Motorola Corporation

James B Hall

Fernando A Bello

Earl W O'Neal

Herng-Der Chiou

Sumner Sheff

Lawrence Duane Mason

Cindy Welt

Martin G Robinson

Ronald C Swift

James S Parsons

Otto Luedke

George W Bailey

A method for pre-shaping a major surface (21,22) of a semiconductor wafer (20) in preparation for polishing includes shaping the major surface (21,22) so that it has a concave shape. In a preferred method, an etching process is used to form the concave shape. The concave shape provides a starting wafer that is extremely flat after polishing.

Method for pre-shaping a semiconductor substrate for polishing and

A single crystal ingot (10) is grown by first inserting a single crystal seed (14) into a melt (11) and pulling the seed (14) at a high pulling rate to grow a single crystal neck (15). The pulling rate is then altered to grow an overhang (18) with a diameter greater than that of the single crystal neck (15). An elongated body (19) is formed below the overhang (18) by adjusting the pulling rate. A multi-arm fixture (30) grabs the overhang (18) to alleviate the tensile and torsional stresses in the single crystal neck (15) that may be caused by the weight and the rotational motion of the single crystal ingot (10).

Single crystal ingot and method for growing the same

An improved method for polishing a semiconductor substrate includes forming a protective layer (21) on one major surface (24) of a substrate (19) to form a protected side and polishing an unprotected surface (26) of the substrate (19) with a double sided polisher (11). During the polishing process, material from the unprotected side (26) is removed at a faster rate than material from the protected side. The method provides a single side polished substrate (19) with improved flatness characteristics. In an additional embodiment, polishing pads (13,23) having different surface contact characteristics are used to support process automation.

Method for polishing a semiconductor substrate

A reduction in the number of impurities and defects on a semiconductor wafer is provided by cleaning the wafer in a hydrochloric acid, hydrofluoric acid, and water solution. This HCl:HF:H.sub.2 O solution removes silicon dioxide as well as metallic impurities from the wafer surface, thus preventing the formation of defects on the wafer and increasing the quality and yield of semiconductor devices.

Method of reducing defects on semiconductor wafers

A reduction in the number of impurities present in semiconductor wafers is obtained by gettering the impurities prior to mechanically lapping both wafer surfaces. Damage is created on both surfaces of the semiconductor wafer by the sawing of an ingot into many wafers. The impurities are then gettered to the damaged surfaces by subjecting the wafer to a high temperature. The subsequent lapping operation then removes the damaged regions along with the gettered impurities.

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Chandler, AZ, United States of America

James B Hall