Overlay and Grating Line Shape Metrology Using Optical Scatterometry
Abstract
This Phase I effort demonstrated the feasibility of using scatterometry to provide sensors for process control and overlay measurement for structures having sub-um linewidths (CDs). The processes which we investigated were poly-Si etch and W selective deposition, with particular attention directed toward application in a cluster tool environment. We analyzed structures having CDs of approx. 0.2 um, 0.35 um, and 0.5 um. We used simulation techniques to show that scatterometry is capable of monitoring the width and height of the lines during these processes. The CD prediction error for all of the studied cases was between 0.4 and 4 nm, with the height prediction error in the range of 5 to 21 nm. These results can be improved by using sub-range prediction techniques. Overlay measurement error was found to be less than 0.5 nm for these cases. These results agree with experimental results obtained for similar line structures. In a Phase II effort we would verify these simulations by constructing scatterometers and implementing them on process reactors. Overlay, Grating, Metrology, Optical scatter, Semiconductor sub-micron, CD, Linewidth, Sensors, Process control
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 11, 1993
- Accession Number
- ADB176711
Entities
People
- John Mcneil
- Richard Krukar