Ion milling device and ion source adjustment method for ion milling device

Abstract

The present invention improves the machining accuracy or the shape reproduction accuracy of an ion milling device that machines a sample by irradiating the sample with a non-focused ion beam. To this end, there are provided a sample chamber (6), an ion source position adjustment mechanism (5) provided in the sample chamber, an ion source (1) that is installed in the sample chamber via the ion source position adjustment mechanism and emits an ion beam, and a sample stage (2) that rotates about a rotation center, wherein if the direction of extension of the rotation center when the ion beam center (B0) of the ion beam and the rotation center (R0) coincide is set as the Z direction and the plane perpendicular to the Z direction is set as the XY plane, the ion source position adjustment mechanism (5) can adjust the position on the XY plane and the position in the Z direction of the ion source (1).

Description

[0001] This invention patent application is a divisional application of the invention patent application with the filing date of February 28, 2018, the entry date into the Chinese national phase of August 24, 2020, the national application number of 201880090114.6 (international application number PCT / JP2018 / 007477), and the invention title of "Ion Milling Apparatus and Ion Source Adjustment Method of Ion Milling Apparatus". Technical Field

[0002] This invention relates to an ion milling apparatus and a method for adjusting the ion source of the ion milling apparatus. Background Technology

[0003] To observe and analyze the internal structure of a sample, it is necessary to expose the desired internal structure on the surface. Previous methods involved cutting and mechanical grinding to prepare samples, but these methods cannot avoid deformation and damage caused by the physical pressure applied to the sample. Ion milling devices irradiate the surface or cross-section of a sample (e.g., metals, semiconductors, glass, ceramics, etc.) with an unfocused argon ion beam accelerated to, for example, several kV, and can use sputtering phenomena to stress-free eject the atomic ions from the sample surface, thus smoothing the sample surface. This is an excellent feature because it allows for smoothing of the sample surface or cross-section for observation using electron microscopes, such as scanning electron microscopes (SEM) and transmission electron microscopes (TEM).

[0004] In ion milling apparatuses, an ion beam irradiation unit that generates an ion beam is installed in a vacuum container to process samples in a vacuum atmosphere. When processing a sample, tiny particles from the sample originating from the processing surface adhere to the ion beam irradiation unit, thus requiring periodic cleaning of the ion milling apparatus. Therefore, the configuration involves removing the ion beam irradiation unit from the vacuum container, reinstalling it after maintenance, but during reinstallation, installation errors may occur, causing the irradiation direction of the ion beam from the ion beam irradiation unit to change from before.

[0005] Patent Document 1 discloses an ion beam irradiation apparatus in which a sample (in this case, a substrate) is held in a substrate holder and reciprocated in a manner that cuts across the irradiation area of ​​the ion beam, and the ion beam irradiation unit irradiates the substrate with an ion beam. To address the aforementioned problem, an ion beam measuring mechanism is provided on the wall of a vacuum container opposite the ion beam irradiation unit to measure the beam current density distribution of the irradiated ion beam. By measuring the center position of the ion beam using the ion beam measuring mechanism, the center position of the reciprocating motion of the substrate is set at the center position of the ion beam or a predetermined position determined based on that position. Therefore, even if an installation error occurs in the ion beam irradiation unit, the uniformity of the ion irradiation amount on the substrate can be guaranteed.

[0006] On the other hand, in recent years, the integration level of semiconductor devices has increased dramatically, and therefore, semiconductor devices that integrate patterns with fine three-dimensional structures in three dimensions are under development. To manage the manufacturing of devices integrating such three-dimensional structures, it is necessary to evaluate the pattern in the cross-sectional direction. Patent Document 2 discloses a technique that, in order to achieve high-precision measurement of the depth (or height) direction of such three-dimensional structures, an inclined surface is formed on the sample surface to measure the depth (height) direction of the pattern.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2017-199554

[0010] Patent Document 2: International Publication No. 2016 / 002341 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] In Patent Document 2, a focused ion beam (FIB) device was used to form an inclined surface on the sample surface to expose the cross-section of a three-dimensional structural pattern. However, the FIB device has a slow processing speed and a narrow processing range, thus consuming a lot of time to form the desired inclined surface on the sample surface. Therefore, the inventors explored forming the inclined surface using an ion milling device that uses a non-focused ion beam with a fast processing speed.

