| 摘要 |
PURPOSE:To enable an optical lithography device to be kept high in stability of refractive index and transmissivity for a long time and lessened in fluorescence by a method wherein an optical system is partially formed of quartz glass which contains OH groups more than a specific value. CONSTITUTION:An optical lithography device carries out a line drawing by a method wherein a KrF laser beam 2 oscillated by a KrF laser resonator is collimated through the intermediary of a turning mirror 31, an image forming lens 32, and a scanning lens 33, the collimated laser beam is made to scan in prescribed directions by a scanning mirror 34 impinging on the scanning mirror 34 and then to impinge on a pattern on a reticle 4 through the intermediary of a scanning lens 35 and a condensing lens 36 to obtain a pattern image 20, and the pattern image 20 is formed on a photoresist 51 deposited on a wafer 5. The laser optical system of this device is at least partially formed of quartz glass of high purity, and quartz glass is made to contain at least OH groups as much in concentration as 300ppm or above. |
