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. 26, 2002
Filed:
Sep. 21, 2000
Lam Research Corporation, Fremont, CA (US);
Abstract
An etch that provides a high oxide to photoresist selectivity in a low-pressure, high-density plasma is provided. An extremely high reverse RIE lag is achieved, wherein the etching of small high-aspect ratio openings is possible, but that of large openings is not. A high-density plasma is generated so that carbon monoxide (CO) is ionized to CO so that at least 1 sccm equivalent of CO is provided. Excited CO neutrals (CO*) are also present within the plasma. Fluorocarbon and hydrofluorocarbon gases are also provided. The excited CO neutrals scavenge free fluorine, near the wafer surface and in the large openings, increasing polymer deposition on the photoresist and in the large openings thus reduce or stop etching in those regions. Concurrently, CO is not hindered by diffusion limitation and is readily accelerated deep into the small openings by an applied electric potential; hence, providing oxygen atoms near the bottom of the small openings which help to remove polymer at the etch front and eliminates the propensity for etch stop.