| 摘要 |
<p>In a projection exposure method for the exposure of a radiation-sensitive substrate arranged in the region of an image surface of a projection objective with at least one image of a pattern of a mask arranged in the region of an object surface of the projection objective, laser radiation having a spectral intensity distribution I(ω) dependent on the angular frequencyωis used. The laser radiation is characterized by an aberration parameterαin accordance with:α:=∫I (ω) ω2 ⅆ ω∫I (ω) ⅆ ωand a coherence timeτin accordance with:τ=∫I (ω) 2 ⅆ ω[∫I (ω) ⅆ ω] 2 The laser radiation is introduced into an illumination system for generating an illumination radiation directed onto the mask, and the pattern is imaged onto the substrate with the aid of a projection objective. The spectral intensity distribution is set so thatατ2≰0.3. The influence of temporally varying speckles on image generation can be reduced by comparison with conventional methods, without simultaneously increasing the influence of chromatic aberrations on image generation.</p> |
