| 摘要 |
PURPOSE:To simplify the setting of processing condition and shorten heat tread ing time in the processing of wafers by forming a heat absorbing film imperme able to infrared ray on a wafer, opening a window in this film, implanting impurity ions through this window to the wafer and finally irradiating the wafer with infrared light for the thermal diffusion of impurities. CONSTITUTION:On a wafer 11 on which a p type region 12 is formed by doping and thermal diffusion, a heat absorbing film 14 and a resist film 15 are successively formed and then the resist film 15 is patterned as the heat absorbing film on the region 13 is exposed. A window is opened through the heat absorbing film 14 and ions are implanted as indicated with arrows in the figure, through the said window to dope n type impurities in the region 13. The species of impurities, accelerating energy and the amount of dose in ion implantation are determined in accordance with the size of n type region to be formed. Finally the resist film 15 is removed and infrared light is imposed on the wafer in the direction of arrows shown in the figure. The required power of infrared light is also determined in the same way as in the case of ion injection. At this time, the p type region 12 is never affected because infrared light is absorbed by the beat absorbing film 14. |
