ION MILLING AS AN ALTERNATIVE TO FOCUSED ION BEAM FOR CROSS-SECTION INTERMETALLIC ANALYSES
Authors: Roger J. Stierman, Becky Holdford, and Maricel Fab Company: Texas Instruments, Inc. Date Published: 1/17/2006
Pan Pacific Symposium
Abstract: Focused ion beam (FIB) systems are one tool used to delineate cross-sections for intermetallic (IMC) analysis of semiconductor chips and packaging connections, such as Au-Al wire bonds or Sn-Cu solder connections. Such systems, while having precise beam control, are expensive, and cutting times are long for large (greater than 50 micron) geometries. Recent developments in ion mill's fixturing have enabled these systems to delineate IMCs on cross-sections. The ion mill beam covers larger areas than the FIB, the delineation takes less machine time, and the total system (SEM + ion mill) is lower cost. Comparisons between ion-milled and FIB-polishing of some Au-Al wire bond and Sn-Cu IMC regions are presented.