| 摘要 |
PURPOSE:To improve the contrast of a resist while maintaining the simplicity of a single-layer resist method, and form stably a resist pattern having a high aspect ratio, by a method wherein photo resist is spread, a specified pattern is exposed applying ultraviolet rays, the whole part of a main surface is irradiated with a far ultraviolet rays, and then development is performed. CONSTITUTION:After a specified pattern is transferred and exposed on a photo resist applying a mask aligner, the whole surface is irradiated by far ultraviolet rays. The dissolving speed of resist of the exposed part at the time of development is given a gradient as follows; the speed is small on the resist surface and becomes larger as the depth increases. Thereby the contrast of resist can be improved. For example, the luminous intensity of whole surface radiation of the far ultraviolet rays is about 10mW/cm<2> according to the result of measurement by a 245nm sensor. As for development condition, the puddle phenomena is employed at 23 deg.C for 40 sec. A contrast value gamma=0.9 in the usual method (wherein, after exposure, development is performed without the whole surface irradiation of the far ultraviolet rays) is improved about twice, that is gamma=1.7, by irradiating the far ultraviolet rays for 6 seconds. When far ultraviolet rays are radiated, the temperature of the wafer is not lower than 80 deg.C and not higher than 130 deg.C, and a remarkable effect can be obtained. |
