David M Swenson

US Patent:

61371122, Oct 24, 2000

Filed:

Sep 10, 1998

Appl. No.:

9/150177

Inventors:

Edward K. McIntyre - Franklin MA
Kevin W. Wenzel - Belmont MA
David R. Swenson - Georgetown MA
Ernst F. Scherer - Hamilton MA
William F. Divergilio - Beverly MA
Kourosh Saadatmand - Merrimac MA

Assignee:

Eaton Corporation - Cleveland OH

International Classification:

H01J 37244

US Classification:

25049221

Abstract:

An ion implanter including a time of flight energy measurement apparatus for measuring and controlling the energy of an ion beam includes an ion source for generating the ion beam, an ion acceleration assembly for accelerating the beam resulting in the beam comprising a series of ion pulses having a predetermined frequency and beam forming and directing structure for directing the ion beam at workpieces supported in an implantation chamber of the implanter. The time of flight energy measurement apparatus includes spaced apart first and second sensors, timing circuitry and conversion circuitry. The time of flight energy measurement apparatus measures an average kinetic energy of an ion included in a selected ion pulse of the ion beam. The first sensor and a second sensor are disposed adjacent the ion beam and spaced a predetermined distance apart, the second sensor being downstream of the first sensor. The first sensor generates a signal when an ion pulse of the ion beam passes the first sensor and the second sensor generates a signal when an ion pulse of the ion beam passes the second sensor.