Ion implanter with multi-level vacuum

An apparatus for implanting a workpiece with ions, comprising:

• a first chamber, a second chamber, a third chamber, and a fourth chamber for holding the workpiece;
• a source of accelerated ions for directing a beam of ions through the first chamber toward the workpiece;
• a first pump coupled to the first chamber for reducing pressure in the first chamber;
• a first bulkhead positioned between the first chamber and the second chamber and having a first aperture enabling fluid communication between the first chamber and the second chamber and the passage of some of the ions therethrough, the first aperture restricting the flow of gas therethrough whereby the pressure level in the second chamber is higher than in the first chamber;
• a second bulkhead positioned between the second chamber and the third chamber and having a second aperture enabling fluid communication between the second chamber and the third chamber and the passage of some of the ions therethrough, the second aperture restricting the flow of gas therethrough whereby the pressure level in the third chamber is higher than in the second chamber;
• a third bulkhead positioned between the third chamber and the fourth chamber and having a third aperture enabling fluid communication between the third chamber and the fourth chamber and the passage of some of the ions therethrough, the third aperture restricting the flow of gas therethrough whereby the pressure level in the fourth chamber is higher than in the third chamber;
• a source of gas coupled to the fourth chamber;
• and
• a second pump coupled to the fourth chamber for reducing pressure in the fourth chamber, the higher pressure level in the fourth chamber enabling the gas to be present in the fourth chamber in sufficient quantities to impact the workpiece and neutralize charge building thereon.

An apparatus for implanting a workpiece with ions, comprising:

• a housing enclosing a first chamber;
• a source of accelerated ions for directing a beam of ions through the first chamber toward the workpiece;
• a second chamber for holding the workpiece;
• a plurality of longitudinally spaced chambers being defined by the housing and a plurality of longitudinally spaced bulkheads, each of the bulkheads having an aperture enabling fluid communication between the plurality of longitudinally spaced chambers and the passage of the beam of ions;
• a source of gas coupled to the second chamber;
• and
• a pumping system for evacuating the first chamber, the second chamber and the plurality of longitudinally spaced chambers, the pumping system and the plurality of longitudinally spaced chambers providing an increase in pressure between the first chamber and the second chamber, the higher pressure level in the second chamber enabling the gas to be present in the second chamber in sufficient quantities to impact the workpiece and neutralize charge building thereon.