| 摘要 |
<p>PURPOSE:To prevent occurrence of troubles, e.g. break-down in a substrate or the like by detecting the emission signal of the substrate resulting from the transmitted light of a laser beam out of a laser light source. CONSTITUTION:A laser light source 11 which emits a laser beam 10 from above to downward is provided in front of a wafer cassette 3 in a cassette housing part 4. Further, a photodetector 12 is installed so that its element and the light source 11 are facing each other and then, the laser beam 10 is disposed so that its laser beam comes in the photodetector. An output signal from this photodetector is inputted into, for example, a detecting part 13 consisting of a microprocessor or the like. Then, the detecting part 13 judges whether the laser beam 10 from the laser source 11 comes into the photodetector 12 and when it is judged that the laser beam 10 does not come, an emission-detecting signal is sent to a principal control part 8. Receiving the emission-detecting signal, the principal control part 8 stops at least carrying in and out of a semiconductor wafer 2 through an automatic carrier mechanism 7 towards the wafer cassette 3 and gives an alarm as well.</p> |
