Impact of the end of range damage from low energy Ge preamorphizing implants on the thermal stability of shallow boron profiles Diffusion of B in Ge is studied in the temperature range 800-900°C using implantation doping and B doped epitaxial Ge layers. Concentration profiles before and after furnace annealing were obtained using high resolution secondary ion mass spectroscopy (SIMS). Diffusion coefficients were calculated by fitting the annealed profiles using TSUPREM. We obtained diffusivity values which are at least two orders of magnitude lower than the lowest values previously reported in the literature. Using our values an activation energy of 4.65͑±0.3͒ eV is calculated. Present experimental results suggest that interstitial mediated mechanism should be considered for B diffusion in Ge in accordance with recent theoretical calculations. Annealed SIMS profiles also suggest that B solid solubility in Ge is ϳ2 ϫ 10 18 cm −3 at 875°C which agrees with literature values.

In this paper we investigate the physical and electrical properties of silicon layers grown by molecular beam epitaxy on 4H-SiC substrates, evaluating the effect of the Si doping, Si temperature deposition, and SiC surface cleaning procedure. Si∕SiC monolithic integration of Si circuits with SiC power devices can be considered as an attractive proposition and has the potential to be applied to a broad range of applications. X-ray diffraction and scanning electron microscopy are used to determine the Si crystal structure (cubic silicon) and morphology. I-V and C-V measurements are performed to evaluate the rectifying diode characteristics along with the Si∕SiC built-in potential and energy band offsets. In the last section, we propose that our Si∕SiC heteojunction diode current characteristics can be explained by an isojunction drift-diffusion and thermoionic emission model where the effect of doping concentration of the silicon layer and its conduction band offset with SiC is analyzed.

Strained Ge p-channel heterostructures have been realized by hybrid-epitaxial growth. Strain-tuning Si 0.4 Ge 0.6 virtual substrates were grown by ultra-high vacuum chemical vapour deposition and active layers were deposited by solid-source molecular beam epitaxy at low temperature. Following ex situ annealing, Hall effect measurements revealed a hole mobility of 1900 cm 2 V −1 s −1 at 300 K (27 000 cm 2 V −1 s −1 at 10 K), with a density of 1.8 × 10 12 cm −2 , giving a conductance in excess of current Ge heterostructures. Using a maximum-entropy mobility-spectrum analysis, 1.0 × 10 12 cm −2 of these holes were found to have a mobility of 2700 cm 2 V −1 s −1 at 300 K.