Surfactant-mediated epitaxy of silicon germanium films on silicon (001) substrates

• Published in: Thin solid films 2014-04, Vol.557, p.27-30
• Main Authors: Wietler, T.F., Schmidt, J., Tetzlaff, D., Bugiel, E.
• Format: Article
• Language: English
• Subjects: Analogies; Chemical interdiffusion; diffusion barriers; Condensed matter: structure, mechanical and thermal properties; Diffusion in solids; Epitaxy; Exact sciences and technology; Germanium; Mechanical and acoustical properties; Physical properties of thin films, nonelectronic; Physics; Roughening; Silicon; Silicon substrates; Silicon-germanium alloy; Strain relaxation; Structure and morphology; thickness; Surface roughness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Surfactant-mediated epitaxy; Surfactants; Thin film structure and morphology; Thin films; Transport properties of condensed matter (nonelectronic)
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2013.08.125

We report on the surfactant-mediated epitaxy (SME) of Si1-xGex films with x=0.23–1 on Si(001) using antimony as surfactant. We observe a transition in strain relaxation at a critical composition xT=0.58-0.66. Above this value full relaxation is achieved by a network of full edge dislocation confined to the interface in analogy to SME of pure germanium on Si(001). 100nm thick Si1−xGex films with surface roughness values less than 1nm and abrupt interfaces are obtained, as the surfactant reduces strain induced roughening and hinders interdiffusion. •Si1−xGex films with x=0.23–1 are grown on Si(001) by surfactant-mediated epitaxy.•We observe a transition in strain relaxation at a composition xT=0.58–0.66.•For x≥0.66 full relaxation is achieved by a network of full edge dislocations.•The surface roughness of 100nm thick Si1-xGex films is less than 1nm.