Specific Process Knowledge/Lithography/EBeamLithography: Difference between revisions
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= Alignment of exposure to existing pattern on wafer = | = Alignment of exposure to existing pattern on wafer = | ||
[[Image:GlobalMark.png|200px|thumb| | [[Image:GlobalMark.png|200px|thumb|Recommended design of global mark: + shaped, 500-1000 microns in length, a few microns in width, clearly labeled.]] | ||
A set of global marks are needed in order to align an exposure to an existing pattern on a wafer. These marks should be clearly visible in a 100keV SEM, i.e. preferably defined by Ti/Au or another 'heavy' metal. Etched global marks or global marks defined by a light metal as Al can be hard to locate manually as well as automatically. | A set of global marks are needed in order to align an exposure to an existing pattern on a wafer. These marks should be clearly visible in a 100keV SEM, i.e. preferably defined by Ti/Au or another 'heavy' metal. Etched global marks or global marks defined by a light metal as Al can be hard to locate manually as well as automatically. | ||