Semiconductor Contact Plug Protective Layer for Adhesion
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Solution Overview
Problem
Conventional techniques for forming metal silicide layers in semiconductor devices often result in a metal gate being partially or entirely removed during the SPM etching process, leading to poor adhesion between the liner and sidewall, which affects IC performance and yield.
Innovation Solution
A protective layer made of silicon oxide or silicon nitride is introduced between the liner and sidewall to enhance adhesion and prevent metal gate removal during SPM operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a liner is formed conformal to the opening to protect the sidewall during sputter etching and SPM operation, then the sidewall is protected from damage, but the liner has poor adhesion to the sidewall and a poor surface, causing the interface between the ILD layer and the etch stop layer to be etched by H2SO4 and H2O2 solution
Solution Approach 1:
A protective layer is introduced as an intermediary between the sidewall and the liner. This protective layer serves as a mediator that provides both protection to the sidewall and a suitable surface for the liner to adhere to, resolving the adhesion problem while maintaining sidewall protection during sputter etching and SPM operation.
2Object-affected harmful factors
If the liner is used to protect the sidewall during SPM operation, then the sidewall is protected from sputter etching damage, but the poor surface quality of the liner causes the H2SO4 and H2O2 solution to etch the interface between the ILD layer and the etch stop layer
Solution Approach 1:
The protective layer acts as an intermediary that prevents the liner's poor surface quality from causing interface etching. It provides a stable barrier that stops the H2SO4 and H2O2 solution from reaching the ILD layer and etch stop layer interface, while still allowing the liner to fulfill its sidewall protection function.
3Stability of the object's composition
If the liner is formed to protect the sidewall, then sidewall integrity is maintained, but the metal gate is partially or entirely removed by the H2SO4 and H2O2 solution etching
Solution Approach 1:
The protective layer serves as an intermediary barrier that prevents the H2SO4 and H2O2 solution from attacking the metal gate. It provides an additional layer of protection that preserves metal gate integrity while the liner continues to protect the sidewall during the etching process.
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
The protective layer effectively prevents metal gate removal, improving IC performance and yield by ensuring better adhesion and surface protection during etching processes.
Implementation Method 1
A protective layer made of silicon oxide or silicon nitride is introduced between the liner and sidewall to enhance adhesion
Implementation Method 2
The protective layer effectively prevents metal gate removal, improving IC performance and yield by ensuring better adhesion and surface protection during etching processes
Data Source
AI summary
A device includes an isolation structure, a source/drain epi-layer, a contact, a first dielectric layer, and a second dielectric layer. The isolation structure is embedded in a substrate. The source/drain epi-layer is embedded in the substrate and is in contact with the isolation structure. The contact is over the source/drain epi-layer. The first dielectric layer wraps the contact. The second dielectric layer is between the contact and the first dielectric layer. The first and second dielectric layers include different materials, and a portion of the source/drain epi-layer is directly between a bottom portion of the second dielectric layer and a top portion of the isolation structure.