Photomasks featuring zero printable defects are essential for the manufacture of high end integrated circuits at the wafer fab. As sizes continuously shrink, the demands and costs associated with these key optical elements raise exponentially and with them the necessity to repair a defective product.
The new high resolution photomask repair tool MeRiT® HR II offers a higher degree of automation and a larger variety of additional repair processes than was previously available. The redesigned system allows the repair of transparent and opaque defects of any geometry on all known mask types such as Binary, OMOG, HD MoSi and EUV.
The sound automation package enables a new level of automation with optimized repair flow. After a short setup routine the processes are able to seamlessly repair numerous defects without the need for human interaction. A higher throughput due to lower idling time is also offered. In case of any doubt a security interlock consults the operator who can intervene when necessary.
MeRiT® HR II is part of ZEISS's unique yield enhancement solution and benefits from a close synergy with the AIMS™ technology from ZEISS which allows instant verification of the repair quality.
The MeRiT® HR II mask repair technology follows two strategies to meet the demands of today's lithography in parallel: The required repair quality in terms of resolution and placement accuracy is being addressed by a novel e-beam platform including an actively controlled mini-environment. This measure provides a currently unsurpassed level of thermal and mechanical stability. On the other hand, minimum repair size as well as new and challenging mask technologies like EUV are being handled by new e-beam processes provided by a process gas supply system of increased capability and flexibility.
The complete mask repair software is embedded in a workflow oriented Graphical User Interface (GUI). This interface guides the repair engineer through system setup, defect navigation, and all repair processes. A seamless interface to all common inspection system files is offered for mask alignment, defect navigation and characterization. The GUI can be accommodated to differing levels of operator skills as required from individual sites.
Etching and deposition processes are the key to successful mask defect repair - the ZEISS MeRiT® platform is the only system covering two repair modes within one process step. Electron beam induced chemical reactions are exploited for etching and deposition of the respective mask materials.
Etching is realized by a reaction between the precursor gas and the substrate materials resulting only in volatile by-products.
Deposition is realized by a fragmentation of different precursor gas molecules, again all the by-products are completely volatile. As the process is purely chemically induced, unwanted side effects, such as ion implantation or sputtering are absent.
Watch our MeRiT® anniversary video - 10 years of state-of-the-art mask repair.
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Critical defects identified by AIMS™ can be repaired precisely with the MeRiT® system based on e-beam technology. It repairs opaque and clear defects with unprecedented precision and stability. After the repair process the AIMS™ is the industry’s solution to validate the quality of the repair.