Solid-state optical and chemical sensors

The simulation capability of HFIELDS has been extended to the case of solid-state sensors after investigating the physics of the interaction of the semiconductor with the external environment [10,31]. This has been done, in particular, for the optical, elastic, and chemical cases, leading to investigations of realistic optical sensors [29,86,87,95], piezoresistive pressure sensors [33,37,89,93,94], and chemical sensors of the ISFET and LAPS type [42,45,100,106,108,110]. In 1998, with Prof. H. Baltes of the ETH Zuerich and Prof. W. Goepel of the University of Tuebingen, M. R. has been awarded with the Koerber Foundation Award for the Project “Electronic ``Micronose'' for Volatile Organic Compounds” (1999-2000). Aim of the Project is the realization of an integrated sensor for detecting molecules of different types present in the environment. The sensing elements are obtained by depositing polymeric membranes over semiconductor devices (e.g., capacitors, vibrating cantilevers) fabricated in a CMOS process supplemented with suitable micromachining steps. The tasks of M. R. and coworkers within the Project are the modeling of the elementary sensors [124], the design of the board performing the digital control of the sensor chip and the data analysis, and the implementation of the recognition algorithms [123].