| 摘要 |
PURPOSE:To form a mask substrate of high flatness having the small strain, by providing a temperature gradient on the main surface substrate part and the peripheral substrate part of the substrate so as to pile up substrate thin films. CONSTITUTION:Nitrided boron films 13 and 14 are formed on a substrate 10 by an LPCVD (reduced pressure chemical gaseous growth) method. B2H6 (N2 dilution 6%) and NH3 are used for raw material gas and the substrate 10 shall be an Si substrate of surface orientation (100). A susceptor shall be of SiO2 and the heaters 11 and 12, which are different in the substrate central part and in the peripheral part, are provided. By keeping the temperature of the two resistance heating heaters 11 and 12 at 400 deg.C in the central part substrate while at 330 deg.C in the peripheral part substrate, a temperature gradient of 50 deg.C between both parts is formed on the same substrate. Accordingly, two thin films having different properties can be formed simultaneously on the substrate 10. Thereby, by providing a change of the substrate temperature distribution by simple heater heating, an X-ray mask main surface substrate having small stress can be manufactured by one chemical gaseous phase growth process. |
