Thanks to the in-house coexistence of both MEMS and CMOS mixed-signal processes, X-FAB is able to offer its customers an optimal environment for the combination of CMOS and MEMS technologies. In order to ensure a smooth integration of both process families, X-FAB devised its own MEMS baseline process, which allows X-FAB to apply the same highly developed quality standards to its MEMS offerings as to its CMOS branch.
MEMS Baseline Process
Combining CMOS and MEMS technologies is especially challenging because some MEMS process steps - such as the use of special materials, the danger of contamination due to the MEMS wet etching processes etc. - are incompatible with the requirements of CMOS technology. Strong attention has thus to be paid to avoid cross contaminations between both process families.
The MEMS baseline process is X-FAB's approach for a safe integration of CMOS and MEMS. Keeping the CMOS and MEMS process stages consistently separated, with the necessary connections occurring only through precisely defined interface procedures, it prescribes a purely unidirectional flow from CMOS processing on. The specific MEMS process steps are carried out in a dedicated MEMS clean room at the end of the flow.