LITHIUM NIOBATE SINGLE CRYSTAL SUBSTRATE, AND MANUFACTURING METHOD THEREOF

• Main Author: KAJIGAYA TOMIO
• Format: Patent
• Language: English; Japanese
• Published: 12.01.2017
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; CHEMISTRY; CRYSTAL GROWTH; METALLURGY; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

PROBLEM TO BE SOLVED: To provide a lithium niobate (LN) substrate that is easy to manage processing conditions concerning temperature, time or the like and has extremely low in-plane distribution of volume resistivity, and a manufacturing method thereof.SOLUTION: A LN substrate is manufactured from a LN single crystal grown by a Czochralski method. The LN single crystal that has an Fe concentration of more than 1,000 mass ppm and 2,000 mass ppm or less and is processed into a substrate state is buried in Al powder or mixed powder of Al and AlOand subjected to heat treatment at a temperature of 450°C or higher and lower than 550°C to manufacture a lithium niobate single crystal substrate having volume resistivity controlled to be in a range of higher than 1×10Ω cm and 2×10Ω cm or lower.SELECTED DRAWING: None 【課題】温度や時間等に係る処理条件の管理が容易で、体積抵抗率の面内分布が極めて少ないニオブ酸リチウム（ＬＮ）基板とその製造方法を提供する。【解決手段】チョコラルスキー法で育成したＬＮ単結晶を用いてＬＮ基板を製造する方法であり、単結晶中のＦｅ濃度が１０００質量ｐｐｍを超え、２０００質量ｐｐｍ以下で、かつ、基板の状態に加工されたＬＮ単結晶を、Ａｌ粉末若しくはＡｌとＡｌ2Ｏ3の混合粉末に埋め込み、４５０℃以上、５５０℃未満の温度で熱処理して体積抵抗率が１×１０10Ω・ｃｍを超え、２×１０12Ω・ｃｍ以下の範囲に制御されたニオブ酸リチウム単結晶基板を製造することを特徴とする。【選択図】なし