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US 6,182,675 B2Granted
Apparatus for recovering impurities from a silicon wafer
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsJiro Naka, Naohiko Fujino, Noriko Hirano, Junji Kobayashi, Kazuo Kuramoto
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Abstract
A method for recovering impurities on a surface of a silicon wafer includes a first step of using a pretreatment solution to decompose an oxide film, a nitride film on an oxynitridation film formed at a peripheral portion on a surface of a silicon wafer and to remove impurities on the peripheral portion and a second step of recovering impurities on the surface of the wafer expect for the peripheral portion.
Claims4
An apparatus for recovering impurities from a central portion of a surface of a wafer comprising:
- means for immersing only a peripheral portion of a surface of a wafer in a first liquid;
- means for rotating the wafer with only the peripheral portion of the surface immersed in the first liquid;
- means for mounting the wafer, after removal of the peripheral portion from the first liquid, with the surface in an oblique orientation;
- means for dripping a second liquid onto a central portion of the surface of the wafer;
- and
- means for collecting the second liquid dripping from an edge of the surface of the semiconductor wafer.
3 more elements
Dependencies are inferred from the claim text.