CMP Slurry Temperature Control for Uniform Wafer Polishing
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Solution Overview
Problem
Chemical mechanical polishing (CMP) processes face challenges in temperature control, leading to performance variations such as dishing or erosion due to heat generated from chemical reactions and mechanical friction, which affects the removal rate and planarization of semiconductor wafers.
Innovation Solution
A slurry temperature control device incorporating a thermo-electric (TE) chip is used to precisely control the temperature of the abrasive slurry, allowing for immediate cooling or heating, thereby regulating the polishing temperature and improving process control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If CMP is carried out using conventional temperature control methods, then the polishing process can be completed, but temperature variations cause performance variations such as dishing or erosion
Solution Approach 1:
The patent pre-cools the slurry before it reaches the polishing zone and uses cooling channels in the platen to maintain optimal temperature throughout the polishing process, preventing temperature-induced performance variations
Solution Approach 2:
The patent incorporates temperature sensors that monitor slurry temperature in real-time and feed this information back to a control system that adjusts cooling flow rates to maintain consistent polishing conditions
2Productivity
If higher removal rate is achieved through increased polishing pressure or speed, then productivity improves, but heat generation increases causing temperature control difficulties
Solution Approach 1:
The patent introduces a slurry cooling system that acts as an intermediary between the polishing zone and the environment, absorbing excess heat generated during high-productivity polishing operations
Solution Approach 2:
The patent dynamically adjusts slurry flow rate and temperature parameters during polishing to optimize the balance between removal rate and heat generation, allowing higher productivity while maintaining temperature control
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 TE chip enables precise temperature management of the abrasive slurry, enhancing the CMP process by maintaining optimal temperatures between 10° C. and 60° C., thus improving the removal rate and reducing manufacturing difficulties associated with temperature variations.
Implementation Method 1
A slurry temperature control device incorporating a thermo-electric (TE) chip is used to precisely control the temperature of the abrasive slurry, allowing for immediate cooling or heating
Data Source
AI summary
A method for polishing a semiconductor substrate includes the following operations. A semiconductor substrate is received. An abrasive slurry having a first temperature is dispensed to a polishing surface of a polishing pad. The semiconductor substrate is polished. The abrasive slurry have a second temperature is dispensed to the polishing surface of the polishing pad during the polishing of the semiconductor substrate. The second temperature is different from the first temperature.