Development of ultraviolet-ozone cleaning as a production process in the packaging of integrated circuits.

摘要

Ultraviolet-ozone (UV-ozone) cleaning was implemented as a production process to improve the cleanliness of metallized ceramic parts before a hermetic solder-sealing operation. The UV-ozone cleaning was developed as an in-situ process that maintained a low moisture content in the sealed package. Sealing yields were improved by as much as 30% with this procedure. Seal quality and therefore, reliability, were also increased. Possible detrimental effects caused by UV-ozone cleaning were investigated. In particular, the possibility for silver from the silver-filled epoxy to electromigrate was studied. UV-ozone cleaning was not found to be a factor in this phenomena. Qualification lots were given Electrical, Group B, Group D, and Life Tests to determine if the UV-ozone cleaning had any detrimental effects on the parts' reliability. No detrimental effects were found on standard complementary metal oxide semiconductor technology integrated circuits. Some evidence has shown, however, that the memory retention of both large-scale integrated and discrete silicon nitride oxide semiconductor structures degrade(s) after UV-ozone cleaning. 6 refs., 8 figs., 2 tabs.