Barrier Lowering Effects for Metal-Silicide Schottky Diodes at High Reverse Bias

Summary

From experimental data, it is first demonstrated that the common field-dependent lowering models are not sufficient to account for the softness of reverse l(V) characteristics of metal-Silicide Schottky power diodes at high reverse bias voltages. In an attempt to explain this behaviour, we first consider by means of numerical simulations as well as experimental characterizations, the effects of Schottky barrier height inhomogeneities: it is shown that these effects cannot explain the above effect. A new barrier lowering model is then derived from experimental characterization of diode structures exhibiting different technological features (Silicide type, doping level, drift region thickness). A single barrier lowering law versus electric field can be expressed for the complete range of Schottky diodes investigated. This allows a description of metal-Silicide Schottky power diode behaviour at high reverse bias voltages, covering a wider voltage range than previous models, with a good agreement between calculated and experimental data. Numerical results obtained from Pisces simulations using this new model gives equally excellent agreement between simulated and measured values.

Key Words:

• Schottky Power Diode
• Metal Semiconductor Contact
• Schottky Barrier
• Barrier Lowering.

Additional information

Notes on contributors

C. Furio

Cyril Furio was-born in Toulon, France. He received the-“Maltrise” degree in Physics of semiconductor hom Montepllier University (France) and the “Docteuren electornique” degree from Toulouse University (France), in 1991 and 1996 respectively

From 1991 to 1993, he collaborated widerhomson CSF Semiconductor Specific in Orsay (France) where he contributed to the development of GaAs MESFET for MMIC’s. In 1993, he joined SGS Thomson Microelectronics in Tours (France) where he mirked on new rectifier designs, in collaboration with LAAS-CNRS (Laboratoired’ Analyse etd’Architecture des Systeme from Toulouse. In 1996, he was with the Research and Development deparunent of SGS Thomson where he worked on discrete components_ He isnow with Solection, Bordeaux. France

G. Charitat

After an engineer degree in Material Physics, obtained in 1979 from the Institut National des Sciences App1iquées-Lyon, Georges Charitat joined LAAS-CNRS in 1981. He received a “Docteur Ingeéniuer degree in 1982 on the Phyisical Mechanisms of boron diffusion in silicon from the same institute.” He then joined the “MOS Power Devices” teem as a full-time researcher in 1984 Where he began his work on the Modeling realization and optimization of high voltage MOS transistors, He was awarded a “Docteur es Science degree in 1990 on “Modelling and Realization of Planar High-Voltage Devices”. When the research group “Power Devices and Integration” was created at LAAS/CNRS in 1992, he was the manager of one of the three operations, namely “Device Physics and New Structures” Since 1995, he is the general manager of this research group. He ha was presented a number of paper in international congresses such as ISPSD, ESSDERC. IEDM, MADEP, EPE., as well as in international scientific journals.

He is a member or the IEEE Electron Devices Society and acts as a scientific commitee member for different international conferences. (Laboratoire d’Analyse et d’Architecture des Systèmes du CNRS, 7 Avenue du Colonel Roche – 31077 Toulouse Codex (F), Tel: [phone]. Fax: [phone].)

J.M. Dilhac

Jean – Marie Dilhac was Born in Villeneuve surLot, France, June 7. 1956. He received a “Docteur en Electronique” degree in 1983. and a “Docteur d’Etat es Sciences” degree in 1988, both from the University of Toulouse. He initially worked on Electron beam Pulsed Annealing of Silicon from 1980 to 1984. In 1985, he Started researchs on Rapid Thermal Preening-More precisely. process Desigh temperature mesurement and control, optical in situ characterization. of silicide Information were the main topics under Study. “He is presently Professor at the Institut National des Sciences Appliquèes” of Toulouse, and works-with a research team at LAAS-CNRS. His present research interested center on application Rapid Thermal Processing to power Integrated citcuits. He authored about 30 papers in refereed journals or international conferences, and holds one patent.