Problem: The Applied Tetra Reticle Clean system is
claimed to be the first mask cleaning system to achieve zero damage and
99 percent particle removal efficiency (PRE) on advanced masks for dry
and immersion technologies. The Tetra Reticle Clean combines a mask
clean chamber and a plasma dry strip and conditioning chamber on one
platform to address the full range of mask cleaning challenges from
photoresist strip to removing post-etch residues and particles while
preserving the integrity of the photomask.
Solution: The system is unique in its streamlined mask handling, integrated dry/wet processing capabilities, and throughput at least double that of equivalent mask cleans products. The mask is handled only to enter and exit the clean chamber, where it is stripped, cleaned, rinsed, and dried without mask flipping. Tetra Reticle Clean is claimed to be the only system employing ‘Uniform Cavitation Megasonics,’ which distributes energy evenly over the entire mask surface, avoiding the damage-causing spikes generated by traditional point-source megasonic cleans. The clean chamber is designed for cleaning the front and back of the mask simultaneously, using different chemistries if necessary with no possibility of mixing. NanoDroplet Technology further enhances damage-free cleaning using an overhead nozzle designed to create uniform high-momentum "nanodroplets" and kinetic energy. Sulfur-free stripping followed by advanced cleaning chemistry outperforms standard chemistries in preserving optical properties of the mask and preventing haze formation.
Applications: Integrated dry/wet processing for all mask types and feature sizes through 32nm and beyond.
Platform: Uses proprietary ‘Uniform Cavitation Megasonics’ (UCM) technology as well as ‘NanoDroplet’ technology. The system can be configured with multiple processing modules, offering mask makers the capacity to eliminate processing bottlenecks and reduce cycle times.
Availability: April 2008 onwards.