| 摘要 |
A photolithographic method uses different exposure patterns. In one aspect, a photo-sensitive layer on a substrate is subject to a first exposure using optics having a first exposure pattern, such as an x-dipole pattern, followed by exposure using optics having a second exposure pattern, such as a y-dipole pattern, via the same mask, and with the photo-sensitive layer fixed relative to the mask. A 2-D post pattern with a pitch of approximately 70-150 nm may be formed in a layer beneath the photo-sensitive layer using 157-193 nm UV light, and hyper-numerical aperture optics, in one approach. In another aspect, hard baking is performed after both of the first and second exposures to erase a memory effect of photoresist after the first exposure. In another aspect, etching of a hard mask beneath the photo-sensitive layer is performed after both of the first and second exposures.
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