| 摘要 |
PURPOSE:To prevent transfer of foreign matter and to improve the yield of a semiconductor product and working efficiency by controlling the air pressure in the hermetic space formed between the surface of a photomask, frames and shielding films thereby changing the space. CONSTITUTION:Bellows-like frames 13, 14 are attached to the peripheral part on the front and rear of a photomask 10 formed with a light non-transmittable film 12 on the surface of a transparent base plate 11 and respective thin transparent shielding films 15, 16 are extended at the other end edges thereof. Air is supplied into the hermetic spaces formed among th photomask 10, the frames 13, 14 and the films 15, 16 inbetween to make the space thereof variable. The space is made large in the stage of exposing to put foreign matter to the outside of the depth of focus even if such foreign matter sticks on the shielding films, thereby preventing transfer and generation of a defect and improving the yield of the semiconductor. The space is decreased to attain tight contact in the stage of inspecting the appearance of the mask 10. The automatic inspection is thus made possible without generation of the deviated focus of the optical system of an inspecting machine by the shielding films and the working efficiency is improved. |
