Why is nitrogen trifluoride the largest-volume specialty gas in semiconductor fabs?

Why is nitrogen trifluoride the largest-volume specialty gas in semiconductor fabs?
NF3 dominates semiconductor specialty gas consumption because it is the workhorse for in-situ CVD chamber cleaning. After each wafer processing run, chamber walls accumulate silicon-, carbon-, and fluorine-containing residues that must be removed to prevent defects and process drift. NF3 decomposes in plasma to release three fluorine radicals per molecule, making it highly efficient at converting residues into volatile SiF4, CF4, and N2. It contains no carbon or oxygen, avoiding secondary contamination, and is stable enough for safe cylinder transport. These properties make NF3 the only gas validated at scale for this critical cleaning step, driving annual global demand to roughly 40,000 tonnes and making it the single largest electronic specialty gas category.