Browse Prior Art Database

Method to form air gaps between copper interconnect lines by dissolving in a solvent a sacrificial solid that may or may not be a dielectric

IP.com Disclosure Number: IPCOM000008795D
Publication Date: 2002-Jul-12
Document File: 3 page(s) / 58K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method to form air gaps between copper interconnect lines by dissolving in a solvent a sacrificial solid that may or may not be a dielectric. Benefits include improved functionality.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 50% of the total text.

Method to form air gaps between copper interconnect lines by dissolving in a solvent a sacrificial solid that may or may not be a dielectric

Disclosed is a method to form air gaps between copper interconnect lines by dissolving in a solvent a sacrificial solid that may or may not be a dielectric. Benefits include improved functionality.

Background

      Parasitic crosstalk occurs between adjacent interconnect lines in the backend of the chip (see Figure 1). Conventionally, this problem is solved by using low-k dielectrics (with a dielectric constant ~ 2.5) between copper lines. The requirement to decrease the dielectric constant further is expected to become increasing important.

              Dummification is the process by which redundant lines are introduced into the interconnect superstructure, in this case to provide structural and mechanical support. The incorporation of dummification to support the interconnect superstructure is not the focus of the disclosed method.

General description

      The disclosed method forms air gaps between copper interconnect lines by dissolving a sacrificial solid in a solvent.

              The key elements of the method include (see Figure 2):

·        Patterning a solid sacrificial material that may or may not be a dielectric

·        Dissolving away the material completely in a solvent to form an air gap

Advantages

      The disclosed method provides advantages including:

·        Improved functionality due to a straightforward process to form air-gaps within backend interconnects

·        Improved cost effectiveness d...