Graphene field-effect transistor simulation with TCAD on top-gate dielectric influences

This paper presents the influence of top-gate dielectric material for graphene field-effect transistor (GFET) using TCAD simulation. Apart from silicon-based dielectric that is typically used for top-gate structure, other high-dielectric constant (high-k) dielectric materials namely aluminum oxide and hafnium oxide are also involved in the analysis deliberately to improve the electrical properties of the GFET. The unique GFET current-voltage characteristics against several top-gate dielectric thicknesses are also investigated to guide the wafer fabrication engineers during the process optimization stage. The improvement to critical electrical parameters of GFET in terms of higher saturation drain current and greater on/off current ratio shows that the use of high-k dielectric material with very thin oxide layer is absolutely necessary

Inline 3D volumetric measurement of moisture content in rice using regression-based ML of RF tomographic imaging

The moisture content of stored rice is dependent on the surrounding and environmental factors which in turn affect the quality and economic value of the grains. Therefore, the moisture content of grains needs to be measured frequently to ensure that optimum conditions that preserve their quality are maintained. The current state of the art for moisture measurement of rice in a silo is based on grab sampling or relies on single rod sensors placed randomly into the grain. The sensors that are currently used are very localized and are, therefore, unable to provide continuous measurement of the moisture distribution in the silo. To the authors’ knowledge, there is no commercially available 3D volumetric measurement system for rice moisture content in a silo. Hence, this paper presents results of work carried out using low-cost wireless devices that can be placed around the silo to measure changes in the moisture content of rice. This paper proposes a novel technique based on radio frequency tomographic imaging using low-cost wireless devices and regression-based machine learning to provide contactless non-destructive 3D volumetric moisture content distribution in stored rice grain. This proposed technique can detect multiple levels of localized moisture distributions in the silo with accuracies greater than or equal to 83.7%, depending on the size and shape of the sample under test. Unlike other approaches proposed in open literature or employed in the sector, the proposed system can be deployed to provide continuous monitoring of the moisture distribution in silos

Simulation and fabrication of extended gate ion sensitive field effect transistor for biosensor application

In this paper, we present the Extended Gate Ion Sensitive Field Effect Transistor (EGFET) which has a same function as the Ion Sensitive Field Effect Transistor (ISFET). In contrast to the traditional ISFET, the EGFET retains the original metal/polysilicon portion of the gate electrode and the sensing membrane is deposited on the other end extended from the metal/polysilicon gate. This type of ion sensor is suitable for in vivo and in vitro measurement, especially for biosensor applications. Basic concept, fabrication techniques and process/device characterization of EGFET for biosensor development will be discussed in this paper. To support the fabrication process, a simulation study of the process flow using the CoventorWare simulator and the Silvaco Athena process simulator has been done. The results showed good current-voltage characteristics of a multi-finger structure transistor suitable to be used for biosensor transducer