Marvin R. LaFontaine

Optimization of High‐Energy Implanter Beamline Pumping

A high‐energy implanter process chamber and its pumping configuration were designed to minimize the residual gas density in the endstation. A modified Nastran™ finite‐element analysis (FEA) code was used to calculate the pressure distribution and gas flow within the process chamber. The modified FE method was readily applied to the internal geometry of the scan chamber, the corrector magnet waveguide, and the process chamber, which included the scan arm assembly, 300mm wafer, and plasma electron flood gun (PEF). Using the modified Nastran code, the gas flow and pressure distribution within the beamline geometry were calculated. The gas load consisted of H2, which is generated by photoresist (PR) outgassing from the 300mm wafer, and Xe from the plasma electron flood gun. Several pumping configurations were assessed, with each consisting of various locations and pumping capacities of vacuum pumps. The pressure distribution results for each configuration are presented, along with pumping efficiency results w...