Radiation performance of Ge technologies

This chapter focuses on the identification of the radiation-induced defects, their annealing behavior, and their impact on the electrical properties. The different defects and defect reactions are critically reviewed. From a device performance viewpoint distinction has to be made between transient and long-term effects resulting from both the ionization and displacement damage. A special form of radiation damage is caused by ion implantation. Wherever relevant, a comparison is made with the well-known radiation damage in silicon. The chapter is structured so that generic issues associated with radiation damage and implantation in semiconductors are considered initially, gradually focusing onto the specifics associated with germanium. In the chapter, the fundamental difference between radiation, which usually creates isolated Frenkel-pairs (gamma and electron) and radiation events creating clusters (alpha, neutron and ion implantation) are contrasted. The chapter also reviews and catalogues defects and defect reactions reported for germanium. Finally, the chapter discusses the impact of radiation damage on the properties of germanium materials and devices. In the chapter, contrasts are made between the behavior of germanium devices when subject to irradiation and the much more extensive literature on silicon technologies. Predictions are made of the likely impact of radiation on germanium metal-oxide-semiconductor (MOS) devices. In this chapter, the implications of residual implant damage are also considered in the context of their device significance.