摘要:
An implanter provides two-dimensional scanning of a substrate relative to an implant beam so that the beam draws a raster of scan lines on the substrate. The beam current is measured at turnaround points off the substrate and the current value is used to control the subsequent fast scan speed so as to compensate for the effect of any variation in beam current on dose uniformity in the slow scan direction. The scanning may produce a raster of non-intersecting uniformly spaced parallel scan lines and the spacing between the lines is selected to ensure appropriate dose uniformity.
摘要:
An implanter provides two-dimensional scanning of a substrate relative to an implant beam so that the beam draws a raster of scan lines on the substrate. The beam current is measured at turnaround points off the substrate and the current value is used to control the subsequent fast scan speed so as to compensate for the effect of any variation in beam current on dose uniformity in the slow scan direction. The scanning may produce a raster of non-intersecting uniformly spaced parallel scan lines and the spacing between the lines is selected to ensure appropriate dose uniformity.
摘要:
This invention relates to a method of implanting ions in a substrate using an ion beam where instabilities in the ion beam may be present and to an ion implanter for use with such a method. This invention also relates to an ion source for generating an ion beam that can be switched off rapidly. In essence, the invention provides a method of implanting ions comprising switching off the ion beam when an instability has been detected whilst continuing motion of the substrate relative to the ion beam to leave an unimplanted portion of a scan line across the substrate, establishing a stable ion beam once more and finishing the scan line by implanting the unimplanted portion of the path.
摘要:
A beam stop (23) has a charge collecting member (40) which extends in the direction of scanning of a scanned beam by less than the total distance scanned, so that variation in the charge signal derived from the collecting member can provide a timing signal for use in monitoring alignment of the scanned beam. In a preferred embodiment, the beam stop plate (42) has slits (65-69) leading to apertures (60-64) containing charge collecting rods (73-75) located within the thickness of the beam stop plate (42).
摘要:
A rotary valve actuator that effects rotary movement of a rotary valve includes a heavy plate member coupled with a linear motive source, which reciprocates the plate member between a first position and a second position. A first pair of flexible pull connectors, such as lengths of roller chain, are attached to the end of the plate member, and wrap around a wheel. At least one second flexible pull connector is disposed between said first flexible pull connectors and is attached to the other end of the plate member, and wraps around the wheel in the opposite direction of winding as for the first flexible connector.
摘要:
A throttling element, and throttling device utilizing the throttle element, provide absolute minimum possible resistance when in the fully opened position yet easily and effectively throttles the flow, so as to introduce a variable pressure drop, upon rotation utilizing conventional actuators. The device cannot be closed off completely, and it is possible to produce it in the same cost range as for butterfly valves yet having significant advantages thereover. The throttling element includes an annular metal substantially spherical segment having an exterior arcuate extent of about 80.degree. or less (e.g. about 60-70.degree.) with first and second elongated metal shaft stubs extending radially outwardly from the exterior of the annular substantially spherical segment, on opposite of the segment the dimension of elongation of the shaft stubs. The element may be mounted in a housing having an interior bore with a first diameter, the throttling element itself having an interior bore with a second diameter substantially the same as the first diameter so that minimum resistance to flow is provided in a fully open position. The width of the exterior extension of the throttling element is between about 50%-70% of the first diameter with the first width and second diameter mentioned so that the throttling element cannot preclude or substantially preclude fluid flow through the housing interior bore regardless of what position the throttling element is rotated to. The housing may be two piece only slightly wider than the throttling element.
摘要:
In a coke drum an outlet arrangement is provided which allows removal of the coke from the drum without endangering the health or safety of workers heading or unheading the coke drum. Instead of using a manually removable bottom flange for the drum, a semiautomatic bottom flange removal system is provided. A spool is attached to the conventional, pre-existing, about 6 feet in diameter drum stationary bottom flange. The spool includes a tapered clamping surface. A new style removable bottom flange also includes a tapered clamping surface. The tapered clamping surfaces cooperate with clamp ring sectors movable by externally mounted hydraulic cylinders into contact with the spool and the flange, and other hydraulic cylinders mounted directly on the ring sectors move male locking surfaces into locking engagement with cooperating female locking surfaces formed on adjacent clamp ring sectors.
摘要:
A rotary valve actuator that effects rotary movement of a rotary valve from 0 to 90°, or to 120°, or to 180°, or even more. The actuator includes a heavy plate member coupled with a linear motive source, which reciprocates the plate member between a first position and a second position. First and second coaxial wheels are fastened together on a single shaft and are rotatably supported tangent to one side of the plate member. A first flexible pull connector, such as a length of roller chain, is attached to the end of the plate member farthest from the linear motive source, and wraps around the first wheel. A second flexible pull connector is attached to the end of the plate member closest to the linear motive source, and wraps around the second wheel, in the opposite direction of winding as for the first flexible connector. When the linear motive source drives the plate member toward a second position, the first flexible pull connector unwraps from around the first wheel, driving the wheel in a first angular direction. When the linear motive force drives the plate member back towards the first position, the second flexible member unwraps from around the second wheel, driving the second wheel in an angular direction, opposite from the first direction. The shaft is rotated when the wheels rotate, and it may be connected to a rotary valve shaft. The actuator may be provided with a tensioning assembly secured to the plate member and cooperating with one of the pull connectors, thereby maintaining a tension force in all the pull connectors.
摘要:
In a coke drum an outlet arrangement is provided which allows removal of the coke from the drum without endangering the health or safety of workers heading or unheading the coke drum. Instead of using a manually removable bottom flange for the drum, a semiautomatic bottom flange removal system is provided. A spool is attached to the conventional, pre-existing, about 6 feet in diameter drum stationary bottom flange. The spool includes a tapered clamping surface. A new style removable bottom flange also includes a tapered clamping surface. The tapered clamping surfaces cooperate with clamp ring sectors movable by externally mounted hydraulic cylinders into contact with the spool and the flange, and other hydraulic cylinders mounted directly on the ring sectors move male locking surfaces into locking engagement with cooperating female locking surfaces formed on adjacent clamp ring sectors.