UHV-CVD growth and annealing of thin fully relaxed Ge films on (0 0 1)Si.

Mathieu Halbwax (1) , M. Rouviere (1, 2) , Yunlin Jacques Zheng (3) , D. Debarre (1) , Lam H. Nguyen (1) , J.-L. Cercus (1) , C. Clerc (4) , V. Yam (1) , S. Laval (1) , E. Cassan (1) , D. Bouchier (1)

1 IEF - Institut d'électronique fondamentale
2 ST-CROLLES - STMicroelectronics [Crolles]
3 IMPMC - Institut de minéralogie et de physique des milieux condensés
4 CSNSM - Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse

The structural effects of single and cyclic thermal annealings on relaxed Ge epilayers on Si(0 0 1) are investigated. The structural morphology of the films is studied ex situ by Rutherford back scattering spectrometry in channelling geometry (RBS-C), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The effects on optical properties are demonstrated by optical transmission spectroscopy. Thermal cycles between 750 and 870 °C were found to be efficient for reducing the threading dislocations density. But, in return for it, thermal cycles result in a strong interdiffusion and a high disorder at the Ge/Si interface, as shown through a χmin value of 14.4%. On the contrary, a single annealing at 720 °C decreases the density of dislocations but does not induce any new disorder. Moreover, the single annealing does not alter the near-IR optical absorption of the Ge layer.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Mathieu Halbwax, M. Rouviere, Yunlin Jacques Zheng, D. Debarre, Lam H. Nguyen, et al.. UHV-CVD growth and annealing of thin fully relaxed Ge films on (0 0 1)Si.. Optical Materials, 2005, 27, pp.822-826. ⟨10.1016/j.optmat.2004.08.005⟩. ⟨hal-00020246⟩