The palladium（o）-catalyzed nitrogen insertion into cyclic Si-Si bonds has been realized by using N-tosylhydrazones/diazo compounds as the nitrogen source. The palladium（Ⅱ） nitrene formation and subsequent migrato...The palladium（o）-catalyzed nitrogen insertion into cyclic Si-Si bonds has been realized by using N-tosylhydrazones/diazo compounds as the nitrogen source. The palladium（Ⅱ） nitrene formation and subsequent migratory insertion process are proposed as the key steps for this reaction.展开更多
Short-channel high-mobility Si/Si_(0.5)Ge_(0.5)/silicon-on-insulator(SOI)quantum-well p-type metal-oxide-semiconductor field effect transistors(p-MOSFETs)were fabricated and electrically characterized.The transistors ...Short-channel high-mobility Si/Si_(0.5)Ge_(0.5)/silicon-on-insulator(SOI)quantum-well p-type metal-oxide-semiconductor field effect transistors(p-MOSFETs)were fabricated and electrically characterized.The transistors show good transfer and output characteristics with Ion/Ioff ratio up to 105 and sub-threshold slope down to 100 mV/dec.HfO_(2)/TiN gate stack is employed and the equivalent oxide thickness of 1.1 nm is achieved.The effective hole mobility of the transistors reaches 200 cm^(2)/V·s,which is 2.12 times the Si universal hole mobility.展开更多
P-type double barrier resonant tunneling diodes (RTD) with the single Si0.6Ge0.4 quantum well and double Si0.6Ge0.4spacer have been realized by using an ultra clean low-pressure chemical vapor deposition system. The e...P-type double barrier resonant tunneling diodes (RTD) with the single Si0.6Ge0.4 quantum well and double Si0.6Ge0.4spacer have been realized by using an ultra clean low-pressure chemical vapor deposition system. The effect of Si_(1-y)C_(y) layer on the characteristics of the devices was shown by comparing the current-voltage (I-V) characteristics of RTD’s of the barriers of Si layers with that of Si/ Si_(1-y)C_(y)/Si structures. The peak voltage was gradually increased and the resonant current decreased obviously with increasing C content in the Si/ Si_(1-y)C_(y)/Si barriers. The origin of the phenomena above can be attributed to the C related deep acceptor levels in the Si/ Si_(1-y)C_(y)/Si barriers. The possible mechanism for the observed I- V characteristics was shown more clearly by increasing C content to 3% and changing the thicknesses of Si and Si_(1-y)C_(y) layers in the Si/Si_(1-y)C_(y)/Si barriers.展开更多
High mobility Si/Si_(l-x)Ge_(x)/Si p-type modulation-doped double heterostructures have been grown by RRH/VLP-CVD(rapid radiant heating/very low pressure-CVD).Hole Hall mobilities as high as about 300cm^(2)/V.s(293 K)...High mobility Si/Si_(l-x)Ge_(x)/Si p-type modulation-doped double heterostructures have been grown by RRH/VLP-CVD(rapid radiant heating/very low pressure-CVD).Hole Hall mobilities as high as about 300cm^(2)/V.s(293 K)and 7500cm^(2)/V.s(77K)have been obtained for heterostructures with x=0.3.The variation of hole mobility with temperature and the influence of Ge fraction on hole mobility were investigated.展开更多
The feature of conduction band （CB） of Tensile-Strained Si（TS-Si） on a relaxed Si1-xGex substrate is systematically investigated, including the number of equivalent CB edge energy extrema, CB energy minima, the po...The feature of conduction band （CB） of Tensile-Strained Si（TS-Si） on a relaxed Si1-xGex substrate is systematically investigated, including the number of equivalent CB edge energy extrema, CB energy minima, the position of the extremal point, and effective mass. Based on an analysis of symmetry under strain, the number of equivalent CB edge energy extrema is presented; Using the K.P method with the help of perturbation theory, dispersion relation near minima of CB bottom energy, derived from the linear deformation potential theory, is determined, from which the parameters, namely, the position of the extremal point, and the longitudinal and transverse masses （m1^＊ and mt^＊）are obtained.展开更多
基金The project is supported by the National Basic Research Pro- gram of China （973 Program, No. 2015CB856600） and the Natio- anal Natural Science Foundation of China （Grant 21332002, 21472004）.
文摘The palladium（o）-catalyzed nitrogen insertion into cyclic Si-Si bonds has been realized by using N-tosylhydrazones/diazo compounds as the nitrogen source. The palladium（Ⅱ） nitrene formation and subsequent migratory insertion process are proposed as the key steps for this reaction.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61306126,61306127 and 61106015the Science and Technology Commission of Shanghai Municipality under Grant Nos 12ZR1453000,12ZR1453100 and 12ZR1436300CAS International Collaboration and Innovation Program on High Mobility Materials Engineering.
文摘Short-channel high-mobility Si/Si_(0.5)Ge_(0.5)/silicon-on-insulator(SOI)quantum-well p-type metal-oxide-semiconductor field effect transistors(p-MOSFETs)were fabricated and electrically characterized.The transistors show good transfer and output characteristics with Ion/Ioff ratio up to 105 and sub-threshold slope down to 100 mV/dec.HfO_(2)/TiN gate stack is employed and the equivalent oxide thickness of 1.1 nm is achieved.The effective hole mobility of the transistors reaches 200 cm^(2)/V·s,which is 2.12 times the Si universal hole mobility.
基金Supported by the National High Technology Research and Development Project of China(No.863-307-1620).
文摘P-type double barrier resonant tunneling diodes (RTD) with the single Si0.6Ge0.4 quantum well and double Si0.6Ge0.4spacer have been realized by using an ultra clean low-pressure chemical vapor deposition system. The effect of Si_(1-y)C_(y) layer on the characteristics of the devices was shown by comparing the current-voltage (I-V) characteristics of RTD’s of the barriers of Si layers with that of Si/ Si_(1-y)C_(y)/Si structures. The peak voltage was gradually increased and the resonant current decreased obviously with increasing C content in the Si/ Si_(1-y)C_(y)/Si barriers. The origin of the phenomena above can be attributed to the C related deep acceptor levels in the Si/ Si_(1-y)C_(y)/Si barriers. The possible mechanism for the observed I- V characteristics was shown more clearly by increasing C content to 3% and changing the thicknesses of Si and Si_(1-y)C_(y) layers in the Si/Si_(1-y)C_(y)/Si barriers.
文摘High mobility Si/Si_(l-x)Ge_(x)/Si p-type modulation-doped double heterostructures have been grown by RRH/VLP-CVD(rapid radiant heating/very low pressure-CVD).Hole Hall mobilities as high as about 300cm^(2)/V.s(293 K)and 7500cm^(2)/V.s(77K)have been obtained for heterostructures with x=0.3.The variation of hole mobility with temperature and the influence of Ge fraction on hole mobility were investigated.
文摘The feature of conduction band （CB） of Tensile-Strained Si（TS-Si） on a relaxed Si1-xGex substrate is systematically investigated, including the number of equivalent CB edge energy extrema, CB energy minima, the position of the extremal point, and effective mass. Based on an analysis of symmetry under strain, the number of equivalent CB edge energy extrema is presented; Using the K.P method with the help of perturbation theory, dispersion relation near minima of CB bottom energy, derived from the linear deformation potential theory, is determined, from which the parameters, namely, the position of the extremal point, and the longitudinal and transverse masses （m1^＊ and mt^＊）are obtained.
