Making trench capacitor with insulating collar in substrate for use as semiconductor memory cell, employs selective masking, filling, lining and removal techniques

摘要

The trench (5) is formed in the substrate (1) using a mask (3). Capacitor dielectric (30) and conductive filling is provided in the upper and central regions of the collar (10), both reaching the same height relative to the top surface (OS) of the substrate. A liner (50) added in the trench, is then filled (60), the filling being encapsulated by it (50). A mask (70b) on the filling defines the trenched contact (80) structure. Using the mask, the filling is removed. The underlying liner is removed, laying bare part of the collar (10). The part of the collar associated with the contact (80) is removed. The trenched contact (80) is formed between the filling (20) and the substrate (1).