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The BEOL Barrier-Seed deposition process is a key component in achieving the desired electrical and electro-migration performance while balancing the step coverage. The process also has a multifold impact on wafer yield parametric since it serves multiple passes for the various metal levels. Two major challenges with the barrier sputter deposition are: (A) achieving optimal within-feature barrier coverage while balancing resistance parameters; (B) flake defectivity — the process is prone to flake defectivity due to inherent adhesive properties of nitride films. Several different parameters play a role in dictating the quality and quantity of the barrier film that is being deposited. This paper analyzes the impact of one such critical parameter — the AC bias during barrier deposition to modulate the chamfer coverage and the electrical Via-resistance. Furthermore it elucidates the methodology of addressing the source of massive killer flakes that cause severe pattern damage that act as "killer" defects for the dies. Post implementation of the changes discussed, the massive defects of interest that were sourced from the sputter process were completely eliminated. A detailed study supported by electrical and cross-sectional analysis allowed zeroing in on the optimal Bias power to derive the best possible chamfer stability while being able to achieve a lower Via-resistance as desired.

Vertical arrays of one-dimensional tin nanowires on silicon dioxide (SiO2)/silicon (Si) substrates have been developed as anode materials for lithium rechargeable microbatteries. The process is complementary metal-oxide-semiconductor (CMOS) compatible for fabricating on-chip microbatteries. Nanoporous anodized aluminum oxide (AAO) templates integrated on SiO2/Si substrates were employed for fabrication of tin nanowires resulting in high surface area of anodes. The microstructure of these nanowire arrays was investigated by scanning electron microscopy and X-ray diffraction. The electrochemical tests showed that the discharge capacity of about 400 mA h g−1 could be maintained after 15 cycles at the high discharge/charge rate of 4200 mA g−1. Keywords: Lithium microbattery, Anode material, Tin nanowire, Anodized aluminum oxide