Characterization of Doped Oxide Films PSG/BPSG/FSG via DSIMS in Order to Eliminate Nonzero Kilometer Failures from Semiconductors Used in Automotive Industry : Topic/category: Yield Enhancment/Advanced Metrology

Abstract

Doped oxide films with phosphorus and boron (PSG/BPSG) are widely used in the semiconductor processing on the first dielectric above FEOL films, to protect transistors from failures due to mobile ionic contamination (Na, Li, K, Mg & Ca). Fluorine doped films are utilized as alternatives to un-doped SiO2 films for lower capacitance at the BEOL for smaller geometry aluminum back end technologies. Several in-line metrology techniques such as XRF and FTIR are utilized to characterize and monitor the integrity of those films but only provide limited information about the films and the dopant distribution. DSIMS/TOFSIMS depth profiles of the entire film stack do provide a clear understanding of dopants distribution and highlight any variations that have been proven to be the cause of failures and eliminate defective device deployment in the field, especially devices utilized in automotive industries.