As-grown donor-like traps in low-k dielectrics and their impact on intrinsic TDDB reliability

作者：Tang B J^*; Croes K; Barbarin Y; Wang Y Q; Degraeve R; Li Y; Toledano Luque M; Kauerauf T; Boemmels J; Tokei Zs; De Wolf I

来源：Microelectronics Reliability, 2014, 54(9-10): 1675-1679.

DOI：10.1016/j.microrel.2014.07.089

• Donor-like trap
• C-V hysteresis
• Low-k
• TDDB
• BEOL reliability

Highly porous low-k dielectrics are essential for downscaling of the interconnects for 20-10 nm technologies. A planar capacitor test vehicle was used to investigate the intrinsic time dependent dielectric breakdown (TDDB) reliability of low-k dielectrics and the origin of an observed C-V hysteresis was studied. We hypothesize that the hysteresis is caused by donor-like traps present in the bulk of the low-k but not by electron/hole trapping or mobile charges. It is proposed that porogen/carbon residues are the source of these donor-like traps. Using I-leak vs. time measurements, it was found that the donor-like traps accelerate the dielectric degradation due to an enhanced E-OX, causing a localized partial breakdown. The intrinsic TDDB reliability of the low-k film was improved by adding a sealing layer as such layer blocked the donor-like traps discharging.

• 出版日期2014-10