Semiconductor devices are sensitive to trace metallic contamination. Mobile ions in oxide can cause threshold drifts in MOS transistors, and fast-diffusing impurities in silicon can degrade gate oxide integrity, lifetimes and refresh times, and increase junction leakage. Traditionally, the industry has tried to keep wafers clean in front-end processes by minimizing equipment contamination through materials selection and careful procedures, and frequent cleaning with chlorine-containing gases.

ELEMENT	EFFECTS	SIA 130 nm node (/cm2)
Na	mobile ion in silicon dioxide	<2x109
K	mobile ion in silicon dioxide	<2x109
Fe	precipitates lead to junction leakage	<2x109
Cu	precipitates lead to junction leakage; degrades lifetime	<2x109
Cr	fast diffuser in Si; degrades lifetime	<2x109

Now process engineers have a new tool to actively protect wafers from contamination. Sizary's unique patented Promecon™ technology creates an electric field between the wafers and the process environment during annealing and oxidation, driving metallic contaminants away and protecting sensitive device structures from degradation. With Promecon process engineers can improve yields, guard against contaminant "spikes", reduce or eliminate chlorine-based cleans, and improve tool utilization.