Material Characterization of Ge1-x Sn (x) Alloys Grown by a Commercial CVD System for Optoelectronic Device Applications

作者：Mosleh Aboozar^*; Ghetmiri Seyed Amir; Conley Benjamin R; Hawkridge Michael; Benamara Mourad; Nazzal Amjad; Tolle John; Yu Shui Qing; Naseem Hameed A

来源：Journal of Electronic Materials, 2014, 43(4): 938-946.

DOI：10.1007/s11664-014-3089-2

• Germanium alloys
• semiconductor growth
• silicon
• pseudomorphic growth
• CVD
• GeSn

High-quality compressive-strained Ge1-x Sn (x) /Ge films have been deposited on Si(001) substrate using a mainstream commercial chemical vapor deposition reactor. The growth temperature was kept below 450A degrees C to be compatible with Si complementary metal-oxide-semiconductor processes. Germanium tin (Ge1-x Sn (x) ) layers were grown with different Sn composition ranging from 0.9% to 7%. Material characterizations, such as secondary-ion mass spectrometry, Rutherford backscattering spectrometry, and x-ray diffraction analysis, show stable Sn incorporation in the Ge lattice. Comparison of the Sn mole fractions obtained using these methods shows that the bowing factor of 0.166 nm (in Vegard's law) is in close agreement with other experimental data. High-resolution transmission electron microscopy and atomic force microscopy results show that the films have started to relax through the formation of misfit and threading dislocations. Raman spectroscopy, ellipsometry, and photoluminescence (PL) techniques are used to study the structural and optical properties of the films. Room-temperature PL of the films shows that 7% Sn incorporation in the Ge lattice results in a decrease in the direct bandgap of Ge from 0.8 eV to 0.56 eV.

• 出版日期2014-4