Applied Materials, Inc.

Nicholas J Bright

Bernard F Harrison

Derek Aitken

Frederick G Plumb

Christopher P Wright

Hiroyuki Ito

David Richard Burgin

Craig J Lowrie

Michael T Wauk

Timothy G Morgan

Bernard Woods

Jose-Antonio Marin

An ion implantation system is modified to allow variation in the size of the aperture of the mass resolving system, thereby allowing more ions of one mass or ion of more than one mass, such as isotopes, to pass through said opening. Including all isotopes of the desired dopant ions to be collected increases beam current, and consequently the throughput of the implantation process, reduces contamination, and improves the dosage control.

Improved ion implantation using a variable mass resolving system

Method and apparatus for the control of the rate of emission of electrons added to an ion implantation beam to neutralize charging effects on semiconductor wafers being processed. A net charging current, or equivalent voltage, is sensed continuously, but is sampled only when a selected wafer, or multiple selected wafers, are positioned to receive the entire cross section of the ion beam. The sampled charging current is used to control the addition of charge-neutralizing electrons to the ion beam, thereby eliminating problems that ensue from the use of an averaged charging current that is sensed without regard to the relative beam position or the number of wafers being processed.

Method and apparatus for controlling the rate of emission of electrons

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

Growing community of inventors

Cowfold, United Kingdom

Nicholas J Bright