Patent Description:
An ion milling apparatus is an apparatus that processes a sample by an ion beam. The ion milling apparatus is used to manufacture a sample to be observed with an electron microscope such as a scanning electron microscope and a transmission electron microscope or a sample to be analyzed with an electron probe microanalyzer, an auger microscope, or the like. In a case where the sample is processed by the ion milling apparatus, a shielding member that shields the ion beam is used, and the sample is irradiated with the ion beam through the shielding member (see, for example, <CIT>).

The conventional ion milling apparatus includes, for example, a configuration illustrated in <FIG> in order to set the sample on the shielding member.

In <FIG>, a sample <NUM> is attached and fixed to a sample placing stand <NUM>. A plate-shaped shielding member <NUM> is arranged on the opposite side of the sample placing stand <NUM>. The sample <NUM> is sandwiched and fixed between the sample placing stand <NUM> and the shielding member <NUM>.

Meanwhile, in <FIG>, the sample <NUM> is fixed with a clip <NUM>. The clip <NUM> is supported so as to be swingable about a fulcrum portion <NUM>. The clip <NUM> is biased in one direction by force F1 of a spring <NUM>. The plate-shaped shielding member <NUM> is arranged on the opposite side of the clip <NUM>. The sample <NUM> is fixed to the shielding member <NUM> by pressing force F2 applied from the clip <NUM> to the sample <NUM>. The pressing force F2 is force generated by biasing the clip <NUM> in one direction by the force F1 of the spring <NUM>.

The sample <NUM> fixed as described above is irradiated with an ion beam <NUM> emitted from an ion source (not illustrated) via the shielding member <NUM>. As a result, a part 200a of the sample <NUM> protruding from an edge portion 220a of the shielding member <NUM> is removed by etching. Therefore, a cross section of the sample <NUM> is formed immediately below the edge portion 220a of the shielding member <NUM>.

<CIT> discloses a cross section sample preparation apparatus and a rotational cross section sample preparation apparatus which enable preparation of a sample for scanning electron microscope (SEM) analysis, and each of the apparatuses may comprise: at least one first milling machine for irradiating a first surface of a target with a first beam so as to mill the first surface; and at least one second milling machine for irradiating a second surface, which is the opposite surface to the first surface of the target, with a second beam so as to mill the second surface.

However, the conventional ion milling apparatus has the following problems.

In a case where the sample <NUM> is irradiated with the ion beam <NUM> via the shielding member <NUM> as described above, the current density of the ion beam <NUM> that determines a processing rate decreases as the ion beam <NUM> goes away from the ion source. That is, the longer a distance from the ion source is, the lower the processing rate is. The distance from the ion source increases as the ion beam <NUM> goes away from the shielding member <NUM> in the thickness direction of the sample <NUM>, that is, as the ion beam <NUM> goes toward the lower parts of <FIG>. Therefore, when a processing rate on an upper surface side of the sample <NUM> close to the shielding member <NUM> is compared with a processing rate on a lower surface side of the sample <NUM> far from the shielding member <NUM>, the processing rate is lower on the lower surface side of the sample <NUM> than on the upper surface side. As a result, as illustrated in <FIG>, a cross section 200b of the sample <NUM> has a shape gently inclined from the upper surface side of the sample <NUM> toward the lower surface side thereof. In addition, the inclination of the cross section 200b of the sample <NUM> appears more remarkably as the thickness dimension of the sample <NUM> increases.

Therefore, for example, as illustrated in <FIG>, in a case where a processing target of the sample <NUM> is a through-hole <NUM>, the following problems occur even if an ion beam is emitted with the edge portion 220a of the shielding member <NUM> accurately aligned with the center of the through-hole <NUM>. When the cross section of the sample <NUM> processed by the irradiation of the ion beam is inclined as illustrated by a wavy line in the figure, a part 300a of the through-hole <NUM> remains without being subjected to cross-section processing on the lower surface side of the sample <NUM>. As a result, as illustrated in <FIG>, the part 300a of the through-hole <NUM> does not appear in the cross section 200b of the sample <NUM> and cannot be observed. In addition, in order to eliminate the inclination of the cross section 200b of the sample <NUM>, it is necessary to continue to irradiate the lower surface side of the sample <NUM> with an ion beam having a low current density, which increases processing time.

An object of the present invention is to provide an ion milling apparatus and a method of manufacturing a sample that are capable of efficiently manufacturing a sample having a cross section whose inclination is reduced.

An ion milling apparatus according to the present invention includes a pair of shielding members that sandwich a sample, an ion source that irradiates the sample with an ion beam,a sample holder having the pair of shielding members, a sample stage to and from which the sample holder is attachable and detachable and a rotation mechanism configured to rotate the sample holder. The ion milling apparatus is configured to be capable of irradiating the sample with the ion beam in a first mode and a second mode. The first mode is a mode of irradiating the sample with the ion beam via one shielding member of the pair of shielding members. The second mode is a mode of irradiating the sample with the ion beam via the other shielding member. The ion milling apparatus is further configured to be switchable between the first mode and the second mode by rotating the sample holder by the rotation mechanism.

A method of manufacturing a sample with the aforementioned ion milling apparatus according to the present invention includes a first processing step of sandwiching the sample between the pair of shielding members and irradiating the sample with the ion beam via one of the shielding members and a second processing step of irradiating the sample with the ion beam via the other shielding member. The ion milling apparatus is further configured to be switchable between the first mode and the second mode by rotating the sample holder by the rotation mechanism.

According to the present invention, it is possible to efficiently manufacture a sample having a cross section whose inclination is reduced.

In the present specification and the drawings, elements having substantially the same function or configuration will be denoted by the same reference numerals, and redundant description will be omitted.

<FIG> is a schematic diagram illustrating a configuration example of an ion milling apparatus <NUM> according to a first embodiment of the present invention.

The ion milling apparatus <NUM> illustrated in <FIG> is used, for example, for manufacturing a sample to be observed with a scanning electron microscope or a transmission electron microscope, or for manufacturing a sample to be analyzed with an electron probe microanalyzer, an auger microscope, or the like. The ion milling apparatus <NUM> is an apparatus that irradiates a sample <NUM> that is an object to be processed with an ion beam <NUM> to process the sample <NUM> into a shape suitable for observation with a scanning electron microscope or a transmission electron microscope. The sample <NUM> is formed in a flat plate shape.

