Patent Application
20080224374
This application claims priority under 35 U.S.C. ยง119 to Japanese Patent Application No. JP2006-032146 filed Feb. 9, 2006, the entire content of which is hereby incorporated by reference.
The present invention relates to a sample holding mechanism positioning and holding a sheet-like sample, and a sample working/observing apparatus possessing the sample holding mechanism and performing working/observation of the sample.
Hither to, as to a photomask used in manufacture of a flat panel display of liquid crystal or the like and an exposure process of semiconductor manufacture, a correction has been performed by a focused ion beam apparatus and the like. In order to precisely work and observe the sample, such as the photomask like this, or a substrate patterned by a photomask, it is necessary to precisely position the sample inside an apparatus such as the focused ion beam apparatus, and it is necessary to dissolve influences of expansion and contraction due to a temperature change in apparatus inside/outside. In order to cope with the problems like this, e.g., as an exposure apparatus for patterning the substrate that is the sample, there is proposed one in which, in a pre-alignment chamber existing on a path along which the sample is carried from the outside into the apparatus, there has been possessed means for raising a temperature of atmosphere in the pre-alignment chamber (e.g., JP-A-2005-32906). And, according to the exposure apparatus like this, in the pre-alignment chamber, it is possible to previously raise a temperature of the substrate by the temperature raising means during a process for pre-aligning the substrate. Therefore, when making the atmosphere in the apparatus into a vacuum state, even if the temperature of the substrate has changed by an adiabatic expansion of a gas, it is deemed that it is possible to adjust the temperature of the substrate so as to become the same temperature as an outside air temperature to thereby dissolve a distortion of the substrate, and further it is unnecessary to separately provide a time taken for the temperature adjustment.
However, in a case where only the sample having the same size is carried, although it is possible to directly carry the sample by a carrying system having a certain standard as mentioned above, in order to correspond to samples of various sizes, it is necessary to hold them by a sample holder so as to become the same carrying condition. Further, e.g., when the sheet-like sample like the photomask is carried between an outside and the apparatus inside, it is necessary to prevent a flexure of the sample and, in order to precisely position the sample, it is necessary to carry the sample while being held by the sample holder. From a necessity that the sample holder holds the sample, since the sample holder is formed, e.g., by a metal material or the like, whose rigidity is high, its thermal expansion coefficient is high in comparison with the sample, so that the flexure due to the temperature change is large. Further, a heat capacity is large, so that a time is required for becoming thermally equilibratory with an ambient temperature environment. Therefore, like JP-A-2005-32906, even if the temperature adjustment has been made only during the process for pre-aligning, the sample holder whose heat capacity is large cannot be thermally equilibrated. That is, inside the apparatus, the sample holder expands or contracts due to the temperature change and thus a position of the sample held by the sample holder changes (drifts), so that there has existed a problem that it becomes impossible to perform the precise working and observation.
This invention is one having been made in view of the above-mentioned circumstances, and one providing a sample holding mechanism in which, even if it expands or contracts due to the temperature change, the position of the sample being held is not changed and thus the sample can be precisely positioned and held, and a sample working/observing apparatus having possessed this sample holding mechanism.
In order to solve the above problems, this invention proposes the following means.
The present invention is a sample holding mechanism having possessed a sample holder mounting and holding a sheet-like sample on its upper face, and a base detachably supporting the sample holder, and characterized in that, between the sample holder and the base, there are detachably provided respectively a rotation support part supporting the sample holder so as to be rotatable with respect to the base, a slide support part supporting the sample holder so as to be slidable with respect to the base from a rotation center of the rotation support part toward a predetermined X-direction, and at least one butting support part supporting the sample holder so as to be slidable with respect to the base in the X-direction and a Y-direction intersecting perpendicularly to the X-direction, and, in the upper face of the sample holder, there are provided an X-direction positioning member disposed along the Y-direction from the rotation center of the rotation support part and positioning the sample in the X-direction while butting against one side of the sample, and a Y-direction positioning member disposed along the X-direction from the rotation center of the rotation support part and positioning the sample in the Y-direction while butting against the other side adjoining the one side of the sample.
