| 摘要 |
PURPOSE:To reduce the damage to be inflicted on the X-ray lead-out window and to make thinner the film of the window by a method wherein the direction of the normal of the X-ray lead-out window and the central axis of a group of electrodes to be used for growing plasma are mutually inclined, and at the same time, the central position of the X-ray lead-out window is deviated from the extension line of the axial direction of the plasma. CONSTITUTION:X-rays 8 are irradiated from high-temperature and high-density plasma 7 on the central axis of a group of an upper electrode 5 and a lower electrode 6; and ions, electrons, high-temperature gas and so forth, which are generated in the degradative process of the high-density plasma 7, are emitted in addition to the X-rays 8. The X-rays 8 are nearly radiated isotropically from each point of the plasma 7 on the periphery of a wafer 12, while to the X-rays, the ions, the electrons and the high-temperature gas and so forth are emitted to the axial direction of the plasma. In this case, when an X-ray lead-out window 10 is set up at a position with a constant angle from the axial direction of the plasma, the damage to be inflicted on the X-ray lead-out window by the particle groups 9 can be almost ignored. Meanwhile, in the X-ray exposure, an out-of-focussed image delta=2rs/D is generated according to the diameter 2r of the X-ray source, the gap (s) between the wafer 12 and a mask 11 and the distance D between the X-ray source and the mask 11. It is not desirable for the normal of the X-ray lead-out window to make an angle to exceed 45 deg. with the central axis of the electrodes because the out-of-focussed image becomes larger when the angle exceeds 45 deg.. The effective lower limit of the inclination angle is sufficient at 2-3 deg.. |
