| 摘要 |
PURPOSE:To reduce the area of a Schottky barrier diode (SBD) element by eliminating the step of matching a mask in the step of forming a guard ring of the SBD element. CONSTITUTION:After an N<+> type buried layer 2 is formed on the surface of a P type silicon semiconductor substrate 1, an N type epitaxial layer 3 is formed. A maks layer 4 formed of a silicon nitride film is formed further on the surface region, and with the layer 4 as a mask an epitaxial layer 3 is selectively etched. Subsequently, a P type impurity is introduced to the selective etched surface of the epitaxial layer to form a P type semiconductor region 10. Thereafter, a selective oxidation is conducted thereon to form a silicon oxide film 5 thereon, and a guard ring 7 is formed thereon. Then, after the layer 4 is removed, a metallic layer of aluminum or the like is evaporated, a metallic electrode 8 is formed thereon, and an SBD element is thus formed thereon. Thus, it can suppress the increase in the area of the element due to the displacement of the mask. |
