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. 17, 1998
Filed:
Jun. 03, 1997
Taiwan Semiconductor Manufacturing Company, Ltd., Hsin-Chu, TW;
Abstract
A method of testing a dry oxidation furnace for leaks which permit the entry of moisture into the oxidizing ambient is described. Such moisture, when present in sufficient concentration, can cause a high degree of boron depletion in silicon at p-type contact interfaces in the manufacture of p-channel MOSFETs. The depleted silicon presents a high resistance component to the contact thereby compromising its performance. A test wafer is subjected to a non-oxidizing ambient in the furnace according to a prescribed procedure. Measurements of the thickness of an oxide layer on the test wafer before and after the procedure indicate the presence of a leak of sufficient proportions to cause a deterioation of contact performance if the oxide grown during the test procedure exceeds between about 25 to 35 Angstroms. The procedure is also useful as a simple means of monitoring an oxidation furnace to provide a record of performance and signal the development of trends which suggest appropriate remedial maintenance.