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Title: Simulation of temperature dependent dielectric breakdown in n{sup +}-polySi/SiO{sub 2}/n-6H-SiC structures during Poole-Frenkel stress at positive gate bias

Abstract

We present for the first time a thorough investigation of trapped-hole induced gate oxide deterioration and simulation results of time-dependent dielectric breakdown (TDDB) of thin (7–25 nm) silicon dioxide (SiO{sub 2}) films thermally grown on (0 0 0 1) silicon (Si) face of n-type 6H-silicon carbide (n-6H-SiC). Gate oxide reliability was studied during both constant voltage and current stress with positive bias on the degenerately doped n-type poly-crystalline silicon (n{sup +}-polySi) gate at a wide range of temperatures between 27 and 225 °C. The gate leakage current was identified as the Poole-Frenkel (PF) emission of electrons trapped at an energy 0.92 eV below the SiO{sub 2} conduction band. Holes were generated in the n{sup +}-polySi anode material as well as in the oxide bulk via band-to-band ionization depending on the film thickness t{sub ox} and the energy of the hot-electrons (emitted via PF mechanism) during their transport through oxide films at oxide electric fields E{sub ox} ranging from 5 to 10 MV/cm. Our simulated time-to-breakdown (t{sub BD}) results are in excellent agreement with those obtained from time consuming TDDB measurements. It is observed that irrespective of stress temperatures, the t{sub BD} values estimated in the field range between 5 and 9 MV/cm bettermore » fit to reciprocal field (1/E) model for the thickness range studied here. Furthermore, for a 10 year projected device lifetime, a good reliability margin of safe operating field from 8.5 to 7.5 MV/cm for 7 nm and 8.1 to 6.9 MV/cm for 25 nm thick SiO{sub 2} was observed between 27 and 225 °C.« less

Authors:
;  [1]
  1. Department of Electrical Engineering, University of South Carolina, Columbia, South Carolina 29208 (United States)
Publication Date:
OSTI Identifier:
22597670
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 120; Journal Issue: 6; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANODES; BREAKDOWN; DIELECTRIC MATERIALS; DOPED MATERIALS; ELECTRIC FIELDS; ELECTRONS; EMISSION; FILMS; HYDROGEN 6; LEAKAGE CURRENT; NITROGEN IONS; RELIABILITY; SILICA; SILICON CARBIDES; SILICON OXIDES; SIMULATION; STRESSES; TEMPERATURE DEPENDENCE; THICKNESS; TIME DEPENDENCE

Citation Formats

Samanta, Piyas, E-mail: piyas@vcfw.org, and Mandal, Krishna C., E-mail: mandalk@cec.sc.edu. Simulation of temperature dependent dielectric breakdown in n{sup +}-polySi/SiO{sub 2}/n-6H-SiC structures during Poole-Frenkel stress at positive gate bias. United States: N. p., 2016. Web. doi:10.1063/1.4960579.
Samanta, Piyas, E-mail: piyas@vcfw.org, & Mandal, Krishna C., E-mail: mandalk@cec.sc.edu. Simulation of temperature dependent dielectric breakdown in n{sup +}-polySi/SiO{sub 2}/n-6H-SiC structures during Poole-Frenkel stress at positive gate bias. United States. doi:10.1063/1.4960579.
Samanta, Piyas, E-mail: piyas@vcfw.org, and Mandal, Krishna C., E-mail: mandalk@cec.sc.edu. Sun . "Simulation of temperature dependent dielectric breakdown in n{sup +}-polySi/SiO{sub 2}/n-6H-SiC structures during Poole-Frenkel stress at positive gate bias". United States. doi:10.1063/1.4960579.
@article{osti_22597670,
title = {Simulation of temperature dependent dielectric breakdown in n{sup +}-polySi/SiO{sub 2}/n-6H-SiC structures during Poole-Frenkel stress at positive gate bias},
author = {Samanta, Piyas, E-mail: piyas@vcfw.org and Mandal, Krishna C., E-mail: mandalk@cec.sc.edu},
abstractNote = {We present for the first time a thorough investigation of trapped-hole induced gate oxide deterioration and simulation results of time-dependent dielectric breakdown (TDDB) of thin (7–25 nm) silicon dioxide (SiO{sub 2}) films thermally grown on (0 0 0 1) silicon (Si) face of n-type 6H-silicon carbide (n-6H-SiC). Gate oxide reliability was studied during both constant voltage and current stress with positive bias on the degenerately doped n-type poly-crystalline silicon (n{sup +}-polySi) gate at a wide range of temperatures between 27 and 225 °C. The gate leakage current was identified as the Poole-Frenkel (PF) emission of electrons trapped at an energy 0.92 eV below the SiO{sub 2} conduction band. Holes were generated in the n{sup +}-polySi anode material as well as in the oxide bulk via band-to-band ionization depending on the film thickness t{sub ox} and the energy of the hot-electrons (emitted via PF mechanism) during their transport through oxide films at oxide electric fields E{sub ox} ranging from 5 to 10 MV/cm. Our simulated time-to-breakdown (t{sub BD}) results are in excellent agreement with those obtained from time consuming TDDB measurements. It is observed that irrespective of stress temperatures, the t{sub BD} values estimated in the field range between 5 and 9 MV/cm better fit to reciprocal field (1/E) model for the thickness range studied here. Furthermore, for a 10 year projected device lifetime, a good reliability margin of safe operating field from 8.5 to 7.5 MV/cm for 7 nm and 8.1 to 6.9 MV/cm for 25 nm thick SiO{sub 2} was observed between 27 and 225 °C.},
doi = {10.1063/1.4960579},
journal = {Journal of Applied Physics},
number = 6,
volume = 120,
place = {United States},
year = {Sun Aug 14 00:00:00 EDT 2016},
month = {Sun Aug 14 00:00:00 EDT 2016}
}