CMP System O3/DIW Buffing for Residue Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The semiconductor industry faces challenges in achieving effective planarization and cleaning of metal gate structures during the fabrication of advanced ICs, particularly due to residue corrosion inhibitors and metal residues left after chemical mechanical polishing (CMP) processes, which can lead to interfacial adhesion issues and metal corrosion.
Innovation Solution
A CMP system incorporating an ozone (O3) and deionized water (DIW) solution is used for buffing and cleaning, which reacts with residue corrosion inhibitors and metal residues, forming a stable aluminum oxide layer to improve interfacial adhesion and prevent corrosion, while also using megasonic cleaning and brushing to ensure thorough removal of contaminants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If chemical mechanical polishing (CMP) is used for planarization, then wafer planarity is improved, but residue corrosion inhibitors and metal residues remain on the surface causing adhesion issues and corrosion
Solution Approach 1:
The patent extracts and removes the harmful residues (corrosion inhibitors and metal residues) left by CMP processing through a dedicated cleaning process using ozone/demineralized water solution, separating the planarization function from the residue removal function
Solution Approach 2:
The patent introduces an intermediary cleaning process using ozone/demineralized water solution between the CMP step and subsequent processing steps to eliminate harmful residues without affecting the planarity achieved by CMP
2Object-generated harmful factors
If conventional cleaning methods are used after CMP, then some residues are removed, but interfacial adhesion issues and metal corrosion persist
Solution Approach 1:
The patent employs ozone, a strong oxidant, to effectively remove organic residue corrosion inhibitors and convert metal residues into stable oxide forms that do not cause adhesion issues or corrosion, thereby improving both cleanliness and reliability
Solution Approach 2:
The patent converts the harmful metal residues into beneficial stable oxide layers through oxidation, transforming the corrosion risk into a protective layer that actually improves interfacial adhesion and prevents further corrosion
3Reliability
If thorough cleaning is performed to remove all residues, then adhesion and corrosion resistance improve, but processing time and complexity increase
Solution Approach 1:
The patent creates a multi-functional cleaning process that simultaneously removes organic residues, converts metal residues to stable oxides, and prepares the surface for optimal adhesion in a single integrated step, reducing overall processing complexity
Solution Approach 2:
The patent changes the chemical parameters of the cleaning solution by using ozone-demineralized water with specific pH and concentration ranges to achieve multiple cleaning objectives under optimized conditions, simplifying the process while maintaining high reliability
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 O3/DIW solution effectively removes organic residues and forms a thicker, more dense aluminum oxide layer, enhancing interfacial adhesion and preventing metal corrosion, thereby improving the reliability and performance of subsequent film deposition and etching processes.
Implementation Method 1
ozone (O3) and deionized water (DIW) solution is used for buffing and cleaning, which reacts with residue corrosion inhibitors and metal residues, forming a stable aluminum oxide layer
Implementation Method 2
using megasonic cleaning and brushing to ensure thorough removal of contaminants
Data Source
AI summary
A chemical mechanical polishing (CMP) system and associated semiconductor fabrication methods are disclosed herein. An exemplary method includes performing a planarization process in a polishing unit of a CMP system to planarize a surface of a material layer using a CMP slurry. The method further includes, after performing the planarization process, performing a buffing process in the polishing unit of the CMP system to buff the surface of the material layer using an ozone gas dissolved in deionized water (O3/DIW) solution. The method further includes controlling the performing of the planarization process and the performing of the buffing process, such that the CMP slurry is received by the polishing unit from a first pipeline during the planarization process and the O3/DIW solution is received by the polishing unit from a second pipeline during the buffing process.