CMP Pad Temperature Control Using Staged Purging and Slurry
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Solution Overview
Problem
The chemical mechanical polishing process in semiconductor device fabrication is prone to generating heat due to friction between the substrate and the polishing pad, leading to variations in polishing rate and efficiency.
Innovation Solution
A method and apparatus that utilize a polishing pad with a purging compound supply unit to control temperature by providing a first purging compound at a higher temperature and a second purging compound at a lower temperature, followed by a first slurry and a second slurry with corresponding temperature adjustments, to manage the polishing process effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a chemical mechanical polishing process is performed using a polishing pad and slurry, then the layers on the substrate are planarized efficiently, but heat is generated due to friction between the substrate and the polishing pad causing variation in polishing rate
Solution Approach 1:
The patent applies parameter changes by controlling the temperature of the purging compound supplied to the polishing pad. By adjusting the purging compound temperature (e.g., supplying warmer purging compound during high material removal phases and cooler purging compound during precision phases), the polishing temperature is dynamically controlled to maintain optimal polishing rate and prevent excessive heat generation while preserving high productivity
Solution Approach 2:
The purging compound acts as an intermediary between the slurry and the polishing pad surface. It serves multiple functions: removing excess slurry and by-products, controlling thermal conditions through temperature-adjusted purging, and maintaining optimal surface conditions for consistent polishing performance without directly contacting the substrate
2Duration of action of moving object
If the polishing temperature increases due to frictional heat, then the polishing process continues, but the polishing rate changes leading to reduced manufacturing precision
Solution Approach 1:
The system implements feedback control by monitoring polishing conditions and adjusting the purging compound temperature accordingly. When polishing temperature rises and causes polishing rate variation, the purging compound temperature is adjusted to restore optimal conditions, ensuring consistent manufacturing precision while maintaining continuous operation
Solution Approach 2:
The patent changes the temperature parameter of the purging compound dynamically during the polishing process. By supplying purging compound at different temperatures based on real-time polishing conditions, the system maintains stable polishing rate and high manufacturing precision throughout the continuous polishing operation
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 allows for precise control of the polishing temperature, enhancing the polishing rate and flatness by efficiently removing by-products from the polishing pad and maintaining optimal surface conditions, thereby improving the overall efficiency and consistency of the chemical mechanical polishing process.
Implementation Method 1
a chemical mechanical polishing (CMP) process is widely used as a planarization technique for removing a step between layers formed on a substrate
Implementation Method 2
Such a chemical mechanical polishing process may be prone to generating heat due to friction between the substrate and the polishing pad, and this frictional heat increases the polishing temperature
Data Source
AI summary
A chemical mechanical polishing method is provided. A chemical mechanical polishing method comprising providing a polishing pad, supplying a first purging compound having a first temperature onto the polishing pad, supplying a first slurry having a third temperature onto the polishing pad supplied with the first purging compound, supplying a second purging compound having a second temperature lower than the first temperature onto the polishing pad, and supplying a second slurry having a fourth temperature lower than the third temperature onto the polishing pad supplied with the second purging compound.