Beryllium-containing II-VI semiconductor devices

An additional approach to further improve the reliability of ZnSe based devices is to use beryllium containing II-VI compounds. BeS, BeSe and BeTe are characterized by a considerable amount of covalent bonding and a high bond energy. This distinguishes these materials from the conventional ionic wide gap II-VI semiconductors like ZnSe, ZnTe or CdTe. Recently, thin film structures using Be- compounds have been fabricated and characterized. It became clear that--besides the application aspects--these materials are also very interesting from a more fundamental point of view. Using Be-containing II-VI compounds, ionic and covalent lattice matched II-VI materials can be combined in quantum well structures. The type II band alignment of BeTe and ZnSe gives additional freedom in the band gap engineering, and it is possible to grow lattice method quaternaries of low polarity onto silicon. Here, basic principles of Be containing II-VI compounds will be described, and the potential of these novel materials will be discussed.