Laser-assisted discharge produced plasma (LDP) EUV source for actinic patterned mask inspection (APMI)

Improved lithography resolution provided by EUVL simplifies the patterning process and makes it possible to use less restrictive design rules. This in turn enables cost effective scaling with extendibility. There are several technical challenges and infrastructure gaps that need to be resolved to make EUVL suitable for high volume manufacturing (HVM). These gaps relate to development of a stable and reliable high power EUV source, EUV resist and EUV compatible photomask infrastructure. Realization of Actinic patterned mask inspection (APMI) capability is a critical component of the required Photomask infrastructure [1,2]. Most critical enabler of actinic patterned mask inspection technology/capability has been the EUV source. In this contribution, we will discuss key aspects of the developed High-Volume Manufacturing (HVM) worthy LPD EUV source for APMI. These include performance aspects such as brightness and spatial position stability of the EUV emission, dynamics of the EUV-emitting plasma and long-term stability of the source