Abstract
Now the days, the technology of Micro- Electro- Mechanical System (MEMS) is primary using the semiconductor manufacture technology. As technology developed and semiconductor manufacture technology improved, the chip size start to narrow down from micrometer to nanometer. Therefore, the nano-size component has attracted lots of attention. Various nano material have been used to develop thin film sensors and actuators of nano-size. Nanoporous anodic aluminum oxide (np-AAO) has good dielectric property. Due to the nanoporous structure, the volume-to-surface is large than other continuous material, and the area contacting surrounding is also large. Thus, this study uses the nanoporous structure to implement capacitive relative humidity sensor (RH sensor). After moister absorbing, the dielectric constant change of np-AAO will lead sensing capacitance change. The present RH sensors has two merits, (1) dual-layer np-AAO will increase the area for moister absorbing, (2) the electric field of embedded sensing electrodes will pass through both top and bottom np-AAO layers to increase the sensing signals.