Lower Wiring Layer Silicide Capping for Resistance Increase
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Solution Overview
Problem
As integrated circuit devices have been downscaled, there is a need for a low-resistance metal wiring layer with improved reliability due to reduced line widths and pitches, which existing technologies have not adequately addressed.
Innovation Solution
The integration of a lower conductive barrier film surrounding the lower wiring layer, combined with a first and second metal silicide capping layer, enhances the reliability of the metal wiring layer by protecting it from physical deterioration during the formation of contact holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If line widths and pitches of metal wiring layers are reduced to achieve device downsaling, then device integration density is improved, but wiring layer reliability deteriorates due to increased resistance and susceptibility to physical deterioration
Solution Approach 1:
The patent applies preliminary action by forming protective capping layers (conductive barrier film and metal silicide capping layer) on the lower wiring layer before subsequent processing steps. These layers are prepared in advance to prevent physical deterioration during contact hole formation and other manufacturing processes, thereby maintaining wiring layer reliability despite reduced dimensions.
Solution Approach 2:
The patent implements beforehand cushioning by introducing protective layers that cushion and protect the lower wiring layer from mechanical damage. The conductive barrier film and metal silicide capping layer act as protective cushions that prevent direct exposure of the wiring layer to harmful processes, thus maintaining reliability in downscaled devices.
2Reliability
If protective layers are added to protect the lower wiring layer, then wiring layer reliability is improved, but device complexity increases
Solution Approach 1:
The patent applies universality by designing protective layers that perform multiple functions simultaneously. The conductive barrier film provides both mechanical protection and electrical barrier functions, while the metal silicide capping layer offers both protection and low-resistance conduction. This multi-functionality reduces the need for additional separate protective structures, thereby limiting complexity increase.
Solution Approach 2:
The patent uses composite materials by combining different metal layers with distinct properties. The lower wiring layer (first metal) is combined with a conductive barrier film (second metal) and a metal silicide capping layer, creating a composite structure that leverages the advantages of each material to provide both protection and electrical performance without requiring overly complex single-material solutions.
Data Source
AI summary
An integrated circuit device includes an insulating film on a substrate, a lower wiring layer penetrating at least a portion of the insulating film, the lower wiring layer including a first metal, a lower conductive barrier film surrounding a bottom surface and a sidewall of the lower wiring layer, the lower conductive barrier film including a second metal different from the first metal, a first metal silicide capping layer covering a top surface of the lower wiring layer, the first metal silicide capping layer including the first metal, and a second metal silicide capping layer contacting the first metal silicide capping layer and disposed on the lower conductive barrier film, the second metal silicide capping layer including the second metal.