MICRO:Product Technology News (Feb 99)

Designed for making semiconductors with geometries 0.18 µm, the AIT II patterned process tool monitor minimizes the number of wafers exposed to out-of-control process conditions. The system incorporates double-darkfield technology, which combines low-angle illumination and low-angle collection optics. The technology suppresses color variation and grainy background noise, increases small-particle sensitivity, and provides surface selectivity. This last capability minimizes the detection of previous-layer defects. The tool is particularly suitable for monitoring CMP and etch processes. The system's programmable spatial filters enhance defect collection on array structures, and selectable polarization of the illumination beam minimizes surface noise. The MultiSpot option provides multiple laser spot sizes for varying defect signal-to-noise ratios and optimizing throughput. The PAS 5500/700B system's stepping speed of 500 mm per second and scanning speed of 250 mm per second give the photolithography tool a throughput of 104 wafers per hour. Designed for 0.15-µm design rule processes, the 200-mm system is equipped with a Carl Zeiss Starlith 700 lens possessing an NA of 0.7 for high resolution. Its Aerial II illuminator provides a transmission of 248-nm-wavelength light. Overlay accuracy using a through-the-lens phase-grating alignment system is specified at <40 nm for single-machine and <60 nm for matched-machine applications. The tool's Athena alignment scheme uses two different illumination wavelengths and collects information from seven diffracted orders separately at each wavelength. This capability makes the system suitable for multilayer film stack processes such as advanced CMP and copper metallization. The ARIS-i is designed for inspection of reticles using resolution enhancement techniques such as advanced optical proximity correction and phase shift. The UV-wavelength-based system targets reticles used in making semiconductors with linewidths 0.18 µm. Dual image-processing channels, an advanced CCD camera, and high-speed computing are standard features. The system's linewidth error detector monitors local and regional geometry variations. Die-to-database inspection capability compares each reticle's