Wet bottling process for small diameter deep trench capacitors

摘要

A method including forming a deep trench in a semiconductor-on-insulator substrate including an SOI layer directly on top of a buried oxide layer directly on top of a base substrate, masking only a top surface of the SOI layer and a sidewall of the SOI layer exposed within an upper portion of the deep trench with a dielectric material without masking any surface of the base substrate exposed within a lower portion of the deep trench, and forming a bottle shaped trench by etching the base substrate exposed in the lower portion of the deep trench selective to the dielectric material and the buried oxide layer.

主权项

1. A method comprising:
forming a deep trench in a semiconductor-on-insulator substrate comprising an SOI layer directly on top of a buried oxide layer directly on top of a base substrate; masking a top surface of the SOI layer and an entirety of a sidewall of the SOI layer exposed within an upper portion of the deep trench with a dielectric material, wherein a bottommost surface of the dielectric material in the deep trench is located above an interface between the buried oxide layer and the base substrate; and forming a bottle shaped trench by etching the base substrate exposed in the lower portion of the deep trench selective to the dielectric material and the buried oxide layer.