Abstract: A diode for alternating current (DIAC) electrostatic discharge (ESD) protection circuit is formed in a silicon germanium (SiGe) hetrojunction bipolar transistor (HBT) process that utilizes a very thin collector region. ESD protection for a pair of to-be-protected pads is provided by utilizing the base structures and the emitter structures of the SiGe transistors.
Abstract: Minute materials which can be undesirably left on the backside of a semiconductor wafer are detected by scanning the semiconductor wafer with an infra-red (IR) light following the completion of a process step that forms and then selectively removes a material from the top surface of the wafer. Any detected material can then be removed from the backside of the wafer to ensure that that backside of the wafer is clean and flat.
Abstract: A silicon-based light emitting structure is formed as a high density array of light-emitting p-n junctions that substantially increases the intensity of the light emitted in a planar region. The p-n junctions are formed using standard CMOS processing methods, and emit light in response to applied voltages that generate avalanche breakdown and an avalanche current.
Type:
Grant
Filed:
September 19, 2008
Date of Patent:
July 13, 2010
Assignee:
National Semiconductor Corporation
Inventors:
Peter J. Hopper, Philipp Lindorfer, William French, Vladislav Vashchenko
Abstract: A switch structure substantially reduces the effect of contact resistance by placing two mechanical switches in parallel between a source and a load, and sequentially closing and opening the mechanical switches so that one switch closes before the other switch, and opens after the other switch. The switch structure with the two mechanical switches can be realized with standard micro machined switches or as a micro-electromechanical system (MEMS) cantilever switch.
Type:
Grant
Filed:
February 27, 2007
Date of Patent:
July 13, 2010
Assignee:
National Semiconductor Corporation
Inventors:
Trevor Niblock, Roozbeh Parsa, Peter J. Hopper
Abstract: The manufacturing yield of an A/D converter semiconductor chip is significantly increased by utilizing a number of A/D converter circuits that include a group of redundant A/D converter circuits. As a result, the semiconductor chip can be wired to form a “good” A/D converter semiconductor chip as long as the number of “bad” A/D converter circuits does not exceed the number of redundant A/D converter circuits.
Abstract: A semiconductor chip is ESD protected, in part, by utilizing floating lateral clamp diodes. Unlike conventional clamp diodes, which are based upon parasitic bipolar devices associated with large MOS transistors, the floating lateral clamp diodes utilize a well formed in the substrate as the cathode, and a plurality of regions of the opposite conductivity type which are formed in the well as the anode.
Abstract: An edit structure is disclosed that allows the input of a logic gate to be changed by modifying any one of the metal and via masks that are used to form the metal interconnect structure. As a result, a first permanent logic state provided by a tie-in circuit can be changed to a second permanent logic state by modifying any one of the metal and via masks that are used to form the metal interconnect structure.
Abstract: A number of modified lateral DMOS (LDMOS) transistor arrays are formed and tested to determine if a measured value, such as a series on-resistance, substrate current, breakdown voltage, and reliability, satisfies process alignment requirements. The modified LDMOS transistor arrays are similar to standard LDMOS transistor arrays such that the results of the modified LDMOS transistor arrays can be used to predict the results of the standard LDMOS transistor arrays.
Abstract: A copper-topped interconnect structure allows the combination of high density design areas, which have low current requirements that can be met with tightly packed thin and narrow copper traces, and low density design areas, which have high current requirements that can be met with more widely spaced thick and wide copper traces, on the same chip.
Abstract: An integrated circuit inductor has a number of vertical metal segments, a number of lower metal straps that electrically connect alternate metal segments, and a number of upper metal straps that electrically connect alternate metal segments to form a continuous electrical path. Layers of a ferromagnetic material are formed normal to the metal segments to extend past at least two sides of each metal segment to increase the inductance of the inductor.
Abstract: The bow in a wafer that results from fabricating a large number of MEMS devices on the top surface of the passivation layer of the wafer so that a MEMS device is formed over each die region is reduced by forming a stress relief layer between the passivation layer and the MEMS devices.
