Producing a low aspect ratio structure and buried strap for a trench DRAM forms and fills trench in semiconductor substrate with initial and sacrificial layers and selectively removes especially at sidewalls

摘要

Producing a low aspect ratio structure comprises forming a semiconductor substrate (1) with surface (2) openings (3) all covered by an initial layer, forming a sacrificial layer overall (9) and removing the external layers. The low aspect ratio structure (8) is then formed by removing part of the initial layer at the sidewalls within the opening and then the remaining sacrificial layer. An independent claim is also included for a method of forming a single-sided buried strap for a trench DRAM memory cell.