Oxygen '96

Early Stages of Oxygen Precipitation in Silicon

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INFRARED STUDIES OF THE EARLY STAGES OF OXYGEN CLUSTERING IN SILICON

Department of Physics and Measurement Technology, Linköping University, S-581 83 Linköping, Sweden

Keywords: oxygen, silicon, annealing, thermal donors

Clustering of oxygen atoms in silicon in the temperature range 350-470 degrees C will be discussed based on results from studies of infrared vibrational absorption bands.

Several vibrational bands have been reported in the wavenumber range 716-748 and 975-1015 cm^-1. These bands correlate well with the formation of thermal donors (TDs). Bands at 975, 988 and 999 cm^-1 have been found to be related to the three first appearing double TDs. A band at 1006 cm^-1 correlates with the development of the rest of the double TDs. The 1012 cm^-1 band is suggested to originate from a different type of donor, possibly the shallow thermal donors. All these bands have a corresponding band in the 716-748 cm^-1 range.

A broad absorption band with a maximum at 1060 cm^-1 also grows up during annealing in this temperature range. It is suggested that 90-95 % if the oxygen atoms lost from the interstitial position during such a treatment gives rise to this band, which probably originates from a type of oxygen precipitate.

Different aspects of the TDs will be discussed such as: the bistability of the first two appearing double TDs, the influence on the TD formation process from other impurity atoms, from electron irradiation (2 MeV) and from dispersion treatments.

Last modified: Mon Feb 19 12:11:12 GMT 1996 JG