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:
Mar. 09, 1993
Filed:
Apr. 29, 1991
Klaus Beyer, Poughkeepsi, NY (US);
Edward C Fredericks, Manassas, VA (US);
Louis L Hsu, Fishkill, NY (US);
David E Kotecki, Hopewell Junction, NY (US);
Christopher C Parks, Beacon, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method of providing sublayer contacts in vertical walled trenches is proposed. In accordance with the present invention, the phosphorus doped amorphous silicon is deposited at temperatures less than 570.degree. C. The conversion into the extremely large crystal low resistivity polysilicon is accomplished by a low temperature anneal at 400.degree. C. to 500.degree. C. for several hours and a short rapid thermal anneal (RTA) treatment at a high temperature approximately 850.degree. C. for twenty seconds. These two conversion heat treatments are done at sufficiently low thermal budget to prevent any significant dopant movement within a shallow junction transistor. After anneal, the excess low resistivity silicon is planarized away by known techniques such as chemical/mechanical polishing. In addition, due to the trench filling abilities of the amorphous silicon CVD process, in one preferred embodiment of the invention the capability of accessing subsurface silcon layers at different trench depths is demonstrated.