As illustrated in <FIG>, the ion milling apparatus <NUM> includes a vacuum chamber <NUM>, a sample stage pull-out mechanism <NUM>, an ion source <NUM>, a sample stage <NUM>, a rotation mechanism <NUM>, an evacuation unit <NUM>, an evacuation control unit <NUM>, a camera <NUM>, a control unit <NUM>, a voltage power supply <NUM>, a rotation drive unit <NUM>, and a display unit <NUM>. The control unit <NUM> includes an ion source control unit 23a and a rotation control unit 23b.

The vacuum chamber <NUM> is a hollow chamber. The evacuation unit <NUM> is connected to the vacuum chamber <NUM>. Driving of the evacuation unit <NUM> is controlled by the evacuation control unit <NUM>. The evacuation unit <NUM> is driven under the control of the evacuation control unit <NUM> to discharge air in the vacuum chamber <NUM>.

The sample stage pull-out mechanism <NUM> is a mechanism for pulling out the sample stage <NUM> from the vacuum chamber <NUM>. The sample stage pull-out mechanism <NUM> is attached to the vacuum chamber <NUM> so that the sample stage pull-out mechanism <NUM> is openable and closable so as to close an opening of the vacuum chamber <NUM>. The sample stage <NUM> and the rotation mechanism <NUM> are attached to the sample stage pull-out mechanism <NUM>.

In a state in which the sample stage pull-out mechanism <NUM> closed, the sample stage <NUM> is accommodated in the vacuum chamber <NUM>. In addition, in a state in which the sample stage pull-out mechanism <NUM> is opened, the rotation mechanism <NUM> is arranged while being pulled out to the outside of the vacuum chamber <NUM>. The open and close states of the sample stage pull-out mechanism <NUM> are switchable by moving the sample stage pull-out mechanism <NUM> with respect to the vacuum chamber <NUM> in a left-right direction in <FIG>. The sample stage <NUM> is a stage that supports the sample <NUM> via the sample holder <NUM>. The sample holder <NUM> is a holder that supports the sample <NUM>. The sample holder <NUM> includes a holder body <NUM> that serve as a base and a shielding member <NUM>. The sample holder <NUM> is attachable and detachable to and from the sample stage <NUM>. The shielding member <NUM> is a member that shields the sample <NUM>. The shielding member <NUM> is formed in a plate shape.

The rotation mechanism <NUM> is a mechanism that rotates the sample holder <NUM> via the sample stage <NUM>. A rotation axis 19a of the rotation mechanism <NUM> is arranged in a direction orthogonal to a central axis <NUM> of the ion beam <NUM> and parallel to a direction (Y direction in the figures) in which the sample <NUM> protrudes from the shielding member <NUM>. The rotation mechanism <NUM> rotates the sample holder <NUM> according to the driving of the rotation drive unit <NUM>. At this time, the sample holder <NUM> rotates about the rotation axis 19a of the rotation mechanism <NUM>. The rotation control unit 23b controls the rotation of the sample holder <NUM> via the rotation drive unit <NUM>. The rotation mechanism <NUM> may be a mechanism that rotates the sample holder <NUM> integrally with the sample stage <NUM>, or may be a mechanism that rotates the sample holder <NUM> separately from the sample stage <NUM>.

The ion source <NUM> is arranged in an upper portion of the vacuum chamber <NUM>, that is, in a ceiling portion. The ion source <NUM> is a portion that emits the ion beam <NUM>. The ion source <NUM> includes, for example, a gas ion gun. The gas ion gun is an ion gun that emits an ion beam by ionizing argon gas by discharge. The ion source <NUM> emits the ion beam <NUM> vertically downward toward the internal space of the vacuum chamber <NUM>.

In the following description, one direction of biaxial directions orthogonal to the central axis <NUM> of the ion beam <NUM> is defined as an X direction and the other direction is defined as a Y direction. In addition, a direction parallel to the central axis <NUM> of the ion beam <NUM> and orthogonal to the X direction and the Y direction is defined as a Z direction. In the first embodiment of the present invention, the X direction and the Y direction are horizontal biaxial directions, and the Z direction is a vertical direction (up-down direction). In addition, the central axis <NUM> of the ion beam <NUM> is an axis parallel to the vertical direction.

The voltage power supply <NUM> is electrically connected to the ion source <NUM>. The voltage power supply <NUM> is a power supply that applies a voltage to the ion source <NUM>. The voltage power supply <NUM> applies a voltage to the ion source <NUM> under the control of the ion source control unit 23a, whereby the ion beam <NUM> is emitted from the ion source <NUM>. The ion source control unit 23a controls the ion source <NUM> via the voltage power supply <NUM>.

The camera <NUM> is provided so as to be rotatable by a camera rotation mechanism <NUM>. The camera rotation mechanism <NUM> is attached to an upper portion of the sample stage pull-out mechanism <NUM> and moves integrally with the sample stage pull-out mechanism <NUM>. The camera <NUM> can be arranged at a first position and a second position by the rotation of the camera rotation mechanism <NUM>. The first position is a position where an optical axis of the camera <NUM> is arranged parallel to the Z direction. When the camera <NUM> is arranged at the first position, the optical axis of the camera <NUM> is arranged so as to pass through a processing position of the sample <NUM>. As illustrated in <FIG>, the second position is a position where the camera <NUM> is arranged to be greatly inclined with respect to the Z direction.

The camera <NUM> photographs the sample <NUM> supported by the sample holder <NUM> and the shielding member <NUM>. For this photographing, an optical microscope may be used instead of the camera <NUM>. The display unit <NUM> displays an image captured by the camera <NUM>. The display unit <NUM> includes a monitor (display) or a touch panel.

<FIG> is an enlarged diagram of a main part of the ion milling apparatus <NUM> according to the first embodiment of the present invention. As illustrated in <FIG>, the sample holder <NUM> includes a pair of shielding members <NUM> (29a and 29b) sandwiching the sample <NUM>. The reason why the sample holder <NUM> is provided with the pair of shielding members <NUM> is to enable the sample <NUM> to be processed from either an upper side or a lower side. The ion milling apparatus <NUM> according to the first embodiment of the present invention has a configuration in which an orientation of the sample holder <NUM> supporting the sample <NUM> can be vertically inverted, or a configuration in which the attachment position of the ion source <NUM> in the vacuum chamber <NUM> can be vertically inverted. In the following description, the shielding member <NUM> arranged on the upper side in <FIG> is referred to as a first shielding member 29a, and the shielding member <NUM> arranged on the lower side is referred to as a second shielding member 29b.

