Impact of UV Nanosecond Laser Annealing on Composition and Strain of Undoped Si0.8Ge0.2 Epitaxial Layers

Léa Dagault (1, 2) , P. Acosta-Alba (1) , S. Kerdiles (1) , J. P. Barnes (1) , J. M. Hartmann (1) , P. Gergaud (1) , T. T. Nguyen (1) , A. Grenier (1) , A. M. Papon (1) , N. Bernier (1) , V. Delaye (1) , J. Aubin , Fuccio Cristiano (2)

1 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
2 LAAS-MPN - Équipe Matériaux et Procédés pour la Nanoélectronique

Ultraviolet Nanosecond Laser Annealing (UV-NLA) was performed on 30 nm-thick Si0.8Ge0.2 epitaxial layers. The various regimes encountered, depending on the melt depth after single pulse UV-NLA, are described and discussed in this paper. Energy densities around 2.00 J/cm(2) and above led to the formation of pseudomorphic layers with a strong Ge redistribution. Starting from uniform Si0.8Ge0.2 layers, Ge segregation toward the surface resulted in the formation of a Ge-rich surface layer with up to 55 at.% Ge for 2.00 J/cm(2). Such pseudomorphic SiGe layers with a graded composition and a Ge-rich surface may find promising applications such as contact resistance lowering in doped layers.

Domaines: Sciences de l'ingénieur [physics]

Léa Dagault, P. Acosta-Alba, S. Kerdiles, J. P. Barnes, J. M. Hartmann, et al.. Impact of UV Nanosecond Laser Annealing on Composition and Strain of Undoped Si0.8Ge0.2 Epitaxial Layers. ECS Journal of Solid State Science and Technology, 2019, 8 (3), pp.202-208. ⟨10.1149/2.0191903jss⟩. ⟨cea-02186445⟩