder 11 through the current introduction terminal 22 as shown in FIG. Further, the current integrated value that is the output of the current integrator 16 can be displayed on the display device 17.

  In FIG. 1, the power regulator 19 and the stop controller 18 are illustrated, but these are used in the second embodiment, and will be described later.

Next, the principle for enabling uniform beam irradiation in the ion milling apparatus according to the present embodiment will be described with reference to FIGS.
FIG. 4 is an explanatory diagram of the radial distribution of the ion beam in the ion milling apparatus according to the first embodiment of the present invention. FIG. 5 is a diagram for explaining the principle of uniform beam irradiation in the ion milling apparatus according to the first embodiment of the present invention.

  Here, in the case of an ion source having a structure in which an ion beam is extracted from a plasma source in which a multipolar permanent magnet is arranged around the plasma generation chamber, a uniform beam region is obtained by extracting an ion beam using a normal porous extraction electrode. Limited to the central part.

  On the other hand, the inventors of the present application have found that the radial distribution of the extracted beam varies depending on the high frequency power as a result of the extraction test.

  FIG. 4 shows the relationship between the high frequency power supplied to the high frequency coil and the current distribution in the radial direction of the extracted ion beam.

  In FIG. 4, the horizontal axis indicates the distance from the center, and the vertical axis indicates the beam current value.

  As described above, a substantially uniform current distribution can be obtained as indicated by the solid line A by adjusting the electrode spacing and the lead-out hole diameter. Even in this case, as shown by the solid line A, the uniform beam region is limited to the central portion, and the beam current value slightly decreases on the outer peripheral side.

  In this state, when the high frequency power applied to the high frequency coil 4 is changed, it has been found by the extraction test of the present inventor that the radial distribution of the extracted beam changes. For example, if the high-frequency power value in the case indicated by the solid line A is 1 kW, if the high-frequency power value is lower than this, the beam current value on the outer peripheral side further decreases as shown by the solid line B, and the beam current value The radial distribution is not uniform.

  Further, when the high-frequency power value is increased, as indicated by the solid line C, the beam current value on the outer peripheral side is increased, and the radial distribution of the beam current value is not uniform.

  In any case, it has been found that when the high frequency power applied to the high frequency coil 4 is changed, the radial distribution of the extracted beam changes.

  As shown by a solid line A in FIG. 4, it can be seen that although the central portion is relatively uniform, the peripheral region has poor uniformity. Therefore, the amount of ion beam processing of the sample 12 was poor in processing uniformity in the processing without rotating the sample holder. Even when the sample holder is rotated, the sample size capable of performing uniform ion beam processing is limited to a small one having a diameter of about 150 mm.

  Recently, increasing the size of the sample has been studied, and samples having a diameter of 200 mm or 300 mm have been studied. For such a large sample, the processing accuracy cannot be increased with a beam having uniformity as shown by the solid line A in FIG.

  In order to solve such a problem, in the present embodiment, a high-frequency power that includes a small-hole Faraday cup 20, a current integrator 16, and a display device 17 and that can vary the power value of the high-frequency power supplied to the coil 4. A source 5 is provided.

  The plurality of small hole Faraday cups 20 for measuring the ion beam current shown in FIGS. 1 and 2 are arranged in a line along the radial direction of the sample holder 11. Each current value flowing into the Faraday cup during the ion milling operation is measured by the plurality of Faraday cups 20. The current integrator 16 integrates each current value flowing into the Faraday cup during the ion milling operation for each Faraday cup. The integrated current value is displayed on the display device 17 as a current distribution in the radial direction. By manually adjusting the output of the high frequency power supply 5 while observing the integrated current distribution displayed on the display device 17, the integrated current distribution at the end of the ion milling process can be made uniform.

  Here, the principle of uniform beam irradiation in the ion milling apparatus according to the present embodiment will be described with reference to FIG.

  In FIG. 5, the horizontal axis indicates the distance from the center, and the vertical axis indicates the integrated current value.

  In FIG. 5, the solid line A indicates the integrated current distribution at the end of the ion milling process. The accumulated current value X is a predetermined value, and the accumulated current distribution indicates that it has been processed uniformly in the radial direction.