A distal end surface 31a of the first shielding member 29a is slightly inclined with respect to the central axis <NUM> of the ion beam <NUM>, and the distal end surface 32a of the second shielding member 29b is also slightly inclined with respect to the central axis <NUM> of the ion beam <NUM>. The inclination of the distal end surface 31a is to enable an edge portion 31b of the first shielding member 29a and a protruding amount of the sample <NUM> from the edge portion 31b to be observed by the camera <NUM>. Similarly, the inclination of the distal end surface 32a is to enable an edge portion 32b of the second shielding member 29b and a protruding amount of the sample <NUM> from the edge portion 32b to be observed by the camera <NUM>.

The first shielding member 29a is fixed to a first holder body 28a by a screw <NUM>. The second shielding member 29b is fixed to the second holder body 28b by a screw <NUM>. The holder body <NUM> includes the first holder body 28a and the second holder body 28b. The rear end portion of each of the first holder body 28a and the second holder body 28b can be mounted on the sample stage <NUM> from either an up or down direction by, for example, a dovetail groove type coupling structure.

Note that a means for fixing the first shielding member 29a to the first holder body 28a is not limited to the screw <NUM> described above. For example, a magnet may be used, or a plate spring, a pin, or the like may be used. In a case where the first shielding member 29a is fixed to the first holder body 28a with a magnet, one of the first holder body 28a and the first shielding member 29a includes a magnetic material, the magnet is embedded in the other, and the first shielding member 29a is fixed to the first holder body 28a by magnetic attraction force generated between the magnetic material and the magnet. In addition, in a case where a leaf spring, a pin, or the like is used, the first holder body 28a and the first shielding member 29a are sandwiched by the leaf spring, the pin, or the like, whereby the first shielding member 29a is fixed to the first holder body 28a. The points described above similarly apply to a means for fixing the second shielding member 29b to the second holder body 28b.

Subsequently, procedures in the case of processing the sample using the ion milling apparatus <NUM> according to the first embodiment of the present invention will be described. The procedures to be described below include a method of manufacturing a sample.

First, as illustrated in <FIG>, the sample <NUM> is set in the sample holder <NUM>. In the first embodiment of the present invention, the sample <NUM> is sandwiched by the pair of shielding members <NUM> (29a and 29b) included in the sample holder <NUM>, whereby the sample <NUM> is supported. At this time, the sample <NUM> is sandwiched by the pair of shielding members <NUM> so that the edge portion 31b of the first shielding member 29a and the edge portion 32b of the second shielding member 29b are at the same position in the Y direction, that is, flush with each other. The sample <NUM> is arranged to protrude from each of the edge portions 31b of the first shielding member 29a and the edge portion 32b of the second shielding member 29b by a predetermined amount. The protruding amount of the sample <NUM> is defined on the basis of each of the edge portions 31b of the first shielding member 29a and the edge portion 32b of the second shielding member 29b. Although the protruding amount of the sample <NUM> depends on the position of a processing target, the protruding amount of the sample <NUM> is often set within a range of <NUM> or more and <NUM> or less.

After the sample <NUM> is set in the sample holder <NUM> as described above, the sample holder <NUM> is mounted on the sample stage <NUM>. The sample holder <NUM> is mounted with the sample stage <NUM> pulled out to the outside of the vacuum chamber <NUM> by the sample stage pull-out mechanism <NUM>. At this time, the sample holder <NUM> is mounted on the sample stage <NUM> with the first shielding member 29a on the upper side and the second shielding member 29b on the lower side. In addition, the protruding amount of the sample <NUM> is confirmed using a photographed image of the camera <NUM>. In a case where the protruding amount of the sample <NUM> is confirmed, the camera <NUM> is arranged at the first position by the rotation of the camera rotation mechanism <NUM>, and in this state, the photographed image of the camera <NUM> is displayed on the display unit <NUM>. As a result, an operator of the ion milling apparatus <NUM> can confirm the protruding amount of the sample <NUM> using the photographed image of the camera <NUM> displayed on the display unit <NUM>.

Next, after the camera <NUM> is arranged at the second position by the rotation of the camera rotation mechanism <NUM>, the sample stage <NUM> is pushed into the vacuum chamber <NUM> by the sample stage pull-out mechanism <NUM>, whereby the sample stage <NUM> is accommodated in the vacuum chamber <NUM>. At this time, the sample holder <NUM> and the sample <NUM> are accommodated in the vacuum chamber <NUM> together with the sample stage <NUM>. At this stage, as illustrated in <FIG>, a through-hole <NUM> formed in the sample <NUM> is not exposed to the outside. The through-hole <NUM> serves as a target when the sample <NUM> after processing by the ion milling apparatus <NUM> is observed with an electron microscope. Therefore, the ion milling apparatus <NUM> needs to process the sample <NUM> so that the through-hole <NUM> of the sample <NUM> is set as the processing target and the entire through-hole <NUM> is exposed to the outside.

In the first embodiment of the present invention, the sample <NUM> is processed by a first processing step and a second processing step. The first processing step is a step of processing the sample <NUM> in a first mode of irradiating the sample <NUM> with the ion beam <NUM> via the first shielding member 29a. The second processing step is a step of processing the sample <NUM> in a second mode of irradiating the sample <NUM> with the ion beam <NUM> via the second shielding member 29b. In both the first processing step and the second processing step, the evacuation unit <NUM> evacuates the air in the vacuum chamber <NUM> according to a control command from the evacuation control unit <NUM>, whereby the sample <NUM> is processed in a state in which the inside of the vacuum chamber <NUM> is maintained at a predetermined degree of vacuum.

In the first processing step, the sample <NUM> is irradiated with the ion beam <NUM> via the first shielding member 29a by emitting the ion beam <NUM> from the ion source <NUM> in a state illustrated in <FIG>. At this time, the ion source <NUM> emits the ion beam <NUM> when the voltage power supply <NUM> receives a control command from the ion source control unit 23a and applies a voltage to the ion source <NUM>. As a result, the sample <NUM> is etched by irradiation with the ion beam <NUM> as illustrated in <FIG>. At this time, the sample <NUM> is etched more (faster) on an upstream side where a current density is high in an irradiation direction of the ion beam <NUM>, that is, the upper side than the lower side. Therefore, in the first embodiment of the present invention, the first processing step ends in a stage in which a cross section <NUM> including the through-hole <NUM> appears in the sample <NUM> due to the irradiation of the ion beam <NUM> described above, as illustrated in <FIG> and a part 13a of the through-hole <NUM> remains without being subjected to cross-section processing. At this stage, as illustrated in <FIG>, part of the sample <NUM> protruding from the edge portion 31b of the first shielding member 29a remains as a protrusion 11a, and the lower side of the cross section <NUM> of the sample <NUM> is inclined.

