A new process for gate dielectric fabrication named in situ steam generation （ISSG） is reported. Based on the Deal-Grove model, an oxidation mechanism is proposed to break the Si- Si bond by an active atomic O and f...A new process for gate dielectric fabrication named in situ steam generation （ISSG） is reported. Based on the Deal-Grove model, an oxidation mechanism is proposed to break the Si- Si bond by an active atomic O and form a Si- O - Si bond during the oxidation process. The breakdown characteristics are investigated through a MOS-capacitor for both ISSG and furnace wet oxidation. The gate dielectric material generated by ISSG oxidation has a superior electrical performance owing to sufficient oxidation of weak Si-Si bonds relative to furnace wet oxidation,indicating a promising application in sub-micron IC device manufacturing.展开更多
Most of the coal reservoirs in China are of low-permeability, so hydraulic fracturing is widely used to improve the per- meability in the extraction of gas by ground drilling. The ground stress around the well was ana...Most of the coal reservoirs in China are of low-permeability, so hydraulic fracturing is widely used to improve the per- meability in the extraction of gas by ground drilling. The ground stress around the well was analyzed by using theory of elasticity. The pressure when the well fractured is formulated and the effect of ground stress on pressure is discussed. The effect of ground-stress-differences on hydraulic fracturing was analyzed by using the numerical software RFPA2D-Flow in reference to the tectonic stress in Jincheng coal area. The results show that: 1) the position where initial fracture appears is random and fracture branches emerge when the fractures expand if ground stresses in any two directions within a horizontal plane are equal; 2) other- wise, the fractures expand in general along the direction of maximum ground stress and the critical pressure decreases with in- creasing ground-stress-differences and 3) the preferred well-disposition pattern is diamond shaped. The preferred well spacing is 250 m×300 m. This study can provide a reference for the design of wells.展开更多
文摘A new process for gate dielectric fabrication named in situ steam generation （ISSG） is reported. Based on the Deal-Grove model, an oxidation mechanism is proposed to break the Si- Si bond by an active atomic O and form a Si- O - Si bond during the oxidation process. The breakdown characteristics are investigated through a MOS-capacitor for both ISSG and furnace wet oxidation. The gate dielectric material generated by ISSG oxidation has a superior electrical performance owing to sufficient oxidation of weak Si-Si bonds relative to furnace wet oxidation,indicating a promising application in sub-micron IC device manufacturing.
基金Projects 2007CB209400 supported by the National Basic Research Program of China50490273 by the National Natural Science Foundation of China
文摘Most of the coal reservoirs in China are of low-permeability, so hydraulic fracturing is widely used to improve the per- meability in the extraction of gas by ground drilling. The ground stress around the well was analyzed by using theory of elasticity. The pressure when the well fractured is formulated and the effect of ground stress on pressure is discussed. The effect of ground-stress-differences on hydraulic fracturing was analyzed by using the numerical software RFPA2D-Flow in reference to the tectonic stress in Jincheng coal area. The results show that: 1) the position where initial fracture appears is random and fracture branches emerge when the fractures expand if ground stresses in any two directions within a horizontal plane are equal; 2) other- wise, the fractures expand in general along the direction of maximum ground stress and the critical pressure decreases with in- creasing ground-stress-differences and 3) the preferred well-disposition pattern is diamond shaped. The preferred well spacing is 250 m×300 m. This study can provide a reference for the design of wells.
