Method for controlling the oxygen level of silicon rods pulled according to the czochralski technique
CA 1182385 A · Owner: International Business Machines Corporation · Inventors: Felix, Jean-Claude; Combronde, Jacques
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract The present invention relates to an improved method for pulling semiconductor monocrystalline rods in parti-, cular silicon rods, according to the Czochralski technique. The average oxygen concentration profile (02) is first determined for a given pulling equipment as a function of the length (L) of the rods pulled at a constant crucible rotation speed, that is (02) = f(L). The improvement consists in pulling the rods at a crucible rotation speed VRC which varies as a function of L according to a predetermined profile to ensure an oxygen concentration profile which is about constant along the rod. In practice under normal. conditions, it is sufficient to ensure at any moment that:, …
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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 February 12, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 12, 2002.
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Timeline
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.