| 摘要 |
PURPOSE:To prevent the generation of an error in detection of the endpoint by a method wherein the position of the material to be processed is detected, a measuring light is made to irradiate on the detected position in synchronization with the rotation of a spinhead, the reflected light sent from the above- mentioned part is received, and the endpoint is detected. CONSTITUTION:The XY table 22 and the motor 23 of an orientation flat detector 21 are operated, and the light projector 26 and the light receiver 27, provided at the tip part of an arm 25, are brought closer to one side of an wafer 1 by the pivotal movement of the arm 25. Subsequently, the wafer 1 held by a spinhead 10 is rotated slowly, and the wafer 1 is projected by the light projector 26. When the light projected on the wafer 1 passes through an orientation flat in association with the rotation of the wafer, it is received by a light receiver 27. As a result, the position of the orientation flat 1a on the wafer 1 held by the spinhead 10 is detected by the output of the light receiver 27, and the detection of endpoint can always be conducted constantly. |
