Memc Electronic Materials, Inc.

Jing Chai

Henry Frank Erk

Ronald D Bartram

Eugene R Hollander

Jackie Watson

Thomas Eugene Doane

Judith Ann Schmidt

An apparatus for cleaning semiconductor wafers includes a tank for containing a liquid and receiving a wafer holder with at least a portion of the wafers immersed in the liquid in the tank. A sonic energy generator imparts sonic energy to the liquid. A wafer-moving mechanism in the tank reciprocates and rotates the semiconductor wafer so that at least a portion of the wafer repeatedly passes through an upper surface of the liquid. The wafer-moving mechanism comprises a camming mechanism rotatably received in the tank and a drive for rotating the camming mechanism about a fixed central longitudinal axis of the camming mechanism to reciprocate and rotate the wafer. The camming mechanism includes a cam body having opposing flats spaced apart on opposite sides of its longitudinal axis and opposing gripping surfaces extending between the flats. The cam body has a cross-section defining a major axis and a minor axis, with the major axis of the cam body cross-section being greater than the minor axis. The gripping surfaces have a circumferentially extending groove for receiving a peripheral edge of the semiconductor wafer therein. The groove is sized for gripping the edge of the wafer as the camming mechanism rotates thereby to inhibit slippage of the wafer relative to the camming mechanism and to maintain uniform rotation and reciprocation of the wafer.

Apparatus for cleaning semiconductor wafers

A process for cleaning contaminants from the surface of a semiconductor wafer after the wafer has been lapped. The process comprises contacting the wafer with an oxidizing agent to oxidize organic contaminants which may be present on the surface of the wafer. The wafer is then immersed in an aqueous bath comprising citric acid into which sonic energy is being directed to remove metallic contaminants which may be present on the surface of the wafer. After being immersed in the citric acid bath, the wafer is contacted with hydrofluoric acid to remove a layer of silicon dioxide which may be present on the surface of the wafer. The wafer is then immersed in an aqueous bath comprising an alkaline component and a surfactant, and into which sonic energy is being directed.

Post-lapping cleaning process for silicon wafers

A method of cleaning a semiconductor wafer comprises placing liquid in a bath with a gas-liquid-interface defined at the surface of the liquid. A semiconductor wafer is placed in the bath so that it is oriented in a generally upright position with at least part of the wafer being in the liquid and below the gas-liquid-interface. Sonic energy is directed through the liquid. At least one of the position of the semiconductor wafer and the level of liquid in the bath relative to the semiconductor wafer is varied so that the entire surface of the wafer repeatedly passes through the gas-liquid-interface.

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St. Charles, MO, United States of America

Jing Chai