| 摘要 |
PURPOSE:To obtain a highly integrated read only memory device, by utilizing the side walls of groove parts provided in a semiconductor substrate as active regions for memory plane, and arranging memory cells on the side walls of the groove parts in a self-aligning pattern. CONSTITUTION:Photoresist 17 is formed on a polycrystalline silicon layer in a selected region other than vertical-groove forming regions. The entire surface is etched. The polycrystalline silicon layer is made to remain on the side walls of vertical grooves 15 and on each surface directly beneath the photoresist 17. Thus gate electrodes of memory cells 18-22 and a gate electrode of a selector transistor 11 are formed. A mask is written by implanting arsenic ions. N-type diffused layers 26 and 27, which become a source and a drain, respectively, are formed. Memory cells have the gate electrodes 18-22 and have the different depression types and enhancement types. A memory plane, in which said memory cells are arranged, is completed together with the selector transistor having the gate electrode 11. Thus the integration density of double value can be achieved. |
