| 摘要 |
PURPOSE:To improve the quality of a pattern to be formed on a photoresist and to extend the life of a photomask by forming a groove to the part of the photomask where the mask contracts the peripheral edge of a semiconductor wafer. CONSTITUTION:The groove 12 is bored to the photomask 11 in the part where the mask contacts the circumferential edge of the wafer 100 to be brought into pressurized contact with the mask in alignment to the pattern thereof. This groove is formed to 2-5mm width A to meet the size of the wafer to be applied as the diameter of the wafer, mask pattern area, the transfer position of the pattern to the wafer, etc., are increasingly higher in accuracy in recent. Of the groove width A, 30-40% inner width B is tapered in the groove bottom, is shallower toward the inside and has a large depth of 0.5mm on the outside which is constant up to the outside edge. The mask is, therefore, protected against the damage by the circumferential edge of the wafer to be brought into pressurized contact therewith as the mask is kept free from contact with chipping, flawing, etc., by the groove. The service life of the mask is thereby extended 2-3 times and since the transfer of many sheets of the patterns with the damaged mask is not carried out, the yield of the product is improved by several %. |
