Method of making a semiconductor memory device

US7230877B1 · kind B1 · utility

Assignee

• Infineon Technologies AG · DE

Inventors

• Andreas Rusch · Dresden, DE
• Steffen Rothenhäusser · Dresden, DE
• Alexander Truby · Dresden, DE
• Yoichi Otani · Radeberg, DE
• Ulrich Zimmermann · Waldbrunn, DE

Key dates

• Filing date: Oct 10, 2000
• Grant date: Jun 12, 2007
• Expiry date: Aug 26, 2023

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D84/038

Abstract

A method for fabricating a semiconductor memory device is described. An insulating layer is disposed on a semiconductor substrate. A matrix of semiconductor memory elements is disposed in the substrate. The semiconductor memory elements include a plurality of contact holes formed in the insulating layer. One contact hole is formed in the insulating layer for each of the semiconductor memory elements. A bit definition region is disposed in the semiconductor substrate underneath each of the contact holes. A contact plug is disposed in each of the contact holes and is in electrical contact with the bit definition region. The bit definition region is configured such that a contact resistance between the semiconductor substrate and the contact plug defines a bit to be stored in the semiconductor memory elements, An evaluation circuit is connected to and evaluates the contact resistance of the semiconductor memory elements.