Disclosure of Invention
The invention aims to solve the problems that the repair cleaning cost of the original factory is high, the ultrahigh frequency voltage cleaning is not undercut and the like of a polluted three-dimensional atom probe local area electrode in the prior art, thereby providing a method for cleaning the three-dimensional atom probe near local area electrode by using focused ion beams.
In order to achieve the technical purpose and achieve the technical effect, the invention is realized by the following technical scheme:
a method for cleaning a three-dimensional atom probe near-local electrode by using focused ion beams is characterized in that the annular focused ion beams are used for cleaning the annular inner surface of the three-dimensional atom probe near-local electrode center.
And aligning the outer ring of the ring-cutting ring of the focused ion beam with the root of the protruding defect on the three-dimensional atom probe near-local-area electrode central ring, and aligning the inner ring of the ring-cutting ring with the top edge of the protruding defect on the central ring, thereby cleaning the protruding defect.
The method comprises the following steps:
step S1: mounting the three-dimensional atom probe near-local electrode on a focused ion beam sample table, tilting the sample table, adjusting an imaging compensation angle and adjusting a working distance;
step S2: aligning the center of the ring-cutting ring with the center of the three-dimensional atom probe near-local-area electrode in an FIB imaging mode;
step S3: aligning an outer ring of a ring cutting ring of the FIB with the root of a protrusion defect on a three-dimensional atom probe near-local-area electrode central ring, and aligning an inner ring of the ring cutting ring with the top edge of the protrusion defect on the central ring;
step S4: and performing circular cutting until no impurities exist between the inner ring and the outer ring of the circular cutting ring.
The step S1 specifically includes the following steps:
s11: fixing the three-dimensional atom probe near-local electrode on a sample table;
s12: discharging nitrogen in the buffer bin, and opening a bin door of the buffer bin;
s13: loading a sample table onto a buffer bin sample table base in a buffer bin;
s14: closing a buffer bin door;
s15: transferring the sample table, and pushing the sample table from the sample table base of the buffer bin to the sample table base of the working bin;
s16: closing a working bin door;
s17: opening the electron gun, and adjusting the sample platform to be right below the electron gun after the electron gun is opened;
s18: the tilting sample stage is tilted by 54 degrees so that the plane of the three-dimensional atom probe near the local electrode is vertical to the ion gun;
s19: and adjusting the working distance, namely specifically adjusting the working distance to 5.1mm, so that the working distance is the working distance of the ion gun.
The step S2 specifically includes the following steps:
s21: opening the ion gun;
s22: adjusting the field of view in the SEM image mode to be consistent with the field of view in the FIB image mode;
s23: the focused ion beam is adjusted to tune out the ring-cut.
The step S3 specifically includes the following steps:
s31: aligning an outer ring of a ring cutting ring of the FIB with the root of a protrusion defect on a three-dimensional atom probe near-local-area electrode central ring;
s32: the inner ring of the FIB ring cut was aligned with the top edge of the protrusion defect on the center ring.
The step S4 specifically includes the following steps:
s41: starting circular cutting;
s42: adjusting the position of the circular cutting ring, wherein the adjustment of the position of the circular cutting ring is carried out after one circular cutting is suspended, so that the next circular cutting position is ensured to be correct;
s43: and finishing circular cutting when no impurities exist between the inner ring and the outer ring of the circular cutting ring.
The step S22 of the step S2 specifically includes the following steps:
s221: adjusting the current of an ion gun to 2nA before switching the image to an FIB mode;
s222: switching the image to an FIB mode after selecting an image reference point;
s223: the image is adjusted to be clear after being switched to an FIB mode, and the image adjustment to be clear is realized by adjusting amplification, focusing, astigmatism, brightness and contrast;
s224: and switching to the FIB mode to adjust the image to be clear, and adjusting the FIB image and the SEM image to the same position.
The invention has the beneficial effects that: according to the method for cleaning the three-dimensional atom probe near-local area electrode, the local area electrode is cleaned through the focused ion beam, so that the three-dimensional atom probe near-local area electrode is thoroughly cleaned, especially the inside of the three-dimensional atom probe near-local area electrode is thoroughly cleaned, and the cost is saved. The invention cleans the three-dimensional atom probe near-local electrode by the focused ion beam, thereby not only obtaining good cleaning result, but also saving a great deal of time and cost.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.
