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Title: High temperature and low pressure chemical vapor deposition of silicon nitride on AlGaN: Band offsets and passivation studies

Abstract

In this work, we employed X-ray photoelectron spectroscopy to determine the band offsets and interface Fermi level at the heterojunction formed by stoichiometric silicon nitride deposited on Al{sub x}Ga{sub 1-x}N (of varying Al composition “x”) via low pressure chemical vapor deposition. Silicon nitride is found to form a type II staggered band alignment with AlGaN for all Al compositions (0 ≤ x ≤ 1) and present an electron barrier into AlGaN even at higher Al compositions, where E{sub g}(AlGaN) > E{sub g}(Si{sub 3}N{sub 4}). Further, no band bending is observed in AlGaN for x ≤ 0.6 and a reduced band bending (by ∼1 eV in comparison to that at free surface) is observed for x > 0.6. The Fermi level in silicon nitride is found to be at 3 eV with respect to its valence band, which is likely due to silicon (≡Si{sup 0/−1}) dangling bonds. The presence of band bending for x > 0.6 is seen as a likely consequence of Fermi level alignment at Si{sub 3}N{sub 4}/AlGaN hetero-interface and not due to interface states. Photoelectron spectroscopy results are corroborated by current-voltage-temperature and capacitance-voltage measurements. A shift in the interface Fermi level (before band bending at equilibrium) from the conduction band in Si{sub 3}N{sub 4}/n-GaN to the valence band in Si{sub 3}N{sub 4}/p-GaNmore » is observed, which strongly indicates a reduction in mid-gap interface states. Hence, stoichiometric silicon nitride is found to be a feasible passivation and dielectric insulation material for AlGaN at any composition.« less

Authors:
; ; ; ; ; ; ; ; ; ;  [1];  [1]
  1. Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695-7919 (United States)
Publication Date:
OSTI Identifier:
22594604
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 119; Journal Issue: 14; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM NITRIDES; BENDING; CAPACITANCE; CHEMICAL VAPOR DEPOSITION; COMPARATIVE EVALUATIONS; DIELECTRIC MATERIALS; ELECTRIC POTENTIAL; ELECTRONS; FERMI LEVEL; GALLIUM NITRIDES; HETEROJUNCTIONS; INTERFACES; PASSIVATION; SILICON; SILICON NITRIDES; TEMPERATURE RANGE 0400-1000 K; X RADIATION; X-RAY PHOTOELECTRON SPECTROSCOPY

Citation Formats

Reddy, Pramod, Washiyama, Shun, Kaess, Felix, Hernandez-Balderrama, Luis H., Haidet, Brian B., Alden, Dorian, Franke, Alexander, Sarkar, Biplab, Kohn, Erhard, Collazo, Ramon, Sitar, Zlatko, Hayden Breckenridge, M., and REU, Physics Department at Wofford College, Spartanburg, South Carolina 29303. High temperature and low pressure chemical vapor deposition of silicon nitride on AlGaN: Band offsets and passivation studies. United States: N. p., 2016. Web. doi:10.1063/1.4945775.
Reddy, Pramod, Washiyama, Shun, Kaess, Felix, Hernandez-Balderrama, Luis H., Haidet, Brian B., Alden, Dorian, Franke, Alexander, Sarkar, Biplab, Kohn, Erhard, Collazo, Ramon, Sitar, Zlatko, Hayden Breckenridge, M., & REU, Physics Department at Wofford College, Spartanburg, South Carolina 29303. High temperature and low pressure chemical vapor deposition of silicon nitride on AlGaN: Band offsets and passivation studies. United States. doi:10.1063/1.4945775.
Reddy, Pramod, Washiyama, Shun, Kaess, Felix, Hernandez-Balderrama, Luis H., Haidet, Brian B., Alden, Dorian, Franke, Alexander, Sarkar, Biplab, Kohn, Erhard, Collazo, Ramon, Sitar, Zlatko, Hayden Breckenridge, M., and REU, Physics Department at Wofford College, Spartanburg, South Carolina 29303. Thu . "High temperature and low pressure chemical vapor deposition of silicon nitride on AlGaN: Band offsets and passivation studies". United States. doi:10.1063/1.4945775.
@article{osti_22594604,
title = {High temperature and low pressure chemical vapor deposition of silicon nitride on AlGaN: Band offsets and passivation studies},
author = {Reddy, Pramod and Washiyama, Shun and Kaess, Felix and Hernandez-Balderrama, Luis H. and Haidet, Brian B. and Alden, Dorian and Franke, Alexander and Sarkar, Biplab and Kohn, Erhard and Collazo, Ramon and Sitar, Zlatko and Hayden Breckenridge, M. and REU, Physics Department at Wofford College, Spartanburg, South Carolina 29303},
abstractNote = {In this work, we employed X-ray photoelectron spectroscopy to determine the band offsets and interface Fermi level at the heterojunction formed by stoichiometric silicon nitride deposited on Al{sub x}Ga{sub 1-x}N (of varying Al composition “x”) via low pressure chemical vapor deposition. Silicon nitride is found to form a type II staggered band alignment with AlGaN for all Al compositions (0 ≤ x ≤ 1) and present an electron barrier into AlGaN even at higher Al compositions, where E{sub g}(AlGaN) > E{sub g}(Si{sub 3}N{sub 4}). Further, no band bending is observed in AlGaN for x ≤ 0.6 and a reduced band bending (by ∼1 eV in comparison to that at free surface) is observed for x > 0.6. The Fermi level in silicon nitride is found to be at 3 eV with respect to its valence band, which is likely due to silicon (≡Si{sup 0/−1}) dangling bonds. The presence of band bending for x > 0.6 is seen as a likely consequence of Fermi level alignment at Si{sub 3}N{sub 4}/AlGaN hetero-interface and not due to interface states. Photoelectron spectroscopy results are corroborated by current-voltage-temperature and capacitance-voltage measurements. A shift in the interface Fermi level (before band bending at equilibrium) from the conduction band in Si{sub 3}N{sub 4}/n-GaN to the valence band in Si{sub 3}N{sub 4}/p-GaN is observed, which strongly indicates a reduction in mid-gap interface states. Hence, stoichiometric silicon nitride is found to be a feasible passivation and dielectric insulation material for AlGaN at any composition.},
doi = {10.1063/1.4945775},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 14,
volume = 119,
place = {United States},
year = {2016},
month = {4}
}