Formation of silicon nanostructure based metal oxide gas sensors

In this work, Silicon nanowires were fabricated using metal assisted chemical etching method. After etching process ZnO thin films were deposited onto Si substrate via ALD and gas sensor properties of this structure were characterized. For this purpose Si substrates were deep into the 0.02 M AgNO3 solution and were kept in this solution for 5, 10, 30 and 60 minutes durations. The linear relation between etching duration and length of nanowire were determined by using SEM images. We determined Si nanowire structures with different length. 24 nm ZnO thin films were deposited onto Si nanowire structures 200 cycle by using ALD. SEM images and XRD graphics were examined after thin film deposited. After we were determined properties of structure, by using thermal evaporating device Al evaporated onto this structure via hole mask. For the measurements of gas sensor properties we were obtained point contact. As a result manufactured structure has a gas sensing properties because of its large surface volume ratio. Key Words: Silicon nanowire, gas sensor, metal oxide, atomic layer deposition