The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 04, 2003
Filed:
Dec. 18, 2001
Cateno M. Camalleri, Catania, IT;
Simona Lorenti, Catania, IT;
Denise Cali′, Catania, IT;
Patrizia Vasquez, Acireale, IT;
Giuseppe Ferla, Catania, IT;
STMicroelectronics S.r.l., Agrate Brianza, IT;
Abstract
A method of controlling the quantity and uniformity of distribution of bonded oxygen atoms at the interface between the polysilicon and the monocrystalline silicon includes carrying out, after having loaded the wafer inside the heated chamber of the reactor and evacuated the chamber of the LPCVD reactor under nitrogen atmosphere, a treatment of the wafer with hydrogen at a temperature generally between 500 and 1200° C. and at a vacuum generally between 0.1 Pa and 60000 Pa. The treatment is performed at a time generally between 0.1 and 120 minutes, to remove any and all the oxygen that may have combined with the silicon on the surface of the monocrystalline silicon during the loading inside the heated chamber of the reactor even if it is done under a nitrogen flux. After such a hydrogen treatment, another treatment is carried out substantially under the same vacuum conditions and at a temperature generally between 700 and 1000° C. with nitrogen protoxide (N O) for a time generally between 0.1 and 120 minutes.