| 摘要 |
PURPOSE:To suppress the effect of a heat treatment step utmost, to prevent expansion of a diffusing region and to enhance the reliability of a device, by forming a capacitor and a transistor, and thereafter electrically connecting a storing electrode and a diffused layer. CONSTITUTION:A P epitaxial layer on a P<+> substrate is isolated with a P+ layer 25 and SiO2 23. The laminated masks of Si3N4 25 and SiO2 26 are provided. A groove 27 is formed by RIE, and the masks are removed. Multilayered films 28 of Si3N4 and SiO2 and poly Si are provided in the groove, and a storage electrode 32 is formed. Then, an SiO2 mask 30 is provided, and a gate insulating film 33 is formed. The surface is covered with N-type poly Si 34. A resist mask 31<-2> is provided. A window is provided by etching. An N<+> layer 35 is provided by ion implantation. The surface is covered with SiO2 37 incorporating B and P. A connecting part 40 utilizing an N-type poly Si conductor layer 39 is provided in the vicinity of the upper end of the groove 27 by using the resist mask. An SiO2 film 41 is overlapped. A window is opened on an N<+> layer 35. An Al wiring layer 44 is attached. In this constitution, deterioration in element isolating characteristics and deterioration of bonding breakdown strength for the ground substrate can be prevented, and the highly reliable memory device is obtained. |
