CMP Polishing Pad Debris Removal via Liquid Jet
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Solution Overview
Problem
The chemical mechanical polishing (CMP) process in semiconductor integrated circuit manufacturing faces challenges in maintaining polishing rate and reducing wafer scratching due to debris accumulation on the polishing pad, which affects the reliability and efficiency of the process.
Innovation Solution
A CMP system utilizing a cleaning liquid jet assembly to remove polishing debris from the polishing pad, either independently or in conjunction with a conditioning disk, to maintain surface roughness and prevent wafer scratching, with parameters such as pressure, temperature, and flow rate optimizing the conditioning process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conditioning disk is used to remove debris from the polishing pad, then the polishing rate is maintained, but the wafer surface may be scratched by loose debris
Solution Approach 1:
The patent extracts and removes loose debris from the polishing pad surface using a liquid jet or vacuum mechanism before the wafer contacts the pad. This prevents the harmful loose debris from scratching the wafer surface while the conditioning disk continues to maintain the polishing rate by removing embedded debris.
Solution Approach 2:
The patent introduces an intermediary cleaning mechanism (liquid jet or vacuum) between the conditioning disk and the wafer. This intermediary step captures and removes loose debris that would otherwise be transferred to the wafer, acting as a protective barrier while maintaining the overall polishing process efficiency.
2Object-affected harmful factors
If debris is removed from the polishing pad, then wafer scratching is reduced, but the polishing pad surface roughness may be compromised
Solution Approach 1:
The patent performs preliminary removal of loose debris from the polishing pad surface before the wafer contacts it. By pre-removing these harmful loose particles through liquid jet or vacuum mechanisms, the wafer is protected from scratching while the conditioning disk subsequently restores the necessary surface roughness for effective polishing.
Solution Approach 2:
The patent applies different treatments to different regions or aspects of the polishing pad surface. Loose debris is removed from the surface layer to prevent scratching, while the underlying structure and porosity are preserved or restored by the conditioning disk to maintain surface roughness and polishing effectiveness.
3Productivity
If a cleaning liquid jet is applied to the polishing pad, then debris is removed and polishing performance is maintained, but additional process complexity is introduced
Solution Approach 1:
The patent employs a liquid jet mechanism (hydraulic principle) to remove debris from the polishing pad surface. This approach uses fluid dynamics to achieve effective cleaning without complex mechanical contact, simplifying the overall system while maintaining high polishing performance through continuous debris removal.
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 cleaning liquid jet effectively maintains polishing performance by removing debris and preventing wafer scratching, enhancing the CMP process efficiency and yield by ensuring a uniform and fresh polishing surface.
Implementation Method 1
A cleaning liquid jet is used to condition and/or remove particles from a polishing pad
Implementation Method 2
parameters such as pressure, temperature, and flow rate optimizing the conditioning process
Data Source
AI summary
Embodiments of mechanisms for performing a chemical mechanical polishing (CMP) process are provided. A method for performing a CMP process includes polishing a wafer by using a polishing pad. The method also includes applying a cleaning liquid jet on the polishing pad to condition the polishing pad. A CMP system is also provided.