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Octafluorocyclobutane

Octafluorocyclobutane is a colorless, odorless, non-flammable liquefied gas. It is shipped as a liquefied gas under its own vapor pressure.

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Octafluorocyclobutane

Formula: C4F8

CAS No: 115-25-3

Octafluorocyclobutane (C4F8) is a colorless, non-flammable fluorocarbon gas widely used in semiconductor manufacturing for plasma etching and deposition processes. Its molecular structure enables the formation of fluorocarbon plasmas that support both material removal and sidewall passivation.

In semiconductor fabrication, C4F8 is used to achieve highly anisotropic etching profiles, particularly in advanced patterning applications. It enables precise control of feature geometry by balancing etching and polymer deposition, which is critical for high-aspect-ratio structures.

Applications include:

  • Used in plasma etching of silicon, silicon dioxide, and dielectric materials.
  • Enables sidewall passivation for anisotropic etching and high-aspect-ratio features.
  • Supports advanced patterning in semiconductor device fabrication.
  • Applied in deposition processes involving fluorocarbon films.
  • Used in specialty fluorination and electronics manufacturing applications.

EFC Gases & Advanced Materials supplies high-purity octafluorocyclobutane with tight control of moisture and critical impurities to ensure consistent performance in demanding applications.

Applications
Specifications
Further Specifications
Cylinder Sizes
  • Etch silicon, SiO₂, and dielectric materials.
  • Enable anisotropic etching and sidewall passivation.
  • Support advanced semiconductor patterning.
  • Deposit fluorocarbon films.
  • Use in fluorination and electronics applications.
Grade 3 Grade 3.8 Grade 4.5 Grade 5
Purity 99.9% 99.98% 99.995% 99.999%
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 < 0.1 ppmv < 0.1 ppmv
Chemical & Physical Properties
Molecular Weight 200.03
Specific Volume 1.85 cu.ft/lb
Pressure @ 70º F 23.5 psig
Valve Outlet CGA 660 DISS 716
Shipping Data
DOT Name Octafluorocyclobutane
Hazard Class 2.2
DOT No. UN 1976
DOT Label Green, Non-flammable gas
CAS No. 115-25-3
Cylinder Size Fill Weight (lb)
49L/Size 300 118
44L/Size 200 100
16L/Size 80 35
7L/Size 35 15

Moisture level guaranteed only when EFC Gases & Advanced Materials 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.