Local Synthesis of CuO Nanowires on CMOS Microhotplates for Gas Sensing Applications

S. Steinhauer, T. Maier, G.C. Mutinati, K. Rohracher, J. Siegert, F. Schrank, A. Koeck
Materials Center Leoben Forschung GmbH, AT

Keywords: CuO, nanowire, gas sensor, integration

Summary:

CuO nanowires are locally synthesized on CMOS microhotplates leading to the realization of functional gas sensing devices. Only approximately 20mW are needed in order to heat the CMOS microhotplates to a temperature around 350°C, which is suitable for the growth of CuO nanowires with small diameters between 10nm and 30nm by thermal oxidation of Cu microstructures. By this method, direct CuO nanowire device integration can be achieved without the necessity of post-processing steps. First results show that ppm-level concentrations of the toxic gas carbon monoxide CO (10ppm, 50ppm and 100ppm) can be clearly detected validating the good gas sensor performance suitable for safety applications. Our approach combines miniaturization, low power consumption and CMOS integration, which are crucial factors for the future realization of smart gas sensors for daily life applications.