| 摘要 |
PROBLEM TO BE SOLVED: To detect a coated state of a protective film on a machined surface of a wafer using an infrared camera without being affected by unevenness in heat by a heater held by a holding table. SOLUTION: When the coated state of the protective film 170 is detected, the infrared camera 140 detects infrared rays radiated from the whole surface of the wafer 10 while there is a prescribed gap 180 between a backside 10b of the wafer 10 held by a ring frame holding means 130 and a holding surface 111 of the holding table 110, thus transferring the heat of the heater 112 as radiative heat, relieving the unevenness of heat, and allowing unevenness in the infrared rays detected by the infrared camera 140 to be unevenness depending on the covered state of the protective film. COPYRIGHT: (C)2010,JPO&INPIT |
