Rare earth fluoride spray powder and rare earth fluoride-sprayed article

Inactive Publication Date: 2013-05-16
SHIN ETSU CHEM IND CO LTD
View PDF4 Cites 20 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The invention is a rare earth element fluoride spray powder that can be used in plasma spraying. The powder has smooth flow and is not decomposed by plasma spraying. The particles are almost spherical and have an aspect ratio of up to 2, with an average particle size of 10 to 100 m. The powder has a bulk density of 0.8 to 1.5 g / cm3, and is made of rare earth elements like yttrium, cerium, and ytterbium or a mixture of these. The powder is solid and stable during handling, with no voids that could trap gas components. The technical effects of the invention include a stable and high-quality rare earth element fluoride spray coating that can be obtained using plasma spraying.

Problems solved by technology

While aluminum, chromium and similar metal oxides are often used as the thermal spray material, these spray materials are inadequate for use in the semiconductor fabrication process which may include exposure to hot plasma, corrosive attacks, and in particular, treatment in a halogen-based corrosive gas plasma atmosphere.
On the other hand, the rare earth fluoride sprayed coatings suffer from a technical problem despite good corrosion resistance.
The plasma spraying of rare earth fluoride has the problem that when the rare earth fluoride is passed through a flame at 3,000° C. or higher for melting, the fluoride can be decomposed so that the material partially converts to a mixture of rare earth fluoride and rare earth oxide.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0031]Particulate yttrium fluoride having an average particle size of 5 m and a water / hydroxyl content of 1,000 ppm, 5 kg, was added to deionized water and agitated to form a 30 wt % slurry. The slurry was granulated through a spray dryer into spherical particles having an average particle size of about 40 m.

[0032]The granulated particles were heated in air at 100° C. for 2 hours, obtaining a dry powder of spherical particles. The water content of the granulated powder was measured, finding a water content of about 0.65 wt %. The water content was measured by Karl Fischer's water analysis. On further analysis, the granulated powder had a carbon content of 0.3 wt %, an aspect ratio of 1.2, and a bulk density of 1.3 g / cm3. This yttrium fluoride powder was adequate as the thermal spray material. Notably, the aspect ratio was determined by taking a SEM photo, measuring the length and breadth of 180 particles in the photo, and averaging.

example 2

[0033]Using the yttrium fluoride spray powder of Example 1 and a gas mixture of 40 L / min argon and 5 L / min hydrogen, atmospheric plasma spraying was carried out onto an aluminum substrate. The resulting article had a sprayed coating of about 200 m thick and looked light gray color. The L*a*b* chromaticity of the sprayed coating was measured, finding L*=70.87, a*=0.35, and b*=5.57. It had a carbon content of 0.07 wt %, and an oxygen content of 0.75 wt %.

[0034]The sprayed article was mounted in a reactive ion plasma tester along with a resist-coated silicon wafer. A plasma exposure test was performed under conditions: frequency 13.56 MHz, plasma power 1,000 watts, gas mixture CF4+O2 (20 vol %), flow rate 50 mL / min, and gas pressure 50 mTorr. Following the exposure test, the sprayed coating showed no partial color changes on visual inspection. The L*a*b* chromaticity was measured, finding L*=70.33, a*=0.40, and b*=5.47.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Lengthaaaaaaaaaa
Fractionaaaaaaaaaa
Percent by massaaaaaaaaaa
Login to view more

Abstract

A powder comprising rare earth element fluoride particles having an aspect ratio of up to 2, an average particle size of 10-100 m, a bulk density of 0.8-1.5 g / cm3, and a carbon content of 0.1-0.5 wt % is amenable to atmospheric plasma spraying. An article obtained by spraying the rare earth fluoride spray powder to a substrate undergoes few partial color changes and performs well even when used in a halogen gas plasma.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2011-246164 filed in Japan on Nov. 10, 2011, the entire contents of which are hereby incorporated by reference.TECHNICAL FIELD[0002]This invention relates to a rare earth element fluoride thermal spray powder, especially suited for use to form a sprayed coating having corrosion resistance in a halogen-based corrosive gas plasma atmosphere as encountered in the semiconductor device fabrication process, and a rare earth element fluoride-sprayed article.BACKGROUND ART[0003]In the prior art, sprayed coatings having corrosion resistance are used for protecting substrates in a variety of service environments. While aluminum, chromium and similar metal oxides are often used as the thermal spray material, these spray materials are inadequate for use in the semiconductor fabrication process which may include exposure to hot plasma, corrosive attacks, ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C01F17/00C01F17/206C01F17/265
CPCC01F17/0062C23C4/04C23C4/10C01P2004/54C01P2004/61Y10T428/2982C01P2006/80C01P2006/82C01F17/00Y10T428/256C01P2006/11C01F17/265C01F17/206
Inventor HAMAYA, NORIAKIMAEDA, TAKAOTAKAI, YASUSHI
Owner SHIN ETSU CHEM IND CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap