Alignment target for electron-beam write system
CA 1195437 A · Owner: Fairchild Camera And Instrument Corporation · Inventors: Davis, T. Grant
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An alignment target for an electron-beam direct write system is formed on a wafer of semiconductor material. First a layer of silicon oxide is formed on a surface of the wafer. Then a layer of silicon nitride is formed on the oxide. Next, an opening is etched in the nitride layer to expose a surface portion of the oxide. The surface portion of the oxide is then etched to form a hole in the oxide. The hole is formed such that the oxide layer is undercut beneath the nitride layer such that a cantilevered nitride overhang is formed around the perimeter of the hole. A layer of aluminum is then deposited over the nitride layer.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted October 15, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 15, 2002.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.