Abstract: A method of manufacturing a unipolar component of vertical type in a substrate of a first conductivity type, including the steps of: forming trenches in a silicon layer of the first conductivity type; coating the lateral walls of the trenches with a silicon oxide layer; filling the trenches with polysilicon of the second conductivity type; and annealing to adjust the doping level of the polysilicon, the excess dopants being absorbed by the silicon oxide layer.

Abstract: A method for manufacturing a vertical power component on a substrate formed of a lightly-doped silicon wafer, including the steps of boring on the lower surface side of the substrate a succession of holes perpendicular to this surface; diffusing a dopant from the holes, of a second conductivity type opposite to that of the substrate; and boring similar holes on the upper surface side of the substrate to define an isolating wall and diffuse from these holes a dopant of the second conductivity type with a high doping level, the holes corresponding to the isolating wall being sufficiently close for the diffused areas to join laterally and vertically.

Abstract: A valve includes a valve housing having a fluid conduit communicating between an inlet port and an outlet port, a valve closure member that is movable between a closed position and an open position, and a radiation-absorbing coating on at least a part of the fluid conduit. The radiation-absorbing coating may be disposed on inside surfaces of mounting flanges of the valve. The coating may be black chrome or a black anodized surface, for example.

Abstract: A method for manufacturing a semiconductor device having improved adhesion at an interface between layers of dielectric material, comprising the steps of forming a first layer of dielectric material on at least one part of a structure defined in a semiconductor substrate and forming a second dielectric material layer superimposed on the least one part of the first layer. The method further includes the step of forming, in the part where the first and second layers are superimposed, an intermediate adhesion layer comprising a ternary compound of silicon, oxygen and carbon. The formation of the adhesion layer takes place at low temperature and in an atmosphere kept essentially free of oxidative substances different from those serving to provide the silicon and the carbon to the layer. Preferably the layer is formed by the plasma enhanced chemical vapour deposition technique.

Abstract: A tip seal for use in a scroll-type vacuum pump includes a seal element and an energizer element affixed to the seal element. The scroll-type vacuum pump includes first and second scroll blades that are nested together to define one or more interblade pockets, and an eccentric drive that produces orbiting movement of the first scroll blade relative to the second scroll blade. At least one of the first and second scroll blades has a seal groove along an edge thereof. The tip seal is positioned in the seal groove between the first and second scroll blades. The energizer element is formed of a resilient material having multiple compressible voids, so that the energizer element having compressible voids is more compressible than the resilient material alone, when confined by the seal groove. In one embodiment, the energizer element is a foam such as a low porosity urethane foam. In another embodiment, the energizer element is an elastomer material having a predetermined pattern of voids.

Abstract: The invention concerns a vacuum pumping device comprising: a vacuum pump (100) having a casing (101), provided with a suction port (119) and an exhaust port (120), in which there is defined a first portion (102), housing the gas pumping stages formed by rotor disks (113, 114) secured to a pump rotatable shaft (123), and stator rings (115, 116) secured to the vacuum pump casing and cooperating with said rotor disks (113, 114); and a second portion (103) housing the electric motor (121) of the vacuum pump and at least one bearing (122) for supporting the shaft (123); an electronic control unit (1) comprising a housing (2) defining an inner space (17) containing the electronic components of an electronic circuit feeding the electric motor (121), and wherein at least the second portion (103) of the pump casing (101) is located within the inner space (17) containing the electronic components.

Abstract: Vacuum pumping apparatus includes a non-scroll type auxiliary pump and a scroll pump disposed in a single housing. The auxiliary pump and the scroll pump are connected in series and are driven by a common motor. Typically, the auxiliary pump has a relatively high pumping speed and the scroll pump has a relatively high compression ratio. The auxiliary pump may be a regenerative blower, a roots-type blower or a screw-type blower. When a co-rotating scroll pump is utilized, a regenerative blower may be formed at or near the outer periphery of a disk on which the non-orbiting scroll blade is mounted. In another configuration, first and second scroll pumps are disposed within a housing. The scroll blade sets of the first and second scroll pumps have different orbiting radii. Scroll pump leakage may be reduced by forming a closed-loop seal around the inlet region of the scroll pump and connecting the inlet region to an intermediate pressure.

