Patent Description:
An ion milling apparatus is a machine for milling a sample by means of an ion beam. Ion milling apparatus are used to produce either samples observed with an electron microscope (such as a scanning electron microscope or a transmission electron microscope) or samples analyzed by an analytical instrument (such as an electron probe microanalyzer or an Auger microscope). Where a sample is milled by an ion milling apparatus, a shield member is used to shield the portion of a sample that is not to be milled, and an ion beam is directed at the sample via the shielding member (see, for example, patent document <NUM>).

The prior art ion milling apparatus is equipped with a configuration, for example, as shown in <FIG>, to enable a sample to be set on the shielding member. In <FIG>, the sample, <NUM>, is bonded and secured to a sample support stage <NUM>. The shielding member, <NUM>, in the form of a flat plate is placed above the support stage <NUM>. The sample <NUM> is sandwiched and held between the sample support stage <NUM> and the shielding member <NUM>. The sample <NUM> held in this way is irradiated with an ion beam <NUM> via the shielding member <NUM>, the beam being emitted from an ion source (not shown). As a result, a front end portion 200a (hereinafter may be referred to as the milled portion) of the sample <NUM> which protrudes from an edge portion 220a of the shielding member <NUM> is etched away. This produces a cross section of the sample <NUM> immediately under the edge portion 220a of the shielding member <NUM>. By forming a cross section in this way, there is obtained a sample adapted for observation with an electron microscope or analysis by an analytical instrument.

In the prior art ion milling apparatus, the front end portion of the shielding member <NUM> is located close to the front end portion 200a of the sample <NUM> but the front end portion of the sample support stage <NUM> is positioned remotely from the front end portion 200a of the sample <NUM>. Therefore, as shown in <FIG>, if the handled sample <NUM> is in thin film form, the sample <NUM> cannot retain its own shape and so the front end side of the sample <NUM> undergoes flexure.

Accordingly, patent document <NUM> sets forth a technique for bonding the sample <NUM> to a baseplate <NUM> with adhesive and then squeezing the sample <NUM> and the baseplate <NUM> between the sample support stage <NUM> and the shield member <NUM> as shown in <FIG>. If the sample <NUM> is in thin film form, this technique assures that the milled portion 200a of the sample <NUM> can be supported.

In the prior art ion milling apparatus set forth in patent document <NUM>, the ion beam <NUM> emitted from the ion source is made to impinge on the sample <NUM> via both the shielding member <NUM> and the baseplate <NUM>. Therefore, as shown in <FIG>, if the front end portion of the sample <NUM> is located retracted from the front end portion of the baseplate <NUM>, the milled portion 200a of the sample <NUM> is shielded by the shielding portion <NUM> and the baseplate <NUM> as viewed from the upstream side relative to the direction of the ion beam <NUM>. As a result, the ion beam <NUM> cannot impinge on the sample <NUM> and thus the sample <NUM> cannot be milled.

Furthermore, with the prior art ion milling apparatus shown in the above-cited <FIG>, if the sample <NUM> is in block form or resilient, and if it is sandwiched in between the shielding member <NUM> and the sample support stage <NUM>, the front end of the sample <NUM> and its vicinities may tilt relative to the center axis of the ion beam <NUM> as shown in <FIG>, producing a gap <NUM> between the sample <NUM> and the shielding member <NUM>. If so, material <NUM> sputtered off by the illumination by the ion beam <NUM> moves through the gap <NUM> and adheres to the sample <NUM>. This phenomenon is referred to as redeposition. The redeposited material <NUM> is not removed by the irradiation by the ion beam <NUM> but rather remains on the sample <NUM> after the milling. Furthermore, if the sample <NUM> tilts relative to the center axis of the ion beam <NUM>, and if the milled portion or target of milling <NUM> (such as a through hole) exists down into a deep position within the sample <NUM> as shown in <FIG>, then a line <NUM> milled by the irradiation with the ion beam <NUM> deviates from the milled portion <NUM>. This problem also occurs where a portion to be milled is present only at a deep position within the sample <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.

It is an object of the present invention to provide an ion milling apparatus and sample holder capable of reliably supporting a portion of a sample to be milled and of suppressing material sputtered off by ion beam irradiation from remaining on the sample.

The present invention provides an ion milling apparatus which mills a sample by ion beam irradiation and which is equipped with a sample holder for supporting the sample. The sample holder has both a shield member for shielding the sample except for a portion to be milled and a sample locking member cooperating with the shield member such that the sample is sandwiched and held therebetween. The shield member has an edge portion that determines a milling position on or in the sample. The sample locking member is disposed downstream of the edge portion in the direction of the ion beam irradiation and has at least one support portion cooperating with the edge portion to support the milled portion therebetween. The support portion has a first surface making contact with the sample and a second surface making a given angle to the first surface. The given angle is equal to or less than <NUM>°. The sample and said sample locking member are arranged to be simultaneously milled by the ion beam irradiation.

The present invention provides a sample holder for use in an ion milling apparatus for milling a sample by ion beam irradiation. The sample holder has both a shield member for shielding the sample except for a portion to be milled and a sample locking member cooperating with the shield member such that the sample is sandwiched and held therebetween. The shield member has an edge portion for determining a milling position on or in the sample. The sample locking member has a support portion which is disposed downstream of the edge portion in the direction of the ion beam irradiation and which cooperates with the edge portion to support the milled portion therebetween. The support portion has a first surface making contact with the sample and a second surface making a given angle to the first surface. The given angle is equal to or less than <NUM>°. The sample and said sample locking member are arranged to be simultaneously milled by the ion beam irradiation.

According to the present invention, the portion of the sample to be milled can be supported reliably. Also, material sputtered off by ion beam irradiation can be suppressed from remaining on the sample.

The preferred embodiments of the present invention are hereinafter described in detail with reference to the drawings. In the present specification and drawings, elements having substantially identical function or configuration are indicated by identical reference numerals and a repetition of the description thereof is omitted.

<FIG> is a schematic view of an ion milling apparatus associated with a first embodiment of the present invention, illustrating one example of the configuration of the ion milling apparatus. This ion milling apparatus, indicated by reference numeral <NUM>, is used to produce a sample which is either observed, for example, with a scanning electron microscope or a transmission electron microscope or analyzed by an analytical instrument such as an electron probe microanalyzer or an Auger microscope. The ion milling apparatus <NUM> mills a sample <NUM> into a shape adapted for observation with a scanning electron microscope or a transmission electron microscope by directing an ion beam <NUM> at the sample <NUM> that is to be milled.

As shown in <FIG>, the ion milling apparatus <NUM> has a vacuum chamber <NUM>, a sample stage pull-out mechanism <NUM>, an ion source <NUM>, a sample stage <NUM>, a rotational mechanism <NUM>, an exhaust portion <NUM>, an exhaust control portion <NUM>, a camera <NUM>, a controller <NUM>, a voltage power supply <NUM>, a rotational drive mechanism <NUM>, and a display portion <NUM>. The controller <NUM> is equipped with an ion source controller section 23a and a rotation control section 23b.

The vacuum chamber <NUM> is a hollow container. The exhaust portion <NUM> is coupled to the vacuum chamber <NUM>. Operation of the exhaust portion <NUM> is controlled by the exhaust control portion <NUM>. The exhaust portion <NUM> exhausts air inside the vacuum chamber <NUM> by operating under the control of the exhaust control portion <NUM>.

The sample stage pull-out mechanism <NUM> is used to pull the sample stage <NUM> out of the vacuum chamber <NUM>. The pull-out mechanism <NUM> is mounted to the vacuum chamber <NUM> so as to be able to open and close it, the pull-out mechanism <NUM> plugging the opening of the vacuum chamber <NUM>. The sample stage <NUM> and the rotational mechanism <NUM> are mounted to the sample stage pull-out mechanism <NUM>.

When the sample stage pull-out mechanism <NUM> is closed, the sample stage <NUM> is received inside the vacuum chamber <NUM>. When the pull-out mechanism <NUM> is opened, the sample stage <NUM> is pulled out of the vacuum chamber <NUM>. The pull-out mechanism <NUM> can be switched between its open and closed states by moving the pull-out mechanism <NUM> relative to the vacuum chamber <NUM> in the left/right direction in <FIG>. The sample stage <NUM> supports the sample <NUM> via a sample holder <NUM>. The sample holder <NUM> that supports the sample <NUM> has a holder body <NUM> forming a base and a shield member <NUM>. The shield member <NUM> will be described in detail below. The sample holder <NUM> can be mounted to and detached from the sample stage <NUM>. The sample <NUM> is shaped in the form of a flat plate.

The rotational mechanism <NUM> rotates the sample holder <NUM> via the sample stage <NUM>. The rotational mechanism <NUM> has an axis of rotation 19a which is perpendicular to the center axis of the ion beam <NUM> and which is parallel to a direction (Y direction in the figure) in which the sample <NUM> protrudes from the shield member <NUM>. The rotational mechanism <NUM> rotates the sample holder <NUM> according to the operation of the rotational drive mechanism <NUM>. At this time, the sample holder <NUM> rotates about the axis of rotation 19a of the rotational mechanism <NUM>. The rotation control section 23b controls the rotation of the sample holder <NUM> via the rotational drive mechanism <NUM>. The rotational mechanism <NUM> may rotate the sample holder <NUM> integrally with or independent of the sample stage <NUM>.

The ion source <NUM> is disposed at the top of the vacuum chamber <NUM> and emits the ion beam <NUM>. The ion source <NUM> is made of a gas ion gun, for example. The gas ion gun ionizes argon gas by electric discharge and emits an ion beam. The ion source <NUM> emits the ion beam <NUM> vertically downward into the inner space of the vacuum chamber <NUM>.

In the description provided so far, it is assumed that one of two directions perpendicular to the center axis of the ion beam <NUM> is an X direction and that the other is a Y direction. It is also assumed that a direction running parallel to the center axis of the ion beam <NUM> and perpendicular to the X and Y directions is a Z direction. In the preferred embodiments of the present invention, the X and Y directions are two horizontal directions. The Z direction is the vertical direction, or up/down direction. The center axis 12a (see <FIG>) of the ion beam <NUM> is parallel to the vertical direction.

The voltage power supply <NUM> is electrically connected to the ion source <NUM> and operates to apply a voltage to the ion source <NUM>. The power supply <NUM> causes the ion source <NUM> to emit the ion beam <NUM> by applying the voltage to the ion source <NUM> under control of the ion source controller section 23a which controls the ion source <NUM> via the voltage power supply <NUM>.

The camera <NUM> is mounted so as to be capable of being rotated by a camera rotating mechanism <NUM> that is mounted at the top of the sample stage pull-out mechanism <NUM> and moves with this pull-out mechanism <NUM>. The camera <NUM> can be placed either into a first position or into a second position by rotation of the camera rotating mechanism <NUM>. In the first position, the optical axis of the camera <NUM> is parallel to the Z direction. When the camera <NUM> is placed in the first position, the optical axis of the camera <NUM> passes through a milling position on or in the sample <NUM>. In the second position, the camera <NUM> is tilted through a great angle relative to the Z direction, as shown in <FIG>.

