GROWTH OF PIEZOELECTRIC-CRYSTALS BY CZOCHRALSKI METHOD

The Czochralski method is one of the most widely used industrial techn ique to grow single-crystals, since it applies to a very large range o f compounds, such as semiconductors, oxides, fluorides, etc... Many ex hibit piezoelectric properties and some of them find applications in S urface-Acoustic-Waves or Bulk-Acoustic-Waves devices. That explains th e large amount of work made on the development of the corresponding gr owth processes and the high levels of production achieved in the world today. We will review the basic principle, main features and paramete rs of the Czochralski method, and the configuration which is used by C rismatec. Then we will discuss in more details the growth parameters f or the two piezoelectric crystals that we are producing, LiNbO3 and Li TaO3, and present the state-of-the-art for both crystals : pulling axi s, diameter and quality. We will also discuss some preliminary results on the growth of the new La3Ga5SiO14 langasite crystal.