[0013] When using a non-focused ion beam for sample processing, the processing speed depends on the intensity of the ion beam irradiating the sample, specifically the velocity and number of ions applied by the accelerating voltage, and the irradiation angle. Ideally, the intensity of the ion beam emitted from the ion source is considered to have a binomial distribution shape, with the intensity highest at the center of the ion beam and gradually decreasing towards the periphery. However, the ion beam emitted from the ion source is affected by contamination of the electrode components constituting the ion source, fluctuations in the number of ions due to electrode component wear, and interference from environmental electric fields, making it difficult to maintain a constant ion beam intensity irradiating the sample. Furthermore, the difference in milling speed caused by the sample composition and incident angle leads to unevenness formation. Therefore, when processing the sample by irradiating it with a non-focused ion beam, in an ion milling apparatus, the sample is rotated around the ion beam center while being irradiated with the ion beam to suppress unevenness formation and obtain a smooth processed surface suitable for observation and measurement under an electron microscope.

[0014] The subject matter of this invention will be described. Figure 2A The main components of the ion milling apparatus are shown. It includes an ion source 21, a sample stage 22 for mounting the sample 20, and a sample stage rotation drive source 23 that rotates the sample stage 22 about a rotation center R0 along the R direction. An ion beam from the ion source 21 irradiates the sample 20 mounted on the sample mounting surface of the sample stage 22 in a radially expanding manner about the ion beam center B0. Ideally, the rotation center R0 and the ion beam center B0 should be aligned, but sometimes due to installation errors of the ion source 21, such as… Figure 2A The rotation center R0 and the ion beam center B0 shown are in a state deviating from ε. Figure 2B This indicates the processing depth formed on the surface of sample 20 at this point. As shown in waveform 25, the processing depth is deepest at the ion beam center B0, where the ion beam intensity is highest at a position offset from the rotation center R0 from ε. The processing depth decreases as the beam separates from this point. Conversely, the processing depth is represented by waveform 26 when the rotation center R0 and the ion beam center B0 are aligned. Thus, it can be seen that due to the installation error of the ion source 21, the shape of the processed surface is significantly different from the intended processed surface. In extreme cases, such as… Figure 2B As shown in waveform 25, the processed surface fluctuates. In particular, when an observation surface or inclined surface is intentionally formed on the sample for the purpose of observing and measuring fine three-dimensional structural patterns, the change in the shape of such processed surface can be ignored.

[0015] In addition, Figure 2AIn the example, the ion beam is irradiated perpendicularly to the surface of the sample 20 (or the sample mounting surface of the sample stage 22) with the ion beam center B0. However, the sample stage 22 can also be tilted in the C direction to irradiate the surface of the sample 20 with the ion beam at a low incident angle. This allows for the acquisition of a large-scale processed surface. In this case, the ion beam is irradiated onto the sample 20 while the sample stage 22 is rotated about the rotation center R0 in a tilted state. Therefore, if the rotation center R0 and the ion beam center B0 deviate (on the surface of the sample 20, the rotation center R0 and the ion beam center B0 do not intersect), the deviation between the rotation center R0 and the ion beam center B0 will manifest as a change in the shape of the processed surface, resulting in the inability to obtain the desired observation surface or tilted surface.

[0016] In conventional apparatuses where the ion source is directly mounted within the vacuum chamber, periodic cleaning necessitates the ion source's removability, preventing the machining tolerances of the ion source assembly within the sample chamber from being set to zero. Therefore, misalignment during reinstallation of the ion source cannot be avoided. For example, using... Figure 2A As explained in section B, this leads to uneven machining accuracy in the ion milling device and reduces the reproducibility of the machined surface shape.

