Formula: C4F8 or R318, Halocarbon 318
Octafluorocyclobutane is a colorless, odorless, non-flammable liquefied gas. It is shipped as a liquefied gas under its own vapor pressure (25 psig @ 70º F). C4F8, also identified as Refrigerant-C318, is used in some specialty refrigeration applications.
Octafluorocyclobutane can be used as an extinguishing agent in fire suppression systems. This is due the large total heat absorbed in going from the fluid at room temperature up to a temperature of 1400 K. And, C4F8 is used in semiconductor manufacturing for plasma etching. In the RF field C4F8 generates reactive species that selectively etch silicon. In the etching process the C4F8 plasma free radicals can form a protective polymer that blocks chemical attack on features and can provide sidewall protection.
- plasma etching
|Grade 3||Grade 3.8||Grade 4.5||Grade 5|
|Nitrogen||< 80 ppmv||< 8 ppmv||< 3 ppmv|
|Oxygen||< 20 ppmv||< 2 ppmv||< 1 ppmv|
|Air (N2+O2+CO+CO2)||< 300 ppmv|
|Moisture||< 10 ppmv||< 10 ppmw||< 3 ppmw||< 1 ppmw|
|Tetrafluorocarbons||< 50 ppmv|
|Other Fluorocarbons||< 50 ppmv||< 10 ppmv||< 4 ppmv|
|Other Organics||< 1000 ppmv|
|Acidity||< 0.1 ppmv/w||< 0.1 ppmv/w||< 0.1 ppmv/w|
|Chemical & Physical Properties|
|Specific Volume||1.85 cu.ft/lb|
|Pressure @ 70º F||23.5 psig|
|Valve Outlet||CGA 660 DISS 716|
|DOT No.||UN 1976|
|DOT Label||Green, Non-flammable gas|
|Cylinder Size||Fill Weight (lbs)|
**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.