Semiconductor Base Layer for Au Migration Prevention
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Solution Overview
Problem
Existing semiconductor devices fail to effectively inhibit the migration of Au electrodes into the interlayer interface between insulating films, leading to increased electrical resistance and potential delamination, as current barrier layers are not designed for Au and do not adequately prevent diffusion into insulating films.
Innovation Solution
The semiconductor device incorporates base layers with a major component of Ti or W, and projecting sections modified with O or N, which provide good adhesion to insulating films, preventing moisture penetration and oxidation, thus isolating OH groups and suppressing Au migration, while also exhibiting a photocatalytic effect to remove residues and prevent delamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an upper-surface barrier metal layer containing Ti, TiW, or similar metal components is used to inhibit Cu diffusion, then Cu diffusion into the interlayer insulating film is prevented, but electrical resistance increases due to metal compound formation between Cu and the barrier layer materials
Solution Approach 1:
The patent applies different materials with specific local functions: Ru or Rh are used specifically at the interface with the interlayer insulating film where diffusion prevention is needed, while Cu is used in the bulk interconnect where low resistance is needed. This local differentiation resolves the contradiction by placing diffusion-preventive materials only where diffusion occurs, not throughout the entire interconnect structure.
Solution Approach 2:
The patent introduces Ru or Rh as intermediary barrier layers between Cu and the interlayer insulating film. These intermediary materials prevent direct contact and reaction between Cu and the insulating film, while also having lower reactivity with Cu compared to Ti or TiW, thus preventing metal compound formation and maintaining low electrical resistance.
2Reliability
If a TiNO layer is used as a diffusion barrier for Al, then Al diffusion is reduced, but the layer forms an insulating film that prevents effective application of bias electrode
Solution Approach 1:
The patent uses Ru or Rh with specific local properties: these materials form conductive or semi-conductive barrier layers rather than insulating films like TiNO. The barrier function is localized at the interface where diffusion occurs, while the bulk material maintains electrical conductivity, allowing bias electrode application throughout the electrode structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration ensures reliable electrical contact, prevents Au migration into the interlayer interface, maintains low electrical resistance, and increases yield by effectively removing residues and inhibiting delamination at the interlayer interface.
Implementation Method 1
a composition of a projecting section of the base layer projecting in a direction of an interlayer interface between insulating films is modified to include O or N in addition to Ti or W
Implementation Method 2
the base layer... exhibiting a photocatalytic effect to remove residues and prevent delamination
Data Source
AI summary
A semiconductor device includes electrodes which contain Au and which are placed above conductive layers in a region adjacent to stacked insulating films and also includes base layers which are composed of compositionally modulated layers and which are placed between the electrodes and the conductive layers. The base layers include lateral end sections composed of single layers projecting from lateral end sections of the electrodes in the direction of the interlayer interface between the insulating films; sections which are located under the electrodes and of which a major compositional component is Ti or Ti and W; and projecting sections which project from under the electrodes in the direction of the interlayer interface between the insulating films and of which compositional components are compositionally modulated to Ti and O, to Ti, O, and N, or to Ti, W, O, and N.