Lithium niobate or lithium tantalate wafer blackening method based on ion implantation

Abstract

The invention provides a lithium niobate or lithium tantalate wafer blackening method based on ion implantation, and the method comprises the following steps: obtaining a wafer which is a lithium niobate wafer or a lithium tantalate wafer; carrying out reductive ion implantation processing on the wafer to obtain a wafer into which reductive ions are implanted; and carrying out annealing treatmenton the wafer implanted with the reducing ions. According to the method, wafer blackening is carried out on the basis of ion implantation, and the high-quality blackened wafer can be obtained under thecondition that the piezoelectric property of the material is not affected. According to the method, an ion implantation technology is utilized, reducing ions such as Fe<2+> are injected into the lithium niobate or lithium tantalate wafer. The injection of Fe<2+> and the like occupies the lattice points of ions with higher valence state in the crystal lattice, the oxygen vacancy concentration in the lithium niobate or lithium tantalate crystal is increased, the carrier concentration in the wafer is improved, the conductivity of the wafer is further improved, the resistivity is reduced, then the wafer is annealed and repaired, and the pyroelectric effect of the crystal can be effectively reduced.

Description

technical field [0001] The present application relates to the technical field of post-processing of crystal materials, in particular to a method for blackening lithium niobate or lithium tantalate wafers based on ion implantation. Background technique [0002] Lithium niobate (LiNbO 3 , LN) and lithium tantalate (LiTaO 3 , LT) crystal is a very typical multifunctional crystal, because of its excellent ferroelectric, piezoelectric, pyroelectric, acousto-optic, electro-optic, photorefractive and nonlinear properties, it is currently widely used in surface acoustic wave devices (SAW), optical communication and optoelectronics and other fields. Surface acoustic wave filter is one of the very important application directions of LN and LT crystals. Due to the crystal cutting and polishing, the color is close to transparent and has high optical transmission, as well as its inherent pyroelectric effect, the preparation of SAW devices still exists Many inconveniences. [0003] Fi...

AI Technical Summary

Problems solved by technology

However, there are some problems in the above methods. Reducing gases such as carbon monoxide and hydrogen are prone to explosion during heating treatment, which has great potential safety hazards. Wafer contact blackening treatment may cause different degrees of wafer blackening and uneven color. The use of carbonates and hydrides for reduction has insufficient reducibility and requires a relatively long processing time. Some potential disadvantages of other methods include the impact of particles adsorbed on the wafer surface on wafer quality and the difficulty in requiring corresponding equipment.

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