Scanning electron microscopy has been employed as an imaging and measurement tool for more than 50 years and it continues as a primary tool in many research and manufacturing facilities across the world. A new challenger to this work is the helium ion microscope (HIM). The HIM is a new complementary imaging and metrology technology for nano- imaging and metrology. Essentially, substitution of the electron source with a helium ion source yields a tool visually similar in function to the scanning electron microscope, but very different in the fundamental imaging and measurement process. The imaged and measured signal originates differently than the scanning electron microscope and that fact and its single atom source diameter may be able to push the obtainable resolution lower, provide greater depth-of-field, and ultimately improve the metrology. Successful imaging and metrology with this instrument entails understanding and modeling of new ion beam/specimen interaction physics. As a new methodology, HIM is beginning to show promise and the abundance of potentially advantageous applications for nanometrology have yet to be fully exploited. This paper discusses some of the progress made at NIST and IBM to understand the science behind this new technology.
Citation: Measurement Science and Technology
Pub Type: Journals
Helium ion, microscope, HIM, scanning electron microscope, SEM, nanomanufacturing, nanometrology, critical dimension