This application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. JP2008-011503 filed on Jan. 22, 2008, the entire content of which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a tweezers system for a scanning probe microscope utilized when a defect of a sample of a circuit pattern or the like of a semiconductor apparatus is observed, or the defect is corrected, a scanning probe microscope apparatus having the system, and a dust removing method of removing a dust on a sample by using the scanning probe microscope.
2. Description of the Related Art
In recent years, by a progress in a nanotechnology, an advanced technology of a small region of a nanomachine, an electronic device, a memory or the like attracts attention and promotion of a working technology thereof is requested. As one of the microworking means, a method of using a scanning probe microscope (SPM) attracts attention. Although the scanning probe microscope does not reach a working technology of mass production as in a semiconductor process, the apparatus per se is an apparatus having a high working accuracy of nanoscale although the apparatus is simple and at a comparatively low price. Therefore, attention is attracted to that the apparatus is used in a technology of trially fabricating a fundamental device in a high density memory, nanoelectronics, and a nanomachine or the like of next generation, or correcting a mask or the like.
As a technology of utilizing a scanning probe microscope, for example, there is proposed a method of removing a dust adhered to a circuit board in steps of forming a circuit pattern of a semiconductor apparatus by using a tweezers of nanometer order attached to a scanning probe microscope (refer to, for example, JP-A-2007-298587).
According to the method of removing the dust by using the tweezers of the nanometer order attached to the scanning probe microscope, there is achieved an advantage of capable of removing the dust without destructing a miniaturized mask without damaging the mask and while reducing a number of times of cleaning by directly grasping dust on the mask by the tweezers.
However, the following problem remains.
There poses a problem that there is brought about a dust which cannot be removed depending on a shape of a mask, a position of adhering the dust and a shape thereof or the like.
That is, when the dust is solidly adhered to the mask, by simply grasping to pull the dust, there is also a case of destructing the dust in the midst and it is difficult to remove the dust from a root thereof. Further, when a shape of a dust is in a powder state, grabbing by tweezers per se is difficult. Further, when a dust invades inside of a groove, a front end of a tweezers cannot invade inside of the groove, in this case, there poses a problem that removal of the dust is obliged to be abandoned.
Further, when the front end of the tweezers is contaminated in the operation, there also poses a problem that a total of the tweezers needs to be interchanged.
The invention has been carried out in view of the above-described situation and it is an object thereof to provide a tweezers system for a scanning probe microscope, a scanning probe microscope apparatus and a method of removing a dust, in which a shape of a front end of a work can be freely interchanged in accordance with an object (for example, removal of a dust or the like), in addition thereto, even a case of contaminating the work can be easily dealt with.
In order to resolve the above-described problem, a tweezers system for a scanning probe microscope of the invention comprises a tweezers comprising two arms having probes arranged opposedly to a sample and integrated to a scanning probe microscope and constituting an object of observation or working respectively at front ends thereof, and a plurality of kinds of interchanging works one of the plurality of kinds of which is selectively grasped by the tweezers.
According to the invention, in accordance with a content to be operated, for example, in a case of an operation of removing a dust, depending on a situation of adhering a dust, a shape of a dust per se or the like, an optimum one of a plurality of kinds of interchanging works is selected to be integrated to the tweezers, thereby, an operation can efficiently be progressed. Further, when the interchanging work is contaminated in the operation, by only interchanging the interchanging work to other interchanging work, harm of contamination can be prevented.
According to the tweezers system for a scanning probe microscope of the invention, it is preferable that as the plurality of kinds of interchanging works, there are provided at least two kinds of interchanging works of an observing stylus work to be scanned along a surface of the sample, a work for a contact hole of raking out a dust at inside of a contact hole of the sample, a corner moving work of moving the dust disposed at a corner portion of the sample, a cutting work of cutting the dust adhered to the sample, and a spatula shape work of moving the dust disposed at a groove of the sample.
In this case, in an operation of removing a dust, an optimum one of a plurality of kinds of interchanging works, for example, the observing stylus work, the work for a contact hole, the corner moving work, the cutting work, or the spatula shape work can be selected, and the operation can be dealt with specifically in accordance with a situation of adhering the dust, the shape of the dust per se or the like.
According to the tweezers system for a scanning probe microscope of the invention, it is preferable that an engaging projected portion is provided at one of portions of the tweezers and the interchanging work brought into contact with each other and an engaging recess portion is provided at to the other, and by engaging the engaging projected portion and the engaging recess portion, when the interchanging work is grasped by the tweezers, positioning of the engaging projected portion and the engaging recess portion is carried out.
In this case, by engaging the engaging projected portion provided at one of portions of the tweezers and the interchanging work brought into contact with each other and the engaging recess portion provided at the other, positions of the tweezers and the interchanging work relative to each other are always determined constant. Thereby, an operation by the interchanging work is facilitated by only inputting the positional relationship previously to a control portion of the scanning probe microscope as data.
