Carbon tetrafluoride, with the chemical formula CF4, is an inorganic fluorocarbon gas. It has a tetrahedral molecular geometry consisting of a central carbon atom surrounded by four fluorine atoms. Here are some of the notable physical and chemical properties of CF4:
Carbon tetrafluoride (CF4) has become an essential gas for the electronics industry, especially in plasma etching and chemical vapor deposition processes. With its high fluorine content, CF4 disassociates into reactive F radicals and ions that selectively etch materials like silicon dioxide over silicon. This allows precision patterning and shaping of the insulating oxide layers on semiconducting wafers during microchip production. CF4 is also useful for cleaning deposition chambers through its ability to remove stubborn silicon-containing residues. Additionally, CF4 can selectively etch tungsten and titanium while not removing aluminum. With tunable plasma conditions, CF4 plasmas enable anisotropic etching essential for maintaining vertical sidewalls on etched features for integrated circuit manufacturing.
At standard temperature and pressure, it is a non-flammable, colorless gas. It has a slightly faint ethereal odor. It is moderately soluble in organic solvents. It has a high density of 3.72 g/L at STP, around 3 times heavier than air. It is one of the most chemically and thermally stable carbon fluorides.
CF4 remains inert across a wide temperature range up to around 500°C. It cannot be easily liquefied except under high pressures. A key property is its high electronegativity and dielectric strength, around 2 times higher than air. This makes it well-suited as a gaseous dielectric medium. Overall, CF4 is a highly symmetric, stable, and non-reactive gas except in the presence of extreme heating or electrical discharges.
Post time: Oct-16-2023