Abstract: A magnetron sputtering source for forming a sputtered film on a substrate in a magnetron sputtering apparatus includes a target having a surface from which material is sputtered and a magnet assembly that is rotatable about an axis of rotation with respect to the target. The magnet assembly produces on the target an erosion profile that is calculated to yield a desired depositional thickness distribution and inventory. A method for configuring the rotatable magnet assembly includes the steps of determining an optimal erosion profile that yields the desired depositional thickness distribution and inventory, determining a plasma track on the surface of the target that produces an acceptable approximation to the optimal erosion profile, and determining a magnet structure that produces the plasma track.

Abstract: A flat workpiece is placed in contact with a flat platen in a vacuum chamber, and is held by a uniformly-distributed force while a small mass flow of gas is introduced along a contour to form a uniform pressure region between the flat workpiece and the platen. Separation of the two surfaces due to aplanarity or surface roughness is less than the gas mean free path, and high rates of heat transfer are obtained uniformly over the area of the workpiece. A scavenging port, located outwardly of the gas introduction contour is differentially pumped to reduce the rate of gas leakage into the chamber. Preferably, pressure is provided by an electrostatic clamp (for non-insulating substrates) or other clamping arrangement which does not occlude the front surface of the workpiece. In the electrostatic clamp, the voltage activation sequence prevents workpiece vibration, while a clamping current sensor immediately detects degree of contact, e.g., due to debris on the platen, and initiates a suitable warning or control.

Abstract: A molecular drag compressor includes a rotor disk and a stator that defines a tangential flow channel having an inlet and an outlet. A stationary baffle is disposed in the tangential flow channel adjacent to the outlet. The baffle is spaced from the rotor disk by a gap. A surface of the baffle facing the rotor disk has surface irregularities including peaks for defining the gap and valleys between the peaks for accumulation of particles. The surface irregularities may form a series of grooves. The molecular drag compressor is preferably utilized in a high vacuum pump which includes an axial turbomolecular compressor and a molecular drag compressor. Additional features which limit the effect of particulate accumulation in molecular drag compressors are disclosed.

Abstract: An electron source includes a negative electron affinity photocathode on a light-transmissive substrate and a light beam generator for directing a light beam through the substrate at the photocathode for exciting electrons into the conduction band. The photocathode has at least one active area for emission of electrons with dimensions of less than about two micrometers. The electron source further includes electron optics for forming the electrons into an electron beam and a vacuum enclosure for maintaining the photocathode at high vacuum. In one embodiment, the active emission area of the photocathode is defined by the light beam that is incident on the photocathode. In another embodiment, the active emission area of the photocathode is predefined by surface modification of the photocathode. The source provides very high brightness from an ultra-small active emission area of the photocathode.

Abstract: A vacuum gate valve includes a valve body having an opening therethrough and a valve seat surrounding the opening, and a swing gate assembly rotatable about a pivot axis between an open position and a closed position. The swing gate assembly includes a swing gate body, a resilient seal gasket mounted to the swing gate body so as to sealingly engage the valve seat in the closed position, and a spreader for flattening the resilient seal gasket in a region that engages the valve seat. The gate valve further includes an actuator for rotating the swing gate assembly between the open position and the closed position. In a preferred embodiment, the seal gasket is a resilient tube, and the spreader is located within the tube. The swing gate assembly may include a mechanism for adjusting the spreader to thereby adjust the tension applied to the seal gasket.

Abstract: Turbomolecular vacuum pumps having structures which provide increased pumping speed, increased discharge pressure and decreased operating power in comparison with prior art turbomolecular vacuum pumps. In a first embodiment, the stators of one or more axial flow vacuum pumping stages in proximity to the exhaust port of the vacuum pump have progressively lower conductance so that the bulk velocity of the gas being pumped is increased. In a second embodiment, one or more stages near the inlet port of the vacuum pump are provided with a peripheral channel to utilize the centrifugal component of the gas being pumped. In a third embodiment, one or more stages in the vacuum pump are molecular drag stages, each including a disk rotor. One or more pumping channels in the stator adjacent to the upper surface of the disk are connected in series with one or more pumping channels adjacent to the lower surface of the disk.

