Ultra-Precise Dispensing for Rapid and Flexible Through-Silicon Via Filling.

Area of Science:

• Microelectronic Engineering
• Materials Science
• Additive Manufacturing

Background:

• Three-dimensional integrated circuits (3D ICs) are crucial for continued microelectronics scaling.
• Through-silicon vias (TSVs) are essential for vertical interconnectivity in 3D ICs.
• Traditional TSV metallization processes are complex and limit design flexibility.

Purpose of the Study:

• To investigate Ultra-Precise Dispensing (UPD) of silver nanoparticle pastes as an alternative TSV metallization method.
• To evaluate the feasibility of UPD for fabricating high-aspect ratio TSVs.
• To demonstrate a simplified and adaptable approach for TSV fabrication.

Main Methods:

• Utilized Ultra-Precise Dispensing (UPD) technology with novel silver nanoparticle-based pastes.
• Investigated the TSV filling process for metallization.
• Analyzed the morphology, filling quality, and electrical performance of the fabricated TSVs.

Main Results:

• Successfully achieved filled TSVs through a 280 μm thick silicon substrate.
• Fabricated TSVs with diameters as small as 20 μm, achieving aspect ratios up to 14:1.
• Demonstrated favorable electrical properties for the UPD-fabricated TSVs.

Conclusions:

• UPD offers a simple, adaptable, and potentially lower-cost alternative for TSV metallization.
• This additive manufacturing approach facilitates dense, high-aspect ratio TSV fabrication.
• The method increases design flexibility and reduces complexity in standard technology processes.