Two-Dimensional Carrier Profiling in Submicron Structures

In this work a review of the basic concepts of recently developed two-dimensional profiling techniques is given. The methods are based on spreading resistance measurements, atomic force surface topography and transmission electron microscopy. The use of spreading resistance for two-dimensional profiling has been introduced three years ago. In the mean time the experimental procedure and the interpretation of the results has improved making this method quite accurate and reliable. The techniques based on atomic force and transmission electron microscopy exploit the selective chemical etching of silicon containing impurity profiles in order to obtain surface topography related to the local carrier concentration. Atomic force microscopy is used to image this topography with atomic resolution, while transmission electron microscopy allows to evidence with high contrast different regions of submicron structures. A few examples of application are reported.