Atom probe tomography: An imaging tool at the Atomic Scale using ultrafast laser pulses

Due to the continuous miniaturisation of microelectronic devices, the development of new analysis techniques is an important challenge. In the active parts of most recent MOS nano-transistors, the electrical properties are controlled by only a few tens of dopant atoms. Thus, as stressed by the International Technology Roadmap for Semiconductors, it is essential to develop new methods for quantitative 3D dopant distribution measurement at the nanometer scale and with a high sensitivity. Among the wide panel of techniques used today in the investigation of semiconductor devices, there is still a lack in the capability of imaging a nano device in the three dimensions on a nearly atomic scale. The 3D atom probe, has been successfully used in the investigation of metallic materials for almost twenty years. However, this technique has long been limited to materials with a good electrical conductivity. The emergence of the laser assisted 3D atom probe in 2005 has extended the field application of the instrument to poorly conductive materials such as semiconductors or oxides. Over the last couple of years, many examples of useful and successful applications on real nano-electronics devices have been reported demonstrating the potentialities of this new tool.