Technologies for Realizing Carbon Nanotube Vias

XU Hua2017101326 Nov 2014

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Content

• Introduction of CNT technology

• Types of via fabrication process– Top-down fabrication process– Bottom-up fabrication process

• Problems to solve

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Introduction of CNT technology

• Trends of applying CNT technology

• Benefits:– CNT is very good heat

conductor to allow faster processing

thermal conductivity:

3500 W·m−1·K−1

Defects:– The resistance of CNT is not

low enough

Uncertainty:– Toxicity of CNT and its catalyst

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Top-down fabrication process

Synthesizing:Carbon nanotube (CNT) are grown from catalyst: Co, Fe, Ni Gas source: CH4, C2H2 etc; H2 & N2 as etching gas

equipment for catalyst deposition schematic of top-down process

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Top-down fabrication process

Examples of top-down process

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Top-down fabrication process

Result of top-down process----large variation

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Bottom-up fabrication process

Schematic of bottom-up process

Advantages:

More stable structure;Chemical mechanical polishing result in smooth surface;The CNT have the same height.

Disadvantages:

Tetraethylorthosilicate CVDform voids inside;CNT are not perfectly aligned.

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Bottom-up fabrication process

Defect in bottom-up process

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Problems to solve

• Resistance not low enough– 0.59 Ω for 2-μm CNT via in top-down process– 300 kΩ for 2-μm CNT via in bottom-up process– Higher CNT density will decrease the resistance

• The structure synthesized varies a lot– The two technologies can be combined to have better CNT structure

References:[1] Shintaro Sato, Mizuhisa Nihei, Atsushi Mimura, Novel approach to fabricating carbon nanotube via interconnects usingsize-controlled catalyst nanoparticles, 2006 IEEE

[2] Makoto Suzuki,Yusuke Ominami, Takashi Sekiguchi, and Cary Y. Yang, Secondary electron imaging of embedded defects in carbon nanofiber via interconnects, 2008 American Institute of Physics

[3] Jun Li, Qi Ye, Alan Cassell, Hou Tee Ng, Bottom-up approach for carbon nanotube interconnects, January 2003, Applied Physics Letters

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Thank you!