Surface Analysis of Chamber Coating Materials Exposed to CF4/O2 Plasma

Abstract

Coating the inner surfaces of high-powered plasma processing equipment has become crucial for reducing maintenance costs, process drift, and contaminants. The conventionally preferred alumina (Al2O3) coating has been replaced with yttria (Y2O3) due to the long-standing endurance achieved by fluorine-based etching; however, the continuous increase in radio frequency (RF) power necessitates the use of alternative coating materials to reduce process shift in a series of high-powered semiconductor manufacturing environments. In this study, we investigated the fluorine-based etching resistance of atmospheric pressure-sprayed alumina, yttria, yttrium aluminum garnet (YAG), and yttrium oxyfluoride (YOF). The prepared ceramic-coated samples were directly exposed to silicon oxide etching, and the surfaces of the plasma-exposed samples were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. We found that an ideal coating material must demonstrate high plasma-induced structure distortion by the fluorine atom from the radical. For endurance to fluorine-based plasma exposure, the bonding structure with fluoride was shown to be more effective than oxide-based ceramics. Thus, fluoride-based ceramic materials can be promising candidates for chamber coating materials.

Correlation with the Microstructure and Synergistic Physiochemical Etching Resistance of Nanocomposites under Fluorine-Containing Plasma Conditions

“…Since parts have short lifespans of several months, the higher the utilization rate, the faster the replacement cycle. Contaminant particles originating from eroded ceramic components rise to the top of the wafer and cause short circuits between gate electrodes and source/drain, so it is of utmost importance to limit the generation of contaminants and choose an appropriate ceramic composition for long-time use. − Y 2 O 3 aerosol deposition coatings or bulk ceramics are now being proposed and utilized since they have a higher dry etching resistance. − YF 3 thin layers are also being studied because this material is predicted to generate fewer contamination particles based on passivation film and its plasma erosion resistance. , It is known that a nonvolatile reactant thin film is formed on the surface of Y 2 O 3 and YF 3 in fluorine-based plasma environments, and Ar + ions are prevented from directly hitting specimens, thereby improving etching resistance . However, when the etching process is dominated by physical ion bombardment, contaminant particles are generated in the fluorinated layer on the surface, and they are affected by the microstructure of ceramics .…”

The Effect of Zn and Zn–WO3 Composites Nano-Coatings Deposition on Hardness and Corrosion Resistance in Steel Substrate

“…In addition, the alloy processing route as the corrosion inhabitant method is not ideally suitable for highly sensitive engineering service environments when there is a lack of high-temperature stability in base or conventional material [ 13 , 25 ]. In recent years, surface coating methods (electro-spark deposition, laser cladding, magnetron sputtering, thermal spray process and chemical-vapor deposition) have become practiced widely in industries [ 26 , 27 ]. Thermal spraying and electroplating techniques are widely applied coating techniques to protect or repair the metallic surfaces of mechanical parts [ 28 , 29 ].…”