Next, the inside of the vacuum chamber <NUM> is returned to a normal temperature and normal pressure state, and the sample stage <NUM> is pulled out to the outside of the vacuum chamber <NUM> by the sample stage pull-out mechanism <NUM>. Next, after the sample holder <NUM> is removed from the sample stage <NUM>, the orientation of the sample holder <NUM> is changed. Specifically, as illustrated in <FIG>, the orientation of the sample holder <NUM> is vertically inverted, and the sample holder <NUM> is mounted on the sample stage <NUM>. Next, the sample stage <NUM> is pushed into the vacuum chamber <NUM> by the sample stage pull-out mechanism <NUM>, whereby the sample stage <NUM> is accommodated in the vacuum chamber <NUM>. As a result, the sample <NUM> and the sample holder <NUM> are accommodated in the vacuum chamber <NUM> together with the sample stage <NUM>. In addition, as illustrated in <FIG>, the sample <NUM> is arranged in an orientation in which the part 13a of the through-hole <NUM> is located on the upper side. In addition, as illustrated in <FIG>, the protrusion 11a of the sample <NUM>, which is a processing residue in the first processing step, is arranged on the upper side by vertically inverting the sample holder <NUM> described above.

In the second processing step, the sample <NUM> is irradiated with the ion beam <NUM> via the second shielding member 29b by emitting the ion beam <NUM> from the ion source <NUM> in a state illustrated in <FIG>. As a result, the sample <NUM> is etched by irradiation with the ion beam <NUM> as illustrated in <FIG>. At this time, the protrusion 11a (see <FIG>) of the sample <NUM> is arranged on the upstream side where the current density is high in the irradiation direction of the ion beam <NUM>, that is, on the upper side. Therefore, the protrusion 11a of the sample <NUM> is efficiently etched by irradiation with the ion beam <NUM>. In the first embodiment of the present invention, the second processing step ends in a stage in which the entire through-hole <NUM> appears in the cross section <NUM> of the sample <NUM> due to the irradiation of the ion beam <NUM> described above, as illustrated in <FIG> and the inclination of the cross section <NUM> is reduced to be sufficiently small.

As described above, the ion milling apparatus <NUM> according to the first embodiment of the present invention includes the pair of shielding members <NUM> sandwiching the sample <NUM>. Then, in the first processing step, the sample <NUM> is irradiated with the ion beam <NUM> via the first shielding member 29a, and in the second processing step, the sample <NUM> is irradiated with the ion beam <NUM> via the second shielding member 29b. As a result, the sample <NUM> can be processed by irradiating the sample <NUM> with the ion beam <NUM> from one side and the other side in the Z direction. That is, the sample <NUM> can be processed from both upper and lower surfaces. Therefore, it is possible to efficiently manufacture the sample <NUM> having the cross section <NUM> whose inclination is reduced. In addition, processing time until a desired processed cross section is obtained can be shortened.

The effect of shortening the processing time can be more remarkably obtained, for example, in a case where the through-hole <NUM> of the sample <NUM> having a large thickness dimension is exposed to the outside by cross-section processing using the ion beam <NUM>. Specifically, when the sample <NUM> is irradiated with the ion beam <NUM> from only the one side in the Z direction, the processing rate decreases due to a decrease in the current density of the ion beam <NUM> on the downstream side of the ion beam <NUM> where a distance from the ion source <NUM> increases, and the processing time until a desired processed cross section is obtained increases. In contrast, when the sample <NUM> is irradiated with the ion beam <NUM> from the one side and the other side in the Z direction, the sample <NUM> can be processed in a state in which the current density of the ion beam <NUM> is high, that is, at a high processing rate. Therefore, the processing time until a desired processed cross section is obtained can be shortened as compared with a case where the ion beam <NUM> is irradiated only from the one side in the Z direction.

Note that in the first embodiment, first, the sample <NUM> is irradiated with the ion beam <NUM> via the first shielding member 29a, and then the sample <NUM> is irradiated with the ion beam <NUM> via the second shielding member 29b. However, the present invention is not limited thereto, and the processing order may be reversed. Specifically, first, the sample <NUM> may be irradiated with the ion beam <NUM> via the second shielding member 29b, and then the sample <NUM> may be irradiated with the ion beam <NUM> via the first shielding member 29a.

In addition, in the first embodiment, after the first processing step ends and before the second processing step starts, the orientation of the sample holder <NUM> attached to the sample stage <NUM> is vertically inverted. However, the present invention is not limited thereto, and the position of the ion source <NUM> may be vertically inverted instead of vertically inverting the orientation of the sample holder <NUM>.

In addition, in the first embodiment, in a case where the sample <NUM> is irradiated with the ion beam <NUM> via the first shielding member 29a, the sample <NUM> may be inclined by the rotation mechanism <NUM>. This point similarly applies to a case where the sample <NUM> is irradiated with the ion beam <NUM> via the second shielding member 29b. By performing such an inclination operation in the first processing step and the second processing step, it is possible to remove processing streaks generated in an ion beam irradiation direction and expand a range of the ion beam <NUM> with which the sample <NUM> is irradiated, that is, a processing range. In addition, in the case of performing the inclination operation described above, it is preferable that the sample stage <NUM> has a eucentric function so that the upper surface of the sample <NUM> arranged vertically upward becomes the eucentric center.

An ion milling apparatus <NUM> according to the second embodiment of the present invention is configured to be switchable between a first mode and a second mode described above by rotating a sample holder <NUM> by a rotation mechanism <NUM>.

<FIG> is an enlarged diagram of a main part of the ion milling apparatus <NUM> according to the second embodiment of the present invention.

As illustrated in <FIG>, the sample holder <NUM> includes a pair of shielding members <NUM> (29a and 29b) sandwiching a sample <NUM>, and a pair of holder bodies <NUM> (28a and 28b) supporting the sample <NUM> via the pair of shielding members <NUM>. The pair of holder bodies <NUM> is attached to a rotating body <NUM>. Therefore, the sample <NUM>, the pair of shielding members <NUM>, and the pair of holder bodies <NUM> rotate integrally with the rotating body <NUM>. The rotating body <NUM> is one of elements constituting the rotation mechanism <NUM> described above. The rotation mechanism <NUM> is capable of rotating the sample holder <NUM> by <NUM>°. However, in order to switch between the first mode and the second mode by the rotation of the sample holder <NUM>, the rotation mechanism <NUM> only needs to be capable of rotating the sample holder <NUM> by <NUM>°. The technical significance of being capable of rotating the sample holder <NUM> by <NUM>° will be described later.

