Nano-Scale Defectoscopy
An advanced atomic force microscope (AFM),
high-resolution, wide field-of-view optical microscope (OM) and a color CCD
camera integrated into the Microscopy Head of the Universal Nano+Micro Tester
are shown in Figure 1.
Large sample of semiconductor wafer (from 1” to 4” in regular configuration, 6”
and 8” optional), magnetic disk (including 0.8”, 1”, 1.8”, 2.5”, 3.0” and 3.5”
hard disks, 3.5” and 5.25” floppy disks), optical disk (including DVD, CD and
PD), optical display (including LED, LCD and plasma), etc. can be fast
positioned on the instrument table with a precision chuck (either vacuum or
mechanical clamp).
Figure 1. UNMT with AFM, OM and sample on a rotary drive.
Depending on application, the table can
be chosen to have an either rotary or linear motion with sub-micron positioning
resolution. Together with precision 2-directional motion of the Microscope Head,
synchronized with the state of the art control hardware and software, it allows
for fast and precision AFM positioning over target areas on the sample. The
instrument locates the target areas on the sample surface, for example, defects,
based on the coordinates easily transferred from optical or other surface
pre-characterization devices.
Specifications:
AFM Scanning range xy:
80x80mm
AFM Scanning range z: 6µm
AFM resolution:
0.5 nm
Scanning modes:
contact and non-contact
OM field of view:
500 µm
OM resolution:
3 µm
Table position accuracy: 1µm
Rotary positioning range: 360 degrees
Radial positioning range: 75 mm
Additionally, the UNMT can perform all common tribological and mechanical tests
on the same samples, with easy-exchangeable Micro-Tribology Head (for
micro-scratching, micro-wear, micro-adhesion, micro-friction and
micro-indentation tests) and Nano-Mechanics Head (for nano-indentation tests).
Multiple swaps of the Heads maintain their position over the target sample area
with an accuracy of better than 10 mm, which is a fraction of both the AFM and
OM fields of view and so more than sufficient for close correlation of the
pre-test and post-test images with the mechanical test data.
Process artifacts of the laser textured hard
magnetic disk were investigated for the process control applications. A CCD
camera view shown in Figure 2 depicts laser texture bumps and process artifacts.
An image of the AFM laser beam can be seen in the background.
Figure 3 shows a 70x70mm AFM contact image of the laser textured disk area,
which was located using a quick find mode. Several 5-um diameter laser texture
bumps and several 2-mm wide surface scratches can be seen in the image.
Figure 2. CCD camera image of laser texture bumps on disk surface
Figure 3. AFM image of laser texture bumps
on disk surface