The camera <NUM> captures images of the sample <NUM> supported to the sample holder <NUM> and of the shield member <NUM>. For this purpose, an optical microscope may be used instead of the camera <NUM>. The display portion <NUM> displays the images captured by the camera <NUM>. The display portion <NUM> is made of a monitor or a touch panel display.

<FIG> is a schematic side elevation showing main portions of the ion milling apparatus associated with the first embodiment of the present invention. As shown in <FIG>, the sample holder <NUM> has a sample locking member <NUM> and a sample support stage <NUM> as well as the aforementioned holder body <NUM> and shield member <NUM>. The shield member <NUM> is shaped in the form of a flat plate and has an edge portion 29a at its front end. The shield member <NUM> has a front end surface 29b that is slightly tilted relative to the center axis 12a of the ion beam <NUM>.

The edge portion 29a of the shield member <NUM> determines the milling position on or in the sample <NUM>. That is, the sample <NUM> is milled based on the edge portion 29a of the shield member <NUM>. Therefore, the portion of the sample <NUM> to be milled is placed in alignment with the position of the edge portion 29a of the shield member <NUM>. When the sample <NUM> is observed with a scanning electron microscope or a transmission electron microscope, the milled portion is the subject of observation. When the sample <NUM> is analyzed with an electron probe microanalyzer, an Auger microscope, or the like, the milled portion is the subject of analysis. The edge portion 29a of the shield member <NUM> is formed at the angled corner at the intersection between the front end surface 29b of the shield member <NUM> and a shield surface 29c of the shield member <NUM>, the shield surface 29c making contact with the sample <NUM>. The shield surface 29c shields the sample <NUM> except for the milled portion 11b. That is, the shield member <NUM> shields the sample <NUM> except for the milled portion 11b, i.e., shields the non-milled portion.

The shield surface 29c of the shield member <NUM> is placed in contact with the top surface of the sample <NUM>. A part of the sample <NUM>, including the front end surface 11a of the sample <NUM>, is placed so as to protrude from the edge portion 29a of the shield member <NUM>. The protruding portion is the milled portion 11b which is removed by irradiation by the ion beam <NUM>.

The sample locking member <NUM> cooperates with the shield member <NUM> such that the sample <NUM> is sandwiched and held therebetween. The sample locking member <NUM> is shaped like a flat plate. The sample locking member <NUM> has a support portion <NUM> formed by both a first surface <NUM> and a second surface <NUM>. The first surface <NUM> is equivalent to the top surface of the sample locking member <NUM>. The first surface <NUM> touches the sample <NUM> on the opposite of the shield surface 29c of the shield member <NUM>. That is, the first surface <NUM> is placed in contact with the bottom surface of the sample <NUM>. The second surface <NUM> makes a given angle θ to the first surface <NUM>.

The support portion <NUM> is disposed downwardly of the edge portion 29a of the shield member <NUM> in the direction of irradiation by the ion beam <NUM>. The milled portion 11b of the sample <NUM> is supported between the support portion <NUM> and the edge portion 29a. The given angle θ between the first surface <NUM> and the second surface <NUM> forming the support portion <NUM> is less than <NUM>° and greater than <NUM>°. Preferably, the given angle θ is an acute angle, preferably less than <NUM>°, more preferably less than <NUM>°, still more preferably less than <NUM>°. Where the given angle θ is set to a small value in this way, the support portion <NUM> is shaped like a wedge.

The sample <NUM> is placed over the sample support stage <NUM> via the sample locking member <NUM>. The sample locking member <NUM> is secured to the sample support stage <NUM> with a screw <NUM>. The sample support stage <NUM> is located on the opposite side of the sample locking member <NUM> from the shielding member <NUM> in the Z direction.

Then, a procedure for milling a sample using the ion milling apparatus associated with the first embodiment of the present invention is described. This procedure includes a method of preparing the sample.

First, as shown in <FIG>, the sample <NUM> is set on the sample holder <NUM> in the following procedure. The operator of the ion milling apparatus <NUM> first brings the edge portion 29a of the shield member <NUM> and the front end 31a of the sample locking member <NUM> into contact with a reference plane (not shown) to thereby adjust the edge portion 29a and the front end 31a in position, that is, they assume the same position in the Y direction as shown in <FIG>, i.e., they are flush with each other. The front end 31a of the sample locking member <NUM> is the end of the target illuminated with the ion beam <NUM> in the Y direction. Then, the operator inserts the sample <NUM> between the shield member <NUM> and the sample locking member <NUM> which have been already adjusted in position. At this stage, a gap greater than the thickness-wise dimension of the sample <NUM> is secured between the shield member <NUM> and the sample locking member <NUM>. That is, the position of the sample <NUM> is not fixed but rather rendered freely movable. Then, as shown in <FIG>, the operator mounts the protrusion amount setting member <NUM> on the sample holder <NUM>, and the amount of protrusion of the sample <NUM> is set using the setting member <NUM>. In particular, the protrusion amount setting member <NUM> is brought into contact with the front end surface 29b of the shield member <NUM>. Also, the front end surface 11a of the sample <NUM> is brought into contact with a recessed portion <NUM> of the protrusion amount setting member <NUM>. Consequently, the milled portion (target of milling) 11b of the sample <NUM> is made to protrude a given amount from the edge portion 29a of the shield member <NUM>. This amount of protrusion of the milled portion 11b is defined based on the edge portion 29a of the shield member <NUM>. The amount of protrusion of the milled portion 11b varies depending on the position of the milled portion. In many cases, the amount of protrusion is set between <NUM> and <NUM>, inclusively.

Then, the operator squeezes the sample <NUM> in between the shield member <NUM> and the sample locking member <NUM> while maintaining the front end surface 11a of the sample <NUM> in contact with the recessed portion <NUM> in the protrusion amount setting member <NUM>, thus securing the sample <NUM>. At this time, the front end of the sample <NUM> is supported from above and below by the shield member <NUM> and the sample locking member <NUM>. The milling position on or in the sample <NUM> is located sandwiched between the edge portion 29a of the shield member <NUM> and the front end 31a of the sample locking member <NUM>. Therefore, if the sample <NUM> is thin and filmy, the milled portion 11b of the sample <NUM> can be supported reliably without the front end side of the sample <NUM> being flexed. Furthermore, the front end of the sample <NUM> and its vicinities are pressed against the shield member <NUM> by the support portion <NUM> of the sample locking member <NUM>. Therefore, if a sample in the form of a block or a resilient sample is handled, the sample <NUM> can be supported without tilting the front end of the sample <NUM> and its vicinities relative to the center axis 12a of the ion beam <NUM>. Consequently, the shield member <NUM> and the sample <NUM> can be held together while in intimate contact with each other.

After the sample <NUM> is set as described above, the operator takes the protrusion amount setting member <NUM> out of the sample holder <NUM> and then mounts the sample holder <NUM> on the sample stage <NUM> while the sample stage <NUM> is pulled out from 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> while placing the shield member <NUM> on the upper side and the sample locking member <NUM> on the lower side. The amount of protrusion of the sample <NUM> is confirmed by making use of the image captured by the camera <NUM>. Where the amount of protrusion of the sample <NUM> is checked, the camera <NUM> is brought into the first position by rotation of the camera rotating mechanism <NUM>. Under this condition, the image captured by the camera <NUM> is displayed on the display portion <NUM>. Consequently, the operator can check the amount of protrusion of the sample <NUM> while utilizing the image which is captured by the camera <NUM> and displayed on the display portion <NUM>.

Then, the operator places the camera <NUM> into the second position by rotation of the camera rotating mechanism <NUM>. Then, the sample stage <NUM> is pushed in and received in the vacuum chamber <NUM> by the sample stage pull-out mechanism <NUM>. At this time, the sample holder <NUM> and the sample <NUM> are received in the vacuum chamber <NUM> together with the sample stage <NUM>.

Then, the operator performs a manipulation to emit the ion beam <NUM> from the ion source <NUM> under the state shown in the above-referenced <FIG>. Consequently, the ion beam <NUM> is directed at the sample <NUM> via the shield member <NUM>. At this time, the voltage power supply <NUM> applies a voltage to the ion source <NUM> in response to control commands from the ion source controller section 23a, thus causing the ion source <NUM> to emit the ion beam <NUM>. In consequence, the sample <NUM> is etched. If the front end 31a of the sample locking member <NUM> is acute angled, e.g., if the front end 31a of the sample locking member <NUM> protrudes from the front end surface 11a of the sample <NUM> as shown in <FIG>, material sputtered off by the irradiation by the ion beam <NUM> stays less on the sample <NUM> for the following reason.

First, if the sample <NUM> is irradiated with the ion beam <NUM> via the shield member <NUM> as shown in <FIG>, the ion beam <NUM> also hits the front end of the sample locking member <NUM> and so the front end 31a of the sample locking member <NUM> is etched or sputtered as shown in <FIG>. Material <NUM> sputtered off adheres to the front end surface 11a of the sample <NUM>. If the front end 31a of the sample locking member <NUM> is formed into a right angle, then the amount of the sputtered material <NUM> adhering to the front end surface 11a of the sample <NUM> can be reduced as compared with the case where the front end 31a is formed into an obtuse angle. If the front end 31a of the sample locking member <NUM> is formed into an acute angle, a part of the sample locking member <NUM> protruding from the front end surface 11a of the sample <NUM> is etched off earlier than the milled portion 11b of the sample <NUM> as shown in <FIG>. If the front end 31a of the sample locking member <NUM> is acute-angled, generation of the sputtered material <NUM> is suppressed to a low level. Consequently, the amount of the sputtered material <NUM> adhering to the front end surface 11a of the sample <NUM> can be suppressed further.

After partial disappearance of the sample locking member <NUM> protruding from the front end surface 11a of the sample <NUM>, etching of the sample <NUM> and etching of the sample locking member <NUM> will progress at the same time. In other words, the ion milling apparatus mills the sample <NUM> and the sample locking member <NUM> simultaneously by irradiation by the ion beam <NUM>. Therefore, if the sputtered material <NUM> produced by etching of the sample locking member <NUM> adheres to the front end surface 11a of the sample <NUM>, the adhering material <NUM> is quickly etched away by etching of the sample <NUM>. At the stage where the target of milling 11b of the sample <NUM> has been etched away, the sputtered material <NUM> hardly remains on the cross section <NUM> of the sample <NUM> as shown in <FIG>. Thus, if the front end 31a of the sample locking member <NUM> is formed into an acute angle, the sputtered material <NUM> is less likely to remain on the sample <NUM>.

In this way, the ion milling apparatus <NUM> associated with the first embodiment of the present invention is equipped with the sample locking member <NUM> which cooperates with the shield member <NUM> to sandwich and hold the sample <NUM> therebetween. The sample locking member <NUM> has the support portion <NUM> cooperating with the edge portion 29a of the shield member <NUM> to support the milled portion 11b therebetween. Therefore, the milled portion 11b of the sample <NUM> can be supported reliably. The support portion <NUM> of the sample locking member <NUM> has the first surface <NUM> and the second surface <NUM> which together form the right-angled or acute-angled front end 31a of the sample locking member <NUM>. Hence, the material sputtered off by the irradiation by the ion beam <NUM> can be suppressed from remaining on the sample <NUM>.

