Deep Trench Imaging

A Nanonics MultiView SPM system was used to obtain images of a 
silicon wafer sample (below) with deep trenches (prepared by the Bosch process). Deeply etched structures like these are essential for many applications; as such there is an ever increasing demand for improvements in etching technology. This will prove vital for the manufacture of electronic devices, particularly in the development of sensors with greater sensitivity and accuracy.

 

 

 

   

 

A CCD Image of the holes

  2D AFM topographic Image of holes


Above we can see examples of sidewall imaging in trenches with depths of greater than 22 microns. This is only made possible by virtue of Nanonics’ MultiView systems with their 3D Flat Scanner with its large (200 microns) Z range and its combination with our special patented, deep-trench glass cantilevered probes. Such probes, with their extended tip length and high aspect ratios enable the investigation of deep crevices and trenches. 

The image on the upper left shows the AFM image of a Si wafer and its holes /trenches. The probe was then used to image the sidewalls of one of these holes and this is shown in the upper right-hand image. Nanonics probes are able to reach into sidewalls due to their exposed tips and thus scan in X-Z, something impossible to achieve with regular silicon AFM probes. Nanonics cantilevered probes make such fine sidewall imaging a reality! 

 

At the bottom is shown a scanning electron microscope (SEM) image of the same sidewall. Nanonics’ systems are also transparently-integrated with SEM and FIB.

 

SEM image of Trench