Method of polishing waxers using a vertically stacked planarization

Abstract

A vertically stacked planarization machine includes two or more vertically stacked individual platens on which wafers are polished. The wafers are held by wafer holders which may rotate the wafers. The individual platens are also orbited in order to polish the wafers. The platens may have a top and bottom polishing pad for polishing multiple wafers. A single wafer holder, using hydraulic or pneumatic means, between two platens will hold and exert pressure on both a downward wafer and an upward wafer. The pressure exerted onto the top and bottom wafers by the dual wafer holder is designed to be equal to prevent any bowing of the platen. The platens are supported by three vertical members positioned at 120 degree intervals around the circumference of the platens to form a platen stack. Transport elevators are used to carry the wafers to and from the wafer holders and the platens. A polishing pad conditioner is also transported to the polishing pads within the stack periodically by use of a transport elevator in order to unglaze the polishing pad. In order to increase capacity, a single polishing machine may include more than one vertical stack of platens. A cam contains the stack and will drive the stack, during polishing, into an orbital motion. Each of the components of the stack is detachable for servicing and repair. A stack, in its entirety, may also be removed from the polishing machine for servicing.