AIR-GAP STRUCTURE FORMATION WITH ULTRA LOW-K DIELECTRIC LAYER ON PECVD LOW-K CHAMBER

摘要

Methods for reducing the k value of a layer using air gaps and devices produced by said methods are disclosed herein. Methods disclosed herein can include depositing a carbon containing stack over one or more features in a substrate, depositing a porous dielectric layer over the carbon containing stack, and curing the substrate to volatilize the carbon containing stack. The resulting device includes a substrate with one or more features formed therein, a porous dielectric layer formed over the features with an air gap formed in the features.

主权项

1. A method of forming air gaps, comprising:
depositing a carbon containing material stack in one or more features on a substrate, the stack deposition comprising:
depositing a carbon containing material over a substrate, the substrate having:
an upper surface; andone or more features formed on or over the upper surface, the features having side walls, a bottom surface, wherein the carbon containing material is formed over the upper surface, the side walls and the bottom surface;stripping the carbon containing material from the upper surface and the side walls, wherein the carbon containing material remains on the bottom surface; andrepeating the deposition of the carbon containing material and the stripping of the carbon-containing material to create a carbon containing material stack on the bottom surface, the carbon containing material stack filling the features to a desired fill level; forming a silicon containing film over the carbon containing material stack using a flowable chemical vapor deposition (CVD) process with a silicon precursor, the silicon containing film forming over an exposed portion of the upper surface and an exposed portion of the side walls; and curing the carbon containing material stack and the silicon containing film to form an air gap in the features and pores in the silicon containing film, wherein the hydrocarbon material is substantially removed during the cure such that at least one air gap extends between two of the sides walls and to the bottom surface of the feature.