Axcelis Technologies, Inc.

Hans J Rutishauser

Jun Lu

Paul A Loomis

Yongzhang Huang

Michiro Sugitani

Edward K McIntyre

Donald N Polner

Hiroshi Sogabe

Xiangyang Wu

Gerald L Dionne

Donald E DeLuca

Toru Murakami

The present invention concerns a method of tuning a plurality of electrostatic quadrupoles used for focusing an ion beam implanter. The steps of the method include: classifying the plurality of electrostatic quadrupoles into one of a predetermined number of groups, and for each of the predetermined number of groups, tuning the quadrupoles in the group by iteratively substituting values for a voltage ton be applied to each of the quadrupoles in the group using a multi-variable heuristic algorithm and concurrently measuring final beam current measured downstream of the ion accelerator to determine a set of applied voltage values that maximize the final beam current among those applied voltage values tested and utilizing the set of applied voltage values to tune the quadrupoles in the group. If the resulting ion beam is suitable, utilizing the determined applied voltages to tune the quadrupoles. If the resulting ion beam is not suitable, changing the predetermined number of groups and repeating the steps of the method.

Method of tuning electrostatic quadrupole electrodes of an ion beam implanter

A variable aperture assembly (,) is provided for controlling the amount of ion beam current passing therethrough in an ion implantation system (,). The aperture assembly (,) comprises an aperture (,) defined by opposing first and second aperture plates (,A,,B) through which an ion beam passes; control arms (,A,,B) connected, respectively, to the first and second aperture plates (,A,,B); and an aperture drive mechanism (,) for simultaneously imparting movement to the control arms in opposite directions, to adjust a gap (,) between the aperture plates (,A,,B) to thereby control the amount of current passing through the aperture (,). Each of the opposite directions in which the control arms move is generally perpendicular to an axis along which the ion beam passes. A control system (,) is also provided for automatically adjusting the aperture gap (,) based on inputs representing actual ion beam current passing through the implanter, desired ion beam current, and aperture position. The control system (,) includes control logic (,) for receiving the inputs and outputting control signals (,) to the aperture drive mechanism to adjust the aperture gap.

Continuously variable aperture for high-energy ion implanter

A system and method are provided for operating a variable aperture (,) for adjusting the amount of ion beam current passing therethrough in an ion implantation system (,). The system and method comprise means or steps for (i) measuring ion beam current at an implanter location using a current detector (,); (ii) comparing the measured ion beam current with a desired ion beam current; (iii) outputting a control signal (,) based on the comparison of the measured ion beam current with the desired ion beam current; and (iv) adjusting a gap (,), through which through ion beam passes and which is defined by opposing first and second aperture plates (,A,,B), in response to the control signal to control the amount of ion beam current passing therethrough. The current detector (,) provides ion beam current feedback, and a position sensor (,) may be utilized to provide aperture plate (,A,,B) position feedback. The system and method provide a quick, direct, and precise mechanism for effecting significant changes in ion beam current without requiring re-tuning of the source. The gap (,) of the aperture (,) is adjustable in increments of about 5 microns (&mgr;m).

Method and system for operating a variable aperture in an ion implanter

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Lexington, MA, United States of America

Hans J Rutishauser