Reliability of MEMS-based mass-flow controllers for semiconductor processing

Microfabricated components are finding increasing application in semiconductor processing. In this work, we report the results of detailed reliability and MTTF studies on mass-flow controllers (MFCs) created from silicon pressure sensors, microfabricated orifices for use in the flow sensor, and microvalves. Attributes studied include accuracy, response time, inboard leak rate, and particle generation, all monitored versus number of cycles. From these measurements, MTTF is calculated to be greater than 3M cycles. Failure modes are also discussed in detail.