| 摘要 |
PURPOSE:To enable high density integration, by forming all of the constitution elements of a one-transistor one-capacitor type DRAM cell in a trench, and insulating each trench from a base substrate with insulating films. CONSTITUTION:Three poly Si layers form each constitution element of switching transistors in a one-transistor one-capacitor type DRAM. A first layer is a source (storing electrode) 5, a second layer is a channel 6, and a third layer is a drain 9, which are connected to a bit line. An insulating film 10 covering a word wire 8, an insulating film 11 isolating an impurity diffusion layer 2 and a drain 9 between memory cells formed in a trench 3, and an insulating film 12 covering the upper part of a drain 9. In the trench 3, the storing electrode 5 and a switching transistor are formed, and the inner walls of the trench 3 are all covered with the insulating films 10-12, so that interference between adjacent cells does not generate. Thereby, enabling high density integration so far as working size allows. |
