Standard cubic centimetres per minute, a gas flow unit that refers volume to standard conditions, usually 0 °C and 1013 mbar, so it counts molecules rather than local volume. Mass flow controllers on process tools are ranged in sccm or slm (standard litres per minute). One sccm is about 0.0169 mbar·L/s, the conversion vacuum engineers use to check that a process flow will not overload a turbo or push the foreline pressure too high.
Bumped the argon from 30 to 45 sccm and the chamber went from 3 to 4.5 millitorr with the throttle wide open.
Also heard as
- standard cubic centimetres per minute
- SCCM
Related terms
Throughput
How much gas flows past a point each second, counted as pressure times volume, in units such as mbar·L/s.
Gas load
Total gas flow a pumping system must remove, summed from process gas, leaks, outgassing and permeation.
Turbomolecular pump
High vacuum pump whose rotor blades spin at tens of thousands of rpm and bat molecules toward the exhaust.
Bleed
To admit a small, controlled flow of gas into a vacuum system through a needle or leak valve.