MICROMACHINING AND ASIC TECHNOLOGY

A technology to fabricate ASICs can also be used to fabricate microelectronic sensors integrated with electronic circuits. The integration of micromechanical sensors or actuators with electronic circuits, however, requires new processes for micromachining the silicon chip so that 3D shapes are generated. These bulk micromachining processes are not usually compatible with TC processing, so there are few integrated bulk micromechanical sensors available today. In contrast, surface micromachining uses the same processes as in modern CMOS technologies. With proper design, such ASIC technologies can produce micromechanical sensors and integrated circuits on the same chip. The problems arising and constraints involved in combining sensor, actuator and IC technology are discussed, and typical examples of progress made during the last five years are given.