According to the sample holding mechanism concerned with this invention, by the fact that the one side of the sample is butted against the X-direction positioning member and the other side is butted against the Y-direction positioning member, the sample can be carried while being positioned on the upper face of the sample holder having been separated from the base. And, under this state, the sample holder is mounted to the base having been provided in a predetermined position. By the fact that the sample holder is supported with respect to the base by at least three points of the rotation support part, the slide support part and the butting support part, it becomes a state having been certainly supported to the base. Further, since movements in the X-direction and the Y-direction are regulated by the rotation support part, and a rotation about an axis perpendicular to the base is regulated by the slide support part, the sample holder becomes a state having been positioned to the base. Here, in a state in which the sample holder has been mounted to the base, the X-direction positioning member of the sample holder is disposed along the Y-direction from the rotation center of the rotation support part, and the Y-direction positioning member is disposed along the X-direction from the rotation center of the rotation support part. Therefore, in the state in which the sample holder has been mounted to the base, the sample becomes a state in which the one side has been disposed along the Y-direction, the other side has been disposed along the X-direction, and an intersection point between the one side and the other side has been positioned in a position becoming approximately the same when seen in a plane as the rotation center of the rotation support part.
Further, when carrying the sample holder, and additionally just after the sample holder has been mounted to the base, a temperature of the sample holder changes due to a change in its surrounding environment, so that the sample holder itself expands or contracts. The sample holder is supported by the rotation support part so as to be rotatable with respect to the base. Additionally, it is supported by the slide support part so as to be slidable in the X-direction from the rotation center of the rotation support part and, further, supported by the butting support part so as to be slidable in the X-direction and the Y-direction. Therefore, as to the sample holder, there is no fact that a reaction force acts in accordance with the temperature change, and it can freely deform with the rotation support part being made a center. Further, also the X-direction positioning member and the Y-direction positioning member, which have been provided in the upper face of the sample holder, displace respectively in the Y-direction and the X-direction toward the rotation center of the rotation support part. That is, even if the sample holder has expanded or contracted due to the temperature change, the X-direction positioning member and the Y-direction positioning member merely slide with respect to the one side and the other side, of the sample, against which they respectively butt. Therefore, as to the sample, the one side is parallel to the Y-direction, the other side is parallel to the X-direction, and the intersection point between the one side and the other side can always keep the position becoming approximately the same when seen in the plane as the rotation center of the rotation support part.
Further, it is deemed to be more desirable that, in the above sample holding mechanism, in any one of a lower face of the sample holder and an upper face of the base, a convex part is provided in a position corresponding to each of the rotation support part, the slide support part and the butting support part, in the other of the lower face of the sample holder and the upper face of the base, there are formed respectively a fitting concave part fitting to the convex part so as to be rotatable in a position corresponding to the rotation support part, a fitting groove fitting to the convex part so as to be slidable in the X-direction in a position corresponding to the slide support part, and additionally a butting face butting against the convex part in a position corresponding to the butting support part, and the rotation support part is constituted by the fitting concave part and the corresponding convex part, the slide support part by the fitting groove and the corresponding convex part, and the butting support part by the butting face and the corresponding convex part, respectively.
According to the sample holding mechanism concerned with this invention, by fitting the convex part and the fitting concave part, which constitute the rotation support part, fitting the convex part and the fitting groove, which constitute the slide support part, and additionally butting the convex part and the butting face, which constitute the butting support part, the sample holder is easily attachable/detachable and supported to the base under a state having been precisely positioned.
Additionally, it is deemed to be more desirable that, in the above sample holding mechanism, a surface shape of each of the convex parts of the rotation support part, the slide support part and the butting support part is formed in a spherical face, the fitting concave part of the rotation support part is formed like a circular cone capable of fitting to the convex part, and the fitting groove of the slide support part is formed like a V-letter in section, capable of fitting to the convex part.
