Triangular step instability and 2D/3D transition during the growth of strained Ge films on Si(100)

Conference · Sat Apr 01 04:00:00 EST 1995

OSTI ID:100226

Chen, K M; Jesson, D E; Pennycook, S J; Mostoller, M; Kaplan, T; Thundat, T; Warmack, R J

We show that an activation energy barrier exists to the formation of wavy step edges due to stress-driven 2D instability. The barrier height and the barrier width depend sensitively on the surface stress anisotropy and step free energy. The large misfit strain of Ge films significantly reduces the barrier by lowering the S{sub B} step energy, inducing S{sub A} steps to undergo a triangular instability even during low temperature growth of Ge on Si(100). The step instability results in a novel arrangement of stress domains, and the interaction between the domains causes a spatial variation of surface strain with a surprisingly large influence on the energy barrier for island nucleation. Calculations indicate a dramatic enhancement in the nucleation of 3D islands at the apex regions of triangular steps, in good agreement with our experimental measurements.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 100226
• Report Number(s): CONF-950412--51; ON: DE95014261
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DEPOSITION
GERMANIUM
INSTABILITY
MICROSTRUCTURE
NUCLEATION
SILICON
SURFACE ENERGY