Piotr Firek and Bartłomiej Stonio
The purpose of this paper is to present the influence of gate dielectric etching on obtained MISFET (metal insulator semiconductor field effect transistor) structures. Because of…
Abstract
Purpose
The purpose of this paper is to present the influence of gate dielectric etching on obtained MISFET (metal insulator semiconductor field effect transistor) structures. Because of its properties, aluminum nitride (AlN) layers can be successfully used in a large area of applications. In addition, AIN has a wide bandgap (6.2eV) and high thermal conductivity (3.2 W/cm * K). Its melting temperature is greater than 2,000°C. The relative permittivity is about 9. All these features (especially high power, high temperature and high-frequency) make AlN a useful material in the fields of electronic, optical and acoustic applications.
Design/methodology/approach
To fabricate n-channel transistors, silicon technology was used. The 50-nm thick AlN films were deposited using the magnetron sputtering. After preparation of SiO2/AlN stack as the gate dielectric, the optimization processes of dry etching in plasma environment by Taguchi method were realized. In the next step, three methods of AlN etching were selected and used to MISFET device fabrication. Atomic force microscopy and scanning electron microscopy allowed to surfacing of the state observation after etching process. The current–voltage (I–V) output and transfer characteristics of structures with modified etch technology were measured. Keithley SMU 236/237/238 measurement set was used.
Findings
In this research work, a method of AlN etching in a field effect transistor technology was developed and improved. Current−voltage characteristics of obtained MISFET structures were measured and compared. Influence of etching procedure on transistors properties was examined.
Originality/value
The obtained results allow improving the MISFET technology based on AlN film as a gate dielectric. The complete research work will allow using the developed technologies to implement in highly sensitive ion-sensitive field effect transistor (ISFET) structures in the future. The improvement of the etching element in the technology strongly influences the detection capabilities and operating range of the transistor.
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Piotr Firek, Jakub Szarafiński, Grzegorz Głuszko and Jan Szmidt
The purpose of this study is to directly measure and determine the Si/SiO2/AlOxNy interface state density on metal insulator semiconductor field effect transistor (MISFET…
Abstract
Purpose
The purpose of this study is to directly measure and determine the Si/SiO2/AlOxNy interface state density on metal insulator semiconductor field effect transistor (MISFET) structures. The primary advantage of using aluminum oxynitride (AlOxNy) is the perfectly controlled variability of the properties of these layers depending on their stoichiometry, which can be easily controlled by the parameters of the magnetron sputtering process. Therefore, a continuous spectrum of properties can be achieved from the specific values for oxide to the specific ones for nitride, thus opening a wide range of applications in high power, high temperature and high frequency electronics, optics and sensors and even acoustic devices.
Design/methodology/approach
The basic subject of this study is n-channel transistors manufactured using silicon with 50-nm-thick AlOxNy films deposited on a silicon dioxide buffer layer via magnetron sputtering in which the gate dielectric was etched with wet solutions and/or dry plasma mixtures. Furthermore, the output, transfer and charge pumping (CP) characteristics were measured and compared for all modifications of the etching process.
Findings
An electrical measurement of MISFETs with AlOxNy gate dielectrics was conducted to plot the current-voltage and CP characteristics and examine the influence of the etching method on MISFET parameters.
Originality/value
In this report, a flat band and threshold voltage and the density of interface traps were determined to evaluate and improve an AlOxNy-based MISFET performance toward highly sensitive field effect transistors for hydrogen detection by applying a Pd-based nanocrystalline layer. The sensitivity of the detectors was highly correlated with the quality of the etching process of the gate dielectrics.
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Piotr Firek, Michal Cichomski, Michal Waskiewicz, Ireneusz Piwoński and Aneta Kisielewska
The purpose of this paper is to present possibility of fast and certain identification of bovine serum albumin (BSA) by means of ion-sensitive field effect transistor (ISFET…
Abstract
Purpose
The purpose of this paper is to present possibility of fast and certain identification of bovine serum albumin (BSA) by means of ion-sensitive field effect transistor (ISFET) structures. Because BSA can cause allergic reactions in humans, it is one of reasons for development of sensitive sensors to detect residual BSA. BSA is commonly used in biochemistry and molecular biology in laboratory experiments. Therefore, to better understand the mechanism of signal transduction in simulated biological environment and to elucidate the role of adsorption of biomolecules in the generation of a signal at the interface with biological systems, the measurements of ISFET current response in the presence of BSA as a reference protein molecule were performed.
Design/methodology/approach
To fabricate transistors, silicon technology was used. The ISFET structures were coupled to specially designed double-side printed circuit board holder. After modification of the field effect transistor (FET) device with 3-aminopropyltriethoxysilane (APTES), a sensor with high sensitivity toward reference biomolecules was obtained. The current–voltage (I-V) characteristics of structures with and without gate modification were measured. Keithley SMU 236/237/238 measurement set was used. Deionized water solution and 0.05 per cent BSA were used.
Findings
In this research, a method of preparation of a biosensor based on a FET was developed. Sensitivity of APTES-modified FET device toward BSA as a biomolecule was investigated. I-V relationships of FET devices (with and without modification), being the effect of the interactions with the solution containing 0.05 per cent BSA, were measured and compared to the measurements performed for solutions without BSA.
Originality value
Compared to SiO2-containing ISFETs without modification or other different dielectrics, the application of APTES as the part of the membrane induced significant increase in their sensitivity to BSA.
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Jerzy Kalenik, Konrad Kielbasinski, Piotr Firek, Elżbieta Czerwosz and Jan Szmidt
– The purpose of this paper is to present thermal properties of palladium-carbon films prepared by physical vapour deposition (PVD)/chemical vapour deposition (CVD) methods.
Abstract
Purpose
The purpose of this paper is to present thermal properties of palladium-carbon films prepared by physical vapour deposition (PVD)/chemical vapour deposition (CVD) methods.
Design/methodology/approach
Thin palladium-carbon films were prepared at Tele- and Radioresearch Institute. Test structures containing palladium-carbon films and titanium electrodes were made. Temperature-resistance characteristics were measured.
Findings
The results show strong temperature dependence of modified carbon film resistance. The dependence is stable, and so modified carbon films can be applied for various electronic applications.
Originality/value
The paper presents thermal properties of thin palladium-carbon prepared by original PVD/CVD method at Tele- and Radioresearch Institute.