XRD analysis of strained Ge-SiGe heterostructures on relaxed SiGe graded buffers grown by hybrid epitaxy on Si(0Â 0Â 1) substrates

Ge/Si1−xGex inverted modulation doped heterostructures with Ge channel thickness of 16 and 20 nm were grown by a method of hybrid epitaxy followed by ex situ annealing at 650 °C for p-HMOS application. The thicker layers of the virtual substrate (6000 nm graded SiGe up to x = 0.6 and 1000 nm uniform composition with x = 0.6) were produced by ultrahigh vacuum chemical vapor deposition (UHV-CVD) while the thinner, Si(2 nm)-SiGe(20 nm)-Ge-SiGe(15 nm + 5 nm B-doped + 20 nm) active layers were grown by low temperature solid-source (LT-SS) MBE at T = 350 °C. As-grown and annealed samples were measured by X-ray diffraction (XRD). Reciprocal space maps (RSMs) allowed us to determine non-destructively the precise composition (∼1%) and strain of the Ge channel, along with similar information regarding the other layers that made up the whole structure. Layer thickness was determined with complementary high-resolution Rutherford backscattering (RBS) experiments.