Chapters authored
MOS Meets NEMS: The Born of Hybrid Devices
Nowadays, the semiconductor industry is reaching an impasse due to the scaling-down process according to Moore’s Law, initiated back in 1960s, for the Metal-Oxide-Technology in use. To overcome such issue, the semiconductor industry started to foresee novel materials that allow the development of nanodevices with a broad variety of characteristics such as high switching speed, low power consumption, robust, among others; that can overcome the inherent issues for Silicon. A few “exotic materials” appear such as Graphene, MoS2, BN-h, among others. However, the time for the novel technology to be mature is a few decades in the future. To allow the “exotic materials” to mature, the semiconductor industry requires of novel nano-structures that can overcome a few of the issues that Silicon-based technology is facing today. A key alternative is based on hybrid structures. Hybrid structures encompass two dissimilar technologies nano-electromechanical systems with the well known Metal-Oxide-Technology. The hybrid nano-structure provides a broad variety of options to be used in such as transistors, memories and sensors. These hybrid devices can give enough time for the technology based on “exotic materials” to be reliable as Silicon based is.
Part of the book: Complementary Metal Oxide Semiconductor
Toxic Gas Detectors Based on a MnSb2O6 Oxide Chemical Sensor
We synthesized the semiconductor oxide MnSb2O6 through a wet chemical process assisted by low-power microwave radiation. A gas-sensitive sensor was elaborated from the MnSb2O6 powders obtained by calcination at 600°C. The sensor was electrically characterized in static CO and C3H8 atmospheres by measuring direct current signals at 100, 200, and 300°C. The toxic gases’ concentrations were 1, 5, 50, 100, 200, 300, 400, and 500 ppm of C3H8; and 1, 5, 50, 100, 200, and 300 ppm of CO. From the MnSb2O6’s electrical resistance results, a sensor’s operational point and a low-cost analog circuit were proposed, obtaining two new prototypes: one for detecting C3H8 and a second one for detecting CO. We selected the response at 200°C and 5 ppm for both cases. Notably, this concentration (5 ppm) is selectable with a calibration resistance, generating an alarm signal of ≈11.3V at a supply voltage of 120 V AC. The toxic gas detectors showed excellent functionality. The resistive sensor showed high sensitivity and good electrical response, while the analog circuit presented a rapid response. Due to the operating temperature employed (200°C), these devices could find practical applications, for example, exothermic generators and heaters.
Part of the book: Metal-Oxide Gas Sensors