To provide a multiphoton aligner with high compatibility, which can use most of the optical systems of a conventional aligner without modification.
A 2-photon illumination light 1 is composed of a light in a 2-photon state illuminates a reticle 2 from above. Reference numeral 4 is a diffractive direction of a first order diffractive light of the light in a 1-photon state, and as a diffraction angle is large, the light cannot be incident on a projection optical system 3 as shown in the figure. However, as the diffraction angle becomes 1/2 in the light in the 2-photon state, the first order diffractive light advances in a direction shown by reference numeral 5, and the light is incident on the projection optical system 3 to form an image on a wafer 6. Due to a known quantum-mechanical effect, the light in the 1-photon state interferes as a pattern of a cycle 1/2 times that of incidence to form an image, thereby materializing the definition double an image formation limit in the prior art.
OSAWA HISAO
FUKUTAKE NAOKI
OKI YASUSHI
