An investigation on NEG thick film for vacuum packaging of MEMS

An approach to maintain vacuum in MEMS devices, by integrating MEMS fabrication process with getter material preparation, is presented in this paper. A coating process for thick film of getter material on silicon and glass wafers, which are common materials in fabrication of MEMS devices and package, has been investigated in detail. The getter material consists of a powder mixture of zirconium, vanadium and iron, which features high sorption capacity to active gas such as H-2, O-2, N-2, CO and H2O vapor. Several patterned NEG thick films to simulate different needs in MEMS application have been made. The sorption capacity of the coated getter material was examined. The coating of NEG thick film onto the inner surface of a MEMS pressure sensor and the activation of NEG during anodic bonding process were carried out.