Defect Production by Irradiation

Abstract

Defects or impurities are introduced in semiconductors, intentionally or unintentionally, during the growth process or following heat treatments. Quenching, plastic deformation and irradiation are other ways by which defects can be created. The problem with heating, quenching and plastic deformation [8.1] is that the defects produced, practically all unidentified up to now in most materials, are complexes resulting from the interaction of intrinsic defects (vacancies, interstitials, divacancies) with the various impurities present initially in the material. Moreover, the concentration of these defects is difficult, if not impossible, to control (see [Ref.1.1, Sect.6.4] for the discussion of defects resulting from quenching). On the contrary, the concentration, the distribution and (to some extent) the nature of defects produced by an irradiation can be controlled. The defect concentration is proportional to the dose of irradiation; the nature and the distribution of the defects is a function of the nature of the irradiating particle, their energy, and the impurities contained in the material which have the ability to trap the intrinsic defects originally produced by the irradiation. For this basic motivation, but also for practical reasons (knowledge of the behavior of electronic devices submitted to radiations in nuclear reactors, space, etc.) radiation effects in semiconductors have been widely studied [8.2].