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Air Gap Interconnect Structures Using Thermally Decomposed Polymers

IP.com Disclosure Number: IPCOM000032206D
Publication Date: 2004-Oct-26
Document File: 2 page(s) / 92K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method that applies a thermally decomposed polymer (TDP) to create air gap interconnect structures. Benefits include a good mechanical integrity for the air gap structures.

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Air Gap Interconnect Structures Using Thermally Decomposed Polymers

Disclosed is a method that applies a thermally decomposed polymer (TDP) to create air gap interconnect structures. Benefits include a good mechanical integrity for the air gap structures.

Background

Currently, there are process challenges that hinder the TDP from diffusing out of the trench region in the non-hermitic ES thin layer. In addition, hermiticity is required of the ES in the integrated air gap interconnect structures. The thin and weak ES layer may not be able to withstand the stress during the thermal decomposition steps; this may result in ES layer collapses or twisted TDP patterns.

The current state of the art addresses these problems by depositing either an ES or ES+SiO2 layer on top of the crust cap layer in the air gap pocket. The height of the crust layer in the trench is controllable, which determines the total thickness of the ES or ES+SiO2 layers on top of the air gap region.

General Description

The following are the process steps for creating the disclosed method:

1.      A metal pattern (with a barrier metal for Cu patterns) is created (see Figure 1).

2.      A layer of TDP is spin-coated on to the metal pattern wafer to fill the deep trenches (see Figure 2).

3.      Plasma etching removes the TDP on the top of the patterns, and then etches the TDP into the trench region (see Figure 3).

4.      The crust layer is formed on top of the TDP in the trench, after plasma etching; the position of the crust layer...