[0017] Furthermore, regarding the ion beam, the longer the distance from the emission outlet of the ion source, the wider the ion beam diameter, and the lower the current and ion density. Therefore, it can be considered that, in cases where the ion beam measurement position is separated from the actual sample processing position, as in Patent Document 1, the voltage applied to the ion source must be higher than the conditions during actual processing in order to measure the ion beam. However, if the emission conditions of the ion beam are changed, the energy of the ion beam changes, thus changing the milling speed, and also changing the ion density distribution. Furthermore, the magnitude of the influence of the applied interference also changes. Therefore, it is desirable to adjust the position to be the same as the emission conditions during actual processing. Therefore, in order to adjust the position to match the emission conditions during actual processing, sometimes the operator of the ion milling apparatus mounts a processing object such as a copper foil on the sample stage, and then irradiates it with an ion beam under the actual processing conditions, leaving a beam mark on the copper foil, and performs ion source position adjustment in a manner that aligns the beam mark with the rotation center R0. However, such adjustments based on visual or microscopic observation of beam marks have limitations in accuracy, and in most cases require repeated loading and unloading of the ion source for alignment, resulting in poor real-time performance and a heavy adjustment burden on operators.

[0018] In view of this problem, the present invention provides an ion milling apparatus and an ion source adjustment method that can easily and accurately adjust the ion beam center and the sample rotation center after the ion source is loaded and unloaded.

[0019] Solution for solving the problem

[0020] An ion milling apparatus according to one embodiment of the present invention processes a sample by irradiating it with a non-focused ion beam. The ion milling apparatus includes: a sample chamber; an ion source position adjustment mechanism disposed in the sample chamber; an ion source mounted in the sample chamber via the ion source position adjustment mechanism and emitting an ion beam; and a sample stage that rotates about a rotation center. If the direction of extension of the rotation center when the ion beam center and the rotation center coincide is defined as the Z direction, and the surface perpendicular to the Z direction is defined as the XY plane, then the ion source position adjustment mechanism can adjust the position of the ion source on the XY plane and the position in the Z direction.

[0021] Other issues and new features will become clear from the description and accompanying drawings in this specification.

[0022] The effects of the invention

[0023] It can improve the machining accuracy of ion milling equipment, or the accuracy of reproducing the shape of the machined surface. In addition, it can shorten the maintenance time of ion milling equipment. Attached Figure Description

[0024] Figure 1 This is a structural diagram of the main parts of the ion milling apparatus in Example 1.

[0025] Figure 2A This is a diagram illustrating the subject matter of the present invention.

[0026] Figure 2B This is a diagram illustrating the subject matter of the present invention.

[0027] Figure 3 This is a diagram showing an example of the structure of the sample stage.

[0028] Figure 4 This is a block diagram showing the adjustment of the ion source position.

[0029] Figure 5 This is the ion source position adjustment process of Example 1.

[0030] Figure 6A This is an example of the shape of the conductor in the target plate.

[0031] Figure 6B This is another example of the shape of the conductor in the target plate.

[0032] Figure 7 This is a structural diagram of the main parts of the ion milling apparatus in Example 2.

[0033] Figure 8 This is the ion source position adjustment process of Example 2. Detailed Implementation

[0034] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0035] Example 1

[0036] Figure 1 This is a structural diagram of the main components of the ion milling apparatus in Example 1. It includes a sample chamber 6 that maintains a vacuum, an ion source 1, a sample stage 2 for setting the sample (not shown) during processing, and a sample stage rotation drive source 3 for rotating the sample stage about the rotation center R0 along the axial direction R. Furthermore, as... Figure 2A As shown, the sample stage 2 may also have a tilting mechanism for changing the incident angle of the ion beam. Additionally, the sample chamber 6 is provided with an observation window 7 for observing the processed sample.

