Design and Simulation of a Multi-Sensor System Growing a Plurality of Heater Chips on the Same Dielectric Membrane

In micro-sensors, the Micro Hotplate (MHP) is a crucial component, in particularly gas sensors. To control the temperature of the sensing layer, micro-heater is used in metal oxide gas (MOX) sensors as a hotplate. The temperature should be in the requisite temperature range over the heater area. This allows detection of the resistive changes as a function of varying concentration of different gases. Thus, their design is a very important aspect. In this paper, we presented the design and simulation results of a platinum combinative meander-spiral micro heater for a WO3 gas sensor. The objective of this paper is also to model a multi-sensor while growing a plurality of heater chips on the same membrane to improve gas sensors selectivity performance. Four different heating voltages were applied in order to attain four maximum temperatures required to detect O3, H2S, CO and NO2, by a WO3 multi- sensor

Design and Simulation of a Multi-Sensor System Growing a Plurality of Heater Chips on the Same Dielectric Membrane

In micro-sensors, the Micro Hotplate (MHP) is a crucial component, in particularly gas sensors. To control the temperature of the sensing layer, micro-heater is used in metal oxide gas (MOX) sensors as a hotplate. The temperature should be in the requisite temperature range over the heater area. This allows detection of the resistive changes as a function of varying concentration of different gases. Thus, their design is a very important aspect. In this paper, we presented the design and simulation results of a platinum combinative meander-spiral micro heater for a WO3 gas sensor. The objective of this paper is also to model a multi-sensor while growing a plurality of heater chips on the same membrane to improve gas sensors selectivity performance. Four different heating voltages were applied in order to attain four maximum temperatures required to detect O3, H2S, CO and NO2, by a WO3 multi- sensor

A Noise Spectroscopy-Based Selective Gas Sensing with MOX Gas Sensors

International audienceCommunicated by Zoltan Gingl We propose a new method for obtaining a °uctuation-enhanced sensing (FES) signature of a gas using a single metal oxide (MOX) gas micro sensor. Starting from our model of adsorption-desorption (A-D) noise previously developed, we show theoretically that the product of frequency by the power spectrum density (PSD) of the gas sensing layer resistance °uctuations often has a maximum which is characteristic of the gas. This property was experimentally con¯rmed in the case of the detection of NO 2 and O 3 using a WO 3 sensing layer. This method could be useful for classifying gases. Furthermore, our noise measurements con¯rm our previous model showing that PSD of the A-Dnoise in MOX gas sensor is a combination of Lorentzians having a low frequency magnitude and a cut-o® frequency which depends on the nature of the detected gas

Noise modeling in MOX gas sensors

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Impact of wafer charging on hot carrier reliability and optimization of latent damage detection methodology in advanced CMOS technologies

International audienceWe have studied the possibility to use hot carrier stresses to reveal the latent damage due to Wafer Charging during plasma process steps in 0.18 μm and 0.6 μm CMOS technologies. We have investigated various hot carrier conditions in N- and PMOSFETs and compared the results to classical parametric studies and short electron injections under high electric field in Fowler–Nordheim regime, using a sensitivity factor defined as the relative shift towards a reference protected device. The most accurate monitor remains the threshold voltage and the most sensitive configuration is found to be short hot electron injections in PMOSFET’s. The ability of very short hot electron injections to reveal charging damage is even more evidenced in thinner oxides and the better sensitivity of PMOSFET is explained in terms of conditions encountered by the device during the charging process step