Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Fast parallel algorithms for short-range molecular dynamics

An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Semiconductor device, and manufacturing method thereof

An electro-mechanical surgical device, system and/or method may include a housing, at least two opposing jaw, and at least one electrical contact associated with at least one of the jaws. The electrical contact may include at least one of a bipolar electrical contact and an ultrasonic electrical contact. The electrical contact may be a row of electrodes located on one or all of the jaws. A sensor may also be associated with any tissue located between the jaws to sense and report the temperature of that tissue. A piercable ampulla containing fluid may also be placed on at least one of the jaws so that the fluid is releasable when the jaws are in closed position and the electrode(s) pass through the tissue into the piercable ampulla.

Bipolar or ultrasonic surgical device

Process gas discharged from a bypass pipe to a gas exhaust system can be prevented from diffusing back to the inside of a process chamber without having to install a dedicated vacuum pump at the downstream side of the bypass pipe. The substrate processing apparatus includes a process chamber accommodating a substrate, a gas supply system supplying process gas from a process gas source to the process chamber for processing the substrate, a gas exhaust system configured to exhaust the process chamber, two or more vacuum pumps installed in series at the gas exhaust system, and a bypass pipe connected between the gas supply system and the gas exhaust system. The most upstream one of the vacuum pumps is a mechanical booster pump, and the bypass pipe is connected between the mechanical booster pump and the rest vacuum pumps located at a downstream side of the mechanical booster pump.

Substrate Processing Apparatus

A lithographic apparatus configured to project a patterned beam of radiation onto a target portion of a substrate is disclosed. The apparatus includes a first radiation dose detector and a second radiation dose detector, each detector comprising a secondary electron emission surface configured to receive a radiation flux and to emit secondary electrons due to the receipt of the radiation flux, the first radiation dose detector located upstream with respect to the second radiation dose detector viewed with respect to a direction of radiation transmission, and a meter, connected to each detector, to detect a current or voltage resulting from the secondary electron emission from the respective electron emission surface.

Lithographic apparatus, and device manufacturing method

A gas distribution system for uniformly or non-uniformly distributing gas across the surface of a semiconductor substrate. The gas distribution system includes a support plate and a showerhead which are secured together to define a gas distribution chamber therebetween. A baffle assembly including one or more baffle plates is located within the gas distribution chamber. The baffle arrangement includes a first gas supply supplying process gas to a central portion of the baffle chamber and a second gas supply supplying a second process gas to a peripheral region of the baffle chamber. Because the pressure of the gas is greater at locations closer to the outlets of the first and second gas supplies, the gas pressure at the backside of the showerhead can be made more uniform than in the case with a single gas supply. In one arrangement, the first and second gas supplies open into a plenum between a top baffle plate and a temperature controlled support member wherein the plenum is divided into the central and peripheral regions by an O-ring. In a second arrangement, the first gas supply opens into the central region above an upper baffle plate and the second gas supply opens into the periphery of a plenum between the upper baffle plate and a lower baffle plate.

Gas distribution apparatus for semiconductor processing

A gas distribution system for supplying different gas compositions to a chamber, such as a plasma processing chamber of a plasma processing apparatus is provided. The gas distribution system can include a gas supply section, a flow control section and a switching section. The gas supply section provides first and second gases, typically gas mixtures, to the flow control section, which controls the flows of the first and second gases to the chamber. The chamber can include multiple zones, and the flow control section can supply the first and second gases to the multiple zones at desired flow ratios of the gases. The gas distribution system can continuously supply the first and second gases to the switching section and the switching section is operable to switch the flows of the first and second gases, such that one of the first and second process gases is supplied to the chamber while the other of the first and second gases is supplied to a by-pass line, and then to switch the gas flows. The switching section preferably includes fast switching valves operable to quickly open and close to allow fast switching of the first and second gases, preferably without the occurrence of undesirable pressure surges or flow instabilities in the flow of either gas.

Gas distribution system having fast gas switching capabilities

An electrode assembly for a plasma reactor, such as a plasma etch or plasma-enhanced chemical vapor deposition reactor, comprises an electrode plate having a support frame attached to one surface thereof. The electrode plate is composed of a substantially pure material which is compatible with a particular reaction being performed in the reactor, while the support frame is composed of a material having desirable thermal, electrical, and structural characteristics. The support frame is bonded to the electrode plate using a bonding layer, usually a ductile metallic bonding layer, which provides effective thermal and electrical coupling while permitting a degree of thermal expansion mismatch between the support frame and the electrode plate.

Composite electrode for plasma processes

A vacuum plasma chamber for processing a workpiece includes first and second electrodes for electrical coupling with gas in the chamber and respectively connected to first and second relatively high and low frequency RF sources. The chamber includes a wall at a reference potential and a plasma confinement region spaced from the wall. A filter arrangement connected to the sources and the electrodes enables current from the first source to flow to the first electrode, prevents the substantial flow of current from the first source to the second electrode and the second source, and enables current from the second source to flow to the first and second electrodes and prevents the substantial flow of current from the second source to the first source.

Dual frequency plasma processor

An adjustable RF coupling ring is capable of reducing a vertical gap between a substrate and a hot edge ring in a vacuum processing chamber. The reduction of the gap reduces polymer deposits on the substrate and electrostatic chuck and improves wafer processing.

Eric Lenz

Papers

Gas distribution apparatus for semiconductor processing

Gas distribution system having fast gas switching capabilities

Composite electrode for plasma processes

Dual frequency plasma processor

Apparatus for reducing polymer deposition on a substrate and substrate support