A method for cleaning a three-dimensional atom probe near-local area electrode by using Focused Ion beams adopts an FIB/SEM dual-Beam system, wherein the FIB is Focused Ion Beam, and the SEM is Scanning Electron Microscope, namely a Scanning Electron Microscope; the method mainly comprises the following steps:
s1: mounting a three-dimensional atom probe near-local electrode 7 on a focused ion beam sample table 6, tilting the sample table 6, adjusting an imaging compensation angle and adjusting a working distance;
s2: aligning the center of the ring-cutting ring with the center of the three-dimensional atom probe near-local-area electrode 7 in an FIB imaging mode;
s3: aligning an outer ring of a ring cutting ring of the FIB with the root of a protruded defect 1 on a central ring of a three-dimensional atom probe near-local-area electrode 7, and aligning an inner ring with the top edge of the protruded defect 1 on the central ring;
s4: and performing circular cutting until no impurities exist between the inner ring and the outer ring of the circular cutting ring.
The step S1 specifically includes:
s11: fixing a three-dimensional atom probe near-local electrode 7 on a sample table 6;
more preferably, the three-dimensional atom probe near-local area electrode 7 is fixed on the sample table 6 until the sample cannot be screwed tightly, so as to prevent the sample from falling in the instrument.
S12: discharging the nitrogen in the buffer bin 12, and opening a bin door 11 of the buffer bin;
s13: loading the sample stage 6 onto a sample stage base in a buffer bin 12;
s131: after the sample stage 6 is loaded, the sample stage transfer lever is screwed.
More preferably, the sample stage transfer lever is screwed until it is not screwed, so as to prevent the sample stage 6 from falling off.
S14: closing the buffer bin door 11;
s15: a sample transfer stage 6;
s151: the sample stage 6 is pushed up from the buffer bin sample stage base 13 onto the working bin sample stage base.
More preferably, the sample stage 6 is pushed up, in particular to the bottom, from the buffer bin sample stage base 13 to the working bin sample stage base, so as to avoid the sample stage 6 from falling off.
S152: after the sample table 6 is pushed onto the sample table base of the working bin, the transfer rod is unscrewed.
More preferably, the unscrewing of the transfer rod is performed until the transfer rod and the sample stage 6 are not combined, so as to prevent the sample stage 6 from being dragged from the working bin sample stage base to be detached when the transfer rod is retracted.
S16: closing the working bin door 10;
s17: opening the electron gun;
s171: after the electron gun is opened, the sample stage 6 is adjusted to be right below the electron gun;
more preferably, the auxiliary tool CROSS for determining the visual field center is opened for assistance when the sample stage 6 is adjusted to be right below the electron gun so as to accurately determine the position of the visual field center
The adjustment of the sample stage 6 to the position right below the electron gun is to adjust the horizontal position of the sample stage 6 by adjusting the operating lever X/Y.
The adjusting of the position of the sample stage 6 by the adjusting of the operating lever X/Y is to adjust the center of the three-dimensional atom probe near-local area electrode 7 center ring to be consistent with the CROSS center.
S18: a tilting sample stage 6;
the tilting direction for tilting the sample stage 6 is a vertical clockwise direction.
More preferably, the tilting angle for tilting the sample stage 6 is 54 °, so that the plane of the three-dimensional atom probe near-local-area electrode 7 is perpendicular to the ion gun.
S19: adjusting the working distance;
more preferably, the adjusted working distance is adjusted to 5.1mm so that it is at the working distance of the ion gun.
More preferably, the image should be adjusted to be clear in an SEM (scanning electron microscope) imaging mode before the adjustment of the working distance to 5.1mm, so as to ensure that the adjusted working distance is accurate.
S191: the SEM mode is turned on by a CAMERA (CAMERA) before the image is adjusted to be clear in the SEM imaging mode.
The sharpness adjustment of the image in the SEM imaging mode is achieved by adjusting Magnification, Focus, Stigmator, Brightness, Contrast.
The step S2 specifically includes:
s21: opening the ion gun;
s22: adjusting the field of view in the SEM image mode to be consistent with the field of view in the FIB image mode;
before the view field in the SEM image mode and the view field in the FIB image mode are adjusted to be consistent, an image reference point is selected in the SEM image mode to ensure that the adjustment is consistent.
More preferably, the CROSS is opened to assist in determining the reference point when the image reference point is selected.
The opening CROSS assists in determining a reference point to adjust the reference point into the center loop of the CROSS.
The adjustment of the reference point into the center loop of the CROSS is achieved by adjusting the operating lever X/Y.
S221: the ion gun current was adjusted to 2nA before switching the image to FIB mode.
S2212: and switching the image to the FIB mode after selecting the image reference point.
S2213: the image is adjusted to be clear after the image is switched to the FIB mode.
