DRAM capacitor production employs a side wall support structure and an etch-stop layer

摘要

A memory capacitor production process comprises applying a conductive side wall support structure (7) on a structure of an alternating first material and second material layer sequence (61, 62), an etch-stop layer (5) and a first material layer (4), forming an opening (8) through the layer sequence (61, 62) and removing the etch-stop layer (5) and the second material layers (62). A capacitor is produced in a memory IC by: (a) applying a first layer (4) of conductive first material and an auxiliary etch-stop layer (5) on a support (2); (b) applying a sequence of alternating first material layers (61) and second material layers (62); (c) structuring the layer sequence, the auxiliary layer (5) and the first layer (4) to form a layer structure; (d) covering the layer structure side walls with a conductive support structure (7); (e) forming a layer structure opening (8) which extends through the entire layer sequence (61, 62); (f) removing the auxiliary layer (5) and the second material layers (62) selectively with respect to the first material and the support structure; (g) producing a capacitor dielectric onto the exposed surfaces of the first material layers (61) and the support structure (7); and (h) forming a counter-electrode on the dielectric. Preferred Feature: The first material is doped silicon and the second material contains 10-100 mol% germanium and 0-90 mol% silicon. Alternatively, the first material is p<+>-doped polysilicon and the second material is p<->-doped or undoped polysilicon. The support structure consists of the first material.