Properties of Transition Metals in Silicon

Abstract

In spite of their regular outer electron configuration, the properties of the transition metals in silicon differ considerably even within the same sequence of 3d, 4d, or 5d transition metals, resulting in quite different features during and after heat treatments. The main properties which determine the behavior of transition metals in silicon and their impact on device performance are the solubilities and the diffusivities as a function of the sample temperature, and, as a consequence, their electrical activity and their precipitation behavior. Although the respective properties of the specific metals are different, there are general chemical trends which enable a simultaneous discussion of the properties. This holds at least for the 3d transition metals where most of the parameters of interest have been determined in the last decade or before. In contrast to the 3d transition metals the properties of the 4d and 5d transition metals are less known. Because of the lack of data, the chemical features for these two sequences cannot be demonstrated in the same way. Therefore the solubilities, diffusivities, electrical activities and precipitation behavior in the bulk of a silicon sample and at its surface will be discussed together only for the sequence of the 3d transition metals in Sects.3.1–4. The properties of the 4d and 5d transition metals cannot be treated together. However, several technologically important metals of these groups have been studies in more detail.KeywordsAcceptor StateSilicon LatticeInterstitial DefectSubstitutional DefectDenude ZoneThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.