Structure for alignment of an ion source aperture with a predetermined ion beam path

A method for positioning an ion source assembly extraction member within an interior region of an ion beam source assembly housing having at least one access opening in a side wall and an ion source assembly support tube extending into the source assembly housing interior region so that an aperture of the extraction member is axially aligned with a predetermined ion beam path, the method comprising the steps of:

• a) affixing the extraction member to a support ring of a self-centering clamping assembly having a circumferentially adjustable split ring for engaging the support tube;
• b) mounting the extraction member, with the clamping assembly affixed thereto, to a mounting surface of an alignment fixture;
• c) inserting a portion of the alignment fixture, including the mounting surface, through the side wall access opening of the ion beam source assembly housing so that the split ring is adjacent an end of the support tube;
• d) mounting the alignment fixture to the ion beam source assembly housing, the alignment fixture being dimensioned so that the extraction member is axially aligned with the predetermined beam line;
• e) adjusting the split ring to secure the clamping assembly to the support tube;
• f) separating the alignment fixture from the extraction member;
• and
• g) removing the alignment fixture from the source housing.

A method for assembling an extraction electrode assembly including two spaced apart disk half assemblies, two support plates, two support legs and an ion source assembly mounting plate so that a gap defined by the disk half assemblies is axially aligned with a predetermined ion beam path when the mounting plate is secured to an ion beam source assembly housing, the disk half assemblies being secured to respective support plates, the support plates being secured to respective support legs and the support legs extending through slots in and supported by the mounting plate, the steps of the method comprising:

• a) assembling the mounting plate, support legs and the support plates forming a partially assembled extraction electrode assembly;
• b) supporting the partially assembled extraction electrode assembly in a machining fixture;
• c) adding weights to the support legs to simulate the deflection of the legs of a fully assembled extraction electrode assembly mounted to the ion beam source assembly housing;
• d) precision machining a disk half assembly mounting surface of each support plate such that the disk half assembly gap is axially aligned with the predetermined beam path when the fully assembled extraction electrode assembly is mounted to the ion beam source assembly housing;
• e) removing the weights from the support legs;
• f) mounting the disk half assemblies to the disk half assembly mounting surfaces of their respective support plates;
• and
• g) securing the ion source assembly housing mounting plate to the source assembly housing.

An ion source assembly for an ion implantation system, the source assembly comprising:

• a) an ion beam source housing defining an interior region and an access opening;
• b) a support tube supported by the source housing and extending into the interior region;
• c) an ion arc chamber having an open side and defining a cavity into which ionizable source materials are routed, the arc chamber at least partially surrounded by and supported within the support tube;
• and
• d) an extraction member sealingly engaging the arc chamber's open side, the extraction member including an arc slit through which ions generated in the arc chamber cavity exit the arc chamber;
• and
• e) arc slit locating structure having:
• i) a clamping member which engages the support tube to support the extraction member;
• and
• ii) locating means for aligning said arc slit with a predetermined beam line, the locating means adapted to be precisely positioned with respect to the source assembly housing and being moveable with respect to the clamping member prior to securing the clamping member to the support tube end in directions transverse to the predetermined ion beam path.