Patent ID: 6911660
Filing Date: 2005-06-28
Classification: H01J

Abstract:
1. A method of determining beam twist and/or calibrating tilt angles of an ion beam of an ion beam implanter, relative to a first channel of a crystalline target to calibrate an incident angle of the ion beam to the crystalline target, the method comprising: a) providing reference data defining a known relationship between said beam tilt and twist angles and beam channeling in at least one preselected second channel of said crystalline target, at least some of said data providing first and second reference tilt angles at which channeling occurs for a given twist angle, the first and second tilt angles being different, b) without varying the twist angle, measuring channeling severity around a range of estimated tilt angles surrounding each of said first and second reference tilt angles and determining from said measurements a point of maximum channeling severity within each said range; and c) comparing the determined points to the reference data to determine said twist angle and/or calibrate said tilt angle for achieving a desired angular relationship between the incident angle of the ion beam and the crystalline target.