Grant: Idea to Innovation

Atomic force microscope (AFM) is the most popular characterization tool among the scanning probe microscope (SPM) family. Compared to scanning electron microscope (SEM), AFM has lower cost, much more accurate (by one order) in the z-direction and x-y direction if the sample is flat, and can work equally well with insulating sample or even inside a liquid environment. Nevertheless, SEM is still far more popular than AFM for topographical structure characterization, mostly because of the intrinsic limit in the AFM image when mapping a none-flat surface (e.g a deep and narrow hole/trench) where the tip cannot fully follow the sample surface. The natural solution to overcome this issue is by using thin and high aspect ratio tips that can follow the sample surface more precisely.The objective of this project is to develop the fabrication process for high aspect ratio AFM tips. The key feature of the technology is that it is a low-cost batch fabrication process with high yield. The process starts from a wafer of AFM tips containing 380 regular pyramid-shaped tips, and process them simultaneously to produce fine and high aspect ratio pillars at the tip apex.Currently all the commercially available high aspect ratio AFM tips are made one by one, in a slow and costly manner. On the contrary, our process is a batch fabrication process, and is thus with much higher throughput and much lower fabrication cost per tip.