Low Temperature Curable Photo-sensitive Insulator

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.

Section: Introductionmentioning

confidence: 99%

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

Iwashita

Katoh

Nakamura

et al. 2015

“…Hence, photosensitive organic materials with low residual stress have been developed as interlayer dielectrics for semiconductor devices [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Recently, Shoji et al had reported that a photosensitive preimidized polyimide (PI) with low residual stress is developed by introducing special soft segment and utilizing low temperature curable crosslinker [2].…”

Section: Introductionmentioning

confidence: 99%

Development of Positive Tone-Type Photosensitive Materials Based on A Phenolic Resin with A Low Coefficient of Thermal Expansion

Doi,

Shimokawa

2024

We had previously developed a novel negative tone-type photosensitive material that can be patterned by photolithography, based on a chemically amplified system containing a phenolic resin, a crosslinker, and a photochemical acid generator (PAG). It exhibits a low coefficient of thermal expansion and low residual stress after thermally treated at 260 °C. However, when photolithography was performed to form micro-scale hole patterns on a thin film of the photosensitive material, the resin's high absorbance caused overhung profile was observed and which was considered to lead to difficulty in subsequent metal wiring formation on the film. In this study, the normally tapered pattern formation was tried by applying positive tone-type photosensitive materials. The hydroxy groups of phenolic resin were protected by acid cleavable and/or hydrophobic substituents and the protected resin was mixed with the PAG for creating the chemically amplified positive tone-type photosensitive material. We also investigated the photolithography, the effect of heat treatment conditions on residual stress, and the light transmittance and solvent solubility of the resins. We found that the substitution of the side groups with tert-butyl acetate was effective in the formation of normally tapered patterns by photolithography and observed low residual stress of the thin film after heat treatment at 260 °C. This material is a good candidate as an interlayer dielectric for semiconductor devices and wafer-level microfluidic materials for cooling semiconductor chips.

“…Then we studied the process of making thin and uniform seed layer. We studied liquid-type, negative-tone resist which comprises phenolic resin as base resin, epoxy monomer as photosensitive cross-linker (CL), photo acid generator (PAG), and thermal CL [12][13][14][15][16][17]. We investigated the molecular weight of phenolic-resin to improve lithographic properties.…”

Section: Introductionmentioning

confidence: 99%

Trench Wiring Process Applying Electroless Nickel Plating for Fine and High-Aspect-Ratio Pattern

Yokochi

Yoshida

Iwashita

et al. 2019

As increasing demand for advanced electronic devices, finer pitch and higher integration of wirings are required. The trend tends to increase the electrical resistance of wirings. In order to suppress the resistance, it is necessary not only to reduce wiring length, but also to increase the aspect ratio of the finer wiring to ensure its cross-sectional area. We investigated embedded Cu wiring formation process, called as "trench process," and newly developed a photosensitive material and its seeding process. The photosensitive material showed the capability to form resist pattern (line/space=1 μm/1 μm and aspect ratio=5.0) and Cu wiring (line/space=1.2 μm/1.2 μm and aspect ratio≥3.0) with electroless nickel plating, The material is suitable for trench process.