Assessment of the boron impurity in semi-insulating gallium arsenide by localized vibrational mode spectroscopy.

The determination of the boron background contamination in semi-insulating GaAs by localized vibrational mode spectroscopy has been studied. Comparison with secondary ion mass spectrometry shows that there is a strictly linear correlation between the total boron concentration and the strength of the infrared absorption line at 517 cm-1 (11BGa). A new calibration factor is given: f equal 11.5 x 10high16cm-1. The detection limit for the infrared method is at least 1 x 10high16cm-3. Experimental procedures and the influence of temperature and spectral resolution are discussed in detail.