| 摘要 |
PURPOSE:To accurately form a guard ring in a self-matching manner without increasing the number of photoetching process by a method wherein a groove is formed by performing etching on a second insulating film along the circumference of an aperture part in a selfmatching manner, and the guard ring is formed through the intermediary of the groove. CONSTITUTION:The second oxide film 24 is formed on the aperture part 23a which is selectively provided on a first oxide film by selectively performing etching. Then, when a second oxide film 24 is etched using a dilute hydrofluoric acid etchant, a groove 25 is formed on the stepped part of the second oxide film 24 in a self-matching manner. Subsequently, p-type impurities such as boron, for example, are ion-implanted on the surface of a semiconductor substrate through said groove 25. Then, the guard ring 26 consisting of a p-type semiconductor layer is formed on the surface of the semiconductor substrate along the aperture part 23a on the first oxide film 23 by performing a heat treatment. As a result, the guard ring 26 can be formed accurately along the aperture part 23a on the oxide film 23 in a self-matching manner without increasing the number of photoetching process. |
