(November 24, 2010 – JCN Newswire) — Tokyo Electron Limited and Tanaka Kikinzoku Kogyo K.K. have developed a sucessful recycling process for ruthenium precursors (CVD-ruthenium material) used in next-generation semiconductor miniaturization technology.

Ruthenium precursors are currently disposed of without being collected as valuable resources. In this recycling program, ruthenium precursors can now be collected, refined, and re-used without returning them to ruthenium metal. Tokyo Electron Limited developed the recovery system, which collects residue of the ruthenium-CVD precursor not deposited on the wafer, and Tanaka Kikinzoku Kogyo K.K. developed the process to refine and re-use the collected ruthenium precursors.

In semiconductor fabrication there are challenges to scaling, such as improving the copper filling performance in a narrow interconnect. Tokyo Electron has proposed an improvement in copper filling performance by utilizing a ruthenium liner film with excellent adhesion and lower resistivity.

With the goal of lowering overall cost and ensuring a stable supply of ruthenium precursors, Tokyo Electron and Tanaka Kikinzoku Kogyo agreed to jointly develop the recycling process. The process will save almost 20% of ruthenium precursor cost and significantly lower the cost of consumables (COC) of the CVD-ruthenium process. Further, an almost 30% reduction in CO2 emissions is expected utilizing the new recycling process.

Ruthenium is produced primarily in South Africa and is found in platinum ore in amounts of about 10-20%. The annual output of ruthenium worldwide is approximately 30 tons. It is estimated that ruthenium reserve quantities are nearly 6,000 tons. Tanaka Kikinzoku Kogyo is engaged in business with the mining company Anglo Platinum Inc., which has over 40% of world market share in the PGM (Platinum Group Metals): Platinum, Palladium, Rhodium, Iridium, Ruthenium, Osmium metals.

Atomic Number: 44
Melting Point: 2,250 degrees Celsius
Resistivity: 7.6 micro ohm cm
                     – Ru Oxide is electroconductive.
Lattice parameter: Ru(002) 2.14 angstrom
                     – near Cu,  Cu(111) 2.09 angstrom
Chemical stability:  – No dissolution in the plating bath.
                     – Neither diffusion nor the alloy are in Cu.

For details of this release, please see: .

Tokyo Electron Limited (TSE: 8035) lies at the core of the Tokyo Electron Group, one of the world’s top manufacturers of semiconductor production equipment, LCD production equipment, computer systems and electronic components. More information about Tokyo Electron Limited is available at

Tanaka Precious Metals has built a diversified range of business activities focused on the use of precious metals. On April 1, 2010, the group was reorganized with Tanaka Holdings Co., Ltd. as the holding company (parent company) of the Tanaka Precious Metals. Learn more about Tanaka Holdings Co. Ltd. (Holding company of Tanaka Precious Metals) at

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