ICEMask (Image Contrast Reticle)
This Reticle provides a set of test structures that vary image contrast without varying pitch. Depending on the exposure process, image contrasts from 10% to 95% are achievable. This reticle helps you: find the center of Focus and image bias and determine MEEF dependence on image contrast, line edge roughness dependence on image contrast, and the effect of image contrast on Scattermetric signals.
GaAs Mask uses a dark-field, "strong" phase shift mask design to produce quality sub-wavelength images to make discrete GaAs gates. This patent pending method uses phase-shifted, sub resolution assist features to shape the aerial image of the discrete diffraction pattern in order to eliminate zero order light there by improving depth of focus, and to place two non-zero orders of light at the edge of the lens pupil plane reconstructing the desired feature using a two-beam interference.
Sidewall Chrome Alternating Aperture --SCAA Mask
The SCAA mask allows you to evaluate sub wavelength imaging, perform resist profiling and evaluate phase-shift technology with minimal pitch-dependent phase error. At 248, it offers 100nm imaging down to 20 nm pitch. A 193 mask is being built (Spring 2002), and custom masks can be designed to meet your unique specifications. The SCAA test mask provides resolutions to a k1 of .25.
Device-like Test structures
Working with our technology partner Benchmark Technologies, we offer device-like test structures spanning technology nodes down to the 45nm node and beyond. These ideal learning structures are provided with plain controls and with various levels of OPC. We also have modules with programmed defects corrected in such a way that the patterns will print clearly as well as the defect to emulate particles falling on the wafer during exposure or after develop. If our current library does not meet your need we can provide custom designs too.
PAL provides design and manufacturing services for weak illuminators that can be used in exposure tools allowing insertion of a filter aperture.
Illumination can take the form of on-axis or off-axis light. On-axis is used for phase-shifting techniques that use two -beam imaging techniques. Off axis takes the conventional, on-axis three beam imaging and discards one oser of the higher diffraction order of light thus producing a two beam imaging system. The light can be shaped into different field intensity shapes to provide the best illumination for the feature being imaged
Illuminators can be strong, where no light is present between illuminator poles, or weak, where there is light between the poles. Weak off axis illumination provides contrasts that are slightly less than strong illumination, but can accommodate more types of features and pitches.