International Journal of Microwave and Wireless Technologies

Original Article

Impact of the CNT growth process on gold metallization dedicated to RF interconnect applications

Chin Chong Yapa1a2, Dunlin Tana1a2, Christophe Bruna1a3, Hong Lia2, Edwin Hang Tong Teoa1a2, Dominique Baillargeata1 c1 and Beng Kang Taya1a2

a1 CINTRA CNRS/NTU/THALES, UMI 3288, Research Techno Plaza, 50 Nanyang Drive, Border X Block, Level 6, Singapore 637553, Singapore. Phone: +65 81213174; Fax: +65 68967448.

a2 School of Electrical and Electronics Engineering, Nanyang Technological University, Block S1, 50 Nanyang Avenue, Singapore 639798, Singapore.

a3 XLIM UMR 6172, Université de Limoges/CNRS, 123 Avenue Albert Thomas 87060 Limoges, France.

Abstract

Carbon nanotubes (CNTs) are a unique group of materials with high aspect ratio, mechanical and electrical properties, which are of great interests in the field of interconnects, and radio frequency applications. In order to incorporate CNTs into any of these applications successfully, one important issue that has to be resolved is the critical parameters (temperature and reactant gases) associated with the growth of the CNTs. As such, the effect of these growth requirements on the adjacent components should be studied. In this work, we examined specifically the effect of carbon nanotubes growth on the underlying metallization, in particular gold, dedicated for radio-frequency-based applications. The gold coplanar lines were annealed at 800°C in a plasma-enhanced chemical vapor deposition (PECVD) system to simulate the worst-case condition. The reflection and transmission parameters were analyzed using a probe station connected to a vector network analyzer. Carbon nanotubes grown on different barrier layers were also characterized using a scanning electron microscope and Raman spectroscopy to identify a suitable barrier layer for gold. Our results showed that it is promising to integrate carbon nanotubes grown using PECVD onto Au coplanar waveguide without degrading the S-parameters measurements up to 20 GHz.

(Received July 08 2010)

(Revised September 09 2010)

Keywords

  • Carbon nanotube;
  • Radio-frequency;
  • Interconnect

Correspondence:

c1 Corresponding author: D. Baillargeat Email: dbaillargeat@ntu.edu.sg