Assessment of oxygen in gallium arsenide by infrared local vibrational mode spectroscopy

Abstract

Two infrared local vibrational mode (LVM) absorption lines occurring at 715 and 845 cm−1 shift to 679 and 802 cm−1 in gallium arsenide doped with 18O, proving that the lines arise from the vibrations of oxygen impurities. The 715 cm−1 line exhibits a triplet 69,71Ga isotope fine structure consistent with that expected from a quasi-substitional VAs-O center. The 845 cm−1 line appears as a closely spaced doublet expected for a bonded interstitial oxygen atom.