New technique to decrease dislocations in synthetic quartz crystal

Dislocations in synthetic quartz crystal are mainly propagated from the seed crystals. Therefore, low dislocation seed crystals are fundamental when growing low dislocation synthetic quartz. A new technique called "frame seed method" was developed to produce low dislocation seed crystal. In previous studies, it was confirmed that the technique cutting Z-cut seed from the +X region is effective to decrease dislocations. However, this technique has one problem; the Y-dimension becomes shorter than the original seed crystal as the result of the appearance of m-face. This new technique provided low dislocation seed without shortening of the Y-dimension by controlling the appearance of m-face. This technique can remove the other defects such as twins and cracks. Therefore applying this technique to the natural quartz containing twins or cracks, it is expected to remove these defects.