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XE Advantages
XE Technology Innovation
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Decoupled XY and Z-scanners
In the XE platform, the Z-scanner is completly decoupled from the XY-scanner. A specially designed 2-dimensional flexure stage is used as an XY-scanner which moves the sample in the horizontal plane. This configuration provides a flat XY scan with high orthogonality |
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Fast Z-servo Response
The ultra high force Z-scanner, the key innovation that enables True Non-Contact mode, allows a significantly higher resonance frequency than those of conventional piezoelectric tube scanners, In addition, the mass load to the Z-scanner is minimized to increase the Z-servo response. |
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Direct On-Axis Optics
The revolutionary optics design is the first to provide AFM users with a direct on-axis view of their sample. The optical path from the sample to the CCD camera is an unobstructed straight line and provides the natural on-axis top-down view of the sample with unprecedented clarity. This configuratuin provides the hightest optical resolution (1μm) and allows users to quickly find features of interest for AFM measurements. |
The Limitations of Conventional AFM Technology
Piezoelectric tube is Not an Orthogonal 3-D Actuator
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The Conventional AFM uses a piezoelectric tube as an x-y-z scanner, where x-y motion relies on the bending of the tube. However, the bending motion causes z position error and introduces background curvatures. Software flattening is used in order to hide the background curvatures. The amount of curvature, however, depends not only on scan size and scan speed, but also on x-y offset and z position, etc, making it impossible to correctly subtract the curvatures. Therefore, even after software flattening, a flat surface does not "look" flat as shown in the fiqure right. |
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Non-Contact Mode Implementation is Not Possible
| Another major problem of conventional AFM is the slow Z-servo response. Because of its hollow structure, the piezoelectric tube scanner has poor rigidity and a low resonance frequency. Therefore, the Z-servo response is slow and it is not possible to implement Non-Contact mode, and "tapping mode" has to be used as a compromise. |
XE Advantages
Flat and Linear XY Scan : Precession Metrology
Linear XY Scan
on atube scanner, even the X and Y movements are coupled so that the exension of the X axis influences that of the Y. The flexure scanner decouples the X and Y scan motion so that the coupling between X and Y movements is minimized. In addition, position sensors are used to ensure that they move the exact amounts. |
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Flat XY Scan without Bowing
The award-winning XE-platform, which stands for cross-talk elimination,completely eliminates background scanner urvature and shows no bowing, even on scans of the flattest samples, thus enabling precision nanometrology. |
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True Non-Contact AFM
True Non-Contact AFM Can Image Deep Trench and High Walls
 In true Non-Contact mode, the cantilever is oscillated with small amplitude and brought very close to the sample surface. Sensing the tip-sample interaction not only at the end of the tip but also on the sides of the tip, the probe can trace very steep walls without crashing into them. Figure 1 is a deep trench image obtained with True Non-Contact mode. The depth of the trench is 3.7 μm previoudly, in order to obtain such data, it was necessary to cut the wafer and inspect it with an SEM. |
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True Non-Contact AFM Minimizes Tip-Sample Interaction
| In true-Contact mode, the tip-sanple distance is successfully maintained at a few nanometers with high Z-srvo performance, and preserves the sharpness of the tip. Figure 3 is the SEM image of a fresh high aspect ratio tip before imaging the trench sample on the right, and figure 4 is the SEM image of the same tip after taking 20 True Non-Contact AFM images of the same structure.The tip is still in pristine condition. |
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XE-Advantages
