Atomic Force Microscope

Today, atomic force microscopes (AFM) are used nearly everywhere in science and technology from space science to biology. Simplified, an AFM works like an old style gramophone: a sharp tip is moved over a sample surface with constant force. Every time the tip moves over a structure, the tip-holder (called cantilever) is bent. A laser is used to detect this deflection of the cantilever, which can be used to compute the exact size of the structure. Because it is possible to create tips that are only a few dozens of atoms in diameter, it is possible to do measurements with nanometer (nm) resolution. We already demonstrated atomic scale resolution (0.35 nm !) by mapping growth steps of GaAs single-crystals. Besides making topographic images, one can also get various other physical data of sample surfaces using an AFM. Current projects utilizing our AFM are 2D carrier mapping by measuring the local conductivity and capacitance, and the investigation of local  properties of high-k dielectrics.