Second, owing to matter's propensity to absorb EUV light, the entire optical path from the light source to the wafer must be in a near-vacuum (Fig. 2). To maintain this throughout the lifetime of ...
First, because EUV light is absorbed by air (in contrast with 193 nm light), the entire optical system, from source to wafer, must be enclosed in a near-vacuum environment. Second, because EUV ...