#Product Trends
Thin-film deposition: control the reactive gas line by line
Controlling each line upstream shows and stops the drift a chamber gauge cannot see.
In reactive deposition, a chamber gauge reads only total pressure, so it cannot show that a low-flow reactive line has drifted, and the film composition shifts unseen. Controlling each line upstream fixes that: laminar DP mass flow controllers carry the argon or helium working line and the oxygen, nitrogen or hydrocarbon reactive line, with a repeatability of ±(0.1% of reading + 0.02% of full scale), control response as fast as 30 ms and a 10,000:1 control range. Each reports mass flow, volumetric flow, absolute pressure and temperature, and 98 to 130 gas calibrations are selectable in the field. At higher process pressures, a pressure controller between chamber and pump holds the back-pressure down into the low-Torr range.
