Enhancing the Wettability of High Aspect-Ratio Through-Silicon Vias Lined With LPCVD Silicon Nitride or PE-ALD Titanium Nitride for Void-Free Bottom-Up Copper Electroplating
| Autor: | W.H.A. Wien, Fred Roozeboom, Harm C. M. Knoops, H.W. van Zeijl, Wilhelmus M. M. Kessels, M. Saadaoui, R. M. C. M. van de Sanden, C. Kwakernaak, F.C. Voogt, H. T. M. Pham, Pasqualina M. Sarro |
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| Přispěvatelé: | Plasma & Materials Processing, Atomic scale processing, Processing of low-dimensional nanomaterials |
| Rok vydání: | 2011 |
| Předmět: |
Materials science
Silicon chemistry.chemical_element Nanotechnology Chemical vapor deposition Industrial and Manufacturing Engineering chemistry.chemical_compound Atomic layer deposition Copper plating system-in-package Electrical and Electronic Engineering Composite material Electroplating Si interposer TS - Technical Sciences Industrial Innovation Bottom-up copper electroplating Mechatronics Mechanics & Materials Titanium nitride Electronic Optical and Magnetic Materials EAM - Equipment for Additive Manufacturing chemistry Silicon nitride superhydrophilic wetting through-silicon vias wafer level packaging and 3-D integration Titanium |
| Zdroj: | Ieee Transactions on Components Packaging and Manufacturing Technology, 1, 1728-1738 IEEE Transactions on Components, Packaging and Manufacturing Technology, 11, 1, 1728-1738 IEEE Transactions on Components and Packaging Technologies, 1(11), 1728-1738. Institute of Electrical and Electronics Engineers |
| ISSN: | 2156-3950 1521-3331 |
| DOI: | 10.1109/tcpmt.2011.2167969 |
| Popis: | One of the critical steps toward producing void-free and uniform bottom-up copper electroplating in high aspect-ratio (AR) through-silicon vias (TSVs) is the ability of the copper electrolyte to spontaneously flow through the entire depth of the via. This can be accomplished by reducing the concentration gradient of cupric ions from the via mouth to the via bottom by enhancing the wettability of the vias sidewalls. In this paper, we report on a new dry technique to enhance the hydrophilicity in high AR $({sim}{15})$ TSVs as one of the key solutions to face the mass transport limitation. low pressure chemical vapor deposition silicon nitride and atomic layer deposition titanium nitride of composition ${rm SiN}_{0.95}$ and ${rm TiN}_{1.1}$, respectively, are used as both barrier layers and wetting surfaces in these vias. Ammonia plasma immersion is used to treat silicon nitride. X-ray photoelectron spectroscopy shows both a partial oxidation and grafting of hydrophilic components. Alternatively, a rapid flood ultraviolet exposure step in order to photocatalytically activate the surface and induce a partially oxidized titanium nitride is used to create a highly wettable interface with a contact angle close to zero. These wettability enhancement steps were incorporated in a TSV process to produce 3-D cross-Kelvin structures using bottom-up copper electroplating. The vias lined with silicon nitride and titanium nitride exhibited a low average resistance of 25 ${rm m}Omega$ and 50 ${rm m}Omega$, respectively, making them very suitable for radio-frequency signal transmission. This all-dry technology to achieve superhydrophilic barrier layers- - can be employed in both high and low thermal budget processing, thus enabling via-last or via-first flowchart schemes for advanced 3-D interconnects. |
| Databáze: | OpenAIRE |
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