[0037] Here, the ion source 1 is mounted in the sample chamber 6 via an ion source position adjustment mechanism 5 that finely adjusts its position in the X, Y, and Z directions. This allows for fine adjustment of the position of the ion beam center B0 of the ion source 1, specifically, its position on the XY plane (including the X and Y directions) and its operating distance (position in the Z direction, specifically the distance from the ion beam emission position of the ion source 1 to the sample stage 2). Furthermore, as described later, the sample mounting plate of the sample stage 2 can be replaced. When adjusting the position of the ion source 1, a target plate is installed in the area containing the rotation center R0, replacing the sample mounting plate. This target plate contains the conductive material 4 used to detect the current of the ion beam. Figure 1 This status is displayed.

[0038] The ion source position adjustment mechanism 5 includes a support portion for fixing the ion source 1, a substrate for mounting the ion source position adjustment mechanism 5 on the sample chamber 6, and an ion source moving mechanism that can independently move the support portion mounted on the substrate in the X, Y, and Z directions. For example, the position of the ion source 1 can be finely adjusted in each direction using a precision threaded mechanism such as that used for a micrometer.

[0039] By applying a predetermined voltage to the ion source 1, an ion beam is emitted radially from the ion source 1 with the ion beam center B0 as the center, irradiating a target plate disposed on the sample stage 2 and containing a conductive material 4 within a region containing the rotation center R0. Regarding the ion beam emitted from the ion source 1, the current and ion density are high at the ion beam center B0, gradually decreasing outwards. Furthermore, the greater the distance from the ion source 1, the lower the current and ion density. Therefore, by using the conductive material 4 to detect the ion beam current and finely adjusting the position of the ion source 1 using the ion source position adjustment mechanism 5 to achieve the desired ion beam current, the desired processing accuracy or the accuracy of reproducing the processed surface shape can be achieved.

[0040] Figure 3This section illustrates a structural example of the sample stage 2. It shows a state where a target plate 30 with a conductive material 4 is provided. The target plate 30 is configured such that the conductive material 4 is connected to a conductive material connecting plate 31. In this case, the center of the conductive material 4 is set at a position indicated by a dashed line, coinciding with the rotation center R0. An ion beam from the ion source irradiates the area centered on the conductive material 4. However, since the ion beam is emitted radially from the ion source 1, depending on the distance between the ion source 1 and the conductive material 4, there is a possibility that the ion beam may irradiate areas other than the conductive material 4. To prevent current from flowing into the conductive material 4 due to ion beam irradiation of other structural components of the sample stage in such a case, the target plate 30 surrounding the conductive material 4 is provided as an insulating material. The conductive material connecting plate 31 is connected to a rotation shaft 33 that rotates the sample. The conductive material 4 is rotated by the power of a rotating gear 34 driven by the sample stage rotation drive source 3. However, to prevent current from flowing into the rotation shaft 33 from the conductive material 4, an insulating material 32 is provided between the conductive material connecting plate 31 and the rotation shaft 33 to block the current flow. In addition, the current flowing through the conductive material 4 is drawn out by the rotating contact 35, which contacts the conductive material connecting plate 31, and the current detection wiring 36, and the current value is detected. Furthermore, the rotating contact 35 and the current detection wiring 36 are insulated from other structural components through the current detection wiring connector 37.

[0041] Figure 4 This is a block diagram showing the position adjustment of the ion source 1 in the ion milling apparatus of Embodiment 1. Specifically, this is not intended to limit the invention; rather, it illustrates an example using a Penning discharge-based ion source as the ion source 1. A cylindrical positive electrode 12 is disposed between the negative electrodes 11a and 11b, and a discharge voltage V is applied between the negative electrodes 11a and 11b and the positive electrode 12. d Argon gas is introduced into ion source 1 through pipe 15. A magnetic field is applied to the positive electrode 12 by magnet 13, thereby generating ions within the positive electrode 12. The generated ions are then accelerated by voltage V. a The accelerating electrode 14 accelerates the ion and emits it as an ion beam from the ion source 1.