Next, procedures in the case of processing the sample <NUM> using the ion milling apparatus <NUM> according to the second embodiment of the present invention will be described. The procedures to be described below include a method of manufacturing a sample.

First, as illustrated in <FIG>, the sample <NUM> is sandwiched by the pair of shielding members <NUM> with a first shielding member 29a on an upper side and a second shielding member 29b on a lower side, and in this state, the sample holder <NUM> is mounted on a sample stage <NUM>. Next, after a protruding amount of the sample <NUM> is confirmed using a camera <NUM> and a display unit <NUM>, the sample stage <NUM> is accommodated in a vacuum chamber <NUM>. The procedures described so far are similar to the procedures in the first embodiment described above. The subsequent procedures are automatically performed under the control of an evacuation control unit <NUM> and a control unit <NUM> (ion source control unit 23a and rotation control unit 23b).

Next, the evacuation control unit <NUM> drives an evacuation unit <NUM> to evacuate air in the vacuum chamber <NUM>. In addition, the evacuation control unit <NUM> maintains the inside of the vacuum chamber <NUM> at a predetermined degree of vacuum until the processing of the sample <NUM> ends.

Next, the control unit <NUM> processes the sample <NUM> by irradiating the sample <NUM> with an ion beam <NUM> while the sample holder <NUM> is rotated. The rotation of the sample holder <NUM> is performed by a rotation drive unit <NUM> driving the rotation mechanism <NUM> according to a control command from the rotation control unit 23b. The irradiation of the ion beam <NUM> is performed by a voltage power supply <NUM> applying a voltage to the ion source <NUM> according to a control command from the ion source control unit 23a.

<FIG> are time-series diagrams illustrating how the sample <NUM> is processed using the ion milling apparatus <NUM> according to the second embodiment of the present invention. <FIG> illustrates a state in which a rotation angle of the sample <NUM> is <NUM>°, and <FIG> illustrates a state in which the rotation angle of the sample <NUM> is <NUM>°. <FIG> illustrates a state in which the rotation angle of the sample <NUM> is <NUM>°, and <FIG> illustrates a state in which the rotation angle of the sample <NUM> is <NUM>°. <FIG> illustrates a state in which the rotation angle of the sample <NUM> is <NUM>°, and <FIG> illustrates a state in which the rotation angle of the sample <NUM> is <NUM>°. <FIG> illustrates a state in which the rotation angle of the sample <NUM> is <NUM>°, and <FIG> illustrates a state in which the rotation angle of the sample <NUM> is <NUM>°. Note that a state in which the rotation angle of the sample <NUM> is <NUM>° is the same as the state in which the rotation angle of the sample <NUM> is <NUM>°.

First, as illustrated in <FIG>, the control unit <NUM> irradiates the sample <NUM> with the ion beam <NUM> from the ion source <NUM> in a state in which the first shielding member 29a is arranged on the upper side and the second shielding member 29b is arranged on the lower side. At this point, each of the first shielding member 29a and the second shielding member 29b is arranged parallel to a horizontal plane. In addition, the sample <NUM> is irradiated with the ion beam <NUM> via the first shielding member 29a, and the sample <NUM> is arranged vertically without being inclined with respect to a central axis <NUM> of the ion beam <NUM>.

Next, as illustrated in <FIG>, the control unit <NUM> rotates the sample <NUM> integrally with the pair of shielding members <NUM> (29a and 29b) while the sample <NUM> is irradiated with the ion beam <NUM> from the ion source <NUM>. At this time, the sample <NUM> is irradiated with the ion beam <NUM> via the first shielding member 29a. In addition, the sample <NUM> is arranged to be inclined downward to the right in the figure with respect to the central axis <NUM> of the ion beam <NUM>. The sample <NUM> is rotated by the rotation mechanism <NUM>. At this time, the rotation mechanism <NUM> rotates the sample <NUM> together with the rotating body <NUM>. A processing position 11b of the sample <NUM> is arranged on the central axis <NUM> of the ion beam <NUM>. Note that in <FIG>, the sample <NUM> is rotated in a clockwise direction in the figure, but the rotation direction of the sample <NUM> may be a counterclockwise direction.

Next, as illustrated in <FIG>, the control unit <NUM> stops the irradiation of the sample <NUM> with the ion beam <NUM> from the ion source <NUM>. The irradiation of the ion beam <NUM> is stopped when the voltage is not applied from the voltage power supply <NUM> to the ion source <NUM>. A timing of stopping the irradiation of the ion beam <NUM> is controlled by the ion source control unit 23a. Specifically, the ion source control unit 23a controls the voltage power supply <NUM> to stop the irradiation of the ion beam <NUM> at a timing at which the ion beam <NUM> emitted from the ion source <NUM> cannot be shielded by the shielding member <NUM> (29a) or a timing before the timing is reached (more preferably, immediately before the timing is reached). The timing at which the ion beam <NUM> cannot be shielded by the shielding member <NUM> refers to a timing at which the sample <NUM> is irradiated directly with the ion beam <NUM> emitted from the ion source <NUM>.

By stopping the irradiation of the ion beam <NUM> as described above, the processing of a side surface 11c of the sample <NUM> can be reduced.

Next, as illustrated in <FIG>, the control unit <NUM> restarts the irradiation of the sample <NUM> with the ion beam <NUM> from the ion source <NUM>. At this time, the sample <NUM> is irradiated with the ion beam <NUM> via the second shielding member 29b. In addition, the sample <NUM> is arranged to be inclined upward in the figure with respect to the central axis <NUM> of the ion beam <NUM>. A timing of restarting the irradiation of the ion beam <NUM> is controlled by the ion source control unit 23a. Specifically, the ion source control unit 23a controls the voltage power supply <NUM> to restart the irradiation of the ion beam <NUM> at a timing at which the ion beam <NUM> emitted from the ion source <NUM> can be shielded by the shielding member <NUM> (29b) or a timing after the timing is reached (more preferably, immediately after the timing is reached). The timing at which the ion beam <NUM> can be shielded by the shielding member <NUM> refers to a timing at which the sample <NUM> is not irradiated directly with the ion beam <NUM> emitted from the ion source <NUM>.

By restarting the irradiation of the ion beam <NUM> as described above, the sample <NUM> can be processed while the side surface 11c of the sample <NUM> is avoided.

