| 摘要 |
PURPOSE:To detect the optimum position for transferring a semiconductor wafer, prevent the generation of damages in the semiconductor wafer, and thus improve the manufacturing yield by a method wherein a positioning groove provided in a boat for heat treatment is detected by a sensor. CONSTITUTION:A photo receiving element 17 turns on when a pulse signal enters the positioning groove 14 and detects one end part, and turns off when the signal comes out of the groove 14 and detects the other end part. On turning off, the width (a) of the positioning groove 14 is calculated out, in a microcomputer, by the product nXb of pulse feed times between the on and off of the photo receiving element 17 and a time of pulse numbers, which is then divided into two, thus determining the position for transferring the semiconductor wafer. When the photo receiving element 17 turns off, a stage 15 returns to the original position by a control signal from the microcomputer, moves to the transfer position determined by dividing the positioning groove 14 again, and is then stopped. When the stage 15 is stopped at the transfer position, a cassette holder on the stage 15 inclines, and a plurality of semiconductor wafers are transferred to the quartz boat 12 through a comb-form guide part at the same time. |