According to the sample holding mechanism concerned with this invention, by the facts that the surface shape of the convex part is formed in the spherical face and, further, that the corresponding fitting concave part is formed like the circular cone and the fitting groove like the V-letter in section, the fitting concave part and the fitting groove can be more easily fitted with respect to the convex parts, and the sample holder can be more precisely positioned with respect to the base.
Further, it is deemed to be more desirable that, in the above sample holding mechanism, in the upper face of the base, the convex parts are disposed in four places like a square, and, in the lower face of the sample holder, there are disposed the one fitting concave part, the one fitting groove and the two butting faces like the square while corresponding to the convex parts.
According to the sample holding mechanism concerned with this invention, in the upper face of the base, there are disposed the four convex parts like the square and, in the lower face of the sample holder, there are correspondingly disposed the fitting concave part, the fitting groove and the two butting faces like the square. Therefore, by selecting the convex part to be fitted to the fitting concave part, the sample can be made a different direction in every 90 degrees. That is, if the working and the observation are possible about a range of at least a quarter of the whole sample, it is possible to work and observe about the whole sample by changing the direction of the sample by 90 degrees at a time, so that, even if the sample becomes large in size, it is possible to work and observe the whole with a small working/observing range. Incidentally, by the facts that the convex part is provided in the base, and that the fitting concave part constituting the rotation support part is formed in the sample holder to which the sample is held, even if the direction of the sample is changed, a position of the rotation center of the rotation support part and a position of the intersection point between the one side and the other side of the sample can be always made the position becoming approximately the same when seen in the plane. Therefore, even if the sample holder has expanded or contracted due to the temperature change, it is possible to always perform a precise position control with the rotation center of the rotation support part, whose position does not change due to the temperature change, being made a reference point.
Further, it is deemed to be more desirable that, in the above sample holding mechanism, in a center of the base, around which the convex parts have been disposed like the square, there is provided an ascent-and-descent rotation means which pushes up the sample holder having been supported by the base by advancing or retreating in a vertical direction, and can rotate the pushed-up sample holder about an axis vertical with respect to the base.
According to the sample holding mechanism concerned with this invention, by pushing up the sample holder by the ascent-and-descent rotation means, it is possible to easily separate the sample holder with respect to the base. Additionally, under this state, by descending the sample holder while being rotated by 90 degrees at a time to thereby make the sample a direction differing by 90 degrees at a time, the sample holder can be easily mounted to the base.
Further, the present invention is a sample working/observing apparatus having possessed the above sample holding mechanism, and characterized by possessing a sample chamber in which the sample holding mechanism has been accommodated, a two-axis stage moving the sample holding mechanism having been disposed inside the sample chamber in a horizontal direction, and a working/observing means performing working/observation of the sample having been held by the sample holder of the sample holding mechanism.
According to the sample working/observing apparatus concerned with this invention, by the fact that the sample is held by the sample holder of the sample holding mechanism, carried to the inside of the sample chamber, and mounted to the base of the sample holding mechanism, it is possible to precisely position the sample to a predetermined position inside the sample chamber. On this occasion, even if a temperature of the sample holder changes by the fact that temperatures in an outside and the inside of the sample chamber differ or the adiabatic expansion due to the fact that the inside of the sample chamber is made the vacuum state, and the like, the sample can be always kept to a position in which the rotation center of the rotation support part is made a reference. That is, by performing the position control with the rotation center of the rotation support part being made the reference, and driving the two-axis stage, it is possible to precisely work or observe a predetermined position of the sample by the working/observing means.
Further, it is deemed to be more desirable that, in the above sample working/observing apparatus, the working/observing means is a body tube capable of irradiating a charged particle beam to the sample.
