Structural Estimation and Hazard Evaluation of Potentially Explosive Residual Silanes Generated in Semiconductor Manufacturing Processes

We have proposed a scheme to analyze
potentially explosive residual
silanes (RS) generated in silicon-based semiconductor manufacturing
processes in the Yokkaichi Plant, Kioxia Corporation, properly under
an inert gas atmosphere. Thermal analysis and ballistic mortar tests
revealed that the incomplete hydrolyzed RS poses the highest risk.
The mass spectrum suggests that the possible structures of the major
components of the RS are cyclic polychlorosilanes with the number
of silicon atoms less than 16. A combination of instrumental analyses
and theoretical calculations suggest that the hydrolyzed products
of the RS involve Si–OH, Si–O–Si, and Si–Si
moieties. Theoretical calculations predicted the substantial exergonic
processes of a model compound (HO)­H2Si–SiH2(OH) to form a hydroxylsiloxane and H2.