193 results about "Multi grid" patented technology

The invention discloses a three-dimensional semiconductor device comprising a plurality of memory unit transistors and a plurality of selection transistors, wherein the plurality of memory unit transistors are at least partially overlapped in the vertical direction; each selection transistor comprises a first drain electrode distributed along the vertical direction, an active region, a common source electrode formed in a substrate and a metal grid electrode distributed around the active region; each memory unit transistor comprises a channel layer distributed vertical to the surface of the substrate, wherein a plurality of interlayer insulating layers and a plurality of grid electrode stacking structures are alternately stacked along the side wall of the channel layer, and a second drain electrode is located at the top of the channel layer; the channel layer is electrically connected with the first drain electrode. According to the three-dimensional semiconductor device and a manufacturing method thereof disclosed by the invention, multi-grid MOSFETs (Metal-Oxide-Semiconductor Field Effect Transistors) are formed below memory unit string stacks comprising vertical channels so as to be used as the selection transistors, thus the threshold voltage control characteristic of the grid electrode is improved, the off-state leakage current is reduced, the over-etching for the substrate is avoided, and the reliability of the device is effectively improved.

A method and apparatus for modeling and thermal analysis of semiconductor chip designs is provided. One embodiment of a novel method for performing thermal testing of a semiconductor chip design includes calculating full-chip temperatures over the semiconductor chip design (e.g., to identify steep thermal gradients) and modeling the full-chip temperatures in accordance with a geometric multi-grid technique. The geometric multi-grid technique is tailored to determine temperatures within the semiconductor chip design based at least in part on the physical attributes or geometry of the design.

A multi-grid ion beam source has an extraction grid, an acceleration grid, a focus grid, and a shield grid to produce a highly collimated ion beam. A five grid ion beam source is also disclosed having two shield grids. The extraction grid has a high positive potential and covers a plasma chamber containing plasma. The acceleration grid has a non-positive potential. The focus grid is positioned between the acceleration grid and the shield grid. The combination of the extraction grid and the acceleration grid extracts ions from the plasma. The focus grid acts to change momentum of the ions exiting the acceleration grid, focusing the ions into a more collimated ion beam than previous approaches. In one embodiment, the focus grid has a large positive potential. In another embodiment, the focus grid has a large negative potential.

The invention discloses a micro-grid multi-inverter parallel voltage control method for droop control of robust power. The method comprises the following steps of: specific to each inverter in a micro-grid, computing and synthesizing an inverter output reference voltage by adopting a robust power droop controller; and introducing virtual complex impedance containing a resistance component and an inductive impedance component, and keeping inverter output impedance in a pure resistance state under a power frequency condition by adopting a multi-loop voltage control method based on virtual impedance and quasi-resonance PR (Proportional-Resonant) control, thereby realizing micro-grid multi-inverter parallel running and power equation, wherein the robustness of a micro-grid parallel system on numeric value computing errors, parameter drift, noise interference and the like is enhanced. Due to the adoption of the method, the defects of larger loop current of a parallel system, non-uniform power distribution and the like caused by the inductivity of the impedance output by inverters in the conventional droop method are overcome; and the method is suitable for multi-grid parallel uniform current control in a low-voltage micro-grid.

Method for efficient processing of controlled source electromagnetic data, whereby Maxwell's equations are solved [107] by numerical techniques [109] such as finite difference or finite element in three dimensions for each source location and frequency of interest. The Reciprocity Principle is used [103] to reduce the number of computational source positions, and a multi-grid is used [105] for the computational grid to minimize the total number of cells yet properly treat the source singularity, which is essential to satisfying the conditions required for applicability of the Reciprocity Principle. An initial global resistivity model [101] is Fourier interpolated to the computational multi grids [106]. In inversion embodiments of the invention, Fourier prolongation is used to update [120] the global resistivity model based on optimization results from the multi-grids.