| 摘要 |
PURPOSE: To obtain a memory cell where the inner surface region and the capacitance of a trench capacitor increase, by providing a high-capacitance trench capacitor and a self-alignment access device at a memory cell of a fold- back bit line type. CONSTITUTION: A vertical pedestal structure made of p<+> polysilicon 22 is formed in each trench and is connected to p<+> substrate 10 electrically and physically. Then, a capacitor insulator is formed around the pedestal of the polysilicon 22 inside the trench and a p<+> polysilicon 26 is adhered to the inside of the trench and an opposing capacitor electrode is formed. Then, the inside of the trench is completely filled with the p<+> polysilicon. Then, a p<+> source region and a gate polysilicon 40 are formed. Then, after a metal contact stud 48 made of self-alignment tungsten is formed, a layer 50 of CVD-treated silicon dioxide is formed in a planar shape. Further, a bit line contact hole is opened and a metal adhesion layer 52 is formed and patterned. |