The top and bottom surfaces of the sample <NUM> almost totally make intimate contact with the shield member <NUM> and the sample locking member <NUM>. Therefore, when the sample <NUM> generates heat in response to the irradiation by the ion beam <NUM>, the heat can be dissipated to the shield member <NUM> and sample locking member <NUM> from both top and bottom surfaces of the sample <NUM>. Consequently, when the sample <NUM> is milled, the heat dissipation and cooling effects can be enhanced.

In the above-described first embodiment, there is adopted the structure for holding the sample locking member <NUM> to the sample support stage <NUM> with the screw <NUM>. The present invention is not restricted to this example. For example, a structure as shown in <FIG> may also be adopted. In <FIG>, the sample <NUM> is bonded to the sample locking member <NUM> with adhesive or the like. Under this bonded state, the sample <NUM> and the sample locking member <NUM> are adjusted in position such that the front end surface 11a and the front end 31a assume the same position in the Y direction. The sample locking member <NUM> having the sample <NUM> bonded thereto is attached to the sample support stage <NUM> with wax, adhesive, or the like. On the other hand, the shield member <NUM> is placed in position such that its edge portion 29a is placed at the milling position on or in the sample <NUM>. This structure also yields advantageous effects similar to those provided by the first embodiment.

Furthermore, in the first embodiment above, the sample locking member <NUM> is shaped differently from the shield member <NUM>. The present invention is not restricted to this example. The sample locking member <NUM> may be shaped identically to the shield member <NUM>. In this case, the sample locking member <NUM> and the shield member <NUM> are arranged symmetrically up and down about the sample <NUM>.

In addition, in the above first embodiment, the sample support stage <NUM> and the sample locking member <NUM> are secured together with the screw <NUM> (see <FIG>). The present invention is not restricted to this structure. For example, the sample locking member <NUM> may be pushed up toward the shield member <NUM> with a screw or screws (not shown).

Further, in the above first embodiment, the sample locking member <NUM> is mounted independent of the sample support stage <NUM>. The present invention is not restricted to this structure. The sample locking member <NUM> and the sample support stage <NUM> may be formed integrally.

<FIG> is a schematic side elevation showing main portions of an ion milling apparatus associated with a second embodiment of the present invention. <FIG> is a schematic front elevation showing main portions of the ion milling apparatus of <FIG>.

As shown in <FIG>, the sample holder <NUM> has a pair of clamp members <NUM>, <NUM> in addition to the aforementioned shield member <NUM> and sample locking member <NUM>. The clamp members <NUM> and <NUM> are equivalent to first and second clamp members, respectively. The shield member <NUM> is secured to the clamp member <NUM> with a screw <NUM>. The sample locking member <NUM> is secured to the clamp member <NUM> with a screw <NUM>. The shield member <NUM> has an internally threaded portion (not shown) with which an externally threaded portion of the screw <NUM> threadedly engages. The clamp member <NUM> has a stepped hole (not shown) in which the head and shank of the screw <NUM> can be inserted. Similarly, the sample locking member <NUM> has an internally threaded portion with which an externally threaded portion of the screw <NUM> threadedly engages. The clamp portion <NUM> has a stepped portion (not shown) in which the head and shank of the screw <NUM> can be inserted.

The clamp members <NUM> and <NUM> of one pair are secured by a pair of screws 45a, 45b. The screws 45a and 45b of one pair are equivalent to tightening members for tightening the shield member <NUM> and the sample locking member <NUM> via the clamp members <NUM> and <NUM>. The clamp member <NUM> has an internally threaded portion (not shown) with which an externally threaded portion of the screw 45a threadedly engages. The clamp member <NUM> is provided with a stepped hole (not shown) in which the head and shank of the screw 45a can be inserted. Similarly, the clamp member <NUM> is provided with an internally threaded portion (not shown) with which an externally threaded portion of the screw 45b threadedly engages. The clamp member <NUM> is provided with a stepped hole (not shown) in which the head and shank of the screw 45b can be inserted.

<FIG> is a front elevation showing main portions of an ion milling apparatus to be compared with the second embodiment of the present invention. In the comparative example shown in <FIG>, a shield member <NUM> and a sample locking member <NUM> are tightened together with a pair of screws 47a, 47b. A sample <NUM> is disposed between the shield member <NUM> and the sample locking member <NUM>. The sample <NUM> is secured by tightening forces of the pair of screws 47a, 47b.

In this way, if the shield member <NUM> and the sample locking member <NUM> are directly tightened by the pair of screws 47a, 47b, the shield member <NUM> and the sample locking member <NUM> are distorted by the tightening forces. Therefore, when the sample holder <NUM> is viewed from the front, the tightening forces applied to the opposite ends of the sample <NUM> increase but the tightening forces applied to a central portion of the sample <NUM> decrease. That is, the tightening forces impressed on the sample <NUM> become more non-uniform. This impairs the intimateness of contact between the sample <NUM> and the shield member <NUM> and between the sample <NUM> and the sample locking member <NUM>.

On the other hand, when the shield member <NUM> and the sample locking member <NUM> are tightened via the pair of clamp members <NUM> and <NUM>, if the clamp members <NUM> and <NUM> undergo tightening forces from the screws 45a and 45b and are curved, the shield member <NUM> and the sample locking member <NUM> are hardly curved for the following reason. Although the shield member <NUM> and the clamp member <NUM> are secured with the screw <NUM>, these members <NUM> and <NUM> are structurally separate members. If the clamp member <NUM> is curved, the original shape of the shield member <NUM> is retained. Similarly, the sample locking member <NUM> and the clamp member <NUM> are secured with the screw <NUM> but these members <NUM> and <NUM> are structurally separate members. If the clamp member <NUM> is curved, the original shape of the sample locking member <NUM> is maintained. Therefore, if the sample holder <NUM> is viewed from the front, the tightening forces arising from the pair of screws 45a and 45b are uniformly applied to the whole sample <NUM>. Consequently, the intimateness of contact between the sample <NUM> and the shield member <NUM> and between the sample <NUM> and the sample locking member <NUM> is improved. Furthermore, if one or both of the shield member <NUM> and the sample locking member <NUM> are worn away, it is easy to replace the shield member <NUM> and the sample locking members <NUM> which are consumables.

<FIG> is a schematic side elevation showing main portions of an ion milling apparatus associated with a third embodiment of the present invention. As shown in <FIG>, the sample locking member <NUM> has support portions 33a, 33b on its opposite ends in the Y direction. The support portion 33a lies at the front end of the sample locking member <NUM> and is formed by the first surface <NUM> and a second surface 35a. The support portion 33b lies at the rear end of the sample locking member <NUM> and is formed by the first surface <NUM> and a second surface 35b. The second surface 35a tilts at a given angle θ1 relative to the first surface <NUM>. The second surface 35b makes a second given angle of θ2 to the first surface <NUM>. The given angle θ1 is less than <NUM>° and greater than <NUM>°. Preferably, the given angle θ1 is an acute angle, more preferably less than <NUM>°, still more preferably less than <NUM>°, yet more preferably less than <NUM>°. These principles also apply to the second given angle θ2. In the present embodiment, an equality, θ1 = θ2, is established. Alternatively, an inequality, θ1 ≠ θ2, may be established.

By forming the support portion 33a at the front end of the sample locking member <NUM> and the support portion 33b at the rear end in this way, the following effects arise. When the ion beam <NUM> is directed at the sample <NUM> as shown in <FIG>, the ion beam <NUM> also hits the front end portion of the sample locking member <NUM>. Therefore, the sample locking member <NUM> is gradually abraded from its front end 31a and worn off. As the sample locking member <NUM> is worn off more, sharpening of the support portion <NUM> results in less effects. Accordingly, when the amount of abrasion of the sample locking member <NUM> reaches a given amount, the front end and rear end of the sample locking member <NUM> are exchanged in position. Consequently, the sample locking member <NUM> can be used a greater number of times while maintaining the effect of the acute angle of the support portion <NUM> than where the support portion <NUM> is formed on only the front end of the sample locking member <NUM> as shown in <FIG>.

In the above third embodiment, the support portions 33a and 33b are formed at two locations, i.e., front and rear ends, of the sample locking member <NUM>. The present invention is not limited to this example. For example, if the sample locking member <NUM> is in the form of a flat plate that is square within a plane, the support portion <NUM> may be formed on three or all of the four sides. This principle also applies to the case where the sample locking member <NUM> is a polygon having five or more sides within a plane.

<FIG> is a schematic side elevation showing main portions of an ion milling apparatus associated with a fourth embodiment of the present invention. As shown in <FIG>, the sample holder <NUM> is mounted to be tiltable in the Z direction (up/down direction) relative to the X-Y plane parallel to a horizontal plane. On the other hand, the center axis 12a of the ion beam <NUM> is vertical to the X-Y plane, i.e., parallel to the Z direction. As one configuration of the ion milling apparatus, the tilt angle of the sample holder <NUM> may be constant or variable. A rotational mechanism set forth, for example, in <CIT>, can be used to tilt the sample holder <NUM> through an adjustable angle.

If the sample holder <NUM> is tilted as described above, the shield member <NUM>, sample locking member <NUM>, and sample support stage <NUM> tilt together with the sample <NUM>. At this time, the front end 31a of the sample locking member <NUM> is placed higher than its rear end 31b because of the tilt of the sample holder <NUM>. Similarly, the front end surface 11a of the sample <NUM> is placed higher than the rear end surface. That is, the sample holder <NUM> is mounted so as to be tiltable such that the front end 31a of the sample locking member <NUM> is placed higher than the rear end 31b by the rotational mechanism.

Under this arrangement, if the sample <NUM> is irradiated with the ion beam <NUM>, a cross section through the sample <NUM> is formed. This cross section is more closely vertical to the top surface of the sample <NUM> for the following reason.

First, where the sample <NUM> is irradiated with the ion beam <NUM>, the current density of the ion beam <NUM> determining the milling rate decreases with the distance from the ion source. That is, as the distance from the ion source increases, the milling rate drops. The distance from the ion source increases in going away from the shield member <NUM> in the thickness-wise direction of the sample <NUM>, i.e., in going downward. Therefore, in comparing the milling rate for the upper surface of the sample <NUM> closer to the shield member <NUM> with the milling rate for the lower surface of the sample <NUM> remoter from the shield member <NUM>, the milling rate for the lower surface of the sample <NUM> is lower than that for the upper surface. Accordingly, if the sample <NUM> is irradiated with the ion beam <NUM> without tilting the sample holder <NUM>, the cross section <NUM> through the sample <NUM> is mildly tilted (protruded) from the top surface of the sample <NUM> toward the bottom surface as shown in <FIG>.

