Yuki Mitsui

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

Carbonyl fluoride (COF 2 ) has been investigated as an alternative gas for plasma-enhanced chemical vapor deposition (PECVD) chamber cleaning in order to reduce greenhouse gases emitted from the cleaning process in semiconductor manufacturing. The cleaning performance of COF 2 and the environmental impact of its exhaust gases were evaluated using an experimental plasma tool. The results indicated that the cleaning performance of COF 2 was equivalent to that of conventional C 2 F 6 . Furthermore, it was confirmed that the use of COF 2 would enable the reduction of global warming emissions by over 95% relative to the use of C 2 F 6 , and thus COF 2 is considered to be a promising alternative cleaning gas.

Evaluation of FNO and F3NO as substitute gases for semiconductor CVD chamber cleaning

Two types of FNO compounds (FNO and F 3 NO) were evaluated as candidates for new chemical vapor deposition (CVD) 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 (PFC) is thought to be emitted. FNO is a compound highly susceptible to hydrolysis. F 3 ND is expected to decompose more easily than NF 3 in the atmosphere because its N-F bond has been weakened by introducing an N=O 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 ½ 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.

New Alternative Gas Process Feasibility Study for PFC Emission Reduction from Semiconductor CVD Chamber Cleaning

Publisher Summary Global action to cope with global warming is progressing and has been attracting great attention, from the Rio Earth Summit and United Nations Framework Convention on Climate Change (1992) and The Third Conference of Parties to FCCC (1997, COP3, Kyoto Protocol) to the Johannesburg Summit. Activities, results and concepts of the Semiconductor CVD Chamber Cleaning Project have been introduced and reviewed in this chapter. The project target is a new alternative gas process development and feasibility study for PFC emission reduction from the semiconductor CVD chamber cleaning process. This project focused on construction of a complete system providing performance higher than that of the conventional systems by selecting an alternative cleaning gas with a low GWP value and shorter lifetime in the atmosphere, PE- CVD processes and abatement systems. As a result, some scenarios have been shown, according to this guideline—namely, systems using COF2, F2, CF3OF and process optimization. Considering the usage volume, a safe system should be constructed, coveting every phase from production, delivery, and storage to consumption. From this viewpoint, COF2 is a leading contender for use in the next-generation of semiconductor mass-production processes.