An O-Ring, also known as an O-shaped sealing ring, is a rubber seal with a circular cross-section. In semiconductor manufacturing processes, fluorine- and hydrogen-containing gases are often exposed to high temperatures. When these high-energy gases come into contact with the surface of modified materials, they can induce physical and chemical changes, leading to severe corrosion of the sealing materials. Therefore, O-Ring seals used in semiconductor processes must possess properties such as thermal stability, dimensional stability, chemical resistance, low outgassing, low IR (infrared absorption), low permeability, and high purity under high-temperature conditions.
O-Ring seals are widely used in various types of semiconductor equipment, including:
• Single crystal furnaces
• Oxidation furnaces
• Cleaning systems
• Etching equipment
• CVD (Chemical Vapor Deposition)
• PVD (Physical Vapor Deposition)
• CMP (Chemical Mechanical Polishing)
Each application has different performance requirements:
• Lithography equipment requires seals that are resistant to solvents.
• CVD equipment demands seals with excellent thermal stability under vacuum conditions.
• CMP systems need seals that are wear-resistant and can withstand high-pH chemical corrosion.
• Wet etching equipment requires O-Rings made from high-purity materials to prevent elemental contamination (such as particle generation).
• Dry etching systems require materials with strong plasma resistance.
In addition to the above, O-Rings may also need to resist dopants and reactive fluids, maintain low compression set, dimensional stability, and function over a wide operating temperature range.
O-Ring Seal Characteristics in the Semiconductor Industry
Currently, the O-Rings used in the semiconductor field are primarily made from FFKM (perfluoroelastomer), also known as fully fluorinated rubber, a terpolymer of perfluoromethyl vinyl ether, tetrafluoroethylene, and perfluoroalkyl vinyl ether.
EFKM (Perfluoroether Rubber) Characteristics:
• Excellent elasticity
• By adjusting the base polymer, fillers, and curing agents, rubber with varying properties can be produced, such as different hardness, tensile strength, elongation at break, and elasticity
• Good physical and mechanical properties, comparable to FKM (fluoroelastomer), with better resistance to high-temperature compression set
• Superior resistance to both high and low temperatures
• Excellent solvent and chemical resistance
• Low permeability to gases and liquids, good electrical insulation, and flame resistance
• Extremely wide operating temperature range