Next, as illustrated in <FIG>, the control unit <NUM> rotates the sample <NUM> integrally with the pair of shielding members <NUM> (29a and 29b) while the sample <NUM> is irradiated with the ion beam <NUM> from the ion source <NUM>. At this point, each of the first shielding member 29a and the second shielding member 29b is arranged while being parallel to the horizontal plane, the second shielding member 29b is arranged on the upper side, and the first shielding member 29a is arranged on the lower side. That is, at a time point of <FIG> and a time point of <FIG>, a positional relationship between the pair of shielding members <NUM> (29a and 29b) is reversed upside down. In addition, at the time point of <FIG>, the sample <NUM> is irradiated with the ion beam <NUM> via the second shielding member 29b, and the sample <NUM> is arranged vertically without being inclined with respect to the central axis <NUM> of the ion beam <NUM>.

Next, as illustrated in <FIG>, the control unit <NUM> rotates the sample <NUM> integrally with the pair of shielding members <NUM> (29a and 29b) while the sample <NUM> is irradiated with the ion beam <NUM> from the ion source <NUM>. At this time, the sample <NUM> is irradiated with the ion beam <NUM> via the second shielding member 29b. In addition, the sample <NUM> is arranged to be inclined downward to the right in the figure with respect to the central axis <NUM> of the ion beam <NUM>.

Next, as illustrated in <FIG>, the control unit <NUM> stops the irradiation of the sample <NUM> with the ion beam <NUM> from the ion source <NUM>. A timing of stopping the irradiation of the ion beam <NUM> is as described above.

Next, as illustrated in <FIG>, the control unit <NUM> restarts the irradiation of the sample <NUM> with the ion beam <NUM> from the ion source <NUM>. At this time, the sample <NUM> is irradiated with the ion beam <NUM> via the first shielding member 29a. In addition, the sample <NUM> is arranged to be inclined upward in the figure with respect to the central axis <NUM> of the ion beam <NUM>. A timing of restarting the irradiation of the ion beam <NUM> is as described above.

Thereafter, as illustrated in <FIG>, the control unit <NUM> rotates the sample <NUM> in a state in which the first shielding member 29a is arranged on the upper side and the second shielding member 29b is arranged on the lower side, that is, until the rotation angle of the sample <NUM> reaches <NUM>°. In addition, the control unit <NUM> continues a rotation operation of the sample <NUM> until a sample cross section is formed, and stops the rotation of the sample <NUM> and stops the irradiation of the ion beam <NUM> when the sample cross section is created.

As described above, the ion milling apparatus <NUM> according to the second embodiment of the present invention has a first processing mode and a second processing mode. The first processing mode is a mode of irradiating the sample <NUM> with the ion beam <NUM> via the first shielding member 29a by rotating the sample <NUM> sandwiched by the pair of shielding members <NUM> together with the rotating body <NUM>. The second processing mode is a mode of irradiating the sample <NUM> with the ion beam <NUM> via the second shielding member 29b by rotating the sample <NUM> sandwiched by the pair of shielding members <NUM> together with the rotating body <NUM>. As a result, the sample <NUM> can be processed from both upper and lower surfaces. Therefore, it is possible to efficiently manufacture the sample <NUM> having a cross section whose inclination is reduced, and it is possible to shorten processing time until a desired processed cross section is obtained.

In addition, in the second embodiment of the present invention, the sample <NUM> is processed by irradiating the sample <NUM> with the ion beam <NUM> while the sample <NUM> is rotated integrally with the sample holder <NUM> and the rotating body <NUM>. Thus, it is possible to cancel processing streaks generated by the irradiation of the ion beam <NUM>. Thus, the sample <NUM> having a cross section with few processing streaks can be manufactured. In addition, by rotating the sample holder <NUM> supporting the sample <NUM> by <NUM>°, the processing streaks can be canceled without unevenness.

In addition, in the first embodiment described above, it is necessary to change an orientation when the sample holder <NUM> is mounted on the sample stage <NUM> in order to vertically invert the positional relationship between the pair of shielding members <NUM>. Therefore, it is necessary to provide a processing interruption step between the first processing step and the second processing step. The processing interruption step is to return the inside of the vacuum chamber <NUM> to a normal temperature and normal pressure state or to change the orientation of the sample holder <NUM> by pulling out the sample stage <NUM> from the vacuum chamber <NUM>. In contrast, in the second embodiment, the rotation mechanism <NUM> rotates the sample holder <NUM>, whereby the positional relationship between the pair of shielding members <NUM> can be vertically inverted. Therefore, in the second embodiment, after the vacuum chamber <NUM> is set to a predetermined degree of vacuum, the processing of the sample <NUM> can be continued without providing the processing interruption step described above. Therefore, according to the second embodiment, the processing of the sample <NUM> can end in a shorter time than in the first embodiment.

Note that in the second embodiment, the application of the voltage from the voltage power supply <NUM> to the ion source <NUM> is stopped, whereby the irradiation of the sample <NUM> with the ion beam <NUM> is stopped, but the present invention is not limited thereto. For example, the irradiation of the sample <NUM> with the ion beam <NUM> may be stopped by blocking the ion beam <NUM> emitted from the ion beam <NUM> with a shutter (not illustrated) arranged on an upstream side of the sample holder <NUM> while the application of the voltage from the voltage power supply <NUM> to the ion source <NUM> is continued.

In addition, in the second embodiment, the rotation control unit 23b may rotate the sample <NUM> integrally with the sample holder <NUM> by <NUM>° at a constant speed by controlling the rotation of the sample holder <NUM> via the rotation drive unit <NUM>, or may change the rotation speed of the sample holder <NUM> in the middle. For example, in a period in which the sample <NUM> is rotated by <NUM>°, the rotation control unit 23b may variably control the rotation speed of the sample holder <NUM> so that the sample <NUM> is rotated at a first speed during a period in which the sample <NUM> is irradiated with the ion beam <NUM> and the sample <NUM> is rotated at a second speed higher than the first speed during a period in which the sample <NUM> is not irradiated with the ion beam <NUM>. By variably controlling the rotation speed of the sample holder <NUM> in this manner, it is possible to shorten time that does not contribute to processing of the sample <NUM> as compared with a case where the rotation speed of the sample holder <NUM> is controlled at a constant speed. Therefore, the sample <NUM> can be efficiently processed.

