A concept of compositional reverse-grading (RG) in SiGe/Si heteroepitaxy has been proposed, in which the graded layer lattice mismatch starts at the highest value at the RG/Si interface and decreases to a final mismatch at the SiGe/RG interface. Using various characterization techniques, the authors show that this low-dislocation-density strain relaxation mechanism relies on the large nucleation rates of misfit dislocations at the abrupt RG/Si interface and the reduction of threading dislocations at the SiGe/RG interface by facilitating glide. The RG concept enables the growth of high-quality relaxed epitaxial layer on a thin buffer layer, suitable as a substrate for many microelectronic and optoelectronic applications. (c) 2007 American Institute of Physics.
Strain relaxation mechanism in a reverse compositionally graded SiGe heterostructure
Romanato F;
2007
Abstract
A concept of compositional reverse-grading (RG) in SiGe/Si heteroepitaxy has been proposed, in which the graded layer lattice mismatch starts at the highest value at the RG/Si interface and decreases to a final mismatch at the SiGe/RG interface. Using various characterization techniques, the authors show that this low-dislocation-density strain relaxation mechanism relies on the large nucleation rates of misfit dislocations at the abrupt RG/Si interface and the reduction of threading dislocations at the SiGe/RG interface by facilitating glide. The RG concept enables the growth of high-quality relaxed epitaxial layer on a thin buffer layer, suitable as a substrate for many microelectronic and optoelectronic applications. (c) 2007 American Institute of Physics.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
