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A kind of polishing method of lithium tantalate wafer

A lithium tantalate and wafer technology is applied in the polishing field of wafer material lithium tantalate wafer, which can solve the problems of poor roughness and flatness, deterioration of polishing quality, uneven wear of polishing, etc. Device quality, the effect of reducing processing costs

Active Publication Date: 2019-03-22
TDG HLDG CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The non-uniformity of polishing positive pressure will cause non-uniform wear of polishing, which will deteriorate the polishing quality, roughness and flatness

Method used

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  • A kind of polishing method of lithium tantalate wafer
  • A kind of polishing method of lithium tantalate wafer
  • A kind of polishing method of lithium tantalate wafer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] a) Grind the cut lithium tantalate wafer with an abrasive with a particle size of 6um so that the roughness of the lithium tantalate wafer is less than 300nm and the flatness is less than 10um, and then ultrasonically cleaned to obtain a lithium tantalate grinding surface with a rough structure piece;

[0028] b) The lithium tantalate grinding piece is directly chemically etched in a closed container containing a mixed acid of nitric acid and hydrofluoric acid, the etching temperature is 25°C, and the etching time is 4 hours, so that the roughness of the lithium tantalate wafer is <200nm, The flatness is less than 5um, and ultrasonic cleaning is performed to obtain lithium tantalate corrosion sheets with random and disordered pit structures on the surface;

[0029] c) Polish the lithium tantalate wafer on one side with a single polishing machine and polishing liquid, the polishing pressure is 0.25MPa, and the polishing temperature is 30°C, so that the roughness of the l...

Embodiment 2

[0031] a) Grind the cut lithium tantalate wafer with an abrasive with a particle size of 6um so that the roughness of the lithium tantalate wafer is less than 300nm and the flatness is less than 10um, and then ultrasonically cleaned to obtain a lithium tantalate grinding surface with a rough structure piece;

[0032] b) The lithium tantalate grinding piece is directly chemically etched in a closed container containing a mixed acid of nitric acid and hydrofluoric acid, the etching temperature is 25°C, and the etching time is 8 hours, so that the roughness of the lithium tantalate wafer is <200nm, The flatness is less than 5um, and ultrasonic cleaning is performed to obtain lithium tantalate corrosion sheets with random and disordered pit structures on the surface;

[0033] c) Polish the lithium tantalate wafer on one side with a single polishing machine and polishing solution, the polishing pressure is 0.50MPa, and the polishing temperature is 30°C, so that the roughness of the...

Embodiment 3

[0035] a) Grind the cut lithium tantalate wafer with an abrasive with a particle size of 6um so that the roughness of the lithium tantalate wafer is less than 300nm and the flatness is less than 10um, and then ultrasonically cleaned to obtain a lithium tantalate grinding surface with a rough structure piece;

[0036] b) The lithium tantalate grinding piece is directly chemically etched in a closed container containing a mixed acid of nitric acid and hydrofluoric acid, the etching temperature is 25°C, and the etching time is 8 hours, so that the roughness of the lithium tantalate wafer is <200nm, The flatness is less than 5um, and ultrasonic cleaning is performed to obtain lithium tantalate corrosion sheets with random and disordered pit structures on the surface;

[0037] c) Polish the lithium tantalate wafer on one side with a single polishing machine and polishing liquid, the polishing pressure is 0.75MPa, the polishing temperature is 30°C, so that the roughness of the lithi...

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Abstract

The invention discloses a polishing method for a lithium tantalate substrate. The method includes the steps of 1, grinding a cut tantalate lithium wafer with an abrasive material with the particle size of 5-20 microns, and obtaining a lithium tantalate grinding sheet with the surface of a rough structure; 2, directly conducting chemical corrosion on the lithium tantalate grinding sheet in a sealed container filled with the mixed acid of nitric acid and hydrofluoric acid, wherein the roughness of the tantalate lithium wafer is smaller than 200 nm, and the flatness is smaller than 5 microns; obtaining a lithium tantalate corrosion sheet with the surface of a random disordered pit structure; 3, conducting single-side polishing on the lithium tantalate corrosion sheet with a single-polishing machine and a polishing liquid, wherein the polishing pressure is 0.005-1 MPa, the roughness of the tantalate lithium wafer is smaller than 0.5 nm, and the flatness is smaller than 3 microns; obtaining a lithium tantalite polishing sheet. The polishing method has the advantages of one-time polishing, batch production and high polishing efficiency, and the produced lithium tantalate substrate has high surface flatness which determines that the lithium tantalate substrate is not easily broken in the application of devices; the material utilization is high, and the processing yield is high.

Description

technical field [0001] The invention relates to the field of semiconductor materials, in particular to a polishing method for a semiconductor wafer material lithium tantalate wafer. Background technique [0002] Lithium tantalate (LiTaO3, hereinafter referred to as LT) is a crystal with piezoelectric and pyroelectric effects and low hardness (Mohs hardness is 5, Si's Mohs hardness is 6), and is easily broken. Due to its excellent physical properties, LT has received more and more attention, and has been widely used in aviation, aerospace, civil optoelectronic products and other fields, such as surface wave devices, narrow-band filters, sensors, photonic tunable filters, acousto-optic devices, optical gyroscopes, etc. Unlike silicon crystals and sapphire crystals, it is characterized by extremely low fracture toughness and hardness. For example, its fracture toughness is actually one-third that of silicon and one-tenth that of sapphire. Ultra-thin lithium tantalate wafers ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B24B1/00
CPCB24B1/00
Inventor 沈浩顾鑫怡徐秋峰归欢焕丁孙杰
Owner TDG HLDG CO LTD