| 摘要 |
<p>PURPOSE:To reduce the margin for the time necessary to elimination of fixed charge of an electrostatic chuck, and improve the operating efficiency of an equipment and the throughput of processing. CONSTITUTION:The following are provided for constitution; a wafer retaining stand 1 retaining a wafer, lift pins 3 moving the wafer vertically on the wafer retaining stand, and stress sensors 4 detecting the stress applied to the lift pins at the time of vertical movement. The stress sensor is a contact type sensor using a spring, or a piezoelectric element, or a pressure gauge. The signal outputted from the stress sensor is fed back to a CPU governing wafer conveyance, which CPU is constituted so as to have a function to judge whether wafer conveyance is allowable.</p> |
