New AFM imaging for observing a high aspect structure

New imaging technique in AFM has been developed to suppress bending of the probe during scanning. The technique controls the probe such that approaching and gap-controlling are done after only one step xy-scanning is completed (only z-movement is done without scanning), and the xy-scanning is done after lifting the probe up from the sample surface. This technique permits to use very sharpened probe and to observe a steep structure such as a dry-etched groove and a hole, and a photoresist pattern with a high aspect ratio faithfully. It is possible to apply this technique to monitoring the steep structures in the LSI process without cracking the wafer.