More preferably, the adjusting the image sharpness is performed by adjusting the verification, Focus, viewer, Brightness, Contrast.
S2214: and switching to the FIB mode to adjust the image to be clear, and adjusting the FIB image and the SEM image to the same position.
More preferably, when the FIB image and the SEM image are adjusted to the same position, CROSS auxiliary adjustment is opened, and accurate adjustment is ensured.
More preferably, the open CROSS assisted adjustment adjusts a reference point selected in the SEM image mode into the CROSS center ring.
The adjustment of the reference point selected in the SEM image mode into the CROSS center ring is specifically achieved by adjusting X/Z (horizontal X direction/vertical direction).
More preferably, after the reference point selected in the SEM image mode is adjusted into the CROSS center ring, the image is switched to the SEM mode to confirm whether the image positions in the SEM and the FIB are consistent.
More preferably, the switching of the image to the SEM mode is followed by confirming whether the image reference point is in the CROSS center loop.
More preferably, the step of confirming whether the image reference point is in the CROSS center loop is specifically, if so, completed.
More preferably, the confirming whether the image reference point is in the CROSS center ring is that if not, the reference point is adjusted to the CROSS center ring again.
More preferably, said adjusting again the reference point into the CROSS center loop is achieved by adjusting Beam Shift X/Y (horizontal position X/Y of the electron Beam).
S23: adjusting the focused ion beam to call out a ring cutting ring;
and before the ring cutting ring is called out, the control software is firstly opened.
More preferably, the image in the display interface of the control software is adjusted to be clear before the circular cutting ring is called out, so that the accurate circular cutting position is ensured.
More preferably, the image adjustment definition in the display interface of the control software is realized by adjusting Magnification, Focus, Stigmator, Brightness, Contrast.
More preferably, the FIB imaging current is adjusted when the image in the display interface of the control software is adjusted clearly.
More preferably, the adjusting of the FIB imaging current size specifically adjusts the current to 2 nA.
Step S3 specifically includes:
s31: aligning an outer ring of a ring cutting ring of FIB with the root of a protrusion defect 1 on a central ring of a three-dimensional atom probe near-local-area electrode 7;
the alignment of the outer ring of the ring-cutting ring of the FIB and the root of the protrusion defect 1 on the central ring of the three-dimensional atom probe near-local-area electrode 7 is realized by moving the size control point of the inner ring on the inner ring of the ring-cutting ring.
When the outer ring of the ring-cutting ring of the FIB is aligned with the root of the protrusion defect 1 on the central ring of the three-dimensional atom probe local area electrode 7, if the central ring of the three-dimensional atom probe local area electrode 7 is not complete circular, the three-dimensional atom probe local area electrode 7 and the protrusion defect cannot be completely aligned, and the two are aligned as far as possible.
More preferably, the alignment should be such that the intersection of the central ring of the three-dimensional atom probe electrode 7 with the outer ring of the ring-cut ring is not allowed, thereby preventing damage to the body 2 of the three-dimensional atom probe electrode 7.
S32: aligning the inner ring of the ring cutting ring of the FIB with the top end edge of the protruding defect 1 on the central ring;
more preferably, the aligning of the inner ring of the FIB circular cut ring with the top edge of the projected defect 1 on the center ring is performed by moving the outer ring size control point on the outer ring of the circular cut ring.
More preferably, the alignment of the inner ring of the FIB ring-cut ring with the top edge of the protrusion defect 1 on the center ring should be adjusted so that there is no intersection of the ring-cut ring inner ring 3 with any impurities on the center ring.
Step S4 specifically includes:
s41: starting circular cutting;
more preferably, the start loop is implemented by the start of the click control software.
More preferably, the click control software should adjust the ring-cut current before start.
More preferably, the adjusting the ring-cut current is adjusting the ring-cut current to 2 nA.
S42: adjusting the position of the ring cutting ring;
more preferably, the adjustment of the ring cutting position is performed after one ring cutting is suspended or finished, so that the next ring cutting position is ensured to be correct.
The specific operation steps for adjusting the position of the ring-cutting ring are the same as those of step S3.
S43: finishing circular cutting;
more preferably, the finishing ring-cutting is operated when there is no foreign matter between the inner ring and the outer ring of the ring-cut ring.
According to the method, the three-dimensional atom probe near-local area electrode is cleaned by adopting the focused ion beam, so that the three-dimensional atom probe near-local area electrode can be thoroughly cleaned, and pollutants near the electrode can be effectively removed from SEM pictures before and after the local area electrode is circumcised as shown in figure 4; the process of the present invention achieves unexpected beneficial results.