This invention relates to an exposing device for producing a pattern image representative of a pattern on a reticle to irradiate the pattern image to a photo resist layer on a wafer on manufacturing a semiconductor device.
In the manner which will later be described more in detail, a conventional exposing device comprises an illuminating source, an illuminating optical system, a reticle, and a reducing optical system.
The illuminating optical system receives rays from the illuminating source to produce parallel rays. The reticle has a pattern. The reticle receives the parallel rays from the illuminating optical system to produce a reticle pattern image representative of the pattern. The reducing optical system reduces the reticle pattern image to produce a reduced pattern image as a pattern image. The pattern image is irradiated to a photo resist layer on a wafer.
A semiconductor device comprises the wafer, a plurality of isolator layers, and a plurality of conductor layers interposed between adjacent ones of the isolator layers.
A semiconductor device has a central portion and a side portion. The central portion has first through (N+1)-th isolator layers and first through N-th conductor layers, where N represents an integer greater than one. The side portion has first through (M+1)-th isolator layers and first through M-th conductor layers, where M represents an integer greater than one.
The N-th conductor layer has an N-th upper surface having an N-th level. The M-th conductor layer has an M-th upper surface having an M-th level. In case where N is extremely greater than M, the N-th level is extremely higher than the M-th level. Namely, the N-th level is extremely different from the M-th level. As a result, a photo resist layer on the N-th conductor layer and the M-th conductor layer has a central surface and a side surface which is extremely lower than the central surface. Consequently, the pattern image on the photo resist layer is unclear.