In addition, the rotation control unit 23b may control the rotation of the sample holder <NUM> so that a first inclination operation and a second inclination operation are repeated at least once, preferably a plurality of times. The first inclination operation is an operation in which a state changes from a state illustrated in <FIG>, through a state illustrated in <FIG>, and to a state illustrated in <FIG>. The second inclination operation is an operation that is opposite to the first inclination operation and in which a state changes from the state illustrated in <FIG>, through the state illustrated in <FIG>, and to the state illustrated in <FIG>. Similarly, the rotation control unit 23b may control the rotation of the sample holder <NUM> so that a first tilting operation and a second inclination operation are repeated at least once, preferably a plurality of times. The first inclination operation is an operation in which a state changes from a state illustrated in <FIG>, through a state illustrated in <FIG>, and to a state illustrated in <FIG>. The second inclination operation is an operation that is opposite to the first inclination operation and in which a state changes from the state illustrated in <FIG>, through the state illustrated in <FIG>, and to the state illustrated in <FIG>. By controlling the rotation of the sample holder <NUM> in this manner, it is possible to expand a range of the ion beam <NUM> with which the sample <NUM> is irradiated, that is, a processing range can be expanded. In addition, in a case where the first inclination operation and the second inclination operation described above are performed, it is preferable that the sample stage <NUM> has a eucentric function so that the upper surface of the sample <NUM> arranged vertically upward becomes the.

Next, an alternative which is not part of the claimed invention will be described.

A configuration of an ion milling apparatus <NUM> according to the alternative which is not part of the claimed invention is in common with the configuration of the ion milling apparatus <NUM> in the first embodiment described above in that a sample <NUM> is sandwiched and supported by a pair of shielding members <NUM>. However, the configuration of the ion milling apparatus according to the alternative which is not part of the claimed invention is different from the configuration of the first embodiment in the number of ion sources <NUM>. Specifically, as illustrated in <FIG>, the ion milling apparatus <NUM> according to the alternative which is not part of the claimed invention includes a first ion source 17a and a second ion source 17b.

The first ion source 17a and the second ion source 17b are arranged to face each other on the same axis passing through a processing position 11b of the sample <NUM>. The first ion source 17a emits an ion beam <NUM> vertically downward, and the second ion source 17b emits an ion beam <NUM> vertically upward. That is, the first ion source 17a and the second ion source 17b emit the ion beams <NUM> in directions opposite to each other in a vertical direction. In addition, the first ion source 17a irradiates the sample <NUM> with the ion beam <NUM> via a first shielding member 29a, and the second ion source 17b irradiates the sample <NUM> with the ion beam <NUM> via a second shielding member 29b.

In addition, the ion milling apparatus <NUM> according to the alternative which is not part of the claimed invention includes a first shutter 38a and a second shutter 38b. The first shutter 38a is arranged in the vicinity of the first ion source 17a. In addition, the first shutter 38a is arranged between the first ion source 17a and the first shielding member 29a in a Z direction. The second shutter 38b is arranged in the vicinity of the second ion source 17b. In addition, the second shutter 38b is arranged between the second ion source 17b and the second shielding member 29b in the Z direction.

The first shutter 38a is a shutter that blocks an ion beam 12b emitted from the second ion source 17b before the first ion source 17a. The second shutter 38b is a shutter that blocks an ion beam 12a emitted from the first ion source 17a before the second ion source 17b. The first shutter 38a and the second shutter 38b each includes a material that is difficult to be etched even when the material is irradiated with the ion beam <NUM>, for example, titanium.

The first shutter 38a is provided so as to be arrangeable at an opened position illustrated in <FIG> and a closed position illustrated in <FIG>. The second shutter 38b is provided so as to be arrangeable at an opened position illustrated in <FIG> and a closed position illustrated in <FIG>. The arrangements of each of the first shutter 38a and the second shutter 38b are switched by a switching mechanism (not illustrated). The switching mechanism switches the arrangements of each of the first shutter 38a and the second shutter 38b using, for example, a solenoid or a motor as a drive source. In addition, the operation of the switching mechanism is controlled by a control unit <NUM>.

In a case where the first shutter 38a is arranged at the opened position, the passage of the ion beam 12a emitted from the first ion source 17a is allowed by the first shutter 38a. In a case where the first shutter 38a is arranged at the closed position, the passage of the ion beam 12b emitted from the second ion source 17b is blocked by the first shutter 38a.

In a case where the second shutter 38b is arranged at the opened position, the passage of the ion beam 12b emitted from the second ion source 17b is allowed by the second shutter 38b. In a case where the second shutter 38b is arranged at the closed position, the passage of the ion beam 12a emitted from the first ion source 17a is blocked by the second shutter 38b.

Therefore, as illustrated in <FIG>, when the first shutter 38a is arranged at the opened position, the second shutter 38b is arranged at the closed position, and the ion beam 12a is emitted from the first ion source 17a, the sample <NUM> is irradiated with the ion beam 12a via the first shielding member 29a. Therefore, the sample <NUM> is processed from an upper surface side toward a lower surface side. In addition, the ion beam 12a is blocked by the second shutter 38b before the second ion source 17b. Therefore, damage to the second ion source 17b due to the irradiation with the ion beam 12a is reduced. Consequently, the second ion source 17b can be protected from the ion beam 12a.

Meanwhile, as illustrated in <FIG>, when the first shutter 38a is arranged at the closed position, the second shutter 38b is arranged at the opened position, and the ion beam 12b is emitted from the second ion source 17b, the sample <NUM> is irradiated with the ion beam 12b via the second shielding member 29b. Therefore, the sample <NUM> is processed from the lower surface side toward the upper surface side. In addition, the ion beam 12b is blocked by the first shutter 38a before the first ion source 17a. Therefore, damage to the first ion source 17a due to the irradiation with the ion beam 12b is reduced. Consequently, the first ion source 17a can be protected from the ion beam 12b.

Next, procedures in the case of processing the sample <NUM> using the ion milling apparatus <NUM> according to the alternative which is not part of the claimed invention will be described. The procedures to be described below include a method of manufacturing a sample.

First, as illustrated in <FIG>, the sample <NUM> is sandwiched by the pair of shielding members <NUM> with the first shielding member 29a on an upper side and the second shielding member 29b on a lower side, and in this state, the sample holder <NUM> is mounted on a sample stage <NUM>. Next, after a protruding amount of the sample <NUM> is confirmed using a camera <NUM> and a display unit <NUM>, the sample stage <NUM> is accommodated in a vacuum chamber <NUM>. The procedures described so far are similar to the procedures in the first embodiment described above.