Abstract: An electromechanical memory cell utilizes a cantilever and a laterally positioned electrode. The cantilever is spaced apart from the electrode by a distance that is greater than the elastic limit of the cantilever. The memory cell is programmed by applying voltages to the cantilever and the electrode which causes the cantilever to move into a region of plastic deformation without ever touching the electrode.
Type:
Grant
Filed:
September 5, 2006
Date of Patent:
April 20, 2010
Assignee:
National Semiconductor Corporation
Inventors:
Roozbeh Parsa, Trevor Niblock, Mark W. Poulter, Peter J. Hopper
Abstract: A micro-electromechanical system (MEMS) inductor is formed in a saucer shape that completely surrounds a magnetic core structure which is formed from a ferromagnetic material. In addition, an array of MEMS inductors can be formed by dividing up the saucer-shaped MEMS inductor into a number of electrically-isolated MEMS inductor wedges.
Type:
Grant
Filed:
June 19, 2007
Date of Patent:
March 16, 2010
Assignee:
National Semiconductor Corporation
Inventors:
Peter J. Hopper, Peter Johnson, Kyuwoon Hwang, Philipp Lindorfer
Abstract: The power consumed by a positron emission tomography (PET) imaging system is substantially reduced by utilizing an analog memory, such as a switch-capacitor analog memory, to sample and store analog values for a number of gamma ray signals so that only the stored analog values that represent pairs of gamma rays with coincident emission and vectors that are opposite to each other are digitized. In addition, the digitization is performed at a much slower clock frequency.
Abstract: A low thermal pathway is provided from the top surface of a silicon substrate to the bottom surface of the silicon substrate by first forming aluminum plugs in the bottom surface of the silicon substrate that contact the silicon substrate and extend up towards the top surface, and then heating the aluminum plugs to a temperature for a period of time sufficient to cause spikes to grow from the sides of the aluminum plugs.
Abstract: A method of forming an actuator and a relay using a micro-electromechanical (MEMS)-based process is disclosed. The method first forms the lower sections of a square copper coil, and then forms an actuation member that includes a core section and a horizontally adjacent floating cantilever section. The core section, which lies directly over the lower coil sections, is electrically isolated from the lower coil sections. The method next forms the side and upper sections of the coil, along with first and second electrodes that are separated by a switch gap. The first electrode lies directly over an end of the core section, while the second electrode lies directly over an end of the floating cantilever section.
Abstract: The state nodes in a sequential digital circuit are identified by identifying the minimal combinatorial feedback loops that are present in the digital circuit. Each minimal combinatorial feedback loop has at least one driver node, and one driver node from each minimal combinatorial feedback loop is assigned to be the state node for the loop.
Type:
Grant
Filed:
March 28, 2007
Date of Patent:
January 12, 2010
Assignee:
National Semiconductor Corporation
Inventors:
Tathagato Rai Dastidar, Amir Yashfe, Partha Ray
Abstract: A MOS transistor is formed with a dual-layer silicon oxynitride (SiON) etch stop film that protects the transistor from plasma induced damage (PID) and hot carrier degradation, thereby improving the reliability of the transistors. The first SiON layer is formed with SiH4 at a first flow rate, and the second SiON layer is formed with SiH4 at a second higher flow rate.
Type:
Grant
Filed:
December 10, 2007
Date of Patent:
January 12, 2010
Assignee:
National Semiconductor Corporation
Inventors:
Douglas Brisbin, Prasad Chaparala, Denis Finbarr O'Connell, Heather McCulloh, Sergei Drizlikh
Abstract: The loss of photogenerated electrons to surface electron-hole recombination sites is minimized by utilizing a first p-type surface region to form a depletion region that functions as a first barrier that repels photogenerated electrons from the surface recombination sites, and a second p-type surface region that provides a substantial change in the dopant concentration.
Type:
Grant
Filed:
June 28, 2006
Date of Patent:
January 5, 2010
Assignee:
National Semiconductor Corporation
Inventors:
Peter J. Hopper, Michael Mian, Robert Drury
Abstract: A CMOS based input buffer suitable for use with PECL or LVPECL voltage levels is described. The input buffer utilizes a differential voltage comparator that employs positive feedback to provide input hysteresis, symmetric headroom and increased noise immunity. In addition, the input buffer can utilize a reference voltage that is substantially constant over process, voltage, and temperature.