[0042] Discharge voltage V d and accelerating voltage V a The discharge current is generated by the power supply unit 40. The power supply unit 40 also includes ammeters; ammeter 41 measures the discharge current, and ammeter 42 measures the ion beam current received by the conductive material 4. Furthermore, the discharge voltage V... d and accelerating voltage V a The value is set by the control unit 45.

[0043] In addition, the ion source 1 is fixed to the support part 16 of the ion source position adjustment mechanism 5. The position of the ion source 1 can be finely adjusted by the ion source moving mechanism 17, which can move the support part 16 independently in the X, Y and Z directions.

[0044] The power supply unit 40, the ion source moving mechanism 17, and the sample stage rotation drive source 3 are connected to the control unit 45. The control unit 45 sets the ion beam emission conditions and performs ion source adjustment and sample processing according to a predetermined process. Furthermore, the control unit 45 is connected to the display unit 46, which functions as a user interface for the operator to access the control unit 45 and displays sensor data collected by the control unit 45 indicating the operating status of the ion milling apparatus. For example, the sensor data displayed on the display unit 46 includes the discharge voltage value V from the power supply unit 40. d Discharge current value, accelerating voltage value V a Ion beam current value, etc.

[0045] Figure 5 Indicates in Figure 4 The control unit 45 in the ion milling apparatus shown executes the adjustment process of the ion source 1.

[0046] Step S51: The control unit 45 starts the rotation of the sample stage 2 using the sample stage rotation drive source 3. For example... Figure 4 As shown, the sample stage 2 is positioned so that the surface of the conductive material 4 is perpendicular to the ion beam emitted from the ion source 1. By rotating the sample stage 2, the detection deviation of the current caused by the conductive material 4 can be suppressed.

[0047] Step S52: The control unit 45 controls the power supply unit, etc., to irradiate the conductive material 4 with an ion beam from the ion source 1. At this time, the power supply unit 40 applies a discharge voltage V to the ion source 1. d and accelerating voltage V a The voltage applied during actual sample processing is used as the basis for this method. This allows for the high-precision reproduction of the ion beam used during sample processing.

[0048] Step S53: The ion beam current is measured using ammeter 42. The control unit 45 acquires the ion beam current value measured by ammeter 42.

[0049] Step S54: The control unit 45 controls the ion source position adjustment mechanism 5 in a manner that ensures the measured ion beam current value meets a predetermined reference. Here, the ion source moving mechanism 17 of the ion source position adjustment mechanism 5 is controlled by the motor controlled by the control unit 45. It first moves in the X direction, and then moves in the Y direction, adjusting the position of the ion source 1 on the XY plane to the position where the ion beam current value is maximized. Afterward, it moves in the Z direction as needed, thereby fine-tuning the position and movement distance (Z direction position) of the ion beam center B0 of the ion source 1 on the XY plane based on the ion beam current value. This adjustment example demonstrates how the position and movement distance (Z direction position) of the ion beam center B0 of the ion source 1 on the XY plane can be fine-tuned according to the algorithm provided by the control unit 45.

[0050] For example, it can replace the use of ion source position adjustment mechanism 5 for fine adjustment in the Z direction, or, based on the fine adjustment in the Z direction, adjust the discharge voltage value V applied to ion source 1. d Furthermore, the target ion beam current value when adjusting ion source 1 is not limited to the maximum value of the ion beam current; for example, it can also be determined as the ion beam current value during the last processing.

[0051] Furthermore, in the sample stage 2, it is also possible to replace the target plate 30 with one of different shapes for the conductive material 4, or to replace the conductive material 4 with one of different shapes relative to the target plate 30. For example, Figure 6A This is an example of a conductive material 60 arranged in a circular shape with the rotation center R0 as the conductive material. Furthermore, even with the same circular shape, it is preferable to use a target plate with a conductive material in a concentric circular shape having multiple diameters. This allows for adjustment of the ion source using a conductive material with a detection range that corresponds to the diameter of the ion beam. As an example, a conductive material 4 with a diameter smaller than the ion beam diameter irradiating the target plate can be used, and adjustments can be made such that the ion source 1 is slightly moved in the Z direction so that the ion beam current value detected by the conductive material 4 reaches its maximum value.

