Lithium niobate substrate blackening mehtod

Abstract

The invention discloses a lithium niobate substrate blackening method. A reducing reagent utilized in the method is prepared by mixing iron powder and lithium carbonate powder. The lithium niobate substrate blackening method comprises the steps: 1, putting an iron powder and lithium carbonate mixture into a square corundum crucible; 2, flatly putting and burying a lithium niobate substrate into the mixture; 3, putting the square corundum crucible into a thermal treatment furnace and treating in the argon atmosphere; 4, putting into a diluted hydrochloric acid solution to be soaked when a temperature reduces to be close to a room temperature and then washing and spin drying. The method has short reaction time, small consumed time in a lithium niobate substrate blackening process and suitability for large-scale production; by means of high temperature resistance and acid-base resistance, the square corundum crucible can be used for a long time; furthermore, the square corundum crucible brings convenience to taking and putting wafers, and the square corundum crucible is stabler in a furnace tube of the thermal treatment furnace and is not prone to inclining. The method has the advantages of convenience, simpleness and easiness in operation, safety and reliability. By adjusting conditions of a mixture proportion, reaction time, reaction temperature and the like, the lithium niobatesubstrates of different blackened degrees can be obtained.

Description

technical field [0001] The invention relates to the preparation of a lithium niobate substrate, in particular to a blackening method for a lithium niobate substrate, in particular to a blackening method for a lithium niobate substrate which requires high surface quality. Background technique [0002] Lithium niobate is a widely researched and applied artificial crystal. Since the discovery of lithium niobate in 1937, the main research has focused on the crystal structure and basic physical properties. It was not until 1965 that the large-diameter single crystal was obtained by the Czochralski method that the research on the properties of lithium niobate became more in-depth. Especially after it was discovered in 1980 that magnesium-doped lithium niobate can greatly improve the photorefractive resistance, there was an upsurge of research on lithium niobate all over the world. At present, it has been found that lithium niobate crystals have various properties, including piezo...

AI Technical Summary

Problems solved by technology

However, there are some shortcomings in the above methods: 1. When hydrogen, carbon monoxide and other gases are used for reduction, explosions or fires are prone to occur, which is more dangerous.

2. It is safer to use argon reduction or vacuum treatment, but the treatment time is relatively long, which is not suitable for large-scale industrial production

3. When using carbonate for reduction, the processing time is relatively long due to insufficient reducibility

4. It is easy to cause different degrees of blackening and uneven color depth when using deep blackened substrates and untreated substrates alternately stacked for processing

5. Using metal or non-metal powder for reduction treatment will adhere a layer of particles on the surface of the substrate, affecting the surface quality

6. When using a round crucible, the crucible is unstable when placed in the furnace tube of the heat treatment furnace, and it is easy to tilt back and forth, and it is inconvenient to use a round crucible to pick and place wafers