The SEMATECH PFC Strategy/Technology Update

The SEMATECH PFC Strategy/Technology Update 
Walter F. Worth, SEMATECH (SSA Journal Volume 9 Number 3/4 – Fall 1995 pp. 19 – 24 )

The perfluorocompounds (PFCs) are vital to the manufacture of semiconductor microchips, but they have recently come under attack because of their potential contribution to global warming. PFCs such as C2F6 (Zyron 116), CF4 (carbon tetrafluoride) and SF6 (sulfur hexafluoride) are anthropogenic chemicals that are potent infrared absorbers with long atmospheric lifetimes (10,000s of years). It is this chemical stability which makes them such ideal vehicles for delivering the fluorine atoms that do the work in plasma etch and PECVD chamber cleaning operations. This paper reviews the projects and efforts that SEMATECH has initiated to assist the semiconductor industry with its goal of reducing the use of PFCs and decreasing the emissions of these chemicals to the atmosphere. SEMATECH is considering several options which include switching to alternative chemicals, optimizing the PFC processes, recovering and recycling the unused PFCs, and abatement of PFCs through combustion, plasma destruction or chemical/thermal reaction. A cost-effective solution to the problem may lie in a combination of all options and may require the combined efforts of the major stakeholders of the problem, i.e., the chip producers, the gas suppliers, the tool suppliers and the abatement device manufacturers.