Abstract: A compact high current broad beam ion implanter employs a high current density source, a bending magnet to steer the beam and straighten trajectories, and a multipole unit extending across the beam path to tailor a precise one-dimensional beam current distribution which yields a uniform implantation dose with a possibly non-uniform workpiece transport assembly. In one embodiment, the multipole unit is a separate magnet assembly positioned adjacent to a output face of the bending magnet, and includes one or more ranks of closely-spaced pole elements, controlled so the drive current or position of each pole element is varied to affect a narrow band of the beam passing over that element. In another embodiment, the bending magnet is an analyzing magnet which directs a desired species through a resolving slit, and a second magnet deflects the resultant beam while rendering it parallel and further correcting it along its width dimension.
Abstract: A high speed wafer processing apparatus employs two wafer transport robots to move wafers from two load locks past a processing station with gentle vacuum cycling and without pumpdown delays. Both robots alternately transport each wafer from the cassette at a single one of the load locks along a path from the cassette to a transfer position through the process station and back to the cassette, while pumpdown or venting of the other (second) load lock is carried out. They then transport the wafers from the second load lock through the process station. A wafer is "parked" at a transfer or orienting station, rather than handed over from robot to robot, so that the robots are not both tied up with a single wafer, and two or more wafers can move simultaneously along the path. Even for a fast ten second process time, work flow proceeds without interruption, periodic delay or dead time, and three to five minutes are available for venting, loading a new cassette and pumpdown.
Abstract: A compact high current broad beam ion implanter capable of serial processing employs a high current density source, an analyzing magnet to direct a desired species through a resolving slit, and a second magnet to deflect the resultant beam while rendering it parallel and uniform along its width dimension. Both magnets have relatively large pole gaps, wide input and output faces, and deflect through a small radius of curvature to produce a beam free of instabilities. Multipole elements incorporated within at least one magnet allow higher order aberrations to be selectively varied to locally adjust beam current density and achieve the high degree of uniformity along the beam width dimension.
Type:
Grant
Filed:
March 11, 1993
Date of Patent:
September 27, 1994
Assignee:
Diamond Semiconductor Group, Inc.
Inventors:
Nicholas R. White, Manny Sieradzki, Anthony Renau