초록 ▼

A polishing apparatus polishes a workpiece such as a semiconductor wafer while detecting a thickness or a flatness of a surface layer of the workpiece on a real-time basis. The polishing apparatus includes a turntable with a polishing cloth mounted on an upper surface thereof, and a top ring dispose

A polishing apparatus polishes a workpiece such as a semiconductor wafer while detecting a thickness or a flatness of a surface layer of the workpiece on a real-time basis. The polishing apparatus includes a turntable with a polishing cloth mounted on an upper surface thereof, and a top ring disposed above the turntable for supporting a workpiece to be polished and such workpiece against the polishing cloth. The polishing apparatus also has a thickness detector for detecting the thickness of a surface layer of the workpiece supported by the top ring while the workpiece is being polished without exposing the workpiece. The thickness detector includes a sensor mounted in the turntable and including at least one light-emitting element for emitting light toward the surface layer of the workpiece and at least one light-detecting element for detecting light reflected from the surface layer of the workpiece.

대표청구항 ▼

[ What is claimed is:] [1.] A polishing apparatus comprising:a turntable having thereon a polishing surface;a top ring disposed above said turntable for supporting a workpiece to be polished and for pressing the workpiece against said polishing surface; anda thickness detector operable to, during re

[ What is claimed is:] [1.] A polishing apparatus comprising:a turntable having thereon a polishing surface;a top ring disposed above said turntable for supporting a workpiece to be polished and for pressing the workpiece against said polishing surface; anda thickness detector operable to, during relative movement between said top ring and said turntable, detect a thickness of a surface layer of the workpiece by performing a plurality of thickness detection operations over time and thereby to detect the thickness of the entire surface layer of the workpiece, each said thickness detection operation comprising detecting thickness of the surface layer at a plurality of spots spaced radially of said turntable at one time on a real-time basis, said thickness detector including a sensor mounted in said turntable at a position within a path of relative movement between said top ring and said turntable and operable to perform said plurality of thickness detection operations over time, said sensor comprising a plurality light-emitting elements operable to emit respective light beams toward the surface layer of the workpiece and a plurality of light-detecting elements operable to detect respective of the light beams reflected from the surface layer of the workpiece, said plurality of said light-emitting elements and said plurality of said light-detecting elements being spaced radially of said turntable, said light-detecting elements generating signals representative of detected thickness at said plurality of spots, and said signals being processed together to determine the thickness of the surface layer of the workpiece.