Polishing Pad Temperature Regulation for Film Thickness Control
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Solution Overview
Problem
The polishing rate of a substrate in CMP processes is affected by the temperature of the polishing pad, leading to inaccurate film-thickness profiles and potential excessive polishing due to frictional heat, which complicates endpoint detection and reduces throughput.
Innovation Solution
A polishing method and apparatus that regulate the temperature of the polishing pad using a pad-temperature regulating apparatus, allowing for controlled polishing load adjustments based on film-thickness measurements to maintain a predetermined temperature, ensuring consistent polishing rates and accurate film-thickness profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If polishing is performed without temperature regulation, then polishing throughput is maintained, but polishing rate becomes inaccurate due to temperature-induced chemical action changes
Solution Approach 1:
The patent applies parameter changes by actively regulating the polishing pad temperature to a predetermined value. The temperature regulation apparatus adjusts the temperature parameter to compensate for frictional heat generation during polishing, ensuring that the chemical action of the polishing liquid remains consistent and the polishing rate remains accurate throughout the polishing process.
Solution Approach 2:
The patent implements feedback control through a closed-loop temperature regulation system. The temperature regulation apparatus continuously monitors and adjusts the polishing pad temperature based on the predetermined target temperature, creating a feedback mechanism that maintains stable thermal conditions and ensures accurate polishing rates while preventing excessive temperature rise that would affect throughput.
2Productivity
If polishing load is increased to maintain polishing rate at higher temperatures, then throughput is improved, but manufacturing precision deteriorates due to excessive polishing
Solution Approach 1:
The patent changes the temperature parameter to a controlled predetermined value, which stabilizes the chemical action of the polishing liquid. This allows the polishing load to be accurately controlled based on actual polishing rate requirements rather than compensating for temperature-induced rate variations, thereby maintaining both throughput and precision.
3Manufacturing precision
If polishing load is decreased to prevent excessive polishing, then manufacturing precision is improved, but productivity deteriorates due to reduced polishing rate
Solution Approach 1:
By regulating the temperature parameter to a predetermined value, the patent ensures that the chemical action of the polishing liquid remains consistent. This allows the system to operate at optimal polishing loads without risk of excessive polishing, as the stable temperature prevents unexpected increases in polishing rate, thereby maintaining both precision and productivity.
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 enables precise control of the polishing process, maintaining the desired polishing rate and achieving accurate film-thickness profiles while preventing throughput reduction, even when the polishing rate turns down with increased temperature.
Implementation Method 1
temperature of the polishing pad gradually rises during polishing of the substrate due to frictional heat generated by pressing the rotating substrate against the rotating polishing pad
Implementation Method 2
controlling a temperature of a polishing surface of a polishing pad to a predetermined temperature by use of a pad-temperature regulating apparatus
Implementation Method 3
the surface of the substrate is planarized by a chemical action of the polishing liquid and a mechanical action of abrasive grains contained in the polishing liquid
Implementation Method 4
the surface of the substrate is planarized by a chemical action of the polishing liquid and a mechanical action of abrasive grains contained in the polishing liquid
Data Source
AI summary
The present application relates to a polishing method and a polishing apparatus for polishing a substrate, such as a wafer, while pressing the substrate against a polishing surface of a polishing pad, and more particularly to a polishing method and a polishing apparatus for polishing a substrate while regulating a polishing load based on measurement values of a film-thickness measuring device. The polishing method includes: controlling a temperature of a polishing surface of a polishing pad to a predetermined temperature by use of a pad-temperature regulating apparatus; and polishing a substrate while controlling a polishing load for pressing the substrate against the polishing surface based on measurement values from a film-thickness measuring device provided in the polishing pad.