On the other hand, if the sample <NUM> is irradiated with the ion beam <NUM> while tilting the sample holder <NUM> as described above, the cross section through the sample <NUM> tilts relative to the central axis 12a of the ion beam <NUM> in the same manner as in the foregoing, but the sample <NUM> being milled tilts in such a direction as to cancel out the tilt of the cross section. As a result, the cross section through the sample <NUM> is more closely vertical to the top surface of the sample <NUM>. Consequently, if the sample holder <NUM> is tilted, a cross section adapted for observation or analysis of the sample <NUM> is obtained.

On the other hand, where the front end of the sample locking member <NUM> is formed into a right angle rather than an acute angle, for example, as shown in <FIG>, when the sample holder <NUM> is tilted while positionally aligning the front end 31a of the sample locking member <NUM> and the front end surface 11a of the sample <NUM>, the front end 31a of the sample locking member <NUM> protrudes from the front end surface 11a of the sample <NUM>. Therefore, when the sample <NUM> is irradiated with the ion beam <NUM> as shown in <FIG>, the ion beam <NUM> tends to easily hit the sample locking member <NUM>. As a result, the irradiation by the ion beam <NUM> sputters off the material <NUM> from the sample locking member <NUM>, and the sputtered material <NUM> adheres to the front end surface 11a of the sample <NUM>. The material <NUM> adhering to the front end surface 11a of the sample <NUM> is removed to some extent by the irradiation of the sample <NUM> with the ion beam <NUM>. However, the milling of the sample <NUM> using the irradiation by the ion beam <NUM> is carried out while the front end 31a of the sample locking member <NUM> protrudes from the front end surface 11a of the sample <NUM>. Therefore, the front end 31a of the sample locking member <NUM> continues to be etched by the irradiation with the ion beam <NUM> until the sample <NUM> is milled down to just under the edge portion 29a of the shield member <NUM>, i.e., until the milling of the sample <NUM> is completed. Consequently, if the milling of the sample <NUM> is completed, the sputtered material <NUM> remains adhering to the front end surface 11a of the sample <NUM> as shown in <FIG>.

On the other hand, where the front end (support portion <NUM>) of the sample locking member <NUM> is shaped into an acute angle as shown in <FIG>, the front end 31a of the sample locking member <NUM> does not protrude from the front end surface 11a of the sample <NUM> when the sample holder <NUM> is tilted while positionally aligning the front end 31a of the sample locking member <NUM> and the front end surface 11a of the sample <NUM>. Therefore, as shown in <FIG> and <FIG>, if the milling of the sample <NUM> progresses, the front end 31a of the sample locking member <NUM> is hardly etched. However, as shown in <FIG>, when the sample <NUM> is milled down to almost just under the edge portion 29a of the shield member <NUM>, the front end 31a of the sample locking member <NUM> is etched by the ion beam <NUM>. Thus, the material <NUM> sputtered off from the front end 31a of the sample locking member <NUM> by the etching adheres to the front end surface 11a of the sample <NUM>. At this time, if the angle between the first surface <NUM> and the second surface <NUM> forms an acute angle, the front end 31a of the sample locking member <NUM> immediately disappears because of the etching. Also, the material <NUM> sputtered off from the front end 31a of the sample locking member <NUM> and adhering to the front end surface 11a of the sample <NUM> is immediately etched away. Consequently, as shown in <FIG>, on the cross section <NUM> through the sample <NUM> obtained by the milling, only a quite small amount of the material <NUM> remains. Furthermore, this cross section is more closely vertical to the top surface of the sample <NUM>. In this way, the cross section adapted for observation or analysis of the sample <NUM> can be obtained.

Generally, when the sample <NUM> is set on the sample holder <NUM>, the operator of the ion milling apparatus places the camera <NUM> above the shield member <NUM> as shown in <FIG> and captures images of both sample <NUM> and shield member <NUM> with the camera <NUM>. Furthermore, the operator sets the amount of protrusion L of the sample <NUM> from the edge portion 29a to a desired dimension by fine adjusting the position of the sample <NUM> in the Y direction while watching the image displayed on the display portion <NUM>, the image being captured by the camera <NUM>.

In <FIG>, the sample <NUM> is secured using a clip <NUM> which is supported so as to be swingable about a pivot <NUM>. The clip <NUM> is biased in one direction by a force F1 of a spring <NUM>. One end of the spring <NUM> is connected to the clip <NUM>, while the other end of the spring <NUM> is connected to the holder body <NUM>. The holder body <NUM> supports and maintains the shield member <NUM> in locked state. The clip <NUM> applies a pushing force F2 to the sample <NUM> such that the sample <NUM> is secured to the shield member <NUM>. The pushing force F2 is produced by biasing the clip <NUM> in one direction by the force F1 of the spring <NUM>.

As described previously, the operator of the ion milling apparatus needs to set the amount of protrusion L of the sample <NUM> by fine adjusting the position of the sample <NUM> while checking the image captured by the camera <NUM>. This setting operation requires complex manipulations. Where the sample <NUM> is set within a globe box shielded from the atmosphere to avoid chemical reactions of the sample <NUM> in air, it is very difficult to perform the work itself for setting the amount of protrusion. Accordingly, a main object of a fifth and subsequent embodiments of the present invention is to enable the amount of protrusion of the sample to be set with simple manipulations.

<FIG> is a schematic side elevation showing the configuration of a sample positioning jig associated with the fifth embodiment of the present invention. The sample positioning jig is used to place the sample <NUM> in position, the sample <NUM> being an object to be milled by the ion milling apparatus <NUM>. More specifically, the sample positioning jig is adapted for use when the sample <NUM> is set on the sample holder <NUM>.

As shown in <FIG>, the sample positioning jig, <NUM>, has a protrusion amount setting member <NUM>, a first tool <NUM>, and a second tool <NUM>. The protrusion amount setting member <NUM> is in square, block form. The shape of the protrusion amount setting member <NUM> can be varied according to the need. The setting member <NUM> is made of a metal material, for example. As shown in <FIG>, the setting member <NUM> has a first contact portion <NUM> and a second contact portion <NUM>. When the amount of protrusion of the sample <NUM> is set using the protrusion amount setting member <NUM>, the first contact portion <NUM> makes contact with the front end surface 29b of the shield member <NUM>. The second contact portion <NUM> makes contact with the front end surface 11a of the sample <NUM>. The second contact portion <NUM> is recessed relative to the first contact portion <NUM>. In other words, a step D (see <FIG>) is created between the first contact portion <NUM> and the second contact portion <NUM> and has a convex portion and a recessed portion which are formed by the first contact portion <NUM> and the second contact portion <NUM>, respectively.

The step D is set according to the amount of protrusion of the sample <NUM> desired by the operator. <FIG> shows an example of setting the step D between the first contact portion <NUM> and the second contact portion <NUM>. The step D (in µm) between the first contact portion <NUM> and the second contact portion <NUM> is set according to the following Eq. (<NUM>) using the amount of protrusion L (in µm) of the sample <NUM>. <MAT> where θa is the tilt angle of the front end surface 29b of the shield member <NUM> and made between the front end surface 29b and the shield surface 29c. As an example, it is assumed that θa = <NUM>°. In this case, if the desired amount of protrusion L of the sample <NUM> is <NUM>, then Eq. (<NUM>) results in D ≅ <NUM>.

Accordingly, where it is desired to set the amount of protrusion L of the sample <NUM> to <NUM>, the step D between the first contact portion <NUM> and the second contact portion <NUM> is set to <NUM>. The protrusion amount setting member <NUM> may be fabricated according to this setting.

Referring back to <FIG>, the holder body <NUM> is secured to the first tool <NUM> with a screw <NUM>. The second tool <NUM> is secured to the first tool <NUM> with a screw <NUM>. The first tool <NUM> and the holder body <NUM> can be mounted to and detached from each other by attaching and detaching the screw <NUM>. The first tool <NUM> and the second tool <NUM> are mounted to and detached from each other by attaching and detaching the screw <NUM>.

The protrusion amount setting member <NUM> is mounted to the second tool <NUM>. A spring <NUM> is interposed between the protrusion amount setting member <NUM> and the second tool <NUM>. The spring <NUM> is a biasing member for biasing the protrusion amount setting member <NUM> in such a way that the first contact portion <NUM> is pressed against the front end surface 29b of the shield member <NUM>. The spring <NUM> is made of a coil spring, for example. However, no restriction is imposed on the type of the spring. Instead of the spring <NUM>, the biasing member may be made of a rubber-like resilient body (not shown).

A procedure for setting the sample <NUM> on the sample holder <NUM> using the sample positioning jig <NUM> of the above-described configuration is next described. First, as shown in <FIG>, the operator holds together the first tool <NUM> and the holder body <NUM> supporting the shield member <NUM> with the screw <NUM>. Consequently, the first tool <NUM> is held to the holder body <NUM>.

Then, the operator holds together the first tool <NUM> and the second tool <NUM> with the screw <NUM> as shown in <FIG>. Consequently, the second tool <NUM> is mounted to the first tool <NUM>. The protrusion amount setting member <NUM> has been already mounted to the second tool <NUM>. Where the second tool <NUM> is mounted to the first tool <NUM>, the first contact portion <NUM> of the protrusion amount setting member <NUM> is brought into contact with the front end surface 29b of the shield member <NUM>. At this time, the first contact portion <NUM> is pressed against the front end surface 29b of the shield member <NUM> by the biasing force of the spring <NUM>.

Then, as shown in <FIG>, the operator places the sample <NUM> on the shield member <NUM> and pushes the front end surface 11a of the sample <NUM> against the second contact portion <NUM> of the protrusion amount setting member <NUM>. As given in (a)-(d) below, various methods are conceivable as the method of pressing the front end surface 11a of the sample <NUM> against the second contact portion <NUM>.

Whatever method is adopted, the spring <NUM> should have a large spring constant to prevent the position of the protrusion amount setting member <NUM> from moving if pushed by the sample <NUM>. Consequently, as shown in the above-referenced <FIG>, the amount of protrusion L of the sample <NUM> is set to a desired dimension according to the step D between the first contact portion <NUM> and the second contact portion <NUM>. Also, the amount of protrusion L of the sample <NUM> is set based on the edge portion 29a of the shield member <NUM>.

Then, the operator secures the sample <NUM> to the shield member <NUM> with the clip <NUM>. The operator then takes out the second tool <NUM> from the first tool <NUM> and removes the first tool <NUM> from the holder body <NUM>. Consequently, the operation for setting the sample <NUM> on the sample holder <NUM> is completed. The operator then mounts the sample holder <NUM> to the sample stage <NUM>. Subsequently, the sample <NUM> is milled by the same process as in the first embodiment.

Where the sample <NUM> set on the sample holder <NUM> is an electrically charged battery material, when the front end surface 11a of the sample <NUM> is brought into contact with the second contact portion <NUM> of the protrusion amount setting member <NUM>, there is a danger that electrical short circuiting will occur. Therefore, where the sample <NUM> is made of a battery material and treated, it is desired that the protrusion amount setting member <NUM> be made of an insulating material to prevent electrical short circuiting. For this purpose, it is not always necessary that the whole of the protrusion amount setting member <NUM> be made of an insulating material. For example, only the second contact portion <NUM> may be made of an insulating material. Alternatively, the surface of the second contact portion <NUM> with which the front end surface 11a of the sample <NUM> makes contact may be coated with an insulating film. The configuration for electrical insulation between the sample <NUM> and the protrusion amount setting member <NUM> can also be applied to embodiments other than the fifth embodiment. In addition, the method of placing the sample in position using the protrusion amount setting member can also be applied to the foregoing first embodiment (see <FIG>) to fourth embodiment.

