Effect of silicon nitride layers on the minority carrier diffusion length in c-Si wafers

Journal Article · Fri Dec 01 00:00:00 EST 2006 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2390628· OSTI ID:20884915

Tousek, Jiri; Touskova, Jana; Poruba, Ales; Hlidek, Pavel; Loerincik, Jan ^[1]

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1. Faculty of Mathematics and Physics, Department of Macromolecular Physics, Charles University, Ke Karlovu 5, 121 16 Prague (Czech Republic)

Silicon nitride layers prepared from silane and ammonia based gases by microwave assisted plasma enhanced chemical vapor deposition (PECVD) and by low pressure chemical vapor deposition (LPCVD) techniques on p-type c-silicon substrates were studied via the methods of surface photovoltage (SPV), Fourier transform infrared (FTIR), and secondary-ion-mass spectroscopy (SIMS). The effective diffusion length in silicon was evaluated by the SPV method, and it was strongly influenced by the deposited SiN{sub x} layer. The FTIR spectra show the form of chemical bond of hydrogen in the layer. Two absorption bands belonging to Si-H and N-H groups and their modification after temperature treatment were found in the spectra of PECVD samples, while in the spectra of LPCVD samples only N-H bonds were recognized. Transport of H from PECVD silicon nitride into Si subsurface layer during the annealing process is shown by SIMS profiles of hydrogen. Positive influence of the penetrated H manifests in passivation of defects in the subsurface Si layer and, consequently, in better operation of the space charge region below the nitride and in longer effective diffusion length of minority carriers in the Si bulk. The average value of the diffusion length in the Si samples with the LPCVD nitride was shorter and dependent on the location of wafers in the reactor.

• OSTI ID: 20884915
• Journal Information: Journal of Applied Physics, Vol. 100, Issue 11; Other Information: DOI: 10.1063/1.2390628; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION
AMMONIA
ANNEALING
CARRIER LIFETIME
CHEMICAL BONDS
CHEMICAL VAPOR DEPOSITION
DIFFUSION LENGTH
FOURIER TRANSFORM SPECTROMETERS
HYDROGEN
INFRARED SPECTRA
ION MICROPROBE ANALYSIS
LAYERS
MASS SPECTROSCOPY
MICROWAVE RADIATION
PASSIVATION
SILANES
SILICON
SILICON NITRIDES
SPACE CHARGE
SUBSTRATES