Method for fabricating trench capacitors and semiconductor device with trench capacitors

US6878600B2 · kind B2 · utility

Assignee

• Infineon Technologies AG · DE

Inventors

• Albert Birner · Regensburg, DE
• Matthias Goldbach · Dresden, DE
• Martin Franosch · Munich, DE

Key dates

• Filing date: May 12, 2003
• Grant date: Apr 12, 2005
• Expiry date: May 12, 2023

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10B12/0387

Abstract

A method for fabricating trench capacitors having trenches with mesopores, the trench capacitors being suitable both for discrete capacitors and for integrated semiconductor memories, significantly increases the surface area for electrodes of the capacitors and, hence, the capacitance thereof. The mesopores, which are small woodworm-hole-like channels having diameters from approximately 2 to 50 nm, are fabricated electrochemically. It is, thus, possible to produce capacitances with a large capacitance-to-volume ratio. Growth of the mesopores stops, at the latest, when the mesopores reach a minimum distance from another mesopore or adjacent trench (self-passivation). As such, the formation of “short circuits” between two adjacent mesopores can be avoided in a self-regulated manner. Furthermore, a semiconductor device is provided including at least one trench capacitor on the front side of a semiconductor substrate fabricated by the method according to the invention.