Evaluation of FNO and F[sub 3]NO as Substitute Gases for Semiconductor CVD Chamber Cleaning

Abstract

Two types of FNO compounds ͑FNO and F 3 NO) were evaluated as candidates for new chemical vapor deposition ͑CVD͒ chamber cleaning gases. NF 3 and C 2 F 6 were measured as the reference. Like NF 3 , as these gases have no carbon in their molecules, no perfluoro carbon ͑PFC͒ is thought to be emitted. FNO is a compound highly susceptible to hydrolysis. F 3 NO is expected to decompose more easily than NF 3 in the atmosphere because its N-F bond has been weakened by introducing an NϭO bond into the molecule. Hence, the contribution to global warming of these compounds is expected to be small. Performance of these gases was evaluated by measuring their etch rates and their exhaust gases. The results showed that the etch rate of F 3 NO is virtually the same as that of NF 3 , whereas the etch rate of FNO is about 1/2 that of NF 3 . However, from the results of exhaust gas analysis, it was found that an unexpected side reaction had occurred in the chamber, and therefore, it was confirmed that it is important to take this property into account in designing applications.

The Possibility of Carbonyl Fluoride as a New CVD Chamber Cleaning Gas

“…The etch rate of SiO 2 film on the electrode and the SiF 4 concentration analyzed in the exhaust gas is proportional. 8 SiF 4 is also produced by the etching reaction between the cleaning gas and the quartz plate placed upright near the chamber wall as shown in Fig. 1b.…”

Silicon Oxide Etching Process of NF3 and F3NO Plasmas with a Residual Gas Analyzer

“…Studies have been conducted to replace NF 3 [16,17]. Among them, F 3 NO was considered a candidate gas to replace NF 3 [18]. Similar to NF 3 , F 3 NO does not contain perfluorocarbons.…”