| Popis: |
Scanning photo-induced impedance microscopy (SPIM) is an imaging technique for the investigation of impedances on the insulating surface of a semiconductor substrate, based on the monitoring of a photocurrent signal generated by a modulated light. In this research, a gas-sensitive SPIM sensor with a suspended-gate structure is presented, to detect local impedance changes of a sensing film on the sensor surface in response to ethanol vapor. Thanks to the light-addressability of SPIM, a spatially resolved photocurrent signal is captured and converted into 2-dimensional images for the observation of local impedance changes arising from the interaction between ethanol vapor and a SnO 2 film at room temperature. Especially, the proposed gas-imaging sensor has a field-effect structure with an air gap to form a suspended-gate structure, resulting in an electrode contactless platform, which makes it possible to integrate multiple sensing elements on one single chip surface to detect gas mixtures without the need of complex wiring in the future. |
