Hemlock Semiconductor Corporation

Lydia L Hwang

James R McCormick

Richard C Dumler

Michael Bourbina

Scott Allen Wheelock

Joaquin Enrique Luna

Arthur Francis Porsche

Daniel P Rice

Maurice D Lovay

A method for removing metal surface contaminants from silicon metalloid. The method comprises sequentially contacting the silicon with gaseous hydrogen fluoride and then with an aqueous solution comprising at least one-half weight percent hydrogen peroxide. The method is especially useful as a means for recovering metal surface contaminants on semiconductor grade silicon for analysis of surface contamination of the silicon by such metals. The method is useful for recovering copper from the surface of semiconductor grade silicon in an aqueous solution which can be analyzed directly to determine the amount of copper contamination of the surface of the silicon.

Method for removing metal surface contaminants from silicon

The instant invention is a method for converting particulate silicon into monocrystalline silicon suitable for the determination of contaminates present in the particulate silicon. The method uses a silicon vessel, with known levels of the contaminates to be determined, to contain the particulate silicon. The silicon vessel, containing the particulate silicon, is float-zone processed to form a monolithic unit of monocrystalline silicon. The concentration of contaminates in the monocrystalline silicon can then be determined by the more sensitive analytical methods known for analysis of monolithic, monocrystalline silicon. The instant method is especially useful for measuring very low levels of aluminum, boron, phosphorous, and carbon in particulate silicon.

Analytical method for particulate silicon

The present invention is a method for analyzing irregular-shaped chunked silicon for low-level contaminates. The method comprises selecting a zonable-chunk of silicon and float-zoning the chunk of silicon to effect a distribution of surface contaminates into the bulk of a monocrystal of silicon. The float-zoned monocrystalline silicon is then processed into a wafer suitable for analysis for low-level contaminates.

Method for analyzing irregular shaped chunked silicon for contaminates

A method for analyzing and quantifying the individual trace metals content of a semiconductor material in the low to sub-parts per billion (ppba) range. The method comprises (A) float-zone refining of a sample of the semiconductor material creating a melt zone containing essentially all the trace metals of the sample; (B) cooling the melt zone to form a solid zone concentrated in trace metals; (C) separating the solid zone concentrated in trace metals from the sample of the semiconductor material; (D) converting the solid zone concentrated in trace metals into a form suitable for trace metals analysis; (E) analyzing the solid zone with known trace metals analytical techniques; and (F) calculating total trace metals from these analytical results. This method can also be applied to the small tip which forms on the side of the solid zone.

Growing community of inventors

Midland, MI, United States of America

Lydia L Hwang