ION-X Dopant Gas Delivery System Performance Characterization at Axcelis

The performance of ION-X delivering arsine (AsH 3 ), phosphine (PH 3 ), and boron trifluoride (BF 3 ) was evaluated at the Axcelis Advanced Technology Center. ION-X is a sub-atmospheric dopant gas delivery system specifically designed for ion implantation, and the first commercial product that uses Metal-Organic Framework (MOF) materials. MOF materials are a new class of adsorbents with unprecedented surface areas and uniform pore sizes that can be precisely customized to the specific properties of electronic gases. ION-X cylinders were installed in high current implanters and their performance was compared to the incumbent UpTime® gas delivery systems. In all cases, the target dose was 5 × 1015 at/cm2 with beam energies of 40 keV, 20 keV and 15 keV for As+, P+, and BF 2 + ion implants respectively. In-process and on-wafer results of the MOF-based dopant gases compared positively to conventional source gases. The issue of metal contamination was investigated in detail. Specifically, beam and wafer contamination levels (both surface and energetic) were evaluated and compared to the reference qualified products. In all cases the metal levels were below specification limits matching the performance of the ultrahigh purity reference product.