Methods for the measurement of two-dimensional doping profiles

The problem of measuring two-dimensional (2D) diffusion profiles in silicon is a critical one. Several very different methods for 2D dopant profiling have been proposed recently, but the methods are often applied only by specialists to selected problems and wide acceptance of these methods is yet to take place. This article presents a comprehensive review of methods for the measurement of 2D dopant profiles, along with a complete bibliography. The goal is to compare the various methods on the basis of some common factors, and to begin to establish some criteria for selecting 2D dopant profiling methods. First, some issues are raised which, in addition to criteria such as resolution and sensitivity, form a basis for differentiating between various methods. The methods described in the literature to date are then classified and discussed briefly. All reported methods and their variations are at least mentioned with appropriate references. Finally, a comparison of various methods is presented, focusing on specific issues such as resolution, accuracy, complexity of sample preparation, and the complexity of equipment required for the measurement.