Specific examples of the sample positioning jig associated with the fifth embodiment of the present invention are described below. The effects of the sample positioning jig associated with the fifth embodiment of the present invention will be described after the description of the specific examples.

<FIG> is a perspective view showing a first specific example of the sample positioning jig associated with the fifth embodiment of the present invention. As shown in <FIG>, the sample positioning jig, <NUM>-<NUM>, has a protrusion amount setting member <NUM>-<NUM>, a first tool <NUM>-<NUM>, and a second tool <NUM>-<NUM>.

<FIG> is a perspective view showing the configuration of the first tool <NUM>-<NUM> of the sample positioning jig <NUM>-<NUM> shown in <FIG>. <FIG> is a perspective view showing the configurations of the protrusion amount setting member <NUM>-<NUM> and the second tool <NUM>-<NUM> equipped in the sample positioning jig <NUM>-<NUM> shown in <FIG>.

As shown in <FIG>, the first tool <NUM>-<NUM> has a holder receiving portion <NUM>, a holding knob <NUM>, and a pair of guide grooves <NUM>. When the sample holder (not shown) is placed on the first tool <NUM>-<NUM>, the holder receiving portion <NUM> receives the sample holder.

The holding knob <NUM> is used to hold the sample holder placed on the holder receiving portion <NUM>. The holding knob <NUM> has a pair of externally threaded portions (not shown). A pair of internally threaded portions <NUM> matching the externally threaded portions is formed in the first tool <NUM>-<NUM>. The internally threaded portions <NUM> of one pair are formed to the left and right of the front of the first tool <NUM>-<NUM>. The externally threaded portion of the holding knob <NUM> engages one of the internally threaded portions (not shown). Where the internally threaded portions <NUM> are formed on both sides, the holding knob <NUM> can be mounted to the side allowing for easy manipulation and the sample positioning jig <NUM>-<NUM> can be used, irrespective of whether the operator is right-handed or left-handed.

When the second tool <NUM>-<NUM> is mounted to the first tool <NUM>-<NUM>, the guide grooves <NUM> guide the first tool <NUM>-<NUM> to its mounting position. The guide grooves <NUM> of one pair are formed to the left and right of the front of the first tool <NUM>-<NUM>.

As shown in <FIG>, the second tool <NUM>-<NUM> has an abutting portion <NUM>, a holding knob <NUM>, a pair of arm portions <NUM>, and a mounting block <NUM>. When the second tool <NUM>-<NUM> is mounted to the first tool <NUM>-<NUM>, the abutting portion <NUM> is brought into abutting engagement with the first tool <NUM>-<NUM>. The holding knob <NUM> is used to hold the second tool <NUM>-<NUM> to the first tool <NUM>-<NUM>. The holding knob <NUM> has a pair of externally threaded portions (not shown). A pair of internally threaded portions <NUM> matching the externally threaded portions is formed in the second tool <NUM>-<NUM>. The internally threaded portions <NUM> are formed to the left and right of the front of the second tool <NUM>-<NUM>. The externally threaded portion of the holding knob <NUM> engages one (not shown) of the internally threaded portions <NUM>. Where the internally threaded portions <NUM> are formed on both sides, the holding knob <NUM> can be mounted to the side allowing for easy manipulation and the sample positioning jig <NUM>-<NUM> can be used, irrespective of whether the operator is right-handed or left-handed.

When the second tool <NUM>-<NUM> is mounted to the first tool <NUM>-<NUM>, the arm portions <NUM> are inserted into the guide grooves <NUM> of the first tool <NUM>-<NUM>. The arm portions <NUM> are formed to the left and right of the front of the second tool <NUM>-<NUM>. The mounting block <NUM> is used to mount the protrusion amount setting member <NUM>-<NUM>, and is screwed to the abutting portion <NUM>.

In the first specific example, the abutting portion <NUM> and the arm portions <NUM> are formed integrally, and the mounting block <NUM> is screwed to the abutting portion <NUM>. The present invention is not restricted to the use of this structure. For example, the abutting portion <NUM>, arm portions <NUM>, and mounting block <NUM> may be formed integrally.

<FIG> is a cross-sectional view showing a structure for mounting the protrusion amount setting member <NUM>-<NUM> to the second tool <NUM>-<NUM>. <FIG> is a perspective view of this mounting structure. As shown in <FIG> and <FIG>, the protrusion amount setting member <NUM>-<NUM> is mounted to the mounting block <NUM> of the second tool <NUM>-<NUM> using a pair of guide pins <NUM>, a retaining screw <NUM>, and a spring <NUM>. The spring <NUM> is equivalent to a biasing member in the same manner as the aforementioned spring <NUM> (see <FIG>). One end of the spring <NUM> is inserted in a pocket portion 56a formed in the protrusion amount setting member <NUM>-<NUM>, whereas the other end of the spring <NUM> is inserted in a threaded hole 73a formed in the mounting block <NUM>. A set screw <NUM> having a hexagonal hole is inserted in the threaded hole 73a and movable in the direction of the center axis of the threaded hole 73a. The set screw <NUM> can adjust the biasing force of the protrusion amount setting member <NUM>-<NUM> using the spring <NUM> by varying the end position of the spring <NUM> in the direction of the center axis of the threaded hole 73a.

The pair of guide pins <NUM> suppresses positional deviation of the protrusion amount setting member <NUM>-<NUM> in the direction of rotation indicated by the arrows in <FIG>. The guide pins <NUM> are disposed parallel to each other. The guide pins <NUM> guide the protrusion amount setting member <NUM>-<NUM> such that it can move toward and away from the mounting block <NUM>. One end of each guide pin <NUM> is inserted in a respective one of first pin insertion holes (not shown) formed in the protrusion amount setting member <NUM>-<NUM>. The other end of each guide pin <NUM> is inserted in a respective one of second pin insertion holes 73b (see <FIG>) formed in the mounting block <NUM>.

The retaining screw <NUM> defines a maximum allowable distance of the protrusion amount setting member <NUM>-<NUM> from the mounting block <NUM> to prevent one end of the spring <NUM> from coming out of its respective pocket portion 56a and prevent one end of each guide pin <NUM> from coming out of its respective first pin insertion hole. The retaining screw <NUM> has a head 76a, a shank 76b, and an externally threaded portion 76c which are formed internally. The mounting block <NUM> has a stepped hole consisting of a larger hole 73c and a smaller hole 73d. The head 76a of the retaining screw <NUM> is received in the larger hole 73c. The shank 76b of the retaining screw <NUM> is inserted in the smaller hole 73d. The larger hole 73c has a diameter set greater than that of the head 76a. The smaller hole 73d has a diameter set greater than that of the shank 76b. A clearance G1 corresponding to the dimensional difference between the smaller hole 73d and the shank 76b is present between the smaller hole 73d and the shank 76b. Because of the presence of the clearance G1, the mounting block <NUM> can appropriately absorb wobbling motion of the retaining screw <NUM>. On the other hand, the protrusion amount setting member <NUM>-<NUM> is provided with an internally threaded portion 56b. The externally threaded portion 76c of the retaining screw <NUM> engages the internally threaded portion 56b. With respect to the structure of the retaining screw <NUM>, the externally threaded portion 76c may be formed almost over the whole length of the shank 76b.

In the sample positioning jig <NUM>-<NUM> of the configuration described above, the protrusion amount setting member <NUM>-<NUM> is biased away from the mounting block <NUM> while guided by the pair of guide pins <NUM> by the biasing force of the spring <NUM>. The head 76a of the retaining screw <NUM> is urged to bear against the steps of the stepped holes having the larger hole 73c and the smaller hole 73d by the biasing force of the spring <NUM> and so the protrusion amount setting member <NUM>-<NUM> is kept spaced a given distance from the mounting block <NUM>. Under this condition, if the protrusion amount setting member <NUM>-<NUM> is pushed in toward the mounting block <NUM> against the biasing force of the spring <NUM>, the head 76a of the retaining screw <NUM> separates from the steps of the stepped holes (larger hole 73c and smaller hole 73d) as shown in <FIG>.

A procedure for placing the sample <NUM> in position using the sample positioning jig <NUM>-<NUM> is next described. First, the operator places the sample holder including the shield member <NUM> on the holder receiving portion <NUM> of the first tool <NUM>-<NUM>. Then, the operator rotationally manipulates the holding knob <NUM>, thus holding the sample holder to the first tool <NUM>-<NUM>. At this time, the shield member <NUM> and the sample holder are held together by the holding knob <NUM>.

Then, the operator mounts the second tool <NUM>-<NUM> to the first tool <NUM>-<NUM>. During this operation, the operator inserts the arm portions <NUM> of the second tool <NUM>-<NUM> into the guide grooves <NUM> of the first tool <NUM>-<NUM>, and the abutting portion <NUM> of the second tool <NUM>-<NUM> is made to bear against the first tool <NUM>-<NUM>. Consequently, the first contact portion <NUM>-<NUM> of the protrusion amount setting member <NUM>-<NUM> makes contact with the front end surface 29b of the shield member <NUM>. The spring <NUM> biases the protrusion amount setting member <NUM>-<NUM> in such a way as to push the first contact portion <NUM>-<NUM> against the front end surface 29b of the shield member <NUM>. The protrusion amount setting member <NUM>-<NUM> is pushed in towards the mounting block <NUM> against the biasing force of the spring <NUM>.

At this time, as shown in <FIG>, if the clearance G1 is present between the smaller hole 73d and the shank 76b, the clearance G1 permits the retaining screw <NUM> to sway. The swaying motion of the retaining screw <NUM> is caused by tilt of the protrusion amount setting member <NUM>-<NUM> according to the tilt angle θa (see <FIG>) of the front end surface 29b of the shield member <NUM>. Consequently, the first contact portion <NUM>-<NUM> of the protrusion amount setting member <NUM>-<NUM> can be brought into intimate contact with the front end surface 29b of the shield member <NUM>.

Then, the operator holds the second tool <NUM>-<NUM> to the first tool <NUM>-<NUM> by rotationally manipulating the holding knob <NUM>. Then, the operator places the sample <NUM> on the shield member <NUM>. Then, the front end surface 11a of the sample <NUM> is pushed against the second contact portion <NUM>-<NUM> of the protrusion amount setting member <NUM>-<NUM> by the aforementioned method. Then, the operator holds the sample <NUM> to the shield member <NUM> with the clip <NUM>. The following procedure is the same as already described in the fifth embodiment and so a description thereof is omitted.

<FIG> is a side elevation showing a second specific example of the sample positioning jig associated with the fifth embodiment of the present invention. <FIG> is a perspective view showing the configuration of a first tool <NUM>-<NUM> equipped in a sample positioning jig <NUM>-<NUM> shown in <FIG>. <FIG> is a perspective view showing the configurations of a second tool <NUM>-<NUM> and a protrusion amount setting member <NUM>-<NUM> equipped in the sample positioning jig <NUM>-<NUM> shown in <FIG>.

