High Fidelity Pattern Transfer with EUV Mask
With the device scaling to increase bit cost the 193-immersion lithography is seeing an end of scalability due to the shrinking critical dimensions that needs to be patterned. EUV Lithography comes as a very precise patterning solution to meet the needs of scaling. However, there are significant challenges in working with EUV Photo Resist material. Primarily EUV Photo Resist are thin and fragile which leads to low selectivity and marginal pattern transfer performance. The shot noise effect during dosing leads to Line Edge Roughness (LER) in EUV PR and transferred layers.
To address the challenges of EUV etch the process requires a unique capability of mask repair while transferring the pattern to the underlying films. In this talk I will elaborate how to overcome some basis challenges of patterning using EUV mask and the criticality of process space to enable high fidelity pattern transfer. Fundamental mechanism of etch and how that understanding give us an edge for EUV patterning will be discussed.