According to the tweezers system for a scanning probe microscope of the invention, it is preferable that the engaging projected portions or the engaging recess portions respectively provided at base end sides thereof and operating portions provided at front end sides thereof for carrying out observation or working by being brought into contact with a sample are set to the same positional relationship.
In this case, when the interchanging work grasped by the tweezers is interchanged, positions of an operating portion of the interchanging work before having been interchanged and an operating portion of the interchanging work after having been interchanged become the same position, and therefore, regardless of whether the work is interchanged, an operation of using the interchanging work is further facilitated.
According to the tweezers system for a scanning probe microscope of the invention, it is preferable that the tweezers system further comprises a work holding base having a guide portion holding the interchanging work at a predetermined position and guiding the tweezers such that the engaging projected portion and the engaging recess portion are engaged with each other when the tweezers is proximate thereto.
In this case, when the interchanging work held by the work holding base is attached to the tweezers, the tweezers can be made to reach a position capable of engaging with the interchanging work by being guided by the guide portion of the work holding base. In this way, the tweezers can be positioned to a position automatically engageable with the interchanging work previously held at a predetermined position of the work holding base, as a result, an operation of grasping the inserting work by the tweezers is facilitated.
In order to resolve the problem, a scanning probe microscope apparatus of the invention comprises the tweezers system for a scanning probe microscope described above.
According to the invention, an effect similar to that of the tweezers system for a scanning probe microscope is achieved.
A method of removing a dust of the invention is a method of removing a dust of removing a dust on the sample by using the scanning probe microscope apparatus described above, the method comprises a step of observing a shape of a predetermined area of the sample by the tweezers or the interchanging work attached to the tweezers, a step of determining the interchanging work suitable in working the sample from an observation image acquired by the step and attaching the interchanging work to the tweezers, and a step of removing the dust on the sample by working the sample by the attached interchanging work.
According to the invention, the operation is carried out by attaching the optimum interchanging work to the tweezers in accordance with the shape of the sample observed, and therefore, the dust can efficiently be removed.
According to the invention, by selecting the optimum one of the plurality of kinds of the interchanging works in accordance with the operating content to integrate to the tweezers, the operation can be progressed efficiently. Further, when the interchanging work is contaminated in the operation, it is not necessary to interchange all of the tweezers but by only interchanging the interchanging work used to another interchanging work, harm of contamination can be prevented.
An embodiment of the invention will be explained in reference to the drawings as follows.
A support arm 8 is extended from the side plate portion 3. A front end of the support arm 8 is provided with a Z direction drive portion 9. A moving plate 9a at a front end of the Z direction drive portion 9 is attached with an optical microscope 10 for observing the sample at a front end of a tweezers 12 mentioned later.
Further, the moving plate 9a is attached with a finely moving scanner 11 and an output portion of the finely moving scanner 11 is attached with the tweezers 12. The finely moving scanner 11 includes, for example, a piezoelectric element, and can finely be driven along directions of 3 axes of X and Y and Z by applying a voltage from an XYZ scanner control portion, not illustrated. Further, by the finely moving scanner 11, the tweezers 12 is made to move finely in the directions of 3 axis of X and Y and Z.
An upper side of the sample base 6a is provided with displacement measuring means 14 for measuring a displacement of the tweezers 12. The displacement measuring means 14 includes a laser light source 15 of irradiating laser light L to a reflecting face, not illustrated, formed on a side of a back face of the front end of the tweezers 12, and a light detecting portion 16 of receiving the laser light L reflected by the reflecting face by utilizing a mirror. The light detecting portion 16 is, for example, a photodiode an incident face of which is divided into 2 or divided into 4 for detecting a state of vibrating the tweezers 12 from an incident position of the laser light L. Further, the light detecting portion 16 outputs a detected displacement of the state of vibrating the tweezers 12 to a preamplifier as a DIF signal. Further, the DIF signal outputted from the light detecting portion 16 is amplified by the preamplifier, thereafter, transmitted to an alternating current-direct current converting circuit to be converted into a direct current, and transmitted to a Z voltage feedback circuit. The Z voltage feedback circuit subjects a finely moving scanner control portion to feedback control such that the DIF signal converted into direct current becomes always constant. Thereby, when the sample S on the sample base 6a is observed, a distance between the sample base 6a and the tweezers 12 can be controlled such that the state of vibrating the tweezers 12 becomes constant, specifically, an amount of attenuating an amplitude or an amount of deviating a frequency, or an amount of deviating a phase becomes constant.
