Method of using a projection aligner for photoetching
AssigneeSharp Kabushiki Kaisha
InventorAkio Gotou
Life of this patent
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Abstract
When a circuit pattern for a semiconductor device is exposed on a substrate with a coating of photoresist by using a projection aligner with positioning pads to properly position the substrate, photoresist is removed from such areas on the substrate that are expected to come in direct contact with the pads. The removing is effected before the substrate is exposed so that accumulation of photoresist on the pads can be prevented and substrates to be exposed subsequently can also be positioned accurately by using the projection aligner.
Claims6
In a photoetching process on a substrate having a surface covered with photoresist, a method of using a projection aligner having positioning pads for correctly positioning a substrate to be exposed by placing said substrate against said positioning pads, said method comprising the steps of
- placing a substrate on a chuck having an open top end such that one of mutually separated peripheral areas as of said substrate covered with photoresist and intended to come into contact with one of said positioning pads covers said open top end of said chuck, said chuck having inserted therein a tube having a jet nozzle,
- spraying said one of peripheral areas of said substrate with a washing liquid ejected through said jet nozzle of said tube so as to remove said photoresist from said one of peripheral areas of said substrate,
- similarly removing said photoresist from the others of said peripheral areas, thereby removing said photoresist only from selected mutually separated peripheral areas of said substrate corresponding to the positions of said pads, and
- thereafter placing said substrate on said projection aligner such that said mutually separated peripheral areas of said substrate are in contact with and supported by said positioning pads.
Dependencies are inferred from the claim text.