Has the Challenge of PFCs Really Been Solved?

摘要

In the semiconductor industry, chemical vapor deposition (CVD) chambers were traditionally cleaned using perfluorocarbon (PFC) gases such as C_2F_6 and CF_4. These gases decomposed in a plasma within the process chamber, yielding highly reactive fluorine radicals that reacted with process deposits on the chamber walls and furniture. The volatile fluorinated gases thus formed (e.g., SiF_4) could then be pumped away. A relatively small fraction (typically ～ 30%) of the cleaning gas actually took part in the chamber cleaning reactions; the remainder simply passed through into the exhaust — and the atmosphere. The global warming effects of C_2F_6 and CF are well documented.