As shown in <FIG>, the sample positioning jig <NUM>-<NUM> has the protrusion amount setting member <NUM>-<NUM>, the first tool <NUM>-<NUM>, and the second tool <NUM>-<NUM>. As shown in <FIG>, the first tool <NUM>-<NUM> has a holder receiving portion <NUM>, a holding knob <NUM>, a recessed portion <NUM>, three mounting pins <NUM>, and a pair of upper and lower abutting surfaces <NUM>. When a sample holder (not shown) is placed on the first tool <NUM>-<NUM>, the holder receiving portion <NUM> receives the sample holder.

The holding knob <NUM> is used to hold the sample holder placed on the holder receiving portion <NUM>. The holding knob <NUM> has an externally threaded portion (not shown) which engages an internally threaded portion (not shown) formed in the first tool <NUM>-<NUM>. The recessed portion <NUM> is recessed more deeply than the abutting surfaces <NUM>. The recessed portion <NUM> of the first tool <NUM>-<NUM> has a hollow space extending therethrough. The abutting surfaces <NUM> of one pair are formed to be in flush with each other.

The mounting pins <NUM> are used to mount the second tool <NUM>-<NUM> to the first tool <NUM>-<NUM>. The three mounting pins <NUM> are arranged at the vertices of a triangle as the first tool <NUM>-<NUM> is viewed from the front. Two of the three mounting pins <NUM> are arranged on the upper abutting surface <NUM>, while the remaining one pin <NUM> is disposed on the lower abutting surface <NUM>. As shown in <FIG>, each of the mounting pins <NUM> has a head 83a, a shank 83b, and an externally threaded portion 83c which are integral with each other. On the other hand, an internally threaded portion <NUM> is formed in the abutting surface <NUM> of the first tool <NUM>-<NUM>. The mounting pins <NUM> are secured to the first tool <NUM>-<NUM> by bringing the externally threaded portion 83c into engagement with the internally threaded portion <NUM>.

As shown in <FIG>, the second tool <NUM>-<NUM> has three mounting holes <NUM>, a pair of upper and lower abutting surfaces <NUM>, a receiving portion <NUM>, and a recessed groove <NUM>. The three mounting holes <NUM> are formed in the second tool <NUM>-<NUM> in a corresponding manner to the aforementioned three mounting pins <NUM>. Each mounting hole <NUM> has an inside diameter set slightly greater than the outside diameter of the head 83a of each mounting pin <NUM>.

As shown in <FIG>, the second tool <NUM>-<NUM> is provided with threaded holes <NUM> perpendicular to the mounting holes <NUM>. A ball plunger <NUM> is inserted in each threaded hole <NUM> and has a spring (not shown) and a ball 91a biased by the spring. The ball 91a protrudes radially inwardly of the respective mounting hole <NUM> from its inner surface.

A pair of abutting surfaces <NUM> is formed on the second tool <NUM>-<NUM> in a corresponding manner to the pair of abutting surfaces <NUM>. The abutting surfaces <NUM> are formed flush with each other. The receiving portion <NUM> receives the protrusion amount setting member <NUM>-<NUM> and is formed in the center of the second tool <NUM>-<NUM> as viewed from the front of the second tool <NUM>-<NUM>. The recessed groove <NUM> is recessed more deeply than the abutting surfaces <NUM> to permit the operator to check the first contact portion <NUM>-<NUM> and the second contact portion <NUM>-<NUM> of the protrusion amount setting member <NUM>-<NUM> from a side of the sample positioning jig <NUM>. The recessed groove <NUM> is formed horizontally from the left and right ends of the receiving portion <NUM> to the left and right ends of the second tool <NUM>-<NUM> as viewed from the front of the second tool <NUM>-<NUM>.

<FIG> is a cross-sectional view showing a structure for mounting the protrusion amount setting member <NUM>-<NUM> to the second tool <NUM>-<NUM>. As shown in this figure, the protrusion amount setting member <NUM>-<NUM> is mounted in the receiving portion <NUM> of the second tool <NUM>-<NUM> using a retaining screw <NUM> and a spring <NUM>. The spring <NUM> acts as a biasing member in the same manner as the aforementioned spring <NUM> (see <FIG>). One end of the spring <NUM> is inserted in a first pocket portion <NUM> formed in the protrusion amount setting member <NUM>-<NUM>, the other end of the spring <NUM> being inserted in a second pocket portion <NUM> formed in the second tool <NUM>-<NUM>.

The retaining screw <NUM> defines a maximum allowable distance of the protrusion amount setting member <NUM>-<NUM> from the rear end surface 88a of the receiving portion <NUM> to prevent one end of the spring <NUM> from coming out of the first pocket portion <NUM> and prevent the other end of the spring <NUM> from coming out of the second pocket portion <NUM>. The retaining screw <NUM> has a head 92a, a shank 92b, and an externally formed portion 92c which are integral with each other. On the other hand, the second tool <NUM>-<NUM> is provided with a stepped hole consisting of a larger hole 96a and a smaller hole 96b. The head 92a of the retaining screw <NUM> is received in the larger hole 96a. The shank 92b of the retaining screw <NUM> is inserted in the smaller hole 96b. The larger hole 96a has a diameter set greater than that of the head 92a. The smaller hole 96b has a diameter set greater than that of the shank 92b. A clearance G2 corresponding to the dimensional difference between the smaller hole 96b and the shank 92b is present between the smaller hole 96b and the shank 92b. Because of the presence of the clearance G2, the second tool <NUM>-<NUM> can appropriately absorb swaying motion of the retaining screw <NUM>. On the other hand, an internally threaded portion <NUM> is formed in the protrusion amount setting member <NUM>-<NUM>. The externally threaded portion 92c of the retaining screw <NUM> engages the internally threaded portion <NUM>.

As shown in <FIG>, a pair of left and right positioning grooves <NUM> is formed in the top surface of the first tool <NUM>-<NUM>. A pair of left and right positioning grooves <NUM> is formed in the top surface of the second tool <NUM>-<NUM> in a corresponding manner to the positioning grooves <NUM> in the first tool.

Positional deviation of the protrusion amount setting member <NUM>-<NUM> in the direction of rotation is suppressed by a pair of guide pins in the same manner as in the first specific example. With respect to the retaining screw <NUM>, the internally threaded portion 92c may be formed substantially over the whole length of the shank 92b.

In the sample positioning jig <NUM>-<NUM> of the above-described configuration, the protrusion amount setting member <NUM>-<NUM> is biased away from the rear end surface 88a of the receiving portion <NUM> by the biasing force of the spring <NUM>. Because the head 92a of the retaining screw <NUM> is urged to bear against the steps of the stepped hole (96a, 96b) by the biasing force of the spring <NUM>, the protrusion amount setting member <NUM>-<NUM> is kept spaced a given distance from the rear end surface 88a of the receiving portion <NUM>. Under this condition, if the protrusion amount setting member <NUM>-<NUM> is pushed in toward the deepest part of the receiving portion <NUM> against the biasing force of the spring <NUM>, the head 92a of the retaining screw <NUM> separates from the steps of the stepped hole (96a, 96b) as shown in <FIG>.

A procedure for placing the sample <NUM> in position using the sample positioning jig <NUM>-<NUM> is next described. First, the operator places the sample holder including the shield member <NUM> on the holder receiving portion <NUM> of the first tool <NUM>-<NUM>. Then, the operator holds the sample holder to the first tool <NUM>-<NUM> by rotationally manipulating the holding knob <NUM>. At this time, the shield member <NUM> is held together with the sample holder by the holding knob <NUM>.

Then, the operator mounts the second tool <NUM>-<NUM> to the first tool <NUM>-<NUM>. During this operation, the operator aligns the first tool <NUM>-<NUM> and the second tool <NUM>-<NUM> in position while using the positioning grooves <NUM> and <NUM> for the first tool <NUM>-<NUM> and the second tool <NUM>-<NUM>, respectively, as indicia. The operator brings the abutting surfaces <NUM> and <NUM> of the tools into abutting engagement with each other while inserting the pin <NUM> for mounting of the first tool <NUM>-<NUM> in the hole <NUM> for mounting of the second tool <NUM>-<NUM>. Consequently, the first contact portion <NUM>-<NUM> of the protrusion amount setting member <NUM>-<NUM> makes contact with the front end surface 29b of the shield member <NUM>. The spring <NUM> biases the protrusion amount setting member <NUM>-<NUM> in such a way as to push the first contact portion <NUM>-<NUM> against the front end surface 29b of the shield member <NUM>. The protrusion amount setting member <NUM>-<NUM> is pushed in toward the deepest part of the receiving portion <NUM> against the biasing force of the spring <NUM>.

At this time, if the clearance G2 is present between the smaller hole 96b and the shank 92b as shown in <FIG>, the clearance G2 permits the retaining screw <NUM> to sway. Swaying motion of the retaining screw <NUM> is caused by tilt of the protrusion amount setting member <NUM>-<NUM> according to the tilt angle θa (see <FIG>) of the front end surface 29b of the shield member <NUM>. Consequently, the first contact portion <NUM>-<NUM> of the protrusion amount setting member <NUM>-<NUM> can be brought into intimate contact with the front end surface 29b of the shield member <NUM>.

On the other hand, the ball 91a of the ball plunger <NUM> is once pushed in by the head 83a of the mounting pin <NUM> as shown in <FIG>. Then, the ball 91a rises over the head 92a. The ball 91a comes into contact with an inclined surface 83d formed at the boundary between the head 83a and the shank 83b while the abutting surfaces <NUM> and <NUM> are made to abut each other. The ball 91a is pushed against the inclined surface 83d by a force F3 of a spring incorporated in the ball plunger <NUM>. A pull-in force F4 is applied to the second tool <NUM>-<NUM> in a sense parallel to the direction of the center axis of the mounting pin <NUM>. The second tool <NUM>-<NUM> is secured to the first tool <NUM>-<NUM> by the pull-in force F4.

Then, the operator places the sample <NUM> on the shield member <NUM> and then pushes the front end surface 11a of the sample <NUM> against the second contact portion <NUM>-<NUM> of the protrusion amount setting member <NUM>-<NUM> by the method described above. Then, the operator secures the sample <NUM> to the shield member <NUM> with the clip <NUM>. The sequent procedure is the same as the procedure set forth in the fifth embodiment and so a repetition of the description thereof is omitted.

In the second specific example above, in order to mount the second tool <NUM>-<NUM> to the first tool <NUM>-<NUM> and to hold them together, the mounting pin <NUM>, the mounting hole <NUM>, the threaded hole <NUM>, and the ball plunger <NUM> are used. The present invention is not restricted to this structure. For example, the tools may be held together magnetically as in a third specific example given below.

<FIG> is a perspective view showing the configuration of a first tool <NUM>-<NUM> as a third specific example of the sample positioning jig associated with the fifth embodiment of the present invention. <FIG> is a perspective view showing the configurations of a second tool <NUM>-<NUM> and a protrusion amount setting member <NUM>-<NUM>. In this third specific example, only the differences with the configurations of the tools in the second specific example are described. A description of similarities is omitted.

