Applied Materials, Inc.

Christopher P Wright

Bernard F Harrison

Derek Aitken

Frederick G Plumb

Nicholas J Bright

Peter T Kindersley

Richard H Cooke

Peter I Edwards

Stephen S Chamberlain

An ion implanter for implanting ions into a substrate comprises an ion beam generator for generating a beam of ions, support means for carrying a substrate to be implanted with beam ions, scanning means for scanning at least one of the substrate and the ion beam relative to the other so that the beam traverses the substrate along a predetermined path. Monitoring means are arranged to monitor changes in the proportion of the ion beam cross-sectional area incident on the substrate as the ion beam traverses the edge of the substrate from a position in the scan at which the proportion is finite to a position at which the proportion is zero. The implanter further comprises detection means responsive to the monitoring means for detecting the moment when the proportion reaches zero from a finite value as the ion beam and/or substrate moves along the predetermined path, and operative means responsive to the detection means detecting the moment when the proportion of the beam cross-sectional area incident on the substrate reaches zero, for performing a subsequent operation in the ion implanter.

Apparatus and method for improved scanning efficiency in an ion implanter

A method for operating an ion source having a filament-cathode and an anode. The method includes supplying direct current electrical power between the anode and the filament-cathode characterized by substantially constant arc current there between and varying arc voltage on the filament-cathode. Direct current electrical power is also supplied across the filament-cathode. The value of the arc voltage is monitored and the magnitude of electrical power supplied to the filament-cathode is altered in response to detected changes in the arc voltage to return the arc voltage to substantially a preset reference value. The monitoring step and the altering step are carried out at regular preset intervals. The altering step includes deriving an filament power error signal as a prearranged function which includes the difference in values between the monitored arc voltage and the preset reference value multiplied by a predefined integral gain value. The altering step also includes altering the magnitude of electrical power supplied to the filament-cathode by the value of the filament power error signal.

Systems and methods for ion source control in ion implanters

An ion implantation system includes a beam generating arrangement for generating an ion beam characterized by good beam stability and for directing the ion beam along a prearranged path. A beam stopping arrangement is disposed in the path of the beam for stopping and collecting the ions in the beam. A workpiece scanning arrangement is positioned upstream of the beam stopping arrangement for scanning a workpiece through the beam in a prearranged combined fast scan directional motion and a slow scan directional motion with the slow scan directional motion being characterized by an end of scan position in which the ion beam falls completely on the beam stopping arrangement. A dose measuring arrangement is coupled to the beam stopping arrangement and includes arrangements for measuring the ion beam current on the beam stop at the end of scan position of the workpiece scanning arrangement, for calculating the average ion beam current striking the workpiece during each slow scan directional motion as the average of two successive ion beam current measurements before and after the motion, and for calculating the ion dose delivered to the workpiece based on the calculated average ion beam current and know geometrical factors associated with the fast and slow scan motions.

Systems and methods for ion implantation

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West Sussex, United Kingdom

Christopher P Wright