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:
Dec. 14, 2004
Filed:
Mar. 06, 2003
Helmut Puchner, Santa Clara, CA (US);
Sheldon Aronowitz, San Jose, CA (US);
LSI Logic Corporation, Milpitas, CA (US);
Abstract
A method of forming a narrow isolation structure in a semiconducting substrate. The isolation structure is a trench that has a bottom and sidewalls, and that is to be filled with an isolating material. The isolating material has desired electrical properties and desired chemical properties, and is substantially reactively grown from the semiconducting substrate. A precursor material layer is formed on the bottom of the trench and on the sidewalls of the trench. The precursor material layer has electrical properties and chemical properties that are substantially similar to the desired electrical properties and the desired chemical properties of the isolating material. A substantial portion of the precursor material layer is removed from the bottom of the trench to expose the semiconducting substrate at the bottom of the trench, while leaving a substantial portion of the precursor material layer on the sidewalls of the trench. The isolating material is reactively grown in the trench, where the isolating material preferentially grows from the exposed semiconducting substrate at the bottom of the trench at a first rate. The precursor material layer at least partially inhibits formation of the isolating material from the semiconducting substrate at the sidewalls of the trench. The isolating material forms from the sidewalls of the trench at a second rate, where the first rate is substantially higher than the second rate. Thus, by forming a precursor layer that inhibits formation of the isolation material at the sidewalls of the trench, the isolation material preferentially grows from the bottom of the trench rather than expanding sideways from the sidewalls of the trench, which tends to widen the isolation structure. Because the precursor layer has properties that are substantially similar to those that are desired in the isolation material, the precursor layer remains at the sidewalls of the trench near the edge of the isolation structure. Therefore, the isolation structure functions as desired, but is narrower than it otherwise would be, if the precursor layer had not been formed.