  Here, when the integrated current value at the time when the time t has elapsed since the ion milling process is started is displayed on the display device 17 as indicated by the solid line B, the problem continues because the process continues uniformly. Absent. However, as indicated by a broken line C, when the integrated current value on the outer peripheral side is lower than the central portion, the output power of the high frequency power source 5 is manually increased to increase the high frequency power value supplied to the coil 4. To do. As a result, the beam current value becomes higher on the outer peripheral side as indicated by a solid line C in FIG. 4. Therefore, if ion milling is continued in this state, the integrated current value on the outer peripheral side increases in the direction of arrow C ′. Ultimately, it can be uniformly processed in the radial direction as in the integrated current distribution at the end of the ion milling process indicated by the solid line A. Note that the solid line A is shown as a straight line for the sake of explanation, but in actual ion milling, the solid line A is regarded as uniform milling even if unevenness of about ± 3% is included, and is provided for practical use.

  Further, as indicated by a broken line D, when the integrated current value on the outer peripheral side is higher than the central portion, the output power of the high-frequency power source 5 is manually lowered to reduce the high-frequency power value supplied to the coil 4. To do. As a result, the beam current value becomes lower on the outer peripheral side as indicated by a solid line B in FIG. 4. Therefore, if ion milling is continued in this state, the integrated current value on the outer peripheral side becomes smaller in the direction of arrow D ′. Ultimately, it can be uniformly processed in the radial direction as in the integrated current distribution at the end of the ion milling process indicated by the solid line A.

  Conventionally, the processing non-uniformity of ± 3% or more was seen in the sample, but it could be improved to ± 3% or less by manual operation.

  As described above, according to the present embodiment, the distribution of the integrated value of the irradiation current in the radial direction of the sample substrate is made uniform by utilizing the fact that the extracted beam distribution from the high-frequency ion source is changed by the high-frequency power. Ion beam processing becomes possible.

  Next, the configuration and operation of an ion milling apparatus according to the second embodiment of the present invention will be described with reference to FIG.

  In this embodiment, the processing uniformity can be automatically improved by using the power regulator 19 and the stop controller 18 shown in FIG. In the present embodiment, the display device 17 is not necessarily required, but is necessary for monitoring the progress of processing uniformity.

  In this embodiment, as shown in FIGS. 1 and 3, the Faraday cup 20 is divided into a group A on the outer peripheral side and a group B on the inner peripheral side. The integrator 16 calculates and outputs the average value of the integrated current of the Faraday cup 20 of the A group and the average value of the integrated current of the Faraday cup 20 of the B group, respectively.

  The power regulator 19 includes a comparator 19A and a power commander 19B. The comparator 19A outputs the difference between the average value of the integrated current of the F group Faraday cup 20 in the A group and the average value of the integrated current Faraday cup 20 of the B group. The power commander 19B raises and lowers the high-frequency power value according to the difference between the average value of the integrated current of the F group Faraday cup 20 in the A group and the average value of the integrated current Faraday cup 20 of the B group. Specifically, when the average value of the accumulated current of the Faraday cup 20 of the A group is larger than the average value of the Faraday cup 20 of the B group, the command value is changed so as to decrease the high frequency power value, In that case, the ratio which reduces a high frequency electric power value is enlarged, so that the difference of A group and B group is large. In addition, when the average value of the integrated current of the Faraday cup 20 of the A group is smaller than the average value of the Faraday cup 20 of the B group, the command value is changed to increase the high frequency power value, The ratio which raises a high frequency electric power value is enlarged, so that the difference of A group and B group is large.

  Thus, by automatically changing the high frequency power value, it becomes possible to adjust the integrated current value in the A group and the B group to be uniform and have a diameter of 150 mm or more, for example, a diameter of 200 mm or 300 mm. Even for a large sample, a value of ± 3% or less was stably obtained in the in-plane uniformity of the sample. As a result, processing accuracy can be increased.

  The stop controller 18 automatically determines the end of ion beam processing and stops the supply of high-frequency power to the coil. The ion beam processing time for obtaining the predetermined processing varies depending on the current value and the substrate material, but is determined by the integrated current value. Therefore, when the high frequency power is changed by the output from the power regulator 19, not only the distribution but also the extracted ion beam current value is changed. Control is simple and easy by adjusting the processing time according to the change of the ion beam current value or adjusting the ion beam current value according to the change of the high frequency power.

  In general, since a sample to be ion beam processed becomes large in mass production, an integrated current value for performing predetermined processing on the sample can be determined in advance empirically. The stop controller 18 compares the predicted integrated current value X with the actually measured Faraday cup integrated current average value Y, and outputs an off signal to the high frequency power source 5 when the Y value reaches the X value. 5 is turned off, the plasma is extinguished, and the processing ends.

  As described above, according to this embodiment, the distribution of the integrated value of the irradiation current in the radial direction of the sample substrate is automatically made uniform by utilizing the fact that the extracted beam distribution from the high-frequency ion source is changed by the high-frequency power. Therefore, extremely uniform ion beam processing becomes possible.

