Photoelectron scattering and acid release in EUV lithography: a simulation study (Conference Presentation)

Abstract BACKGROUND: The ionizing wavelength in extreme ultraviolet (EUV) resist exposure leads to photoelectron scattering and uncertainty in the resulting acid image, producing line-edge roughness (LER) and poor CD uniformity of the printed features. GOALS: Try to determine how photoelectron and acid exposure blur effects affect EUV lithography and how they might be better controlled. Try to determine whether or not, and if so under what conditions, high resist quantum yields are beneficial to EUV lithography. METHODS: Using a stochastic resist simulator, we study the effects of resist properties upon photoelectric scattering, the uncertainty in the acid release and the properties of the after-development photoresist image in high NA EUV lithography. Uncertainty in the release of acids is the fundamental cause of LER and the ultimate limiter of optical lithography technology.