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. 20, 2001
Filed:
Jan. 02, 2001
Mukul Khosla, San Jose, CA (US);
Lap Tam, Fremont, CA (US);
Ronald A. Powell, San Carlos, CA (US);
Ronald D. Allen, Union City, CA (US);
Robert T. Rozbicki, San Jose, CA (US);
Erich Klawuhn, San Jose, CA (US);
E. Derryck Settles, Sunnyvale, CA (US);
Novellus Systems Incorporated, San Jose, CA (US);
Abstract
Non-volatile and oxide residues that form during semiconductor processing are removed from the semiconductor structure in a two-stage process. An inert gas and a reducing gas are introduced to the reactor. In the first stage, the non-volatile contaminants are sputtered from the semiconductor structure by creating a plasma to ionize the inert gas. The power applied to the plasma is preferably high enough to give the ions of the inert gas a high degree of directionality as they approach the structure. The first stage is continued until the non-volatile contaminants have been sufficiently removed from the structure. In the second stage, the power is reduced and the reducing gas (e.g., hydrogen) reacts with the oxides (e.g., copper oxide) to form elemental metal and water vapor. During the second stage there is no appreciable sputtering, and therefore the damage to the structure is limited as compared with processes that use sputtering and reduction simultaneously.