Method of producing dynamic random-access memory cells.

摘要

This invention relates to a method of producing a one-transistor cell for a dynamic RAM having a capacitor plate (26), a transfer gate (30) and a shallow n<+>-type region (25) and a deeper p<+>-type region (28) for a junction capacitance. After formation of a thin oxide layer (22) of a dielectric for a MOS capacitance, a patterned photo resist layer (24) is formed. Using the photo resist layer (24) as a mask, n-type impurities are doped into a semiconductor substrate (21). The capacitor plate (26) and a masking layer (27) are deposited on the photo resist layer (24) and the thin oxide layer (22). P-type impurities are doped into the capacitor plate (26). Then, portions of the capacitor plate (26) and masking layer (27) on the photo resist layer (24) are removed by removing the photo resist layer (24). An end portion of the capacitor plate (26) is removed from under an edge of the remaining masking layer (27) by etching. The p-type impurities are diffused into the silicon substrate (21) by heating to form the deeper p<+>-type region (28) which does not extend beyond the n<+>-type region (25).