Flexible Multistation Sequential Processing (MSSP) Architecture Delivers ULK Films With 25 Percent Hardness Improvement over Competitive Approach

Novellus Systems (NASDAQ: NVLS) today introduced its next-generation ultra-violet thermal processing (UVTP) system, the SOLA xT. The SOLA xT is used in the manufacturing of advanced logic devices at 45nm and below and incorporates a proprietary UVTP treatment process that modifies the physical characteristics of a previously-deposited film through exposure to ultraviolet light and heat. The new system, featuring on-board UV monitoring and a customizable optics assembly, provides process flexibility and extendibility over multiple device generations. The first SOLA xT system will be shipped to UMC's Fab 12i in Singapore.

The multi-station sequential processing (MSSP) architecture of SOLA allows independent control of temperature, wavelength and intensity at each station to deliver best-in-class uniformity and productivity. This high degree of process configurability results in UV treated ultra low-k (ULK) films with a 25 percent greater hardness compared to single wavelength, single temperature curing solutions. For example, UVTP is used to remove porogen and improve the mechanical strength of ULK dielectric films used as inter-metal layers. This treatment facilitates device integration and prepares the films to withstand subsequent semiconductor processing steps like packaging and chemical mechanical planarization (CMP). Other advanced manufacturing integration schemes use spin-on dielectrics, which sometimes incur damage during etching, wet cleaning or photoresist ashing steps. In this instance, UVTP can be used to repair this damage through chemical bond reconstruction. In the front-end-of-the-line, UVTP may also be employed to induce strain in the transistor channel of N-type Metal Oxide Semiconductor (NMOS) devices. Strain is induced by depositing a high tensile stress dielectric film, and subsequently exposing it to UV, resulting in an increase of device performance.

For all of the applications cited above, monitoring equipment health and delivering uniform wafer performance is necessary to improve production efficiencies in a high volume manufacturing environment. To achieve this goal, the new SOLA xT platform features on-board UV monitoring and advanced algorithms to maintain stable wafer-to-wafer performance. Best-in-class within-wafer uniformity results are achieved with SOLA xT's customizable optics assembly, where the UV lamps and reflectors can be oriented differently at each of the four treatment stations. The MSSP architecture ensures that each wafer is processed through a single wafer path, resulting in one statistical distribution of data compared to competitive solutions with up to four or six different wafer paths, and hence as many different statistical distributions.

"The new SOLA xT is designed to meet the market needs for a robust UVTP system suitable for high volume manufacturing at 32 nm," said Kevin Jennings, senior vice president of the PECVD business unit at Novellus Systems. "The independent control of temperature, UV wavelength, and UV intensity enable SOLA xT to extend to future technology generations, where new materials are likely to be introduced."

For more information about Novellus' UVTP technology, visit www.novellustechnews.com

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