[0052] on the other hand, Figure 6B This example illustrates how a circular conductive material 61 and a ring-shaped conductive material 62 with a diameter larger than 61 are arranged concentrically around a rotation center R0. In this case, the ion beam current values ​​detected by the conductive material 61 and the ion beam current values ​​detected by the conductive material 62 can be independently measured by the power supply unit 40. Specifically, two series of ion beam current extraction sections corresponding to the conductive materials 61 and 62 are provided on the sample stage 2, and the power supply unit 40 measures each ion beam current value. This allows for evaluation including the shape of the irradiated ion beam (the extent of the ion beam distribution, which can be approximated as a binomial distribution), further improving the machining accuracy of the ion milling apparatus and the accuracy of reproducing the machined surface shape.

[0053] The ion milling apparatus of Embodiment 1 has been described specifically with the adjustment of the ion source position as the focus, but various modifications are possible. For example, the control unit 45 may display the ion beam current value measured by the ammeter 42 on the display unit 46, and the operator may manually adjust the movement amount of the ion source moving mechanism 17 of the ion source position adjustment mechanism 5, or the discharge voltage V of the ion source 1, while checking the ion beam current value displayed on the display unit 46. d .

[0054] Example 2

[0055] Figure 7This is a structural diagram of the main parts of the ion milling apparatus of Example 2. Example 2 can align the ion beam center B0 with the rotation center R0 using a simpler mechanism. Here, the same reference numerals are used for structural elements that function the same as in Example 1, and repeated descriptions are omitted.

[0056] An observation microscope (optical microscope) 73 is installed above the sample chamber 6, designed to allow observation of the sample mounting surface of the sample stage 2 through the observation window 7. Additionally, a mirror component 71 is provided on the sample mounting surface of the sample stage 2. This mirror component can be any component capable of reflecting the plasma emission of the ion source 1; for example, besides a general mirror, a wafer could also be used. The mirror component simply replaces the sample mounting plate on the sample stage. The sample stage 2 has a tilting mechanism, allowing it to tilt in the C direction about an axis 72 extending along the X direction. The axis 72 is located on the sample mounting surface of the sample stage 2 at a position intersecting with the rotation center R0. Figure 7 The diagram shows the sample stage 2 tilted at an angle T. Furthermore, the tilt angle T is defined as the angle formed by the ion beam center B0 and the normal to the sample placement surface of the sample stage 2.

[0057] use Figure 8 This describes a method for adjusting the position of ion source 1 in an ion milling apparatus with such a structure.

[0058] Step S81: Tilt the sample stage 2 relative to the ion beam center B0 at an angle T of 45°. Here, the tilting mechanism of the sample stage 2 tilts around axis 72. Therefore, as long as the ion beam center B0 and the rotation center R0 are aligned, the distance to the ion source 1 will not change even if the tilt of the sample stage 2 is altered. Therefore, during sample processing, the tilt angle T can be any desired tilt angle other than 45°.

[0059] Step S82: Start the rotation of the sample stage 2 using the sample stage rotation drive source 3.

[0060] Step S83: Ion beam is irradiated from ion source 1 onto mirror component 71. At this time, the discharge voltage V applied by power supply unit 40 to ion source 1... d and accelerating voltage V a The voltage applied during actual sample processing is used as the basis for this method. This allows for the high-precision reproduction of the ion beam used during sample processing.

[0061] Step S84: Observe the mirror component 71 using the observation microscope 73 to confirm the center position of the plasma emission brightness emitted from the emission port of the ion source 1. If the ion beam center B0 and the rotation center R0 are aligned, the area near the rotation center R0 of the mirror component 71 will appear to emit light in a dotted or circular shape. If the ion beam center B0 and the rotation center R0 are not aligned, the light will appear to emit light in a ring shape due to the rotation of the sample stage 2.

