Semiconductor bulk crystals have to be cut into wafers for further applications. The dominant slicing technique both for microelectronic and photovoltaic applications is the multiwire sawing method. The requirements on the processes and wafer qualities depend on the material and the application. The most advanced techniques have been developed for silicon. Sawing and the subsequent processes such as grinding, lapping, and polishing use abrasive particles for material removal. The fine-tuning and optimization of the wafer processes requires an understanding of the micromechanical interactions between abrasive particles and crystal. The current status of research and development will be described for the major methods and materials. Finally, a brief overview will be given for alternative wafer-processing techniques.