Overlay Accuracy Evaluation in Step-and-Repeat X-Ray Lithography
- 1 July 1988
- journal article
- Published by IOP Publishing in Japanese Journal of Applied Physics
- Vol. 27 (7R), 1275
- https://doi.org/10.1143/jjap.27.1275
Abstract
Overlay accuracy in step-and-repeat X-ray lithography is evaluated through MOS device fabrication using an X-ray stepper applied to four lithography levels. Though relatively good overlay accuracies of 0.15 µm (σ) between two levels are obtained, these values are not satisfactory for sub-half-micrometer ULSI fabrication. To improve overlay accuracy, error factors are investigated. It is found that overlay errors are strongly affected by mask pattern placement errors. The standard deviation of mask errors is as high as 0.1 µm. These errors are introduced by e-beam writing errors and pattern displacement caused by stress relief of absorber and membrane layers in the etching process. The influence of these error factors on pattern placement accuracy is discussed.Keywords
This publication has 12 references indexed in Scilit:
- Subhalf-micrometer p-channel MOSFET's with 3.5-nm gate Oxide fabricated using X-ray lithographyIEEE Electron Device Letters, 1987
- Step-and-repeat X-ray/Photo hybrid lithography for 0.3-µm MOS devicesIEEE Transactions on Electron Devices, 1987
- X-ray mask heating during electron-beam patterningJournal of Vacuum Science & Technology B, 1987
- A statistical analysis of ultraviolet, x-ray, and charged-particle lithographiesJournal of Vacuum Science & Technology B, 1986
- A plasma x-ray source for x-ray lithographyJournal of Vacuum Science & Technology B, 1986
- Influence of absorber stress on the precision of x-ray masksJournal of Vacuum Science & Technology B, 1986
- A step-and-repeat x-ray exposure system for 0.5 μm pattern replicationJournal of Vacuum Science & Technology B, 1985
- Variably shaped electron beam lithography system, EB55: I. System designJournal of Vacuum Science and Technology, 1981
- Chloromethylated Polystyrene as a Dry Etching‐Resistant Negative Resist for Submicron TechnologyJournal of the Electrochemical Society, 1979
- Application of synchrotron radiation to x-ray lithographyJournal of Applied Physics, 1976