According to the sample working/observing apparatus concerned with this invention, without undergoing an influence of the temperature change, it is possible to work the sample by precisely irradiating the charged particle beam to a predetermined position from the body tube. Additionally, it is also possible to precisely observe a surface of the sample by detecting secondary electrons generated by irradiating the charged particle beam, and the like.
Further, in the above sample working/observing apparatus, the working/observing means may be made one that is a probe capable of scanning a surface of the sample.
According to the sample working/observing apparatus concerned with this invention, without undergoing the influence of the temperature change, it is possible to precisely scan the probe to a predetermined position of the surface of the sample, it is possible to perform a precise working, and further it is possible to obtain a precise observation image.
According to the sample holding mechanism of the present invention, by supporting the sample holder with respect to the base by the rotation support part, the slide support part and the butting support part, and further positioning the sample with respect to the sample holder by the X-direction positioning member and the Y-direction positioning member, even if the sample holder has expanded or contracted due to the temperature change, the position of the sample is not changed, so that it is possible to precisely position and hold the sample. Therefore, even if the sample is carried under different temperature environments, it is unnecessary to separately provide a facility or time for thermally equilibrating the sample holder, so that it is possible to contrive a saving of space and a saving of time, and perform a precise position control of the sample. Further, according to the sample working/observing apparatus having possessed the sample holding mechanism like this, there is no fact that it undergoes the influence of the temperature change in the apparatus inside/outside, and it is possible to contrive the saving of space and the saving of time, and perform precise working/observation.
As shown in
As shown in
And, by a four-point support of the one rotation support part 27, the one slide support part 28 and the two butting support part 29, the sample holder 21 is supported to the base 22. Incidentally, as shown in
Further, as shown in
Further, as shown in
Next, there are explained about actions of the focused ion beam apparatus 1 and the sample holding mechanism 20. As shown in
On this occasion, a surface shape of the convex part 23 is formed in the spherical face, the corresponding fitting concave part 24a like the circular cone, and the fitting groove 25a is formed like the V-letter in section. Therefore, even if a position setting of the sample holder 21 by the carrier robot has somewhat deviated, the fitting concave part 24a and the fitting groove 25a can be easily fitted to the convex parts 23 and, further, the sample holder 21 can be precisely mounted with respect to the base 22. And, there can be made a state in which the sample holder 21 has been certainly supported to the base 22 by the four-point support of the rotation support part 27 by the fitting concave part 24a and the corresponding convex part 23, the slide support part 28 by the fitting groove 25a and the corresponding convex part 23, and the two butting support parts 29 by the butting faces 26a and the corresponding convex parts 23. Further, since movements in the X-direction and the Y-direction are regulated by the rotation support part 27 and a rotation about an axis perpendicular to the base 22 is regulated by the slide support part 23, the sample holder 21 becomes a state having been positioned with respect to the base 22. Additionally, as mentioned above, the sample S becomes a state in which the one side S1 has been disposed along the Y-direction, the other side S2 has been disposed along the X-direction, and the intersection point S3 has been positioned in a position becoming approximately the same when seen in the plane as the rotation center 27a of the rotation support part 27. That is, by mounting the sample holder 21 to the base 22, the sample S having been held in the sample holder 21 becomes capable of being precisely position-controlled with the intersection point S3 placed in the rotation center 27a of the rotation support part 27 being made a reference point P1.
