Microsystems Process Integration, Testing, and Packaging

This chapter covers the important topic process integration where a number of individual processing steps (covered in Chaps. 3 and 4 ) are combined into a process sequence for the implementation of MEMS devices. A general outline of yield improvement activities is given. Some of the challenges of process integration for MEMS are discussed including the significant time, cost, and risk that are commonly encountered. Integrated MEMS process sequences are defined as the merging of microelectronics onto the same substrate as the MEMS devices. Reasons why attempting to develop integrated MEMS is so difficult are also explained. Two notable examples of process technologies are reviewed; the first is a generic MEMS surface micromachining process sequence, and the second is an integrated MEMS process technology. Parameter variations that arise in process sequences are discussed, and an example of the parameter variations of a well-known MEMS process technology called PolyMUMPS™ is reviewed. The concept of design rules in microsystems manufacturing is then covered along with a review of the design rules for the PolyMUMPS™ process sequence. This chapter also briefly discusses the testing and packaging of MEMS, including device trimming and calibration.