弾性表面波素子用酸化物単結晶(<特集>機能素子・部品と単結晶育成)

抄録

Oxide single crystals applied to surface acoustic wave (SAW) device field are briefly reviewed. For SAW device applications, X cut-112°Y LiTaO_3, 128°Y cut-X LiNbO_3 substrates have been mainly used. The wafer size of theses single crystal SAW substrates have been scaled up to 5 inches. In scaling up oxide single crystals for SAW device applications, there are two main problems; (l) Suppression of macroscopic crystal defects such as crystal cracks occurring during and after the crystal growth, (2) Improvement on compositional variation. This paper described the development of the wafer diameters and quality improvements for application to SAW substrates. The origins of various crystal defects in pulled crystals and quality factors are discussed for application to SAW devices in mass-production level.