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Method for selectively depositing a dielectric material

IP.com Disclosure Number: IPCOM000042273D
Publication Date: 2005-Feb-03
Document File: 2 page(s) / 10K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for selectively depositing a dielectric material. Benefits include improved functionality.

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Method for selectively depositing a dielectric material

Disclosed is a method for selectively depositing a dielectric material. Benefits include improved functionality.

Background

      The effective dielectric constant of a metal interlayer dielectric stack must be reduced to reduce the line charge signal delay, the capacitance/dielectric constant of the interlayer dielectric. Conventionally, the interlayer dielectric is comprised of two separate dielectric layers with different purposes. One is for insulating and defining the metal lines and is referred to as the ILD. The other is an etch stop (ES) dielectric layer used to stop the etch when etching vias for connecting underlying metal lines. Conventionally, the ES dielectric constant dominates the effective capacitance.

      To reduce the effective dielectric constant of the ILD/ES stack, the conventional approach has been to:

•     Reduce the dielectric constant of one or both dielectric materials

or

•     Reduce the thickness of the typically higher dielectric constant ES

      Conventional etch stop materials are deposited using plasma enhanced chemical vapor deposition (PECVD) with various Si, C, N, and O containing gases. The deposition of ES films using PECVD is not selective. The entire wafer receives the deposited material.

General description

      The disclosed method selectively deposits a dielectric material on a patterned wafer in an atomic layer-by-atomic layer fashion. Sequential and alternating exposures of reactive species, which are dissociatively and/or reactively adsorbed only on the wafer’s pattern.

      The patterning on the wafer contains dissimilar surfaces. They each have stability against and reactivity toward adsorbing various chemical species.

      The disclosed method takes advantage of the lack of reactivity of a hydrogen-terminated carbon doped oxide (CDO) surface to selectively grow an ES film over a reactive cobalt surface.

Advantages

              The disclosed method provides advantages, including improved functionality due to enabling the selective deposition of dielectric material.

Detailed description

      The disclosed method is the capa...