And, if the mounting of the sample holder 21 has completed, next, the inside 2a of the sample chamber 2 is exhausted by the exhaust means not shown in the drawing, thereby being made a higher vacuum state. And, as shown in
Here, by a heat generated from a motor, not shown in the drawing, that the focused ion beam apparatus 1 possesses or the like and the adiabatic expansion of the gas when the inside 2a of the sample chamber 2 is made the vacuum state or the like, temperature environments of the inside 2a of the sample chamber 2 and the outside 8 are different. Therefore, when the sample holder 21 is carried from the outside 8 to the inside 2a of the sample chamber 2 and, further, just after the sample holder 21 has been mounted to the base 22, a temperature of the sample holder 21 changes till it becomes thermally equilibratory with the temperature environment of the inside 2a of the sample chamber 2, so that sample holder 21 itself expands or contracts. On this occasion, the sample holder 21 is supported by the rotation support part 27 so as to be rotatable with respect to the base 22. Further, it is supported by the slide support part 28 so as to be slidable in the X-direction from the rotation center 27a of the rotation support part 27. Additionally, it is supported by the butting support part 29 so as to be slidable in the X-direction and the Y-direction. Therefore, accompanying with the temperature change, there is no fact that a reaction force acts, and the sample holder 21 can freely deform with the rotation support part 27 being made a center.
Further, also the X-direction positioning pin 31 and the Y-direction positioning pin 32, which have been provided in the upper face 21a of the sample holder 21, are displaced respectively in the Y-direction and the X-direction toward the rotation center 27a of the rotation support part 27. That is, even if the sample holder 21 has expanded or contracted due to the temperature change, since the X-direction positioning pin 31 and the Y-direction positioning pin 32 merely slide respectively with respect to the one side S1 and the other side S2 of the sample S, against which they butt, the sample S is parallel to the Y-direction in its one side S1 and parallel to the X-direction in its the other side S2, and the intersection point S3 between the one side S1 and the other side S2 can always keep a position becoming approximately the same as the rotation center 27a of the rotation support part 27. Therefore, in this focused ion beam apparatus 1, even if the sample holder 21 has expanded or contracted due to the temperature change, the position control is precisely performed with the intersection point S3 of the sample S being made the reference point P1 and, further, the working of the sample S can be precisely performed without generating a phenomenon such as the drift in which the position of the sample changes.
Incidentally, as shown in
Incidentally, on this occasion, by the fact that the fitting concave part 24a constituting the rotation support part 27 is formed in the sample holder 21, a position of the rotation center 27a of the rotation support part 27 and a position of the intersection point S3 of the sample S can be always kept approximately the same position when seen in the plane. Therefore, even if the sample holder 21 has been rotated by the ascent-and-descent rotation means 37, there is no fact that the sample S is displaced by undergoing an influence of the temperature change, so that it is possible, with the position of the intersection point S3 of the sample S after the rotation being made a new reference point P2, to perform the position control of the sample S and precisely perform the working of the sample S as to a range A2. Incidentally, like the fact that the reference point when working the range A1 is P1 whereas the reference point when working the range A2 is P2, although the positions to be made the references differ between the range A1 and the range A2, a correlativity can be kept by previously measuring distances of both in the X-direction and the Y-direction.
As shown in
Like the above, according to the sample holding mechanism 20, by supporting the sample holder 21 with respect to the base 22 by the rotation support part 27, the slide support part 28 and the butting support part 29, and by positioning the sample S with respect to the sample holder 21 by the X-direction positioning pin 31 and the Y-direction positioning pin 32, even if the sample holder 21 has expanded or contracted due to the temperature change, the position of the sample S is not changed, so that it is possible to precisely position and hold the sample S. Therefore, even if the sample S has been carried under different temperature environments, there is no fact that there is required a facility or time for thermally equilibrate the sample holder 21, so that it is possible to contrive a saving of space and a saving of time, and perform a precise position control of the sample. Further, in the focused ion beam apparatus 1 having possessed the sample holding mechanism like this, it does not undergo the influence of the temperature change in the outside 8 and the inside 2a of the sample chamber 2, so that it is possible to contrive the saving of space and the saving of time, and perform precise working.
Further, by the fact that the sample holder 21 is detachably supported with the one rotation support part 27, the one slide support part 28 and the two butting support parts 29 being disposed like the square, if the range of at least a quarter of the whole sample S can be worked, it is possible to work the whole of the sample S by dividing the work into four processes. Therefore, it is possible to reduce a moving range by the two-axis stage 4 to thereby contrive miniaturizations of the sample chamber 2 and the two-axis stage 4, and it is possible to correspond to the photomask whose size becomes large in recent years. Further, by possessing the ascent-and-descent rotation means 37, the sample holder 21 can be easily rotated and mounted to the base 22.
