| 摘要 |
PURPOSE:To simultaneously polish both main surfaces of wafer by sequencially controlling the processes of lifting wafer on the carrier after polishing, guiding and holding the holding part on the wafer and then sending wafer to the next process. CONSTITUTION:There are gears 13, 14 on a lower plate 12 of which upper surface is covered with a polishing pad 1 and these gears are engaged with peripheral gears of a circular glass epoxy carrier 15. A wafer is engaged into a hole 15a provided at the center of carrier and it is then caused to rotate by itself and also to rotate in orbit. The lower plate 12 and the upper plate 16 having pad 1 are arranged facing each other and these rotate in opposite direction. The plates 12, 16 are respectively provided with the water path 17, and the water is sprayed, after polishing, from the hole 18 in order to lift the wafer. Then, a holding means 21a rotates in accordance with a command 20, the center detection head of three fingers 21 detects wafer position by making use of difference of light reflectivity and thereby the wafer is held. Thereafter it is carried to the water tank by a carrying mechanism 23 and completes the polishing of both sides. Each of these processes is sequentially driven in the specified schedule in accordance with electrical signal of sequence controll circuit 25. Accordingly, wafer is polished efficiently. |
