Vacuum unit conversion basics
Understanding Torr, mbar, Pa, and other vacuum pressure units used in CVD and etch processes.
Vacuum systems in semiconductor manufacturing use various pressure units. Common units include Torr, mbar (millibar), Pa (Pascal), and sometimes microns (µm Hg, equivalent to milliTorr).
Conversion factors: 1 atm = 760 Torr = 1013.25 mbar = 101325 Pa. For low vacuum: 1 mbar ≈ 0.75 Torr; 1 Pa = 0.0075 Torr.
Process engineers should be familiar with these units when setting up CVD chambers, etch systems, and load locks. Always specify units in recipes to avoid confusion.