Incidentally, in the present embodiment, as the examples, although there have been enumerated the focused ion beam apparatuses 1, 40 capable of irradiating the focused ion beam B from the body tube 3 as the charged particle beam, there are not limited to these, and similar effects can be obtained also, e.g., in a scanning electron microscope capable of irradiating an electron beam by possessing the sample holding mechanism 20, and it is possible to obtain a precise observation image of the sample without undergoing the influence of the temperature change.
As shown in
Also in the scanning probe microscope 50 like this, by possessing the sample holding mechanism 20, similarly to the first embodiment, since the sample S can be precisely positioned without undergoing the influence of the temperature change, it is possible to obtain the precise observation image of the surface of the sample S. Further, by utilizing the explorer 54, it is possible to work the surface of the sample S.
In the above, although there have been detailedly mentioned about the embodiments of the present invention by referring to the drawings, a concrete constitution is not one limited to these embodiments, and there are included also a design modification and the like in a scope not deviating from a gist of the present invention.
Incidentally, as the sample working/observing apparatus, although there have been enumerated the focused ion beam apparatuses 1, 40, the scanning electron microscope and the scanning probe microscope 50, there are not limited to these. In an apparatus for precisely working or observing the sheet-like sample S, at least by possessing the sample holding mechanism 20, it is possible to expect the similar effect.
Further, in the sample holding mechanism 20, although there has been made such that the sample holder 21 is supported by the four-point support of the rotation support part 27, the slide support part 28 and the two butting support parts 29, there is not limited to this. If there is supported by at least three points of the one rotation support part 27, the one slide support part 28 and at least one butting support part, it is possible to certainly support the sample holder 21 and freely deform the sample holder 21 with the rotation support part 27 being made the center accompanying with the temperature change. Further, although there has been made such that the convex part 23 constituting one of each of the rotation support part 27, the slide support part 28 and the butting support part 29 is provided in the base 22 and the other fitting concave part 24a, fitting groove 25a and butting face 26a are formed in the sample holder 21, even if there is made a constitution having been reversed, it is possible to support the sample holder with respect to the base 22 and freely deform the sample holder 21 with the rotation support part 27 being made the center accompanying with the temperature change.
Additionally, although the surface shape of the convex part 23 has been made the spherical face, the corresponding fitting concave part 24a has been made the circular cone shape and the fitting groove 25a has been made one formed like the V-letter in section, there is not limited to this. For example, the shape of the convex part may be made a circular cone having an apical angle of the circular cone forming the fitting concave part 24a and an apical angle which is an acute angle than a bottom angle of the V-letter forming the section of the fitting groove 25a. Further, as the fitting concave part 24a, it may be, e.g., one butting at three points against the convex part 23, or it may be made a spherical face whose curvature corresponds to the convex part 23. Further, similarly, also the fitting groove 25a may be made, e.g., a groove of a circular shape in section, whose curvature corresponds to the convex part 23.
Further, as one positioning the sample S to the sample holder 21, although it has been made one possessing the two X-direction positioning pins 31 and the one Y-direction positioning pin 32, there is not limited to this. For example, it may be made one in which a step part is formed along the Y-direction and the X-direction from the rotation center of the rotation support part. There suffices one in which, at least, one butts against the one side S1 of the sample S to thereby make the one side S1 parallel to the Y-direction, the other butts against the other side S2 of the sample S to thereby make the other side parallel to the X-direction, and the intersection point S3 between the one side S1 and the other side S2 is made approximately the same position when seen in the plane as the rotation center 27a of the rotation support part 27.
| Number | Date | Country | Kind |
|---|---|---|---|
| JP2006-032146 | Feb 2006 | JP | national |
