Semiconductor memory cell capacitor prodn. - involves forming multilayer cylindrical storage electrode

摘要

(A) A semiconductor memory cell capacitor has a cylindrical storage electrode with three or more layers. (B) Prodn. of a semiconductor memory cell capacitor involves (a) producing first, second and third interlayers successively on a conductive substrate and then producing a capacitor contact hole; (b) depositing a first conductive layer on the entire surface ad a fourth interlayer (25) on the first conductive layer; (c) depositing and structuring a second conductive layer (26) to produce a protruding section (27); (d) forming a multilayer stack for alternate third conductive layers (28) and fifth interlayers (29) on the protruding section (27); (e) back-etching the third conductive layers and fifth interlayers to leave multilayer ribs (33) around the second conductive layer (26); (f) etching the fourth interlayer (25) using the ribs (33) as mask; (G0 depositing a fourth conductibe layer; (h) back-etching the fourth, third, second and first conductive layers; (i) etching the fourth and third interlayers by wet etching to form a first storage electrode; and (j) producing a dielectric layer on the first storage electrode and a capacitor electrode plate on the dielectric layer. ADVANTAGE - The capacitor has increased capacitance.