Tetrafluoromethane, also known as carbon tetrafluoride, is the simplest fluorocarbon (CF4). It has a very high bonding strength due to the nature of the carbon–fluorine bond. It can also be classified as a haloalkane or halomethane. Because of the multiple carbon–fluorine bonds, and the highest electronegativity of fluorine, the carbon in tetrafluoromethane has a significant positive partial charge which strengthens and shortens the four carbon–fluorine bonds by providing additional ionic character. Tetrafluoromethane is a potent greenhouse gas.
Tetrafluoromethane is sometimes used as a low temperature refrigerant. It is used in electronics microfabrication alone or in combination with oxygen as a plasma etchant for silicon, silicon dioxide, and silicon nitride.
Chemical formula | CF4 | Molecular weight | 88 |
CAS No. | 75-73-0 | EINECS No. | 200-896-5 |
Melting point | -184℃ | Boling point | -128.1℃ |
solubility | Insoluble in water | Density | 1.96g/cm³(-184℃) |
Appearance | A colorless, odorless, nonflammable, compressible gas | Application | used in plasma etching process for various integrated circuits, and used also as laser gas, refrigerant etc. |
DOT ID Number | UN1982 | DOT/IMO SHIPPING NAME: | Tetrafluoromethane, Compressed or Refrigerant Gas R14 |
DOT Hazard Class | Class 2.2 |
Item |
Value, grade I |
Value, grade II |
Unit |
Purity |
≥99.999 |
≥99.9997 |
% |
O2 |
≤1.0 |
≤0.5 |
ppmv |
N2 |
≤4.0 |
≤1.0 |
ppmv |
CO |
≤0.1 |
≤0.1 |
ppmv |
CO2 |
≤1.0 |
≤0.5 |
ppmv |
SF6 |
≤0.8 |
≤0.2 |
ppmv |
Other fluorocarbons |
≤1.0 |
≤0.5 |
ppmv |
H2O |
≤1.0 |
≤0.5 |
ppmv |
H2 |
≤1.0 |
—— |
ppmv |
Acidity |
≤0.1 |
≤0.1 |
ppmv |
*other fluorocarbons refer to C2F6、C3F8 |
Notes
1) all the technical data indicated above are for your reference.
2) alternative specification is welcome for further discussion.