As shown in <FIG>, the first tool <NUM>-<NUM> has a holder receiving portion <NUM>, a holding knob <NUM>, a recessed portion <NUM>, three set screws <NUM>, and a pair of upper and lower abutting surfaces <NUM>. The holder receiving portion <NUM>, holding knob <NUM>, recessed portion <NUM>, and upper and lower abutting surfaces <NUM> of one pair are similar in configuration to their respective counterparts of the second specific example, i.e., holder receiving portion <NUM>, holding knob <NUM>, recessed portion <NUM>, and upper and lower abutting surfaces <NUM> of one pair.

The three set screws <NUM> are disposed at the positions of the vertices of a triangle as viewed from the front of the first tool <NUM>-<NUM>. Two of the three set screws <NUM> are disposed on the upper abutting surface <NUM>, the remaining one set screw <NUM> being disposed on the lower abutting surface <NUM>. As shown in <FIG>, each of the set screws <NUM> engages a respective one of threaded holes <NUM> formed in the first tool <NUM>-<NUM>. Each set screw <NUM> is made of a magnetic material and has a hexagonal hole. One end of the set screw <NUM> is either flush with the abutting surface <NUM> at the exit of the corresponding threaded hole <NUM> that opens to the abutting surface <NUM> or slightly recessed rearwardly of the threaded hole <NUM> from the abutting surface <NUM>.

As shown in <FIG>, the second tool <NUM>-<NUM> has three magnets <NUM>, a pair of upper and lower abutting surfaces <NUM>, a receiving portion <NUM>, and a recessed groove <NUM>. The upper and lower abutting surfaces <NUM>, receiving portion <NUM>, and recessed groove <NUM> are similar in configuration to the pair of upper and lower abutting surfaces <NUM>, receiving portion <NUM>, and recessed groove <NUM>, respectively, in the above-described second specific example. The protrusion amount setting member <NUM>-<NUM> is mounted to the second tool <NUM>-<NUM>. A structure for mounting the protrusion amount setting member <NUM>-<NUM> to the second tool <NUM>-<NUM> is similar to the mounting structure of the second specific example. As shown in <FIG>, a pair of left and right positioning grooves <NUM> is formed in the top surface of the first tool <NUM>-<NUM>, and a pair of left and right positioning grooves <NUM> is formed in the top surface of the second tool <NUM>-<NUM> in a corresponding manner to the positioning grooves <NUM> in the same manner as in the second specific example.

The three magnets <NUM> are buried in the second tool <NUM>-<NUM> in a corresponding manner to the three set screws <NUM> and secured in the second tool <NUM>-<NUM> by press fit, adhesive bonding, or other technique. One end surface of each magnet <NUM> is in flush with the abutting surface <NUM> or slightly recessed from it.

A procedure for placing the sample <NUM> in position using the sample positioning jig equipped with the first tool <NUM>-<NUM> and the second tool <NUM>-<NUM> of the above-described configurations is next described. First, the operator mounts the second tool <NUM>-<NUM> to the first tool <NUM>-<NUM>. At this time, the operator aligns the first and second tools <NUM>-<NUM>, <NUM>-<NUM> in position using the groove <NUM> for positioning of the first tool <NUM>-<NUM> and the groove <NUM> for positioning of the second tool <NUM>-<NUM> as indicia. Consequently, the three set screws <NUM> and the three magnets <NUM> are aligned in position. The operator brings the magnets <NUM> of the second tool <NUM>-<NUM> close to the set screw <NUM> of the first tool <NUM>-<NUM>. As a result, as shown in <FIG>, a magnetic attractive force F5 produced among the set screws <NUM> and the magnets <NUM> brings the abutting surfaces <NUM> and <NUM> of the tools into abutting engagement with each other. Hence, the second tool <NUM>-<NUM> can be mounted to the first tool <NUM>-<NUM> and both tools can be secured together.

With the sample positioning jig <NUM> associated with the fifth embodiment of the present invention including the above-described first, second, and third specific examples, the amount of protrusion L of the sample <NUM> is established by bringing the first contact portion <NUM> out of the first contact portion <NUM> and the second contact portion <NUM> of the protrusion amount setting member <NUM> into contact with the front end surface 29b of the shield member <NUM> and bringing the second contact portion <NUM> into contact with the front end surface 11a of the sample <NUM>. Therefore, the sample positioning jig <NUM> associated with the fifth embodiment of the present invention makes it possible to set the amount of protrusion L of the sample <NUM> with simple manipulations. Furthermore, where the sample <NUM> is set within a glove box, a work for setting the amount of protrusion can be done easily. Where plural samples <NUM> having different desired amounts of protrusion are handled, plural protrusion amount setting members <NUM> which are different in the aforementioned depth D (see <FIG>) are prepared, and one protrusion amount setting member <NUM> matching the desired amount of protrusion is selected from them and used. This leads to favorable results. Furthermore, as long as the first tool <NUM> capable of holding the shield member <NUM> is equipped, the amount of protrusion L of the sample <NUM> can be set irrespective of the material and shape of the shield member <NUM>.

<FIG> is a schematic side elevation showing the configuration of a sample positioning jig associated with a sixth embodiment of the present invention. This sample positioning jig is similar to the sample positioning jig (see <FIG>) associated with the fifth embodiment except that the first tool <NUM> and the second tool <NUM> are combined in a unitary tool. Specifically, as shown in <FIG>, the sample positioning jig, <NUM>, has a tool <NUM> secured to a holder body <NUM> with a screw <NUM>, the tool <NUM> being of a unitary construction.

In the sample positioning jig <NUM> associated with the sixth embodiment of the present invention, the tool <NUM> is of a unitary construction and so manipulations for mounting the second tool <NUM> to the first tool <NUM> and detaching the second tool <NUM> from the first tool <NUM> are dispensed with, unlike the sample positioning jig associated with the fifth embodiment. Therefore, the amount of protrusion L of the sample <NUM> can be set with simpler manipulations.

<FIG> is a schematic side elevation showing the configuration of a sample positioning jig associated with a seventh embodiment of the present invention. This sample positioning jig is similar to the sample positioning jig (see <FIG>) associated with the fifth embodiment except that the protrusion amount setting member <NUM> is made of a transparent material and that an observation window <NUM> is formed in the first tool <NUM>. Examples of the transparent material of the setting member <NUM> include glass and resins.

The observation window <NUM> is formed at a position where the milled portion 11b of the sample <NUM> can be observed through the protrusion amount setting member <NUM>. The observation window <NUM> is formed, for example, by forming a through hole in the first tool <NUM> and plugging the through hole with a transparent material such as glass or resin. Alternatively, the observation window <NUM> may be made only of a through hole formed in the first tool <NUM>.

With the sample positioning jig <NUM> associated with the seventh embodiment of the present invention, after the amount of protrusion of the sample <NUM> is set using the protrusion amount setting member <NUM>, the amount of protrusion of the sample <NUM> can be checked visually from Z1 direction shown in <FIG> with an optical microscope or a camera. Consequently, it is possible to check on the first tool <NUM> whether the amount of protrusion of the sample <NUM> is coincident with the desired amount of protrusion before the first tool <NUM> is taken out of the holder body <NUM>.

In the sample positioning jig associated with the seventh embodiment of the present invention, the first tool <NUM> is provided with the observation window <NUM>. The present invention is not limited to this structure. The observation window may be formed in the tool <NUM> of the sample positioning jig associated with the fifth embodiment or in the tool <NUM> of the sample positioning jig associated with the sixth embodiment.

<FIG> is a schematic side elevation showing the configuration of a sample positioning jig associated with an eighth embodiment of the present invention. As shown in <FIG>, the sample positioning jig, <NUM>, is made of a protrusion amount setting member <NUM>. This setting member <NUM> has at least one magnet <NUM> in addition to the first contact portion <NUM> and the second contact portion <NUM>. The magnet <NUM> is disposed on the surface of the first contact portion <NUM> and in opposition to the front end surface 29b of the shield member <NUM>. The number of the magnets <NUM> of the protrusion amount setting member <NUM> may be singular or plural. The shield member <NUM> is made of a magnetic material such as a magnetic stainless steel.

Then, a procedure for placing the sample <NUM> in position using the sample positioning jig <NUM> of the above construction is described. First, the operator brings the front end surface 29b of the shield member <NUM> and the first contact portion <NUM> of the protrusion amount setting member <NUM> closer to each other. This produces a magnetic attracting force between the shield member <NUM> and the protrusion amount setting member <NUM>, pushing the first contact portion <NUM> of the protrusion amount setting member <NUM> against the front end surface 29b of the shield member <NUM>.

Then, the operator makes the front end surface 11a of the sample <NUM> strike against the second contact portion <NUM> of the protrusion amount setting member <NUM> while maintaining the first contact portion <NUM> of the protrusion amount setting member <NUM> in contact with the front end surface 29b of the shield member <NUM>. The operator then holds the sample <NUM> to the shield member <NUM> with the clip <NUM>. Then, the operator removes the protrusion amount setting member <NUM> from the shield member <NUM>. Thus, the setting of the sample <NUM> is complete.

With the sample positioning jig associated with the eighth embodiment of the present invention, the amount of protrusion of the sample <NUM> can be set by the use of only the protrusion amount setting member <NUM> having the magnet <NUM>. Therefore, the component count of the sample positioning jig <NUM> can be reduced as compared with the configurations of the above-described fifth through seventh embodiments. Also, miniaturization of the sample positioning jig <NUM> can be accomplished.

<FIG> is a schematic side elevation showing the configuration of a sample positioning jig associated with a ninth embodiment of the present invention. As shown in <FIG>, the sample positioning jig <NUM> has a clip-on protrusion amount setting member 56c which has a first contact portion <NUM> and a second contact portion <NUM>. One end of a clip-on spring <NUM> is attached to an end of the protrusion amount setting member 56c, the other end being attached to a clip part <NUM>. The clip part <NUM> is so supported as to be swingable about a pivotal point <NUM> that is interposed between the protrusion amount setting member 56c and the clip part <NUM>. A force F7 of the spring <NUM> is applied outwardly to the protrusion amount setting member 56c and to the clip part <NUM>.

On the other hand, the shield member <NUM> is held to the holder body <NUM>, for example, by pressing both ends of the shield member <NUM> against the holder body <NUM> with a spring-loaded securing pin (not shown). Where the shield member <NUM> is made of a magnetic material, a magnet (not shown) may be incorporated in the holder body <NUM> so that the shield member <NUM> may be held to the holder body <NUM> by the magnetic attracting force of the magnet.

