Electrical characterization devices

The light-emission characteristics of a white-light-emitting EL device with a doubly doped ZnS Pr,Ce,F phosphor layer have been described. It was observed that optimization of the co-doping of Ce enhances the emission characteristics compared to an EL device with a singly doped ZnS Pr,F layer.22 An electrical characterization of Ce-doped ZnS TbOF EL thin films has been reported Ce doping was seen to improve the radiative emission efficiency leading to improved performance of Ce co-doped film.23... 

Chang, H., Ikram, A., Kosari, F., Vasmatzis, G., Bhunia, A., and Bashir, R. (2002). Electrical characterization of micro-organisms using microfabricated devices. /. Vac. Sci. Technol. B 20, 2058-2064. 

The electrical characterization of polar media is crucial to investigate their suitability for ferroelectric memories, piezo- or pyroelectric devices and many other ferroelectric applications (see Chapter 3). Optical characterization of polar media is fundamental to investigate their ser-vicability for electro-optic devices or applications in the field of nonlinear optics (see Chapter 4). Additionally there are intentions to characterize polar media with a combination of both, electrical and optical methods, such as to understand ferroelectric phenomena that are influenced by the action of light. 

The progress in the development and integration of ferroelectric memories (FeRAM) leads to increasing demand for electrical characterization of sub-micron structures. This article will point out the measurement problems arising from the reduction of the ferroelectric capacitor size e.g. from memory cells or nanostorage devices. Procedures and solutions are presented to overcome these problems and to increase further the resolution and speed of ferroelectric characterization to be ahead of the technological demand. 

D.C. Look [ Electrical Characterization of GaAs Materials and Devices (Wiley, New York, 1989)]... 

More recently the treatment was extended to piezoelectric devices in contact with viscoelastic media (i.e., liquids and polymers). It was then realised that if the deposited mass was not rigidly coupled to the oscillating quartz crystal, separation of inertial mass and energy losses was not possible with the measurement of the resonant frequency alone. Quartz crystal impedance in the acoustic frequencies was introduced in order to study mass and viscoelastic changes and a full electrical characterization of the crystal behaviour near resonance was employed. 

For other devices there will be minor variations in these parameters. A detailed discussion of all of these factors is beyond the scope of this article. I will use some examples to illustrate recent trends in electrical characterization. 

D. P. Kern, Parameter extraction for surface micromachined devices using electrical characterization of sensors, Proc. 

D.P. Kern, Parameter extraction for surface micromachined devices using electrical characterization of sensors, Technical Proceedings of the Fourth International Conference on Modeling and Simulation of Microsystems, Hilton Head Island, South Carolina, Computational Publications, Cambridge, MA, p. 406, 2001. 

The electrical characterization was performed in the high injecton regime (forward direction, Chromium as cathode). For gaining the effective voltage drop the built-in potential (t/eff = Umeasmed - UB0 is subtracted from the measured voltage drop in the device. In Figure 2 the IV characteristics at 3 temperatures are shown. 

In an active device, like an organic field-effect transistor, chemical tailoring can be applied not only to the semiconductor but also to metallic and insulating layers, thus allowing different localizations of the device-sensing area. This possibility broadens the set of sensing principles exploitable for these devices. In addition, from the electrical characterization of an active device it is possible to simultaneously extract different parameters, which correlate to the identification of a chemical species in a mixture. In this way it is possible to obtain a sort of fingerprint of a compound [5]. 

Semiconductor materials have had to meet progressively more stringent requirements as the density and performance of semiconductor devices has increased. This trend will continue. The purity of the matoial, the dimensions of the devices, and the electrical properties require higher precision in their measurement and the ability to determine the device parameters to a resolution and sensitivity that pushes measurement techniques to their very limit. Semiconductor measurements cover a broad range of techniques and disciplines. After a brief listing of optical and physicall chemical characterization methods we give in this chapter a discussion of the general trend in electrical characterization and present a few examples of the charactmzation techniques used today. 

Electrical characterization is the most common characterization method. It gives electrically relevant information but it generally does not uniquely identify impurities the way the other two characterization methods do. The most useful electrical characterization techniques determine the following device parameters... 

Electrical Characterization of Semiconductor Materials and Devices 9 3. DEFECTS... 

Even if pratical applications of organic-based devices in electronics is potentially attractive, one of the most important goal of the electrical characterization of conjugated polymers and oligomers is the analysis and understanding of the charge transport mechanism in these materials. Studies have been performed on temperature... 

T. Katsube, M. Kara, T. Yaji, S. Kobayashi, K. Suzuki, and Y. Nakagawa [1986] Electrical Characterization of a Complemental Electrochromic Device. Japan Display 86. 376-379. 

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