| 摘要 |
PURPOSE:To easily house a guard ring under a field oxidation film by providing a dual mask of poly silicon and silicon dioxide on a silicon tetranitride film of a silicon substrate, injecting an ion after partial-oxidation process, forming a silicon tetranitride mask through removal of a silicon dioxide and then oxidizing the said mask. CONSTITUTION:A silicon tetranitride 22 is provided on a silicon substrate 21 to apply masks of polysilicon and 23 and silicon oxide 24. Following this process, they are thermally oxidized to provide a polysilicon 23' and a silicon dioxide 24', increasing the volume of the layer 24'. After providing an ion injection layer 25, the silicon dioxide 24' is removed and the silicon tetranitride 22 is etched by means of a mask 23'. Next, if a field oxidation film 26 is created through oxidation, the ion injection layer 25 becomes a guard ring 25'. Following this process, the silicon tetranitride 22'' is removed to create an impurity diffusion layer 27 in an active region. Under this constitution, it is possible to house a guard ring under a field oxidation film through a single photographic etching process, controlling a distance between the active region and the guard ring easily and minimizing the increase of an inactive layer. |
