Conformal isolation of high-aspect-ratio TSVs using a low-κ dielectric deposited by filament-assisted CVD

- A filament assisted CVD (FACVD) method to isolate high-aspect-ratio TSV's is investigated.
- SiOCH thin films are deposited using MTES as precursor.
- Post-annealed films exhibit improved electrical characteristics such as low dielectric constant and low leakage current.
- Very high step coverages are obtained (i.e. > 70% for AR 8:1).
- FACVD deposited SiOCH films are promising candidates for use within TSV technologies.

In this study, SiOCH thin films were deposited by filament assisted chemical vapor deposition using methyltriethoxysilane. It is shown that annealing the films at 400 °C (with or without UV-assist) is required to meet specifications in terms of dielectric properties (low-κ values and good insulating properties). This work highlights FACVD as a promising technique to allow the deposition of conformal dielectric thin films within High-Aspect-Ratio TSVs. Step coverage higher than 70% were obtained within 10 ∗ 80 μm TSVs. Then, FACVD deposited SiOCH films can be considered as a promising candidate for use within TSV technologies.

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