Si/SiGe/Si heterostructures grown by ultra-high-vacuum chemical vapor deposition (UHVCVD) werecharacterized by Rutherford backscattering/Channeling (RBS/C) together with high resolution X ray diffraction(HRXRD). High ...Si/SiGe/Si heterostructures grown by ultra-high-vacuum chemical vapor deposition (UHVCVD) werecharacterized by Rutherford backscattering/Channeling (RBS/C) together with high resolution X ray diffraction(HRXRD). High quality SiGe base layer was obtained. The Si/SiGe/Si heterostructures were subject to conventionalfurnace annealing and rapid thermal annealing with temperature between 750 ℃ and 910 ℃. Both strain and its re-laxation degree in SiGe layer are calculated by HRXRD combined with elastic theory, which are never reported inother literatures. The rapid thermal annealing at elevated temperature between 880 ℃ and 910 ℃ for very short timehad almost no influence on the strain in Si0.84Ge0. 16 epilayer. However, high temperature (900℃) furnace annealingfor 1h prompted the strain in Si0.84Ge0.16 layer to relax.展开更多
The hole subband structures and effective masses of tensile strained Si/Si1yGey quantum wells are calculated by using the 6×6 k·p method.The results show that when the tensile strain is induced in the quantu...The hole subband structures and effective masses of tensile strained Si/Si1yGey quantum wells are calculated by using the 6×6 k·p method.The results show that when the tensile strain is induced in the quantum well,the light-hole state becomes the ground state,and the light hole effective masses in the growth direction are strongly reduced while the in-plane effective masses are considerable.Quantitative calculation of the valence intersubband transition between two light hole states in a 7nm tensile strained Si/Si0.55Ge0.45 quantum well grown on a relaxed Si0.5Ge0.5(100) substrates shows a large absorption coefficient of 8400 cm-1.展开更多
基金the National High Technology and Research Development Program(863 Program)of China(No.2002AA321230)partially supported by the National Natural Sciences Foundation of China(No.10075072)
文摘Si/SiGe/Si heterostructures grown by ultra-high-vacuum chemical vapor deposition (UHVCVD) werecharacterized by Rutherford backscattering/Channeling (RBS/C) together with high resolution X ray diffraction(HRXRD). High quality SiGe base layer was obtained. The Si/SiGe/Si heterostructures were subject to conventionalfurnace annealing and rapid thermal annealing with temperature between 750 ℃ and 910 ℃. Both strain and its re-laxation degree in SiGe layer are calculated by HRXRD combined with elastic theory, which are never reported inother literatures. The rapid thermal annealing at elevated temperature between 880 ℃ and 910 ℃ for very short timehad almost no influence on the strain in Si0.84Ge0. 16 epilayer. However, high temperature (900℃) furnace annealingfor 1h prompted the strain in Si0.84Ge0.16 layer to relax.
基金supported by National Natural Science Foundation of China (Grant Nos 50672079,60336010 and 60676027)National Basic Research Program of China (Grant No 2007CB613400)
文摘The hole subband structures and effective masses of tensile strained Si/Si1yGey quantum wells are calculated by using the 6×6 k·p method.The results show that when the tensile strain is induced in the quantum well,the light-hole state becomes the ground state,and the light hole effective masses in the growth direction are strongly reduced while the in-plane effective masses are considerable.Quantitative calculation of the valence intersubband transition between two light hole states in a 7nm tensile strained Si/Si0.55Ge0.45 quantum well grown on a relaxed Si0.5Ge0.5(100) substrates shows a large absorption coefficient of 8400 cm-1.
