A Zinc Oxide Nanorod Ammonia Microsensor Integrated with a Readout Circuit on-a-Chip

Abstract

A zinc oxide nanorod ammonia microsensor integrated with a readout circuit on-a-chip fabricated using the commercial 0.35 μm complementary metal oxide semiconductor (CMOS) process was investigated. The structure of the ammonia sensor is composed of a sensitive film and polysilicon electrodes. The ammonia sensor requires a post-process to etch the sacrificial layer, and to coat the sensitive film on the polysilicon electrodes. The sensitive film that is prepared by a hydrothermal method is made of zinc oxide. The sensor resistance changes when the sensitive film adsorbs or desorbs ammonia gas. The readout circuit is used to convert the sensor resistance into the voltage output. Experiments show that the ammonia sensor has a sensitivity of about 1.5 mV/ppm at room temperature.

A Zirconium Dioxide Ammonia Microsensor Integrated with a Readout Circuit Manufactured Using the 0.18 μm CMOS Process

“…The sensitive material of the sensor was polyaniline, and the sensor had a sensitivity of 0.88 mV/ppm. A comparison to Yang et al [15] and Liu et al [16], the sensitivity of the sensor in this work exceeds that of Yang et al [15] and Liu et al [16]. …”

“…An ammonia sensor integrated with a readout circuit, proposed by Yang et al [15], was manufactured by the commercial 0.35 µm CMOS process and a post-process. The sensitive material of the ammonia sensor was zinc oxide, and its sensitivity was 1.5 mV/ppm.…”

Fabrication of a Micromachined Capacitive Switch Using the CMOS-MEMS Technology

“…In this work, we employ complementary metal oxide semiconductor (CMOS)-MEMS technology to fabricate a micromachined RF switch with low actuation voltage of 12 V, and its pull-in voltage is lower than that of Wang et al [4], Angira et al [5], Gao et al [6], Giffney et al [7], Yang et al [8], Park et al [9] and Zheng et al [10]. The use of commercial CMOS process to fabricate MEMS devices is called CMOS-MEMS technology [11][12][13][14]. Micro sensors and actuators manufactured by this technology usually require a post-CMOS process to add functional materials [15][16][17] or to release suspended structures [18][19][20].…”

Energy Harvesting Thermoelectric Generators Manufactured Using the Complementary Metal Oxide Semiconductor Process

“…Fabrication of MEMS devices using the commercial CMOS process is called CMOS-MEMS technique [9,10], and microdevices manufactured by this technique usually need a post-process to release the suspended structures [11,12] or to add the functional films [13,14]. Because the COMS-MEMS technique is compatible with the commercial CMOS process, micro generators have a potential to combine with integrated circuits on-a-chip if they are produced by this technique.…”