| 摘要 |
<p>PURPOSE:To prevent damage of a wafer or a boat by monitoring a rise or a drop of the boat with a groove detecting sensor and detecting a groove position and width by a groove detection signal and a boat position signal output from a boat position detector. CONSTITUTION:Laser light 15 from a semiconductor laser light emitting element of a projector 1 is shielded by a non-groove part of a boat 3 and received through a groove 3a by a light receiving element of a light receiver 2 resulting in a groove detection signal obtained from the light receiving element. This groove detection signal and a boat position signal output from a boat position detector 5 are input to a boat groove detecting unit 6 where a position and width of the groove of the boat 3 are detected, and the groove position and width signals are input to a main control unit 9 as a data for transfer operation. Thus an operator does not need to position the boat wherein the work of the operator can be relieved as well as accidents due to an error such that a wafer and the boat 3 are brought in contact and collide with each other to have the wafer or the boat 3 damaged can be prevented.</p> |