A procedure for placing the sample <NUM> in position by the use of the sample positioning jig <NUM> of the above-described configuration is then described. First, the operator holds the shield member <NUM> to the holder body <NUM>. Then, the operator mounts the protrusion amount setting member 56c to the shield member <NUM>. At this time, the operator brings one end of the protrusion amount setting member 56c and one end of the clip part <NUM> closer to each other against the biasing force of the spring <NUM>. Under this condition, the shield member <NUM> is squeezed in between the protrusion amount setting member 56c and the clip part <NUM>, and then the force of the spring <NUM> is relieved. The result is that the shield member <NUM> is squeezed between the protrusion amount setting member 56c and the clip part <NUM>. In consequence, the first contact portion <NUM> of the protrusion amount setting member 56c is pushed against the front end surface 29b of the shield member <NUM> by the biasing force of the spring <NUM>.

After placing the sample <NUM> on the holder body <NUM>, the operator makes the front end surface 11a of the sample <NUM> strike against the second contact portion <NUM> of the protrusion amount setting member 56c. The operator then holds the sample <NUM> to the shield member <NUM> with the clip <NUM>. Then, the operator takes the protrusion amount setting member 56c out of the shield member <NUM>. At this time, the operator brings one end of the protrusion amount setting member 56c and one end of the clip part <NUM> closer to each other against the biasing force of the spring <NUM>. Under this condition, the protrusion amount setting member 56c and the clip part <NUM> are separated from the shield member <NUM>. Thus, the setting of the sample <NUM> is complete.

With the sample positioning jig associated with the ninth embodiment of the present invention, the amount of protrusion of the sample <NUM> can be set by the use of only the clip-on protrusion amount setting member 56c. Therefore, the component count of the sample positioning jig <NUM> can be reduced as compared with the configurations of the above-described fifth through seventh embodiments. Also, miniaturization of the sample positioning jig <NUM> can be accomplished.

The clip-on protrusion amount setting member 56c may be used where a protrusion 29d for the clip is formed at the front end of the shield member <NUM> as shown in <FIG>. In this case, the protrusion 29d of the shield member <NUM> is squeezed in between the protrusion amount setting member 56c and the clip part <NUM> by the force F7 of the spring <NUM>. Thus, the first contact portion <NUM> of the protrusion amount setting member 56c is pushed against the front end surface 29b of the shield member <NUM> by the biasing force of the spring <NUM>. Consequently, the amount of protrusion of the sample <NUM> can be set by bringing the front end surface 11a of the sample <NUM> into contact with the second contact portion <NUM> of the protrusion amount setting member 56c.

The clip-on protrusion amount setting member 56c may be mounted to a base member <NUM>, which supports the holder body <NUM>, by the use of the spring <NUM> as shown in <FIG>. Where this configuration is adopted, the operator first pulls in the protrusion amount setting member 56c away from the base member <NUM> against the biasing force of the spring <NUM>. Under this condition, the holder body <NUM> is placed on the base member <NUM>. Then, the operator pushes the protrusion amount setting member 56c against the shield member <NUM> against the biasing force of the spring <NUM>. As a result, the first contact portion <NUM> of the protrusion amount setting member 56c is pushed against the front end surface 29b of the shield member <NUM> by the biasing force of the spring <NUM>. As a consequence, the amount of protrusion of the sample <NUM> can be set by bringing the front end surface 11a of the sample <NUM> into contact with the second contact portion <NUM> of the protrusion amount setting member 56c.

<FIG> is a schematic side elevation showing the configuration of a sample positioning jig associated with a tenth embodiment of the present invention. This sample positioning jig, <NUM>, is similar to the sample positioning jig <NUM> (see <FIG>) associated with the above-described fifth embodiment excep that the sample <NUM> is sandwiched and secured between the shield member <NUM> and the sample locking member <NUM> and that the second contact portion <NUM> of the protrusion amount setting member <NUM> makes contact with the front end 31a of the sample locking member <NUM> and with the front end surface 11a of the sample <NUM>.

Where the sample <NUM> is placed in position by the use of the sample positioning jig <NUM> of the above-described configuration, the first contact portion <NUM> of the protrusion amount setting member <NUM> is first brought into contact with the front end surface 29b of the shield member <NUM> by the biasing force of the spring <NUM>. Then, the sample <NUM> and the sample locking member <NUM> are placed on the shield member <NUM>. Subsequently, the front end surface 11a of the sample <NUM> and the front end 31a of the sample locking member <NUM> are brought into contact with the second contact portion <NUM> of the protrusion amount setting member <NUM>. Under this condition, the sample <NUM> and the sample locking member <NUM> are secured together with the clip <NUM>. As a result, the shield member <NUM>, the sample <NUM>, and the sample locking member <NUM> are placed in position. Also, the amount of protrusion of the sample <NUM> is set. At this time, the front end 31a of the sample locking member <NUM> protrudes from the front end surface 11a of the sample <NUM>.

<FIG> is a schematic side elevation showing the configuration of a sample positioning jig associated with an eleventh embodiment of the present invention. <FIG> is a schematic plan view showing the configuration of the sample positioning jig of <FIG>. In <FIG>, the holder body <NUM>, clip <NUM>, and spring <NUM> are omitted.

The sample positioning jig <NUM> associated with the eleventh embodiment of the present invention is similar to the sample positioning jig <NUM> (see <FIG>) associated with the tenth embodiment except that a pair of protrusive portions 58a is formed on the second tool <NUM>. The protrusive portions 58a have protrusive surfaces 58b which define a reference plane for placing the shield member <NUM> and the sample locking member <NUM> in position.

Where the sample <NUM> is placed in position using the sample positioning jig <NUM> of the above configuration, the second tool <NUM> is mounted to the first tool <NUM> in such a way that the protrusive surfaces 58b of the protrusive portions 58a make contact with the edge portion 29a of the shield member <NUM>. At this time, the first contact portion <NUM> of the protrusion amount setting member <NUM> is brought into contact with the front end surface 29b of the shield member <NUM> by the biasing force of the spring <NUM>. Then, the sample <NUM> and the sample locking member <NUM> are placed on the shield member <NUM>. Then, the front end surface 11a of the sample <NUM> is brought into contact with the second contact portion <NUM> of the protrusion amount setting member <NUM>. Also, the front end 31a of the sample locking member <NUM> is brought into contact with the protrusive surfaces 58b of the protrusive portions 58a. Under this condition, the sample <NUM> and the sample locking member <NUM> are held together with the clip <NUM>. Consequently, the shield member <NUM>, the sample <NUM>, and the sample locking member <NUM> are placed in position, and the amount of protrusion of the sample <NUM> is set. In this case, the edge portion 29a of the shield member <NUM> and the front end 31a of the sample locking member <NUM> are aligned in position by bringing the edge portion 29a of the shield member <NUM> and the front end 31a of the sample locking member <NUM> into contact with the protrusive surfaces 58b of the pair of protrusive portions 58a.

A sample positioning jig associated with a twelfth embodiment of the present invention is applicable to the configuration of the sample holder <NUM> (see <FIG>) equipped in the ion milling apparatus associated with the foregoing second embodiment. <FIG> is a schematic side elevation showing the configuration of the sample positioning jig associated with the twelfth embodiment of the invention.

As shown in <FIG>, the sample positioning jig <NUM> has a protrusion amount setting member <NUM>, a first tool <NUM>, and a second tool <NUM> in the same manner as in the above-described fifth embodiment. The first tool <NUM> and the second tool <NUM> may be integral with each other. The first tool <NUM> has a stand-up portion 57a which is formed integrally with the first tool <NUM>. The present invention is not limited to this structure. Alternatively, the stand-up portion 57a may be secured to the first tool <NUM> with a screw or by other means. The stand-up portion 57a has a vertical reference surface 57b based on which the shield member <NUM> and the sample locking member <NUM> are placed in position.

Where the sample <NUM> is placed in position using the sample positioning jig <NUM> of the above-described configuration, the first tool <NUM> is first mounted to the clamp member <NUM> with the screw <NUM> and the second tool <NUM> is mounted to the first tool <NUM> with the screw <NUM> as shown in <FIG>. At this time, the shield member <NUM> is clamped to the clamp member <NUM> with the screw <NUM> by bringing the edge portion 29a of the shield member <NUM> into contact with the reference surface 57b of the stand-up portion 57a. Also, the sample locking member <NUM> is secured to the clamp member <NUM> with the screw <NUM> by bringing the front end 31a of the sample locking member <NUM> into contact with the reference surface 57b of the stand-up portion 57a. Consequently, the edge portion 29a of the shield member <NUM> and the front end 31a of the sample locking member <NUM> can be aligned in position. At this stage of operation, a gap slightly greater than the thicknesses-wise dimension of the sample <NUM> is secured between the clamp members <NUM> and <NUM>.

Then, the screw <NUM> is loosened to unlock the clamp member <NUM> and the first tool <NUM> from each other and then the sample holder <NUM> and the sample positioning jig <NUM> are reversed in sense relative to each other in the left/right direction as shown in <FIG>. The clamp member <NUM> and the first tool <NUM> are locked together with the screw <NUM>. At this time, the front end surface 29b of the shield member <NUM> is brought into contact with the first contact portion <NUM> of the protrusion amount setting member <NUM>. Before the sample holder <NUM> is placed on the sample positioning jig <NUM>, a sample <NUM> is inserted between the clamp members <NUM> and <NUM>. Then, the front end surface 11a of the sample <NUM> is brought into contact with the second contact portion <NUM> of the protrusion amount setting member <NUM>. Under this condition, the screws 45a and 45b of one pair (only 45b is shown in <FIG>) are tightened. Consequently, the amount of protrusion of the sample <NUM> can be set based on the edge portion 29a of the shield member <NUM>.

A positioning function similar to that of the reference surface 57b of the stand-up portion 57a can be imparted to the sample positioning jigs associated with the foregoing embodiments. For example, as shown in <FIG> above, the shield member <NUM> and the sample locking member <NUM> can be placed in position by forming a stand-up portion 57a-<NUM> on the first tool <NUM>-<NUM> and using the reference surface 57b-<NUM> of the stand-up portion 57a-<NUM>. With the second tool <NUM>-<NUM> shown in <FIG>, a surface on the opposite side of the abutting surface <NUM> is used as a reference surface, and the shield member <NUM> and the sample locking member <NUM> can be placed in position using the reference surface.

Claim 1:
A sample holder (<NUM>) for use in an ion milling apparatus (<NUM>) for milling a sample (<NUM>) by an ion beam, said sample holder (<NUM>) comprising:
a shield member (<NUM>) for shielding the sample (<NUM>) from that ion beam when installed in the ion milling apparatus (<NUM>) except for a portion to be milled, the shield member (<NUM>) having an edge portion for determining a milling position on or in the sample (<NUM>); and
a sample locking member (<NUM>) that cooperates with the shield member (<NUM>) such that the sample (<NUM>) is sandwiched and held therebetween;
wherein the sample locking member (<NUM>) has a support portion (<NUM>) which is disposed downstream of the edge portion in the direction of that ion beam and which cooperates with the edge portion to support the milled portion therebetween; and
wherein the support portion (<NUM>) has a first surface (<NUM>) making contact with the sample (<NUM>) and a second surface (<NUM>) making a given angle to the first surface (<NUM>), the given angle being equal to or less than <NUM>°,
characterized in that said sample (<NUM>) and said sample locking member (<NUM>) are arranged to be simultaneously milled by that ion beam when installed in the ion milling apparatus (<NUM>).