ABSTRACT
The solubility of most impurities in semiconductors has a retrograde character. This means that maximum solubility occurs above eutectic melting temperature and decreases with decreasing temperature. This phenomenon is also known as negative solubility. In most metallic systems, the maximum solubility of one metal in another metal occurs at eutectic temperature. The solubility in such systems had been studied long before this was done in semiconductors. It is probably for this reason that maximum solubility at eutectic temperature was considered as a common rule and retrograde behavior as an exception to this rule.