Next, the configuration and operation of an ion milling apparatus according to the third embodiment of the present invention will be described with reference to FIG.
FIG. 6 is an overall configuration diagram of an ion milling apparatus according to a third embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

  The present embodiment is different from the embodiment shown in FIG. 1 in the configuration of the ion source. The high frequency power is wound outside the quartz cylindrical tube 2 and a permanent magnet 7 is provided in the high frequency plasma chamber 1. The cross-sectional shape regarding the magnet arrangement is the same as in FIG.

  Also in the present embodiment, as in the first embodiment, the integrated current value of the Faraday cup 20 is displayed on the display device 17, and the output power of the high-frequency power source 5 is manually adjusted, so that the same sample uniformity is obtained. Can be processed. Similarly to the second embodiment, by using the integrated current value of the Faraday cup 20 to automatically adjust the output power of the high frequency power supply 5 by the power regulator 19 and the stop controller 18, Equivalent sample uniform processing can be performed.

  As described above, according to this embodiment, the distribution of the integrated value of the irradiation current in the radial direction of the sample substrate is automatically made uniform by utilizing the fact that the extracted beam distribution from the high-frequency ion source is changed by the high-frequency power. Therefore, extremely uniform ion beam processing becomes possible.

Next, the configuration and operation of an ion milling apparatus according to the fourth embodiment of the present invention will be described with reference to FIG.
FIG. 7 is a configuration diagram of an ion source used in an ion milling apparatus according to the fourth embodiment of the present invention. The overall configuration of the ion milling apparatus according to the present embodiment is the same as that shown in FIG. The same reference numerals as those in FIG. 1 denote the same parts.

  The present embodiment is different from the embodiment shown in FIG. 1 in the configuration of the ion source. In introducing the gas into the radio frequency (RF) plasma chamber 1, a quartz disk 24 having a diameter smaller by about 1 to 2 mm than the inner diameter of the cylindrical quartz tube 2 is provided at the gas inlet as shown in the figure. According to this embodiment, gas flows from the periphery of the cylindrical quartz tube into the inside, so that the peripheral plasma tends to become high density, and the ion source operating pressure range in which the extraction current distribution has a peak in FIG. Also, the value of the high-frequency power showing a peak in the periphery was 1000 W or more until then, but it has a peak even at about 600 W or more. As a result, the control for equalizing the current integrated value becomes easy and the controllable operating range is expanded.

  Also in the present embodiment, as in the first embodiment, the integrated current value of the Faraday cup 20 is displayed on the display device 17, and the output power of the high-frequency power source 5 is manually adjusted, so that the same sample uniformity is obtained. Can be processed. Similarly to the second embodiment, by using the integrated current value of the Faraday cup 20 to automatically adjust the output power of the high frequency power supply 5 by the power regulator 19 and the stop controller 18, Equivalent sample uniform processing can be performed.

  It is obvious that the same effect can be obtained even if a quartz disk similar to that of the embodiment shown in FIG. 7 is applied to the ion source shown in FIG.

  As described above, according to this embodiment, the distribution of the integrated value of the irradiation current in the radial direction of the sample substrate is automatically made uniform by utilizing the fact that the extracted beam distribution from the high-frequency ion source is changed by the high-frequency power. Therefore, extremely uniform ion beam processing becomes possible.

In each embodiment described above, as the gas mainly use argon gas, the effect was confirmed by the argon ion beam, separate gas species from the essence of the invention _{(CF 4, CHF 3, 0} 2 , etc. ), The same uniform ion beam processing becomes possible.

  In addition, although the Faraday cups 20 attached to the sample holder 11 are arranged in a row in the radial direction, it is apparent from the essence of the invention that they may be arranged in the circumferential direction.

As described above, if the current integrated value at the time of ion beam processing is measured and displayed by the Faraday cup array provided in the radial direction of the sample holder according to the present invention, and the high frequency power is controlled according to the integrated distribution, the ion beam milling processing At the end, extremely uniform microfabrication can be performed within the sample surface. The effect is remarkably great for industrial fields in which fine processing of materials using ion beams is performed.

