Michael Heiden

First Measurement Data Obtained On The New Vistec LMS IPRO4

The development of reticles for the 65nm node is already completed and development is ongoing at the leading edge mask shops for 45nm technology node reticles. The specifications for 45 nm node reticles CD homogeneity, CD mean to target, and registration (Overlay) are much tighter than previous generation reticles. As a result of the new requirements new metrology systems will be required which provide significantly improved measurement performance compared to currently available systems. The Vistec LMS IPRO4 is the new generation registration metrology system under final development. Initial performance data of the alpha tool is reported and the planned major hardware and software improvements are described.

DUV water immersion technology extends linearity: first results from the new 65nm node CD metrology system LWM500 WI

The increased requirements on reticles for the 65nm technology node with respect to CD homogeneity and CD mean to target requirements call for a metrology system with adequate measurement performance. We report on the new water immersion technique and the system concept of the worlds first optical CD metrology system based on this technology. The core of it is a new DUV immersion objective with a NA of 1.2, using illumination at a wavelength of 248nm. The largest challenge of the water immersion technology was the fluid handling. The key compo-nents, a water injection and removal unit, developed by MueTec, solve this issue. To avoid contaminations the purified DI water is micro-filtered. An environmental chamber guarantees extremely stable measurement conditions. The advantages of optical CD measurements in transmitted light compared to CD-SEM is shown. With this system, already installed, excellent results for short- and longterm repeatability for both linewidth and contact measurements were achieved on COG, KrF HT and ArF HT masks. The linearity range of the system is extended down to 220nm. A comparison of CD measurements between the different tool generations such as the Leica LWM250/270 DUV at 248nm with a NA of 0.9 is shown. An outlook on the future potentials of optical mask CD metrology finalises this report.