タンタル酸リチウム単結晶の焦電性抑制技術

抄録

  In order to suppress the pyroelectric properties of LiTaO₃(LT) substrates, a technique of controlling the volume resistivity of LT via a reduction process was investigated using metallic Al powder. After embedding the LT substrate in mixed powder of Al and Al₂O₃, the reduction process was carried out for 20 hours at 580℃, Before the reduction, the volume resistivity of the substrates was about 1×10¹⁵Ω･cm or more, but after the reduction, it became 1-10×10⁹Ω･cm. In addition, after the reduction, the surface charges generated by the pyroelectric effect were neutralized within a few seconds. Oxygen vacancy concentration formed in the LT substrates by the reduction process was estimated to be tens of ppm order at most.