Method and apparatus for polishing a semiconductor substrate wafer
AssigneeNational Semiconductor Corporation
InventorRahul Jairath
Life of this patent
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Abstract
A semiconductor wafer polishing apparatus includes a housing and a turntable mounted in the housing. The turntable has an axis of rotation and a surface for affixing a semiconductor wafer. The polishing apparatus also includes a motor mounted to the housing and connected to the turntable to supply a torque for rotating the turntable about the axis of rotation. A polishing assembly is connected to the housing and extends adjacent to the turntable surface. A polishing pad is affixed to the polishing assembly and is positionable to contact the semiconductor wafer. Some polishing pads are cylindrical in form. Other polishing pads have a conical form.
Claims12
A method of polishing a semiconductor wafer comprising the steps of:
- affixing a semiconductor wafer to a turntable having a central axis;
- rotating the turntable and affixed semiconductor wafer about the central axis of the turntable at a controlled angular velocity and angular direction;
- positioning a polishing pad at a selected location relative to the semiconductor wafer, the polishing pad having an outer conic quadric surface, having a central axis and having a lateral edge substantially perpendicular to the central axis of the turntable in a plane parallel to the plane of the turntable;
- and
- pressing the polishing pad into contact with the rotating semiconductor wafer at a controlled pressure.
A method of polishing a semiconductor wafer comprising the steps of:
- attaching a semiconductor wafer disk to a horizontal planar surface of a rotary disk turntable, the rotary disk turntable having an essentially circular top view and having a substantially vertical central axis;
- rotating the rotary disk turntable around the substantially vertical central axis;
- positioning a conical polishing pad so that a lateral edge of the conical polishing pad is adjacent to the substantially planar horizontal surface of the semiconductor wafer disk
- rotating the conical polishing pad around the conical polishing pad central axis;
- and
- contacting the lateral edge of the conical polishing pad to the horizontal planer horizontal surface of the semiconductor wafer disk at a controlled pressure.
Dependencies are inferred from the claim text.