The observing arm 20 is fixed with a piezoelectric member 23 of vibrating the observing arm 20. The piezoelectric member 23 is made to be vibrated at a predetermined frequency and a predetermined amplitude by receiving a signal from a piezoelectric member control portion, and the vibration is transmitted to the observing arm 20. Thereby, the observing arm 20 is vibrated at the predetermined frequency and the predetermined amplitude similar to the piezoelectric member 23. That is, the piezoelectric member 23 and the piezoelectric member control portion constitute oscillating means.
The base portion 22 of the observing arm 20 is formed with combteeth 24 on one side. Combteeth 25 on other side are extended from the grasping arm 21 to be opposed to the combteeth 24. A direction of extending teeth of the combteeth 24 and 25 coincide with a direction of separating the two probes 20a and 21a of the tweezers. The two combteeth 24 and 25 are provided with electrodes and the electrodes are connected with a voltage apparatus 26 for combteeth for applying a voltage to the electrodes. By an amount of the voltage applied to the voltage apparatus 26 for combteeth, a clearance between the two combteeth 24 and 25, and therefore, a distance between the two probes 20a, 21a of the tweezers 12 are made to be adjusted.
At a front end of the tweezers 12, an interchanging work 30 (30A, 30B, 30C, 30D, 30E) is grasped. A plurality of kinds of the interchanging works 30 are prepared previously in accordance with object of use, the interchanging work 30 optimum for a corresponding operation is selected therefrom and grasped between the two probes 20a, 21a of the front ends of the tweezers 12. Also as shown in
Further, a flange portion 36 is formed at a middle portion in a length direction of the interchanging work 30. The flange portion 36 is a portion supported in a state of being mounted on a work base 44 formed in a ring-like shape of the work holding base 31 when contained in a state of being supported by the work holding base 31. Further, a front end of the interchanging work 30 is provided with operating portions 37 (37A, 37B, 37C, 37D, 37E) of carrying out various operations by being brought into contact with a surface of the sample S when the sample S is observed or worked.
Here, a distance La from a center of the engaging projected portion 35 to a lower face of the flange portion 36, and a distance Lb from the center of the engaging projected portion 35 to the operating portion 37 are set to the same values in any of the interchanging works 30 (30A, 30B, 30C, 30D, 30E) mentioned later. Further, it corresponds similarly to any of the interchanging works 30 (30A, 30B, 30C, 30D, 30E) that a center of the operating portion 37 is disposed at a center of the interchanging work 30.
Therefore, when the interchanging work 30 supported by the work holding base 31 is grasped by the tweezers 12, when conversely, the interchanging work 30 is returned to the work holding base 31, or when the interchanging work 30 is grasped by the tweezers 12 to actually operate the sample S, the same procedures are carried out for any of the interchanging works 30.
Further, although according to the embodiment, the engaging recess portion 34 is constituted by the recess in the shape of the quadrangular prism, and the engaging projected portion 35 is constituted by the projected portion in the shape of the quadrangular prism in correspondence therewith, the embodiment is not limited thereto but the engaging recess portion 34 and the engaging projected portion 35 may be constituted by other shape, for example, a circular cone shape, a wedge shape, or a trapezoidal shape, in sum, there may be constructed a constitution in which the tweezers 12 and the interchanging work 30 can accurately be positioned by being engaged with each other at the centers.
Further, although in
Further,
Further, although
Therefore, the probes 20a and 21a of tweezers are guided to the inner side faces 42a, 42a of the left and right wing portions such that the engaging projected portion 35 of the interchanging work 30 and the engaging recess portion 34 of the tweezers 12 are disposed at positions of being engaged with each other when the tweezers 12 is set to a predetermined opening angle and is made to be proximate to the work holding base 31 in a state of holding the interchanging work 30 at the work holding base 31. That is, the inner side faces 42a, 42a of the left and right wing portions constitute guide portions of guiding the tweezers 12 such that the engaging projected portions 35 and the engaging recess portions 34 are engaged with each other.
Next, an explanation will be given of a method of removing a dust on a sample by using the scanning probe microscope apparatus in reference to
The sample S provided with information of presence of a dust by a defect inspector is fixed to a predetermined position on the sample base 6a. Further, the X direction drive portion 4 and the Y direction drive portion 5 and of stage 6 are respectively driven such that the front end of the tweezers 12, further specifically, the stylus 20a of the observing arm coincides with a portion on the sample S at which the dust is present based on coordinates information with regard to the dust previously provided from the defect inspector (step S1).
Next, information with regard to dust Z (for example, shape or the like of dust Z) is provided by observing by the optical microscope 10. When the observation cannot be carried out by the optical microscope 10, observation by SEM or AFM may be carried out by a function incorporated in the scanning probe microscope apparatus (step S2).
