Semiconductor Devices: Physics and Technology, 3rd Edition

14

Impurity Doping

14.1 BASIC DIFFUSION PROCESS

14.2 EXTRINSIC DIFFUSION

14.3 DIFFUSION-RELATED PROCESSES

14.4 RANGE OF IMPLANTED IONS

14.5 IMPLANT DAMAGE AND ANNEALING

14.6 IMPLANTATION-RELATED PROCESSES

SUMMARY

Impurity doping is the introduction of controlled amounts of impurity dopants into semiconductor materials. The practical use of impurity doping is primarily to change the electrical properties of the semiconductors. Diffusion and ion implantation are the two key methods of impurity doping. Until the early 1970s, impurity doping was done mainly by diffusion at elevated temperatures, as shown in Fig. 1a. In this method the dopant atoms are placed on or near the surface of the ...