| 摘要 |
PURPOSE:To readily from fine patterns on Si wafers for production of semiconductor elements by using the SOS wafer obtained by anisotropically etching away the required portions of the Si single film formed on the surface as a mask. CONSTITUTION:A SiO2 film 3 is formed on the SOS wafer comprising growing Si single crystal 2 having (100) crystal axis on the (1-102) plane of a sapphire substrate 1, thence openings 4 are provided in the SiO2 film 3 by an ultraviolet exposure method. Next, the Si single crystal film 2 is anisotropically etched by an anisotropic etching solution (potassium hydroxide-hydrazine, etc.) to provide openings 5, whereby patterns for production of semiconductor elements are formed. Next, with the abovementioned SOS wafer as a mask, ultraviolet rays 8 are radiated to the resist 7 on the Si wafer 6 for semiconductor element production to transfer the patterns of the SOS wafer. By the abovementioned method, the ultraviolet light transmission width W of the SOS wafer becomes the value reduced from the initial value W0 as shown by the formula (Wo is width in the SiO2 film 3; t is the thickness of the Si film 2; theta is 54 deg.34'). |
