Study of Adhesion Properties of Cu on Photosensitive Insulation Film for Next Generation Packaging

Abstract

As the demand for advanced packaging is growing, the organic multi-chip package, a combination of organic interposer and organic substrate have attracted increasing attention in realizing further advancements of electronic devices with higher densities and more functions. The semi-additive process (SAP) method has been developed for Cu wiring and blind via in packaging substrate. To make the fine Cu wiring below 5 μm, the sputtering Ti/Cu has been studied. While opening a blind via below 50 μm in diameter, the laser method has problem. Photosensitive organic materials having great mechanical strength and heat resistance were mainly used as protection and insulation layers of very large scale integrated circuit, because they simplify the via formation processing and did not generate the residues during process. Specifically, we have newly developed the film type photosensitive insulation materials. Our photosensitive insulation films (PIFs) showed high resolution, high adhesion strength with Ti/Cu seed layer and suitability to SAP with the sputtering process.

Novel Trench Wiring Formation Process using Photosensitive Insulation Film for Next Generation Packaging

“…The results showed that the diffusion coefficient of polymer and ΔG increased in the order: mono-< di-< tri-functional CL (Figure 3 and 4). The diffusion coefficient of polymer from molecular dynamics simulation is consistent with that obtained from dissolution ratio evaluation in the last report [6].…”

“…We found that CLs having low SP and multi-functional group enhanced dissolution ratio in unexposed area [6]. To discuss this phenomenon, we calculated the diffusion coefficient of polymer and ΔG from molecular dynamics simulation.…”

“…It is phenolic-resin-based negative tone resist containing cross-linkers (CL) and photo acid generator (PAG). The photosensitive insulation film (PIF) showed the high resolution (L/S = 4/4 m and 10 m via for 25 μm-thick film), high adhesion strength with Ti/Cu seed layer and suitability to SAP with sputtering process [6].…”

Novel Photoresist using Photodeprotectable <i>N</i>-Alkoxybenzyl Aromatic Polyamide

“…Photosensitive heat-resistant materials, such as polyimides (PI) or polybenzoxazole (PBO), exhibit excellent mechanical properties and are used in microelectronics application [4][5][6][7][8][9][10] to simplify via formation processing by photolithography. We have developed film-type photosensitive heatresistant materials for high-density packaging, such as phenolic-resin-based negative tone resist containing cross-linkers and photo acid generator (PAG), and these materials provide high resolution (10 μm via for 25 μm-thick film), high adhesion to Ti/Cu sputtering seed layer, and capability to fabricate Cu wiring of less than 5 μm [11,12]. The sputtering method can enhance adhesion strength, but increase in throughput and high cost is problematic.…”

Photodeprotectable N-Alkoxybenzyl Aromatic Polyamides

“…We have developed film-type photosensitive heat-resistant materials for high-density packaging, such as phenolic-resin-based negative tone resist containing cross-linkers and photo acid generator (PAG), and these materials provide high resolution (10 µm via for 25 µm-thick film), high adhesion to Ti/Cu sputtering seed layer, and capability to fabricate Cu wiring of less than 5 µm [6]. The sputtering method can enhance adhesion strength, but it is difficult to increase throughput and production cost is high.…”