Laser-written binary OMOG photomasks for high-volume non-critical 193-nm photolithographic layers

作者：R. Rivière, Selvi Gopalakrishnan, Martin Mazur, Nevzat Öner, Sven Mühle, Rolf Seltmann · 发表于：Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 年份：2014 · DOI：10.1117/12.2059622 · 研究领域：Advancements in Photolithography Techniques、Semiconductor materials and devices、Advanced Memory and Neural Computing

Photomasks are key elements of photolithographic processes, implying that their degradation must be reliably monitored and strongly mitigated. Indeed, the photo-induced oxidation of Cr in Cr On Glass (COG) photomasks and the concomitant electrostatic-field migration present in high-volume production using 193-nm photolithographic scanners severely deteriorate the pattern transfer quality, therefore limiting the lifetime of these reticles. To moderate this effect, Opaque MoSi On Glass (OMOG) photomasks, significantly less prone to such degradation, are currently being massively used in leading-edge microfabrication flows. The type of mask fabrication process normally used involving ebeam writing is however not adapted for non-critical photolithographic layers that do not yet benefit from its inherent performances but still suffer from its high cost and its long processing time. It is therefore proposed in this work to combine the simplicity of laser writing and the resistance of MoSi to degradation by using laser-written binary OMOG photomasks for the non-critical layers (e.g. ion-implantation) of a 28-nm production flow. To evaluate one of this new reticle, its pattern transfer fidelity is compared to the one of a laser-written binary COG mask already qualified for production from a photolithographic quality perspective, both masks being treated using the same optical proximity correction (OPC) model. Dispersive and dissipative properties, critical dimension uniformity, patte...