Enabling Damascene Solutions for 45 nm Beyond

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0991-C11-01

Enabling Damascene Solutions for 45 nm Beyond Manabu Tsujimura Precision Machinery Company, Ebara Corporation, 4-2-1 Hon-Fujisawa, Fujisawa, 251-8502, Japan

ABSTRACT There are several technology developments, which should have been completed in CN 65 nm (Commercial node) device development, but passed over to CN 45 nm device development. Seven items relating with damascene process, especially connecting with planarization process, are nominated and introduced herein including new advent technologies as enabling solutions for CN 45 nm. First one is low-down-force planarization. Although there are several planarization technologies such as CMP (Chemical Mechanical Polisher), ECMP (Electrical Chemical Mechanical Polisher), ECP (Electrical Chemical Polisher), CE (Chemical Etching) and those combination technologies, it is not decided which is the best one and how low down force is optimized taking into account of CoC (Cost of Consumable) issues. In this report, all planarization technologies are explained using ëGeneral Principle governing all planarization technologiesí, and allowable down force is suggested through stress analysis and fracture toughness analysis. Second one is direct polish on ULK. There may be two approaches. One is to adopt CMP hard mask which dielectric constant would not be changed by direct polish. In this case, non-uniformity of CMP in this hard mask is important. Second is to polish directly on ULK, which dielectric constant would be changed by CMP, then restoration technology should be discussed at a same time. Third one is Ru liner application. When is this technology required? Deposition for Ru seed and polishing of Ru integration are reported. Forth one is watermark free drying of ULK. Vacuum drying and IPA drying (Rotagoni) which is necessary for hydrophobic surfaces are reported. Fifth one is cleaning technologies for less than 45 nm FM (Foreign Material). After CN 45 nm, it is difficult to distinguish several defects such as scratches or FM. In this case, soft cleaning methods such as non-contact cleaning would be required. Cavitation jet as one of non-contact type cleanings is reported with its cleaning results. Sixth one is Co-W cap process. Electro-less metal cap technology in order to enhance EM is reported. CMP after Co-W deposition may be useful in order to clean cap surfaces. Seventh one is starting material such as nanotopography and roll off which would affect on CMP performances INTRODUCTION In 2005, device manufactures have already completed the development of CN65 nm device (Commercial Node or Logic Node) and started the development of CN45 nm device in 20061). However, it is often said that there are several development items, which have been passed over from CN65 to CN45. For an example, (1) Low down force planarization technologies. Although there are several planarization technologies such as CMP (Chemical Mechanical Polisher), ECMP (Electrical Chemical Mechanical Polisher), ECP (Electrical Chemical Polisher), CE (Chemical Etching) and those combination tech