Applied Materials, Inc.

Frederick G Plumb

Bernard F Harrison

Derek Aitken

Nicholas J Bright

Christopher P Wright

Hiroyuki Ito

Jonathan Gerald England

Stephen Moffatt

Ian Fotheringham

Anthony Renau

A controlled deceleration potential is provided in an ion implanter between the target and the flight tube through the mass selector, by means of a variable resistance comprising a series of HEXFETs. The series of HEXFETs conduct current absorbed by the substrate back to the flight tube so that a desired decelertion potential can be formed.

Ion implantation apparatus with improved post mass selection deceleration

A plasma flood system for use in the implantation of ions in a semiconductor substrate comprising a plasma and low energy electron source for developing a plasma containing low energy electrons for magnetic field enhanced transmission to a negatively biased, magnetic field assisted electron confinement tube and into an ion beam flowing axially through the tube to the semiconductor substrate for self regulating and neutralizing positive charges on the surface of the substrate without causing significant negative charging of the substrate.

Plasma flood system for the reduction of charging of wafers during ion

A diode flood gun for introducing an amplified current of low energy electrons into an ion beam for neutralizing charge build up on a target such as a semiconductor wafer during irradiation by the beam. The low energy, amplified current is effected by introducing an inert gas into the flood gun.

System and methods for wafer charge reduction for ion implantation

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.

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Horsham, United Kingdom

Frederick G Plumb