Method for reducing transparency and resistivity of lithium niobate or lithium tantalate wafer

Abstract

The invention discloses a method for reducing transparency and resistivity of a lithium niobate or lithium tantalate wafer, which comprises the following steps of: alternately arranging the pretreated lithium niobate or lithium tantalate wafer and pure cotton paper or fiber cloth to form a laminated structure, and performing reduction blackening treatment on the wafer under a specific annealing furnace process condition to obtain the lithium niobate or lithium tantalate wafer. By adjusting the ratio of the thickness of the pure cotton paper or the fiber cloth to the thickness of the wafer, the lithium niobate or lithium tantalate yellow black wafer / grey wafer with different reduction degrees can be controllably prepared, the problems that the wafer blackening speed is too high, the reduction degree of the wafer is difficult to control, and the wafer is completely blackened are effectively solved, meanwhile, the resistivity and the light penetration rate of the wafer are effectively reduced, and the service life of the wafer is prolonged. And the whole process preparation process is environment-friendly and pollution-free, the reduction blackening treatment process is simple, the energy consumption is low, the production efficiency is low, and the method has excellent actual production value.

Description

technical field [0001] The present application relates to the technical field of crystal materials, in particular to a method for reducing the transparency and resistivity of lithium niobate or lithium tantalate wafers. Background technique [0002] Lithium niobate (LiNbO 3 , LN) lithium tantalate (LiTaO 3 , LT) crystal has excellent mechanical properties, is easy to grow large-size single crystal, easy to process, and has excellent physical properties such as electro-optic, birefringence, piezoelectric, pyroelectric and photovoltaic effects, and is widely used in filters, frequency doubling conversion. , holographic storage and other fields, at present, lithium niobate and lithium tantalate crystals have become the main raw materials for the manufacture of high-frequency / ultra-high-frequency SAW filters. [0003] Lithium niobate and lithium tantalate crystals have obvious pyroelectric properties, and the untreated LN and LT crystals have high resistivity. In the SAW filte...

AI Technical Summary

Problems solved by technology

[0006] In order to solve the problem in the prior art, the reduction and blackening treatment of lithium niobate or lithium tantalate wafers by using strong reducing elemental substances or compound powders leads to complete blackening of the wafers, and it is difficult to control the speed of wafer blackening and the degree of wafer reduction, resulting in mechanical The strength is reduced, the wafer is easily broken due to the low strength during the film peeling process, and the reducing metal or compound powder is difficult to fully contact the wafer surface, and the degree of wafer reduction is uneven. At the same time, the wafer resistivity and light transmittance are reduced. To improve wafer performance, improve wafer quality and reduce production costs. The invention discloses a method for reducing the transparency and resistivity of lithium niobate or lithium tantalate wafers. The specific steps include:

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