[0062] Step S85: The position of the ion source 1 is finely adjusted by the ion source position adjustment mechanism 5 so that the center position of the plasma emission brightness of the ion source 1 confirmed in step S84 is consistent with the rotation center R0 of the sample stage 2.

[0063] Furthermore, in the above example, the method of setting the mirror component 71 on the sample stage 2 was described. However, the same effect can also be obtained by setting a light-emitting component that emits light by irradiation with an ion beam, such as a laser light-emitting element, or a sample coated with a phosphor.

[0064] Symbol Explanation

[0065] 1, 21—Ion source; 2, 22—Sample stage; 3, 23—Sample stage rotation drive source; 4, 60, 61, 62—Conductive material; 5—Ion source position adjustment mechanism; 6—Sample chamber; 7—Observation window; 11a, 11b—Negative electrode; 12—Positive electrode; 13—Magnet; 14—Accelerating electrode; 15—Pipeline; 16—Support section; 17—Ion source moving mechanism; 20—Sample; 30—Target plate; 31—Conductive material connecting plate; 32—Insulating material; 33—Rotating shaft; 34—Rotating gear; 35—Rotating contact point; 36—Beam current detection wiring; 37—Beam current detection wiring connector; 40—Power supply section; 41, 42—Ammeter; 45—Control section; 46—Display section; 71—Mirror component; 72—Shaft; 73—Microscope.

Claims

1. An ion milling apparatus, which processes a sample by irradiating it with a non-focused ion beam, characterized in that, have: A sample chamber equipped with an observation window; An ion source position adjustment mechanism is installed in the above-mentioned sample chamber; An ion source that is installed in the sample chamber via the aforementioned ion source position adjustment mechanism and emits the aforementioned ion beam; A sample stage that rotates about a center of rotation and has a mirror component disposed within a region including the center of rotation; the mirror component is a component capable of reflecting the ion beam and emitting light; and An optical microscope for observation is provided above the sample chamber and is configured to allow observation of the sample mounting surface of the sample stage through the observation window. If the direction of the extension of the rotation center when the ion beam center and the rotation center are aligned is defined as the Z direction, and the plane perpendicular to the Z direction is defined as the XY plane, then the ion source position adjustment mechanism can adjust the position of the ion source on the XY plane and the position in the Z direction. The aforementioned sample stage has a tilting mechanism, which allows the sample placement surface of the sample stage to tilt toward the observation window with an axis extending in the X direction as the center. The axis extending in the X direction is located at a position where the sample placement surface of the sample stage intersects with the rotation center. The X direction is a direction contained in the XY plane.

2. An ion milling apparatus, which processes a sample by irradiating it with a non-focused ion beam, characterized in that, have: A sample chamber equipped with an observation window; An ion source position adjustment mechanism is installed in the above-mentioned sample chamber; An ion source installed in the sample chamber via the aforementioned ion source position adjustment mechanism, and which emits the aforementioned ion beam; and A sample stage that rotates about a center of rotation and has a light-emitting component disposed within a region including the center of rotation; the light-emitting component is a component capable of emitting light by irradiation with the ion beam; and An optical microscope for observation is provided above the above-mentioned sample chamber, which is configured to be able to observe the sample placement surface of the above-mentioned sample stage through the above-mentioned observation window. If the direction of the extension of the rotation center when the ion beam center and the rotation center are aligned is defined as the Z direction, and the plane perpendicular to the Z direction is defined as the XY plane, then the ion source position adjustment mechanism can adjust the position of the ion source on the XY plane and the position in the Z direction. The aforementioned sample stage has a tilting mechanism, which allows the sample placement surface of the sample stage to tilt toward the observation window with an axis extending in the X direction as the center. The axis extending in the X direction is located at a position where the sample placement surface of the sample stage intersects with the rotation center. The X direction is a direction contained in the XY plane.

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