Hydrogen release and Si-N bond-healing infrared study of rapid thermal annealed amorphous silicon nitride thin films

Book · Tue Dec 31 04:00:00 EST 1996

OSTI ID:479286

Santos-Filho, P; Stevens, G; Lu, Z; Koh, K; Lucovsky, G ^[1]

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1. North Carolina State Univ., Raleigh, NC (United States)

The authors address aspects of hydrogen bonding and its thermal evolution in amorphous Silicon nitride films grown by Remote Plasma Enhanced Chemical Vapor Deposition (RPECVD) from SiH{sub 4} and NH{sub 3} (or ND{sub 3}) source gases. Rapid Thermal Annealing (RTA) decreases the Si-H(D) and SiN-H(D) bond populations. The hydrogen bonds break, and H{sub 2} (HD, D{sub 2}) forms and evolves from the film with the heat treatment. This molecular hydrogen release is accompanied by Si- and N- bond healing as detected by a SiN infra red stretch mode signal gain. The ex-situ RTA experiment temperatures ranged from 400 to 1,200 C, in 100 C steps and the film structural changes were monitored by Fourier Transform Infrared spectroscopy (FTIR) after each incremental anneal. Gas flow ratios R = NH{sub 3}/SiH{sub 4} > 2 produced films in which SiN-H(D) bonds dissociated, and a gas desorption rate equation estimated an activation energy barrier of Ea = 0.3 eV. The release of hydrogen from the films in the form of H{sub 2} (D{sub 2}) and ammonia radicals was detected by mass spectrometry and is shown here. The re-bonding of nitrogen to silicon upon thermal dissociation of hydrogen`s is consistent with the improvement of the electrical properties of a-SiN:H films following RTA treatment.

• OSTI ID: 479286
• Report Number(s): CONF-951155--; ISBN 1-55899-301-0
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMMONIA
AMORPHOUS STATE
ANNEALING
CHEMICAL VAPOR DEPOSITION
DEUTERIUM
EXPERIMENTAL DATA
INFRARED SPECTRA
MOLECULAR STRUCTURE
SILANES
SILICON NITRIDES
THIN FILMS