Cost of ownership modeling is a critical and emerging tool that provides significant insight into the ways to optimize device manufacturing costs. The development of a model to deal with a particular application, mix-and-match lithography, was performed in order to determine the level of cost savings and the optimum ways to create these savings. The use of sensitivity analysis with cost of ownership allows the user to make accurate trade-offs between technology and cost. The use and interpretation of the model results are described in this paper. Parameters analyzed include several manufacturing considerations -- depreciation, maintenance, engineering and operator labor, floorspace, resist, consumables and reticles. Inherent in this study is the ability to customize this analysis for a particular operating environment. Results demonstrate the clear advantages of a mix-and-match approach for three different operating environments. These case studies also demonstrate various methods to efficiently optimize cost savings strategies.
Steven Holmes, Albert Bergendahl, Diana Dunn, J. Guidry, Mark Hakey, Karey Holland, Andy Horr, Dean Humphrey, Stephen Knight, D. Macaluso, Katherine Norris, Denis Poley, Paul Rabidoux, John Sturtevant, Dean Writer
Lithographers have steadily reduced exposure wavelength and increased numerical aperture (NA) to maintain process window and simplicity. The G-line systems of the 1970s gave way to the I-line systems of the late 80s, and then to the deep ultraviolet (DUV) systems of today. This paper describes our characterization of a DUV lithography system for the manufacture of 16-Mb DRAM chips at 500-nm ground rules. The process consists of a positive-tone, aqueous-base developable photoresist with an overcoat for sensitivity control, and an anti- reflective coating (ARC) on selected levels. The exposure tools used are step-and-scan systems with a 0.36 NA and expose bandpass of 240 - 255 nm. Apply and develop processes are clustered with the expose tool to minimize defects, reduce cycle time, and eliminate process variables.
Each DRAM design generation has required higher reoiution imaging and overlay capability. The 500-nm lithographic ground rules of a 16-Mb chip make deep-UV (DUV) an attractive alternative to,thc more stanth,rd mid-UV (MUV) photolithography presently practiced for less demanding technologies. The shorter wavelength permits an unproved depth of focus by allowing the same resolution at smaller numerical apertures. This approach retains the simplicity of single-layer-resist processing rather th a ii forcing conversion to m ultilayer imaging.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.