Tetrafluoromethane
Tetrafluoromethane is a colorless, nonflammable, noncorrosive gas. It is normally compressed and shipped at high pressure.
Tetrafluoromethane
Formula: CF4
Tetrafluoromethane (FC-14), also known as perfluoromethane, is a colorless, nonflammable and nontoxic gas. Tetrafluoromethane is chemically inert and has a moderately high global warming potential (GWP = 6,630; Greenhouse gas protocol, Fifth Assessment Report AR5). It is used as an important component in some ultra-low temperature refrigeration systems, and also as a reactive ion etching gas in semiconductor materials processing applications.
In semiconductor applications, for example in reactive ion etching, tetrafluoromethane is the largest volume fluorocarbon gas employed. With a fluorine to carbon ratio of 4:1, carbon tetrafluoride provides the highest concentration of highly reactive trifluoromethyl and fluorine radicals without accompanying hydrogen atoms. As a result, semiconductor material plasma etching processes employing tetrafluoromethane are relatively aggressive with respect to fluorine radical formation. On the other hand, plasmas processes involving tetrafluoromethane provide essentially no fluorocarbon film formation properties. In other applications, tetrafluoromethane can be used as a plasma chamber cleaning gas, an expansion agent for polyolefins and polyurethanes, as a propellant for aerosols, as a fire extinguishing agent, and as a gaseous dielectric insulating medium.
Applications
Specifications
Further Specifications
Cylinder Sizes
- Combined with oxygen to etch polysilicon, silicon dioxide, silicon nitrite, some metals and metal silicides
- Can be combined with halocarbon 116 or used alone to clean wafers and chambers.
| Purity | Grade 3.5 | Grade 4 | Grade 4.5 | Grade 5 |
|---|---|---|---|---|
| Purity Specifications | 99.95% | 99.99% | 99.995% | 99.999% |
| Nitrogen | < 400 ppmv | < 60 ppmv | < 30 ppmv | < 5 ppmv |
| Oxygen | < 100 ppmv | <20 ppmv | < 5 ppmv | < 1 ppmv |
| Carbon Monoxide | < 20 ppmv | < 5 ppmv | < 1 ppmv | < 0.5 ppmv |
| Carbon Dioxide | < 10 ppmv | < 5 ppmv | < 1 ppmv | < 2 ppmv |
| Moisture | < 10 ppmv | < 5 ppmv | < 5 ppmv | < 1 ppmv |
| Halocarbon 116 | < 1 ppmv | |||
| Other Halocarbons | < 50 ppmv | < 5 ppmv | < 5 ppmv | |
| Hydrocarbons | < 1 ppmv | |||
| Acidity | < 0.1 ppm/w | < 0.1 ppm/w | < 0.1 ppm/w |
| Chemical & Physical Properties | |
|---|---|
| Molecular Weight | 88.01 |
| Specific Volume | 4.39 cu.ft/lb |
| Pressure @ 70° F | 23.5 psig |
| Valve Outlet | CGA 580 CGA 320 |
| Shipping Information | |
|---|---|
| DOT Name | Tetrafluoromethane |
| Hazard Class | 2.2 |
| DOT No. | UN 1982 |
| DOT Label | Green, Non-Flammable Gas B |
| CAS No. | 75-73-0 |
| Cylinder Size | Fill Weight (lbs) |
|---|---|
| 49L/Size 300 | 72 |
| 44L/Size 200 | 70 |
| 16L/Size 80 | 25 |
| 7L/Size 35 | 11 |
**Moisture level guaranteed only when Electronic Fluorocarbons prepares the cylinders.
All concentrations are on a mol/mol basis unless otherwise stated.
Product sold on the basis of total impurities. Individual impurities may vary slightly.
*This gas not available for purchase online.