At this occasion, the observing stylus work 30A may be grasped by the front end of the tweezers 12, and the dust Z with regard to the sample S may be observed by the observing stylus work 30A. Further, a method of grasping the observing stylus work 30A by the tweezers 12 will be explained later in details.
Next, the interchanging work 30 is selected in accordance with a shape of the dust Z or a situation of adhering the dust Z to the sample S based on a result of the observation (step S3). As a reference of selecting the interchanging work, for example, when the dust invades inside of a contact hole, the work 30B for the contact hole shown in
When selection of the interchanging work is determined, by driving the stage 6, the front end of the tweezers 12 is relatively moved to the work holding base 31 of holding the selected interchanging work. Further, by adjusting an amount of the voltage applied to the voltage apparatus 26 for the combteeth, the clearance between the probes 20a and 21a of the front end of the tweezers is expanded to a size capable of grasping the interchanging work 30. Thereafter, the probes 20a and 21a of the front end of the tweezers are brought into contact with the inner side faces 42a, 42a of the left and right wing portions of the work holding base 31, and the tweezers 12 is moved down under the state. The probes 20a and 21a of the tweezers are moved down by being guided by the inner side faces 42a, 42a of the left and right wing portions of the work holding base 31 and the tweezers 12 is made to stop moving down when the engaging recess portion 34 of the probes 20a and 21a of the tweezers come to a height position of the engaging projected portion 35 of the interchanging work 30. Next, the amount of voltage applied to the voltage apparatus 26 for the combteeth is adjusted again, the clearance between the probes 20a and 21a of the front end of the tweezers is narrowed to grasp the interchanging work 30.
At this occasion, the engaging recess portions 34 of the probes 20a and 21a of the tweezers are engaged with the engaging projected portions 35 of the interchanging work 30, and therefore, a state of locking the tweezers 12 and the interchanging work 30 is uniquely determined and relative positions of the probes 20a and 21a of the tweezers and the operating portion 37 of the interchanging work remain unchanged even when any of the interchanging works 30 is grasped.
Next, the operating portion 37 of the front end of the interchanging work 30 grasped by the tweezers 12 is positioned to an area at which the dust Z of the sample S is present by driving the stage 6 (step S3).
Thereafter, the operating portion 37 of the interchanging work is moved while being brought into contact with the predetermined region of the sample S and a predetermined operation is carried out by the operating portion 37 of the interchanging work. Specifically, the dust is moved, or the moved dust is attracted to the interchanging work by an electrostatic operation (step S4). In
Next, the operated dust Z is observed by the optical microscope 10 or SEM or AFM to determine whether the dust is rootless, in other words, whether the dust has been able to be moved. (step S5).
When it is determined that the dust has been able to be moved, the interchanging work 30 is detached from the tweezers 12 (step S6), the dust Z moved by the tweezers 12 is grasped and the dust Z is moved to a predetermined portion (step S7). That is, in
On the other hand, when it is determined that the dust cannot be moved at the step S5, the interchanging work 30 grasped at the front end of the tweezers 12 is interchanged from the interchanging work for moving the dust to the cutting work 30D. Specifically, the tweezers 12 is relatively moved to the common base 40, the grasped interchanging work 30 is returned to the work holding base 31 which does not hold the interchanging work. Successively, the tweezers 12 is relatively moved again to be opposed to the work holding base 31 holding the cutting work 30D. Further, the cutting work 30D is grasped by the tweezers 12 by repeating the above-described operation again (step S8).
Next, the tweezers 12 is relatively moved to the sample S up to position at which the cutting work 30D grasped by the tweezers 12 is opposed to the dust, the cutting work 30D is vibrated in a state of being brought into contact with the dust or the surface of the sample at a vicinity of the dust to cut to remove the dust (step S9).
Next, the dust is completely removed by being processed by a cleaning step in a publicly-known photolithography technology (step S10).
Further, the above-described embodiment is persistently an exemplification of the invention and can pertinently be changed in design thereof within a range not deviated from the gist of the invention.
Although the embodiment shows an example of utilizing the tweezers system for the scanning probe microscope and the scanning probe microscope apparatus of the invention when the dust on the surface of the sample is removed, the invention is not limited thereto but is applicable also in a case of carrying out an operation for other use, for example, an operation of piercing, an operation of cutting, or an operation of grasping a living body.
Further, although according to the embodiment, as examples of interchanging works, the observing stylus work 30A, the work 30B for the contact hole, the corner moving work 30C, the cutting work 30D, the spatula shape work 30E are pointed out, the invention is not limited thereto but other interchanging work may be used.
Further, although according to the embodiment, all of the exemplified interchanging works 30 are prepared on the work holding base 31, it is not necessary to prepare all of them but only 2 kinds or 3 kinds thereof may be prepared.
Number | Date | Country | Kind |
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JP2008-011503 | Jan 2008 | JP | national |