1 is an overall configuration diagram of an ion milling apparatus according to a first embodiment of the present invention. It is C-C 'sectional drawing of FIG. FIG. 2 is a cross-sectional view showing a configuration of a Faraday cup disposed in the ion milling device according to the first embodiment of the present invention. It is explanatory drawing of radial direction distribution of the ion beam in the ion milling apparatus by the 1st Embodiment of this invention. It is principle explanatory drawing of the uniform beam irradiation in the ion milling apparatus by the 1st Embodiment of this invention. It is a whole block diagram of the ion milling apparatus by the 3rd Embodiment of this invention. It is a block diagram of the ion source used for the ion milling apparatus by the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... High frequency (RF) plasma chamber 2 ... Cylindrical quartz tube 3 ... Plasma expansion chamber 4 ... High frequency coil 5 ... High frequency power supply 6 ... Gas flow regulator 7 ... Permanent magnet 8 ... Porous extraction electrode system 9 ... Ion beam 10 ... Vacuum Exhaust device 11 ... Sample holder 12 ... Sample 14 ... Processing chamber 15 ... Microwave plasma neutralizer 16 ... Accumulator 17 ... Display device 18 ... Stop controller 19 ... Power regulator 20 ... Faraday cup 21 ... Suppressor electrode 22 ... Current introduction Terminal 23 ... Cover 24 ... Quartz disc

Claims (9)

A coil for flowing a high-frequency current is wound around the outer periphery of the quartz cylindrical tube that has been evacuated, and plasma is generated by flowing a gas into the quartz cylindrical chamber. A high-frequency ion source that generates a high-density plasma by arranging magnets in multiple poles and extracts an ion beam using a porous extraction electrode to which a voltage is applied from the plasma;
An ion milling apparatus that performs fine processing of a substrate with an ion beam by irradiating the substrate with an ion beam extracted from the high-frequency ion source,
A plurality of Faraday cups arranged in a row in the radial direction of a disk-shaped sample table on which a plurality of sample substrates are placed, and for measuring an ion beam current;
A current integrator that integrates the current value of each Faraday cup over time;
A display device for displaying the current integrated value calculated by the current integrator;
An ion milling apparatus comprising: a high-frequency power source that supplies high-frequency power to a coil of the high-frequency ion source, and whose high-frequency power value is variable. In the ion milling device according to claim 1,
The high-frequency ion source is arranged directly connected to the quartz cylindrical tube, and has a structure including a plasma expansion chamber in which permanent magnets are arranged in multiple poles in the circumferential direction,
An ion milling apparatus, wherein plasma generated in the quartz cylindrical tube is introduced into the plasma expansion chamber, and the extraction electrode is provided in the plasma expansion chamber to extract an ion beam. In the ion milling device according to claim 1,
The high-frequency ion source includes a quartz disk having a diameter slightly smaller than an inner diameter of the quartz cylinder at a discharge gas introduction port that enters the quartz cylinder. In the ion milling device according to claim 1,
An ion milling apparatus, wherein the sample substrate is rotatable. A coil for flowing a high-frequency current is wound around the outer periphery of the quartz cylindrical tube that has been evacuated, and plasma is generated by flowing a gas into the quartz cylindrical chamber. A high-frequency ion source that generates a high-density plasma by arranging magnets in multiple poles and extracts an ion beam using a porous extraction electrode to which a voltage is applied from the plasma;
An ion milling apparatus that performs fine processing of a substrate with an ion beam by irradiating the substrate with an ion beam extracted from the high-frequency ion source,
A plurality of Faraday cups arranged in a row in the radial direction of a disk-shaped sample table on which a plurality of sample substrates are placed, and for measuring an ion beam current;
A current integrator that integrates the current value of each Faraday cup over time;
While supplying high frequency power to the coil of the high frequency ion source, a high frequency power source whose variable high frequency power value is variable,
The Faraday cup is divided into two groups, and an adjuster is provided for adjusting high-frequency power supplied from the high-frequency power source to the coil based on a difference between average values of integrated values of the groups. Ion milling equipment. In the ion milling device according to claim 5,
An ion milling apparatus comprising: a stop controller that turns off the high-frequency power supply when all the integrated current average values of the plurality of Faraday cups are set to a predicted integrated current value set in advance. In the ion milling device according to claim 5,
The high-frequency ion source is arranged directly connected to the quartz cylindrical tube, and has a structure including a plasma expansion chamber in which permanent magnets are arranged in multiple poles in the circumferential direction,
An ion milling apparatus, wherein plasma generated in the quartz cylindrical tube is introduced into the plasma expansion chamber, and the extraction electrode is provided in the plasma expansion chamber to extract an ion beam. In the ion milling device according to claim 5,
The high-frequency ion source includes a quartz disk having a diameter slightly smaller than an inner diameter of the quartz cylinder at a discharge gas introduction port that enters the quartz cylinder. In the ion milling device according to claim 5,
An ion milling apparatus, wherein the sample substrate is rotatable.

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