Polishing method of potassium aluminate chip

A technology of lithium aluminate and wafer, which is applied in the field of lithium aluminate, can solve problems such as the difficulty of obtaining wafers, affecting the quality of polishing, and the difficulty of breaking through surface roughness, etc., achieving obvious effects and unique methods

Inactive Publication Date: 2006-08-16
SHANGHAI INST OF OPTICS & FINE MECHANICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] However, the polarity and hydrolysis of the lithium aluminate crystal substrate have seriously affected its polishing quality, and it is difficult to obtain a wafer with an average surface roughness better than 0.2nm [see J.Vac.Sci.Technol.B., 2003, 21(4): 1350], at present foreign companies (USA, Germany) have carried out some research on its polishing, but it is difficult to break through the difficulty that the surface roughness is better than 0.2nm

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0014] A polishing method of a lithium aluminate wafer, comprising the following steps:

[0015] The lithium aluminate crystal with a diameter of 2 inches and a length of 80 mm grown by the pulling method is cut into a wafer with a thickness of 0.5 to 1 mm by an inner circle cutting machine;

[0016] Put the wafer into hydrochloric acid or nitric acid with a concentration of 78%, heat it up to 80°C, keep the temperature for 15 minutes, take it out and dry it with nitrogen, observe the corrosion pits on the front and back of the wafer with a large field microscope, and select the corrosion pits The less side is used as the next polishing surface;

[0017] Put the surface of the wafer to be polished on the rubber plate, and use alumina powder to roughen it and polish it. After this process, the crystal surface with an average surface roughness of 5nm is achieved;

[0018] Fine polishing the crystal surface, using SiO with PH=8 2 Polishing liquid, the polishing time is 2 ho...

Embodiment 2

[0021] According to the steps in the above-mentioned technological process, the lithium aluminate crystal with a diameter of 2 inches and a length of 80 mm grown by the pulling method is cut into a wafer with a thickness of 1 mm with an inner circle cutting machine, and the wafer is placed in hydrochloric acid (concentration 80%) Then, the temperature was raised to 100 °C, and the temperature was maintained for 30 minutes; the wafer was taken out, dried with nitrogen, and the surface morphology of the wafer was observed under a large-field microscope, and the crystal plane with fewer corrosion pits was selected as the polished crystal plane. After rough grinding and rough polishing of alumina powder, the crystal plane with an average surface roughness of 10nm is finely polished, and SiO with PH=8 is selected. 2 Polishing solution, the polishing time is 3 hours, the crystal plane with the average surface roughness of 1.6nm can be obtained, and then the crystal plane with the ave...

Embodiment 3

[0023] The specific method is as in Example 1. The wafer is put into nitric acid (concentration 80%), heated to 80° C., maintained for 15 min, dried for observation and selected as the polished crystal plane with few corrosion pits. After rough grinding and rough polishing of alumina powder, the crystal plane with an average surface roughness of 10nm is finely polished, and SiO with PH=8 is selected. 2 Polishing solution, the polishing time is 3 hours, the crystal plane with the average surface roughness of 1.6nm can be obtained, and then the crystal plane with the average surface roughness of 0.18nm can be obtained by polishing with neutral emery for 2 hours.

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Abstract

A method for polishing the wafer of lithium aluminate includes such steps as growing lithium aluminate crystal by pull method, cutting to become wafer, putting it in the solution of hydrochloric acid or nitric acid, heating at 80-100 deg.C for 15-30 min, blowing N2 for drying, choosing more smooth surface by microscope, putting it on rubber disc, coarse grinding with alumina powder, fine polishing with polishing SiO2 liquid, and polishing with neutral diamond sand liquid.

Description

technical field [0001] The present invention relates to lithium aluminate, in particular to a polishing method of lithium aluminate wafer. Background technique [0002] In recent years, blue-green light-emitting diodes, laser diodes and related devices have become research hotspots due to their huge market application prospects, and the research on GaN-based materials is the most prominent. At present, GaN-based blue-green light-emitting diodes (referred to as LEDs) have been commercialized. In 1997, the blue-light laser diode (LD) developed by Nichia using GaN has a continuous working life of more than 10,000 hours. However, it is difficult to further improve the luminous efficiency and lifetime of LEDs and LDs at present, mainly because the lattice mismatch and thermal mismatch between the film and the substrate lead to the complication of the fabrication process and the high defect density caused by the huge stress. In order to solve this problem, people have invented m...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B24B29/00H01L21/304
Inventor 邹军周圣明黄涛华王军周健华
Owner SHANGHAI INST OF OPTICS & FINE MECHANICS CHINESE ACAD OF SCI
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