| 摘要 |
PURPOSE:To cut the access time by forming two pn-junctions with a primary region of one conductive type semiconductor, a secondary region of opposite conductive type semiconductor and a third region of one conductive type semiconductor in lamination structure and by joining the third region with the opposite conductive type substrate which extends through a buried layer. CONSTITUTION:A buried layer 6a allows a substrate 5 to pass through and extend immediately below the center of a region 3. The extending section 5a connects with the lower central section of the region 3. The peripheral section of the lower side of the region 3 connects with the buried layer 6a thus leading out the region 3 to an electrode 7b. When PROM device in this constitution is used as PROM memory cell S11-Snn, a minority carrier, if storaged in the region 3, is led in the substrate 5 which becomes a majority carrier through the connection with the extending section 5a of the substrate 5, thus reducing the time required for dissipation. In this way, it is possible to shorten the access time. |
