| 摘要 |
<p>In the field of immersion lithography, it is known to provide a liquid (107) between an optical exposure system (104) and a wafer (100) carrying layers of photosensitive material to be irradiated with a pattern by the optical exposure system (104). However, bubbles (124) are known to form or exist in the liquid (107), sometimes close to a surface (102) of the wafer (100) resulting in scattering of light emitted from the optical exposure system (104). The scattering causes the pattern recorded in the layers of photosensitive material to be corrupted, resulting in defective wafers. Therefore, the present invention provides a bubble displacement apparatus comprising a drive signal generator (122) for driving a force generator (120, 200, 202, 300) arranged to generate a force in response to a drive signal generated by the drive signal generator (122). The force generated urges the bubble (124) away from the surface (102).</p> |
