Abstract: An apparatus for particle implantation is disclosed employing a plurality of particle generators to effectively process wafers of other target substrates carried on a rotating end station. The invention is particularly useful in SIMOX processes where implanted oxygen ions form a buried oxide layer in silicon wafers. In one embodiment, two or more stationary particle generators are disposed at different sectors of a circular track along which the wafers travel to expose the wafers in sequence as they pass. The ion sources can also be offset regularly from each other to increase the radial exposure area. In an other embodiment, the apparatus can further include at least one particle generator which scans the rotating end station in a radial direction as it rotates to insure that uniform ion doses are achieved.

Abstract: A process for computer-controlled cleaning of particulates from surfaces, in particular those of semiconductor wafers, which are in the volume of an ion-implantation chamber prior to the implantation of electrically active ions into the wafers. The process utilizes the wafer-holding disk, which carries the semiconductor wafers during implantation, to create a strong turbulence of gas within the end station volume of the ion implanter. This loosens particulates from interior surfaces of the end chamber. The airborne particulates are then evacuated from the chamber volume by a vacuum pump. A single sequence, consisting of air agitation followed by flushing and then filling, reduces the particulate count by an incremental amount; a series of such sequences results in the desired asymptotic reduction in particulate contamination.

Abstract: A Cryogenic Camera in which an aluminum refrigeration chamber filled with dry ice or liquid nitrogen makes contact with the back of a metallic filmholder upon closing the hinged back of the camera, to which the refrigeration chamber is bolted. The filmholder is positioned within the camera body so as to form a small volume in front of the film. This volume contains a silica gel dessicant packet that absorbs moisture in this volume, which is sealed upon closing the aforementioned hinged back. Thus frosting of the film and of the Plexiglas window that seals the camera aperture is prevented. The presence of this volume allows integration of an off-axis guide system within the camera, the guide system consisting of a flip-up mirror, rheostat controlled illuminated crosshairs, and a focussing eyepiece. The crosshairs illumination is provided by a red light emitting diode powered by two penlight cells contained within the volume.