Accelerators, Inc.

Veeco/ai, Inc.

Roger B Gault

Larry L Keutzer

Larry F Templeton

A control system is disclosed for an ion implantation system of the type in which the wafers to be implanted are mounted around the periphery of a disk which rotates and also moves in a radial direction relative to an ion beam to expose successive sections of each wafer to the radiation. The control system senses beam current which passes through one or more apertures in the disk and is collected by a Faraday cup. This current is integrated to obtain a measure of charge which is compared with a calculated value based upon the desired ion dosage and other parameters. The resultant controls the number of incremental steps the rotating disk moves radially to expose the adjacent sections of each wafer. This process is continued usually with two or more traverses until the entire surface of each wafer has been implanted with the proper ion dosage.

Ion implantation control system

An Automatic End Station arrangement for use in conjunction with ion implantation apparatus to provide continuous implantation of semi-conductor wafers is disclosed. Wafers are indexed one by one out of a standard cartridge onto a conveyor track from which they are directed into the slot of a downwardly directed slotted passageway which has been defined between two appropriately sealed plate members. The wafer slides down the passageway until it is situated adjacent to a portion of the passageway in communication with an ion implantation apparatus. The wafer is stopped at that point and the passageway sealed above and below the wafer by inflating a pair of resilient tubes which extend through one of the plate members and across the opening of the passageway. An airtight chamber is thus formed from which the air may be evacuated for effective ion implantation. After the appropriate ion dosage has been directed into the wafer, the ion beam is stopped, the inflatable tubes collapsed and the wafer dropped out of the implantation chamber and indexed into another cartridge for transportation, storage or further processing. Intermediate stage evacuation chambers may be provided before and after the implantation chamber in order to prevent exposure of the implantation chamber to the atmosphere.

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Austin, TX, United States of America

Roger B Gault