Extensive investigations of temperature influence on barrier integrity during reliability testing

New failure mechanism during high temperature storage testing and its application on SIV risk evaluation

“…Cu oxidation) or differences in profiles could be found but even the SEM investigation at the samples after testing revealed that the barriers may look differently for the "fibed" and "non-fibed" samples (Fig 13). This again is an indication of changes in barrier as reported in [6] before, even though this effect seems to affect the complete barrier (sidewall and via bottom) and not only the via bottom. Changes in sidewall barrier quality would not affect the overall resistance as much.…”

“…Cu oxidation) or differences in profiles could be found but even the SEM investigation at the samples after testing revealed that the barriers may look differently for the "fibed" and "non-fibed" samples (Fig 13). This again is an indication of changes in barrier as reported in [6] Fig. 11: Top-down SEM image (left) and cross-section schematic (right) of the "oxygen channel".…”

“…Very recently we reported unexpected resistance behavior during high temperature storage tests at temperatures over 250°C [6]. After 1000h stressing we found resistance increases of over 20%.…”

Diffusion Barriers

“…According to XRD results, Cu 3 Si formation is detected prior to TaSi 2 nucleation, which occurs at T = 575 °C [81]. Recently, partial Ta barrier oxidation was found to be the root cause of an unusually large resistance increase during stress migration testing at T = 275 °C [85]. Thus, it is concluded that Cu diffusion into silicon promotes TaSi 2 grain growth [81].…”