Comparison of Erosion Behavior and Particle Contamination in Mass-Production CF₄/O₂ Plasma Chambers Using Y₂O₃ and YF₃ Protective Coatings.

Tzu-Ken Lin,Chi-Tsung Tasi,Dong-Sing Wuu,Wei-Kai Wang,Shih-Yung Huang

doi:10.3390/nano7070183

Tzu-Ken Lin, Chi-Tsung Tasi + Show 3 more

Open Access

https://doi.org/10.3390/nano7070183

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Journal: Nanomaterials	Publication Date: Jul 14, 2017
Citations: 50	License type: CC BY 4.0

Affiliation: National Chung Hsing University, Dayeh University

Abstract

Yttrium fluoride (YF3) and yttrium oxide (Y2O3) protective coatings prepared using an atmospheric plasma spraying technique were used to investigate the relationship between surface erosion behaviors and their nanoparticle generation under high-density plasma (1012–1013 cm−3) etching. As examined by transmission electron microscopy, the Y2O3 and YF3 coatings become oxyfluorinated after exposure to the plasma, wherein the yttrium oxyfluoride film formation was observed on the surface with a thickness of 5.2 and 6.8 nm, respectively. The difference in the oxyfluorination of Y2O3 and YF3 coatings could be attributed to Y–F and Y–O bonding energies. X-ray photoelectron spectroscopy analyses revealed that a strongly fluorinated bonding (Y–F bond) was obtained on the etched surface of the YF3 coating. Scanning electron microscopy and energy dispersive X-ray diffraction analysis revealed that the nanoparticles on the 12-inch wafer are composed of etchant gases and Y2O3. These results indicate that the YF3 coating is a more erosion-resistant material, resulting in fewer contamination particles compared with the Y2O3 coating.

Highlights

Silicon-based ceramics have been extensively used in semiconductor plasma processing equipment as plasma-facing materials, due to their hardness, high wear resistance, dielectric strength, high corrosion resistance, and chemical stability [1,2]
They are used mainly as a shield to protect the ceramic parts inside etchers or chemical vapor deposition reactor chambers from corrosion caused by fluorocarbon corrosive gases such as CF4, CHF3, C4F6, and C2F6 [3,4,5]
Due to the small difference in thermal expansion between the YF3 coating (28.5 × 10−6/K) and the Al substrate (23 × 10−6/K), no cracks were observed in any YF3 coating samples

Summary

Introduction

Silicon-based ceramics have been extensively used in semiconductor plasma processing equipment as plasma-facing materials, due to their hardness, high wear resistance, dielectric strength, high corrosion resistance, and chemical stability [1,2]. These materials interact with plasma and are eroded, resulting in the production of contaminant particles on the wafer. Yttrium fluoride (YF3) coatings ave recently attracted substantial attention because of their high plasma erosion resistance, preventing the generation of fluoride particles on the chamber wall surface, reducing particulate contamination [16].

Results

Conclusion