Integration technology

In the fabrication of fully integrated sensors, which combine sensor and electronics on a single chip, it is essential to ensure that any additional process steps introduced for the sensor do not adversely affect the electronics. Where possible it is desirable to use existing processes or layers to fabricate the sensor. This is not always possible and therefore additional processing steps must be added to that of the electronic circuitry. In the fabrication of MEMS the additional processing is usually one of the forms of micromachining. Many processing steps are not compatible with the electronics and therefore they have to be adjusted which may lay considerable constraints on both materials and processing steps. In this paper the range of options to designer will be discussed.