Abstract: A counterflow helium mass spectrometer leak detector in which a helium sample passes in a reverse direction through a diffusion pump to a mass spectrometer for measurement. The diffusion pump includes a conventional foreline and a second foreline provided with an ejector stage. A test sample is coupled from a test port through a bypass valve to the conventional foreline in a high sensitivity mode and is coupled to the second foreline in a low sensitivity mode. In the low sensitivity mode, the bypass valve is closed. An apertured control plate in the diffusion pump controls the relative reverse rates of duffusion from each foreline to the diffusion pump inlet by controlling the rates of vapor flow an annular pumping stages and to the ejector stage. The ejector stage includes a nozzle for directing a stream of vapor into the second foreline so as to inhibit flow of helium into the diffusion pump and establish a lower reverse diffusion rate at the second foreline.

Abstract: A thin film electroluminescent display device energized with a rapid burst of pulses during a time less than the decay time of the phosphor yields substantially increased light output. Preferably, a burst of between two and forty pulses having a duration in the range between 5 and 20 microseconds and having alternating polarities is applied to the device. The pulse burst technique is advantageously applied to a dot matrix type EL display panel operating at a 60 Hz refresh rate. For a 512.times.256 element display panel, each row is addressed for approximately 65 microseconds, and four pulses of about 12-15 microseconds each are applied to the EL pixels during each row address time. The pulse burst technique provides increased brightness while minimizing the retained image problem.

Abstract: A helium mass spectrometer leak detector includes a spectrometer tube connected to the inlet of a high vacuum pump. Helium tracer gas passes in reverse direction through the high vacuum pump from the foreline to the spectrometer tube. Relatively high pressure gross leak tests are performed, while maintaining the foreline of the high vacuum pump at the required operating pressure of about 100 millitorr, by passing the tracer gas in reverse direction through one or two stages of a mechanical vacuum pump. Test port pressures up to about atmosphere can be accommodated, with only a single mechanical vacuum pump required. According to another feature, high test port pressures are accommodated using a variable flow restrictor and reverse-connected mechanical vacuum pump in combination.

Abstract: A pattern generator for supplying beam deflection and blanking signals in an electron beam lithography system which writes polygon pattern features by sweeping a beam of rectangular cross-section over each polygon and simultaneously varying the length of the rectangular cross-section. The pattern generator converts polygon size and shape data to an upper shape signal and a lower shape signal. The shaping signals are subtracted to provide a beam length signal. The lower shape signal controls the beam position during writing of the polygon. The pattern generator further includes a ramp generator for sweeping the beam over the polygon. The ramp signal and shaping signals are synchronized by detecting the points in the sweep at which polygon turn points occur. The shape signal generators utilize interleaved operation for high speed. A blanking circuit provides uniform exposure of pattern features by controlling the width of the rectangular beam.

Abstract: The implant chamber pressure during ion implantation is controlled within a specified intermediate pressure range higher than the baseline pressure. Implanted dose errors resulting from neutralizing collisions of the beam with residual gas molecules are held constant and can be compensated. The pressure is maintained within the specified intermediate pressure range by a control system including a controllable vacuum valve associated with a vacuum pump, a chamber pressure sensor and a valve controller responsive to the pressure sensor. The valve controller opens and closes the valve to maintain the chamber pressure within the specified range after introduction of a wafer.

Abstract: Normal or constant angle scanning of a target with high current ion beam is provided by positioning a space charge lens between a beam deflection system and the target. The space charge lens is positioned such that its focal point coincides with the virtual center of deflection. The space charge lens steers the scanned beam into parallel paths so as to maintain a constant angle of incidence upon the workpiece. In an electrostatic deflection system, two sets of y-axis deflection plates can be axially positioned on opposite sides of the x-axis deflection plates to provide a single virtual center of deflection. The apparatus is useful for performing ion implantation with higly uniform dose distribution.

Abstract: A first target for a magnetron sputter device has a planar annular emitting surface bounded by an inner radius R1 and an outer radius R2. A second target has a sloped emitting surface defined by a side wall of a frustum of a cone. The second target is limited by an inner radius R3 and outer radius R4. R3 is greater than R2. Each target element has pins in diametrically opposite holes to assist in holding the target elements in situ in bayonet slots in the sputter device. The targets are fit closely in cooling rings so that as the targets heat during operation, thermal expansion of the targets assists thermal conduction into the cooling rings. A coil is formed behind the workpiece to act as a mirror to the plasma. The field of the coil moves the plasma away from the workpiece which permits putting high power R.F. bias on the workpiece. The R.F. bias in combination with gas heating the wafer from behind aids in sputtering a coating of superior conformality.