Excimer Laser Polysilicon Patterning
Original Publication Date: 1986-Jun-01
Included in the Prior Art Database: 2005-Mar-09
Publishing Venue
IBM
Related People
Braren, B: AUTHOR [+3]
Abstract
After blanket deposition on a silicon wafer of a layer, such as polysilicon, it is difficult to detect the alignment patterns for further processing. The method described uses a laser beam defined by a suitable mask to ablate the undesired portion of the blanket layer to reveal the desired alignment marks.
Excimer Laser Polysilicon Patterning
After blanket deposition on a silicon wafer of a layer, such as polysilicon, it is difficult to detect the alignment patterns for further processing. The method described uses a laser beam defined by a suitable mask to ablate the undesired portion of the blanket layer to reveal the desired alignment marks.
It is particularly difficult for automatic alignment equipment to read through a polysilicon layer to underlying alignment marks. Experiments have shown that by using an excimer laser with a 248nm beam through a metal mask, 3500 A thickness of polysilicon was removed without damaging the underlying alignment equipment. This method is simpler than using standard photo- lithographic methods to preserve the marks.
Disclosed anonymously.
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