Apparatus and Method for Alignment With X-Rays for X-Ray Lithography
Original Publication Date: 1988-Dec-01
Included in the Prior Art Database: 2005-Feb-15
By creating a set of high X-ray absorption alignment marks on silicon substrates and adding a solid shutter plus an aperture shutter to an X-ray exposure tool, mask-to-substrate alignment is performed in the exposure tool using X-rays of the wavelength normally used for photoresist exposure. Referring to the figure, a silicon substrate 2 has a set of alignment marks 4 and 6 comprised of a material having high absorption to X-rays. Marks 4 and 6 may be defined by normal photo exposure and etching methods. An X-ray mask 8 has a circuit pattern (not shown) and alignment regions each comprised of an opening in a solid field of high X-ray absorption material.