Improvements in simulation of 2D implantation profiles

Shrinking device dimensions require the reduction of high-temperature steps or their replacement by RTA (rapid thermal annealing). Therefore, an accurate knowledge of implanted dopant profiles becomes more and more important. This means that a very good profile description is required, especially in case of implantation through thin layers, e.g. a scattering oxide, or near nonvertical mask edges, e.g. a photoresist edge, and that the lateral spread and its depth dependence must be modeled accurately. An improved multilayer model for implantation into two-layer structures is introduced. An improved experimental method for the measurement of 2D implantation profiles is presented. The method yields up to five equiconcentration lines within two scanning electron micrographs. It therefore allows the calculation of implantation parameters in two dimensions