A novel beam-assisted thickness measurement technique for nanostructures

A novel method for measuring thickness of thin films has been developed. This method is straightforward, quickly accomplished, and offers resolution of device layers approaching that given by transmission electron microscopy. Ion beam bombardment of a multi-layer structure forms a crater in which the crater sidewalls are beveled at a very shallow angle, revealing various layers within the sample at a high degree of magnification. Beveled film thicknesses are measured by scanning Auger electron spectroscopy. Depth profilometry is used to measure the shallow beveling angle. Through knowledge of the beveled layer thickness and the bevel angle, actual film thicknesses are easily calculated. For structures in which delineation of distinct layers is difficult, chemical etching enhances features on the beveled crater sidewall, enabling resolution of layers as thin as 20A