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. 16, 1999
Filed:
Aug. 14, 1997
John H Givens, Boise, ID (US);
Richard L Elliott, Meridian, ID (US);
Micron Technology, Inc., Boise, ID (US);
Abstract
A method is disclosed for improved side wall and bottom coverage of high aspect ratio space situated upon a substrate in two (2) steps. A lining is formed on a side wall surface of the space that terminated at a bottom surface. An opening then remains to a void defined by the lining and the bottom surface. The void is filled with a material passing through the opening to the space. When sputtered, the lining can be formed by a less-collimated sputtered particle flux, and the void can be filled by a collimated sputtered particle flux. The lining can be formed by flux in a plasma formed from a first gas having a neutral to ion ratio, and the void can be filled by a flux in a plasma formed from a second gas having a neutral to ion ratio lower than that of the first. Also, the lining can be formed by a flux in a plasma formed from a first gas having an atomic mass, and the void can be filled by a flux in a plasma formed from a second gas having an atomic mass lower than that of the first. The lining can be formed by sputtering a target having a crystal structure not preferentially oriented to maximize collimation thereof, and the void can be filled with a flux from a target having a crystal structure preferentially oriented to maximize collimation thereof. A confining magnetic field may be used to reduce electron losses at process chamber walls, allowing for improved collimation of the collimated flux. The substrate may also be heated or biased during exposure to the less-collimated flux to increase the good side wall and step coverage of the less-collimated flux, and cooled or reverse-biased during exposure to the collimated flux to increase the good bottom coverage of the collimated flux. Alternatively, the substrate may be exposed to only a collimated flux, but good side wall coverage can be achieved by alternating the temperature and/or bias of the substrate to provide the desired side wall and step coverage. Varied pressure can also be used to adjust material deposition.