1 Introduction

  During the last decade, numerical modeling of the semiconductor fabrication process has increasingly become an important design and development tool in semiconductor technology. Development of a new or improved semiconductor device runs through a number of distinctive phases. In the first phase there is the initial design of the new device including the first setup of the fabrication process. Mostly options from already well established processes and technologies are taken to form the initial new process. After this first design the process undergoes an optimization loop. Thereby the process is tuned and improved to reach the specifications and device characteristics. Finally, the process is ready for manufacturing, where impacts of manufacturing changes on performance and yield calculations are taken under investigation. In all these phases simulation tools can play a crucial role for the reduction of the cycle time for device prototypes. A modern integrated circuit (IC) process consists of several hundreds of single process steps. The goal of process simulation should now be the full characterization of the most critical parts by means of numerical simulation tools.

Apart from being valuable in development and optimization of IC fabrication processes, process simulators are necessary to predict accurate impurity profiles for subsequent use in device simulator programs. With the decreasing scale of the device dimensions there is a growing demand for process simulators that account for multidimensional effects and accommodate more realistically the physical behavior during processing of the devices. The process models have to fulfill the requirements on accuracy, reproducibility, and predictability even in the development phase, because of the large manufacturing chain. From the process simulation point of view there are still process steps, such as cleaning, which need not be simulated, because their influence on subsequent process steps is insignificant or can be included in the next process step. The simulation task for process simulation can be reduced to the critical structural and impurity related process steps.

• 1.1 Simulation Tasks in Process Simulation
  • 1.1.1 Lithography
  • 1.1.2 Etching and Deposition
  • 1.1.3 Ion Implantation
  • 1.1.4 Annealing
  • 1.1.5 Oxidation
• 1.2 About this Work