Production of a trench capacitor in which a trench is etched into a substrate coated with a layer of Pa dioxide and Si nitride useful in electronics for DRAM storage cells

摘要

Production of a trench capacitor in which a trench (4) is etched into a substrate (1) coated with a layer of Pa dioxide (2) and Si nitride (3). The upper part of the trench has a sacrificial collar in Al oxide (6) which is not structured by the Al 2O 3-layer masked region, and the Al 2O 3 mask is removed after subsequent structuring cby etching. Before deposition of the sacrificial collar (6) an intermediate Si monoxide layer (8) of sufficient thickness is deposited on the masked surface.