Metal Gate CMP Post-Treatment with Chlorine-Oxygen Oxidation
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Solution Overview
Problem
In the manufacturing of transistors with metal gates, existing CMP processes leave behind undesirable substances like metal particles and organic materials, leading to issues such as metal gate loss and delamination between the metal gate and overlying layers, which are not effectively addressed by conventional post-CMP cleaning methods.
Innovation Solution
A method involving a Chemical Mechanical Polish (CMP) followed by a treatment using an oxidation-and-etching solution containing chlorine and oxygen, which oxidizes and etches metal particles and organic residues, thereby removing them and improving adhesion between layers without causing severe metal gate oxidation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If conventional post-CMP cleaning methods are used, then metal particles and organic residues are removed to some extent, but severe metal gate oxidation occurs and adhesion problems persist
Solution Approach 1:
The invention changes the chemical parameters of the cleaning solution by incorporating specific concentrations of hydrogen peroxide (oxidizing agent) and hydrofluoric acid (etching agent), along with controlled water content, to achieve effective removal of contaminants while preventing severe metal gate oxidation and adhesion issues
Solution Approach 2:
The invention uses a composite cleaning solution containing multiple chemical components (hydrogen peroxide, hydrofluoric acid, and water) that work synergistically to remove metal particles and organic residues while protecting the metal gate structure
2Manufacturing precision
If aggressive cleaning treatments are applied to remove all residues, then surface cleanliness improves, but metal gate loss and severe oxidation increase
Solution Approach 1:
The invention optimizes the chemical composition parameters of the cleaning solution, specifically controlling the concentrations of hydrogen peroxide and hydrofluoric acid, to achieve effective contaminant removal while minimizing metal gate loss through controlled etching rather than aggressive mechanical or chemical cleaning
3Reliability
If no post-CMP treatment is applied, then metal gate structure is preserved, but undesirable substances cause delamination and performance degradation
Solution Approach 1:
The invention applies a controlled chemical treatment with specific concentrations of oxidizing and etching agents that selectively removes undesirable substances (metal particles and organic residues) while preserving the metal gate structure integrity, preventing delamination and performance degradation
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 reduces metal gate loss and delamination, eliminating severe oxidation issues associated with conventional post-CMP cleaning, thereby preserving transistor performance by ensuring a clean surface for subsequent layers.
Implementation Method 1
an oxidation-and-etching agent comprising chlorine and oxygen, which oxidizes and etches metal particles and organic residues
Implementation Method 2
an oxidation-and-etching agent comprising chlorine and oxygen, which oxidizes and etches metal particles and organic residues
Data Source
AI summary
A method includes forming a dummy gate of a transistor at a surface of a wafer, removing the dummy gate, and filling a metallic material into a trench left by the removed dummy gate. A Chemical Mechanical Polish (CMP) is then performed on the metallic material, wherein a remaining portion of the metallic material forms a metal gate of the transistor. After the CMP, a treatment is performed on an exposed top surface of the metal gate using an oxidation-and-etching agent comprising chlorine and oxygen.