Metal Gate Oxide Layer for Adhesion and Etchant Protection
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Solution Overview
Problem
The challenge in semiconductor manufacturing lies in forming reliable devices with increasingly smaller feature sizes, where the scaling down of fabrication processes leads to difficulties in achieving reliable semiconductor devices due to poor interfacial adhesion and void formation between layers, resulting in reduced process yields.
Innovation Solution
An oxidation process is employed to convert residues from the removed gate electrode layer into metal oxide structures, which improves adhesion with surrounding layers, and a subsequent oxide film is deposited to enhance interfacial adhesion, preventing etchant diffusion and damage to the gate electrode layer during subsequent process steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feature sizes are decreased to increase functional density, then productivity is improved, but manufacturing precision deteriorates due to poor interfacial adhesion and void formation
Solution Approach 1:
An intermediary oxide layer is formed between the gate electrode layer and surrounding layers to improve interfacial adhesion. This oxide layer acts as a mediator that prevents direct contact between incompatible materials, thereby eliminating void formation and delamination issues while maintaining the scaled-down feature sizes required for high functional density
Solution Approach 2:
The chemical state of the interface is changed by oxidizing the gate electrode layer surface. This parameter change from metallic to oxidized state improves wettability and adhesion properties, allowing for reliable interfacial bonding at smaller feature sizes without compromising manufacturing precision
2Reliability
If gate electrode layer is removed to form metal gate structure, then device performance is improved, but harmful factors increase due to etchant diffusion and damage to remaining structures
Solution Approach 1:
The oxide layer formed on the gate electrode layer serves as a protective intermediary that prevents etchant diffusion into underlying structures. This intermediary barrier allows the gate electrode to be removed or modified while protecting sensitive regions from etchant damage, thereby enabling device performance improvement without introducing harmful side effects
Solution Approach 2:
The oxidation process creates a protective layer in advance before subsequent etching operations. This preliminary anti-action prevents the harmful diffusion of etchants by establishing a barrier that resists etchant penetration, thereby protecting the gate electrode layer and surrounding structures from damage during metal gate structure formation
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 approach significantly improves process yields by ensuring strong adhesion and preventing delamination, thereby maintaining the integrity of the gate electrode layer throughout subsequent manufacturing processes.
Implementation Method 1
An oxidation process is employed to convert residues from the removed gate electrode layer into metal oxide structures
Implementation Method 2
a subsequent oxide film is deposited to enhance interfacial adhesion
Data Source
AI summary
Embodiments of mechanisms for forming a semiconductor device are provided. The semiconductor device includes a semiconductor substrate and a metal gate stack formed over the semiconductor substrate. The semiconductor device also includes an insulating layer formed over the semiconductor substrate and surrounding the metal gate stack, wherein the metal gate stack includes a metal gate electrode. The semiconductor device further includes a metal oxide structure formed over the insulating layer and in direct contact with the insulating layer. The metal oxide structure includes an oxidized material of the metal gate electrode.