Evaluation of ION-X ® Hydride Dopant Gas Sources on a Varian VIISion High Current Implanter

ION-X is a sub-atmospheric gas storage and delivery system that uses metal-organic-framework (MOF) adsorbents to safely store and deliver ion implant dopant gases. MOFs are a new class of crystalline materials with unprecedented surface areas and uniform pore size distributions. The pressure of an ION-X cylinder is below one atmosphere to significantly reduce the hazards associated with a gas release. Compared to zeolite or carbon adsorbent-based legacy products, MOF’s high pore density and uniformity provide advantages in storage capacity and gas purity. Arsine and phosphine ION-X was evaluated at Infineon using a Varian VIISion high current implanter and its performance was compared against SDS®3. The installation of the new source cylinders was seamless and did not require modifications to the existing tool infrastructure. The ion beam stability and spectral purity generated with ION-X sources was within specifications and indistinguishable from the process of record. On-wafer purity analysis was carried out using Vapor-Phase Decomposition – Inductively Coupled Plasma Mass-Spectrometry (VPD-ICPMS) after test wafers were implanted using ION-X and SDS®3 gas sources. The analyses show that all surface trace metals were well below specification limits with no discernable differences between gas sources. Sheet resistance measurements of test wafers were also within the accepted limits with standard deviations similar to the reference. In addition, electrical test data of productive lots show no significant differences in sensitive devices while using ION-X based implants. Based on these evaluations, ION-X hydride dopant gas delivery system performance is reliable, has already been qualified on a pilot tool, and is currently scheduled for roll-out at the Infineon production sites.