DETERMINATION OF ORIENTATION OF LITHIUM TETRABORATE SINGLE CRYSTAL

摘要

PROBLEM TO BE SOLVED: To determine orientation without cutting out a single crystal for determining the orientation by etching {10} face of lithium tetraborate grown by Bridgman's method and determining 001 and 001- orientation from the state of etch pit. ;SOLUTION: [001] face of a grown single crystal 1 of lithium tetraborate is measured by a X-ray diffraction measuring apparatus and a marking 2 is given on the side plane of the crystal. An end part of the single crystal is cut so that an allowance between the end surface of the single crystal 1 and {110} is not more than ±0.05, and an end part 3 (0.5 to 1.0 mm thickness) of the single crystal, impossible to be used as a wafer, and a single crystal 4 which can be used as wafers are obtained. When the end part 3 of the single crystal is etched in pure water at 60°C for 1 h, 001 and 001- are confirmed from the etching pattern, and they coincide with the 001 and 001- confirmed using the single crystal 5 for determining. Thereby, the single crystal for determining 001 and 001- becomes nonessential, and much more wafers can be produced and the reduction of the production cost is realized.;COPYRIGHT: (C)2000,JPO