Diffusion and Ion Implantation Equipment

Both diffusion and ion implantation equipment are used in the doping process for IC manufacturing. By introducing impurities into silicon, the type, concentration, and distribution of the main carriers in the substrate are controlled along with the conductivity and the polarity type of the substrate. Diffusion equipment is based on the principle of high temperature thermal diffusion. It has the advantages of simple structure, high diffusion rate, and high doping concentration. The ion implantation equipment can precisely control the doping concentration and junction depth at lower temperature by introducing energetic dopant ions into silicon substrate. With the advantages of good repeatability and a wide variety of optional impurities, it has become the main doping technology in current IC manufacturing. Due to the cost and complex structure, high-dose doping is time-consuming, and tunneling effects and injection damage may occur. In this chapter, the main types of horizontal diffusion furnaces, vertical diffusion furnaces, and ion implantation machines are introduced in detail. In addition, oxidation furnaces, annealing furnaces, and other process equipment are also introduced.