Publications Details

Micromachined systems-on-a-chip: Technology and applications

Smith, J.H.; Lemkin, M.A.

Sacrificial polysilicon surface micromachining is emerging as a technology that enables the mass production of complex microelectromechanical systems by themselves or integrated with microelectronic systems. Early versions of these micromachined systems-on-a-chip have already found application in the commercial world as acceleration sensors for airbag deployment (for example, ADI`s ADXL50). Two technologies described here, enable systems with increasing degrees of complexity to be fabricated. The first is a three-level polysilicon micromachining process which includes a fourth polysilicon electrical interconnect level, while the other is a single-level (+ second electrical interconnect level) polysilicon surface micromachining process integrated with 1.25 micron CMOS. Samples of systems-on-a-chip built in these processes such as combination locks, pop-up mirrors, and multi-axis accelerometers are also given.