4. Monte-Carlo Simulation with

The Monte-Carlo ion implantation simulator MCIMPL has been developed in the course of the last fifteen years. Hobler [34] has started the development by implementing the physical fundamentals and by calibrating the physical models for the most important ion species used in semiconductor technology. Originally just simple input structures like a block of silicon partly covered by a rectangular mask could be handled. Stippel [78] extended the capability for arbitrary shaped input structures and furthermore, he developed a three-dimensional version of the original two-dimensional simulator. Finally Bohmayer [7] worked on an improvement of the performance of the simulator by the implementation of the Trajectory-Split method and he developed an empirical model to estimate the the generation of amorphous areas.

The current status is, that the Monte-Carlo ion implantation simulator MCIMPL is a multi-dimensional simulator. It handles arbitrarily shaped simulation domains consisting of several domains of amorphous materials and of crystalline silicon. Several segments of the simulation domains can be made of crystalline silicon with the restriction that the crystal orientation has to be identical in all crystalline segments. The only geometrical restrictions are that the bottom, left, right, front and back boundary of the input structure are shaped like a box, but this is not a really a restriction, because the simulation domain is always a cut of the real wafer. Finally an approximation is applied for polycrystalline materials because these materials are treated as amorphous materials, while the crystalline structure of the grains is neglected.

The structure of the simulation domain is provided as a file in the PIF-Format ([21], [22]) which contains all topological information of the wafer. The implantation conditions and model specifications are determined by a command-line interface. The command-line parameters are listed in Appendix A in common with a short description and with references to theoretical and modeling chapters.

- 4.1 Geometry Expansion
- 4.2 Implantation Window
- 4.3 Initial Conditions
- 4.4 Trajectory Calculation
- 4.5 Special Features
- 4.6 Speedup Algorithms

A. Hoessiger: Simulation of Ion Implantation for ULSI Technology