Performance of the aerial image measurement system for 157-nm lithography

The first Aerial Image Measurement System (AIMSTM) for 157 nm lithography worldwide has been brought into operation successfully. Its performance will be demonstrated by AIMSTM measurements at 157 nm wavelength on binary chrome masks. Several through focus series have been measured in order to calculate the process windows for various structures with feature sizes at mask level of 300 nm and below. The latest results on enhanced illumination stability will be presented and a resolution that will enable an extension of the tool usage down to the 45 nm node. Using off-axis illumination 150 nm lines and spaces mask structures have been resolved.