Method and apparatus for low drift chemical sensor array

摘要

An on-chip low baseline drift SAW/LAW chemical sensor array and method of forming the same. A dual SAW delay line includes a common IDT for generating an acoustic wave and a pair of IDT for reception of the acoustic wave. One sensing layer or one reference layer can be deposited in position on each side of the common IDT. An ASIC chip includes on chip dual operational amplifiers and a mixer in order to obtain a differential measurement utilizing a difference being given by the sensing and the reference layers. A 3D technology can be employed in order to connect the sensor array and the ASIC in the same package and thereby form a 3D stack. The chemical sensor array and the ASIC can be configured in different packages and interconnected on the same substrate utilizing 2D technologies. A number of gases can be detected independently, and each gas can be detected differentially, with respect to its associated sensing layer and specific reference layer.