Next, by driving the switching mechanism described above, the control unit <NUM> arranges the first shutter 38a at the opened position and arranges the second shutter 38b at the closed position as illustrated in <FIG>. Next, a voltage power supply <NUM> receives a control command from an ion source control unit 23a and applies a voltage to the first ion source 17a. As a result, the first ion source 17a emits the ion beam 12a. The sample <NUM> is irradiated with the ion beam 12a via the first shielding member 29a. Thereafter, when the time of irradiation with the ion beam 12a by the first ion source 17a reaches predetermined time, the voltage power supply <NUM> receives a control command from the ion source control unit 23a and stops applying a voltage to the first ion source 17a. As a result, the first ion source 17a stops emitting the ion beam 12a.

Next, by driving the switching mechanism described above, the control unit <NUM> arranges the first shutter 38a at the closed position and arranges the second shutter 38b at the opened position as illustrated in <FIG>. Next, the voltage power supply <NUM> receives a control command from the ion source control unit 23a and applies a voltage to the second ion source 17b. As a result, the second ion source 17b emits the ion beam 12b. The sample <NUM> is irradiated with the ion beam 12b via the second shielding member 29b. Thereafter, when the time of irradiation with the ion beam 12b by the second ion source 17b reaches predetermined time, the voltage power supply <NUM> receives a control command from the ion source control unit 23a and stops applying the voltage to the second ion source 17b. As a result, the second ion source 17b stops emitting the ion beam 12b.

As described above, in the ion milling apparatus <NUM> according to the alternative which is not part of the claimed invention, the first ion source 17a irradiates the sample <NUM> sandwiched by the pair of shielding members <NUM> with the ion beam 12a via the first shielding member 29a, and the second ion source 17b irradiates the sample with the ion beam 12b via the second shielding member 29b. As a result, the sample <NUM> can be processed from both upper and lower surfaces. Therefore, it is possible to efficiently manufacture the sample <NUM> having a cross section whose inclination is reduced, and it is possible to shorten processing time until a desired processed cross section is obtained.

In addition, in the ion milling apparatus <NUM> according to the alternative which is not part of the claimed invention, optical axes of the first ion source 17a and the second ion source 17b are adjustable, and the first ion source 17a and the second ion source 17b are arranged to face each other on the same axis passing through the processing position 11b of the sample <NUM>. As a result, an irradiation position of the ion beam 12a with which the sample <NUM> is irradiated from the first ion source 17a and an irradiation position of the ion beam 12b with which the sample <NUM> is irradiated from the second ion source 17b can be easily and accurately aligned with each other.

In addition, the ion milling apparatus <NUM> according to the alternative which is not part of the claimed invention includes the first shutter 38a that blocks the ion beam 12b emitted from the second ion source 17b before the first ion source 17a, and the second shutter 38b that blocks the ion beam 12a emitted from the first ion source 17a before the second ion source 17b. Therefore, the sample <NUM> can be processed while each of the first ion source 17a and the second ion source 17b is protected from the ion beam <NUM>.

Note that in the alternative which is not part of the claimed invention, first, the sample <NUM> is irradiated with the ion beam 12a via the first shielding member 29a by emitting the ion beam 12a from the first ion source 17a, and then the sample <NUM> is irradiated with the ion beam 12b via the second shielding member 29b by emitting the ion beam 12b from the second ion source 17b. However, the processing order may be reversed. Specifically, first, the sample <NUM> may be irradiated with the ion beam 12b via the second shielding member 29b by emitting the ion beam 12b from the second ion source 17b, and then the sample <NUM> may be irradiated with the ion beam 12a via the first shielding member 29a by emitting the ion beam 12a from the first ion source 17a.

In addition, in the alternative which is not part of the claimed invention, an example in which the first ion source 17a and the second ion source 17b are arranged on the same axis has been illustrated, but the present invention is not limited thereto, and the first ion source 17a and the second ion source 17b may be arranged on different axes as illustrated in <FIG>. The first ion source 17a is arranged at a position shifted from a central axis of the ion beam 12b so that the first ion source 17a is not irradiated with the ion beam 12b emitted from the second ion source 17b. The second ion source 17b is arranged at a position shifted from a central axis of the ion beam 12a so that the second ion source 17b is not irradiated with the ion beam 12a emitted from the first ion source 17a.

In addition, the first ion source 17a emits the ion beam 12a in an obliquely downward direction having an inclination with respect to a vertical axis (Z direction), and the second ion source 17b emits the ion beam 12b in an obliquely upward direction having an inclination with respect to the vertical axis. The sample <NUM> is irradiated with the ion beam 12a emitted from the first ion source 17a via the first shielding member 29a, and the sample <NUM> is irradiated with the ion beam 12b emitted from the second ion source 17b via the second shielding member 29b. In addition, the central axis of the ion beam 12a emitted from the first ion source 17a and the central axis of the ion beam 12b emitted from the second ion source 17b intersect with each other at the processing position 11b of the sample <NUM>.

Even in a case where the first ion source 17a and the second ion source 17b are arranged as described above, the sample <NUM> can be processed from both the upper and lower surfaces. Therefore, it is possible to efficiently manufacture the sample <NUM> having a cross section whose inclination is reduced, and it is possible to shorten processing time until a desired processed cross section is obtained. In addition, each of the first ion source 17a and the second ion source 17b can be protected from the ion beam <NUM> without providing the first shutter 38a and the second shutter 38b. In addition, by simultaneously emitting the ion beam 12a from the first ion source 17a and the ion beam 12b from the second ion source 17b, processing can be simultaneously performed from the upper surface side and the lower surface side of the sample <NUM>. As a result, it is possible to further shorten the processing time.

Claim 1:
An ion milling apparatus (<NUM>) comprising:
a pair of shielding members (29a and 29b) sandwiching a sample (<NUM>); and
an ion source (<NUM>) configured to irradiate the sample (<NUM>) with an ion beam (<NUM>),
a sample holder (<NUM>) having the pair of shielding members (29a and 29b);
a sample stage (<NUM>) to and from which the sample holder (<NUM>) is attachable and detachable; and
a rotation mechanism (<NUM>) configured to rotate the sample holder (<NUM>),
wherein
the ion milling apparatus (<NUM>) is configured to be capable of irradiating the sample (<NUM>) with the ion beam (<NUM>) in a first mode of irradiating the sample (<NUM>) with the ion beam (<NUM>) via one shielding member (29a) of the pair of shielding members (29a and 29b) and in a second mode of irradiating the sample (<NUM>) with the ion beam (<NUM>) via the other shielding member (29b), and
the ion milling apparatus (<NUM>) is further configured to be switchable between the first mode and the second mode by rotating the sample holder (<NUM>) by the rotation mechanism (<NUM>).