Title of article :
Structural and optical properties of vertically correlated Ge island layers grown at low temperatures
Author/Authors :
Herbst، نويسنده , , M and Schramm، نويسنده , , C and Brunner، نويسنده , , K and Asperger، نويسنده , , T and Riedl، نويسنده , , H and Abstreiter، نويسنده , , G and Vِrckel، نويسنده , , A and Kurz، نويسنده , , H and Müller، نويسنده , , E، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2002
Pages :
4
From page :
54
To page :
57
Abstract :
We studied the vertical correlation of small hut-like Ge islands in Si–Ge multilayers grown by molecular beam epitaxy (MBE) at 510 °C in the modified Stranski–Krastanov growth mode. The fundamental, structural and optical properties of stacked Ge islands embedded in Si are analyzed by in-situ RHEED, TEM, photoluminescence (PL), and photocurrent (PC) spectroscopy. Ge islands of about 20 nm width and 2 nm height reveal a reduction in the critical Ge coverage for correlated growth for Si spacer widths below about 14 nm. This value is much smaller than observed for dome-like islands of about 80 nm size deposited at higher temperatures. Such a scaling of island separation for stacked growth with island diameter is suggested by finite element simulations of elastic strain relaxation in islands. The correlation affects island size, island density, and local strain fields which may have a direct impact on band offsets and the electronic coupling of stacked islands. This is important for possible application in devices like NIR Si–Ge dot photodetectors and tunneling structures.
Keywords :
RHEED , Vertical correlation , SI , Molecular Beam Epitaxy , GE , Islands
Journal title :
MATERIALS SCIENCE & ENGINEERING: B
Serial Year :
2002
Journal title :
MATERIALS SCIENCE & ENGINEERING: B
Record number :
2137927
Link To Document :
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