| 摘要 |
PURPOSE:To contrive to increase the integration of elements by enabling a fine field oxide film having a small difference in dimensional conversion to be surely formed by a method wherein a film is left so as to cover the inclined surface of at least the etching region of a substrate, and thermal oxidation is carried out by using the first and second remaining nitride films as a mask. CONSTITUTION:A thermal oxide film 12, a nitride film 13, and a CVD oxide film 14 are deposited on the P<-> type Si substrate 11, which are then etched in the section scheduled for the field region, and the second nitride film 17 and the second CVD oxide film (film) 18 are successively deposited; then, the exposed nitride film 17 on the flat surface 16b of said section is etched. Next, a field oxide film 19 is formed by thermal oxidation in a combustion-oxidizing atmosphere with the first nitride film 13 on the section scheduled for the element region and the second nitride film 17 covering at least the inclined surface of the section scheduled for the field region as the oxidation-resistant mask. At the same time, a P type field inversion preventing layer 20 is formed by the activation of a boron ion implanted layer. Succeedingly, the remaining first and second nitride films are removed. |
