POLISHING PAD, POLISHING METHOD, AND POLISHING MACHINE FOR MIRROR-POLISHING SEMICONDUCTOR WAFERS

摘要

THERE IS DISCLOSED A POLISHING PAD FOR MIRROR-POLISHING A SEMICONDUCTOR WAFER, ESPECIALLY IN A FINISH POLISHING PROCESS, BY USE OF A POLISHING MACHINE WHICH INCLUDES A TURN TABLE ON WHICH A POLISHING PAD IS ATTACHED, A UNIT FOR FEEDING A POLISHING AGENT ONTO A SURFACE OF THE POLISHING PAD, AND A MECHANISM FOR PRESSING A SEMICONDUCTOR WAFER ONTO THE SURFACE OF THE POLISHING PAD. THE POLISHING PAD INCLUDES A TOP LAYER FORMED OF A POROUS SOFT MATERIAL, A BOTTOM LAYER FORMED OF A RUBBER ELASTOMER, AND AN INTERMEDIATE LAYER FORMED OF A HARD PLASTIC SHEET. THE HARD PLASTIC SHEET IS DISPOSED BETWEEN THE TOP LAYER AND THE BOTTOM LAYER AND IS BONDED TO THE BOTTOM LAYER. IN THE POLOSHING PAD, UNDULATION PRODUCED IN THE BOTTOM LAYER DUE TO A HORIZONTAL FORCE GENERATED DURING POLISHING IS PREVENTED FROM BEING TRANSFERRED TO THE TOP LAYER OF THE POLISHING PAD, AND UNEVENNESS IN POLISHING STOCK REMOVAL STEMMING FROM WARPAGE OR UNDULATION OF A WAFER ITSELF CAN BE MITIGATED.