Polishing Apparatus Temperature Sensor Array for End Point Detection
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Solution Overview
Problem
The existing polishing process technologies face challenges in precisely detecting the end point in time due to variations in polishing speed caused by differences in grain size across the target layer, leading to incomplete polishing of the desired thickness.
Innovation Solution
A polishing process apparatus equipped with a plurality of temperature sensors that measure temperatures across different regions of the polishing object during the process, allowing the controller to derive temperature change data and accurately determine the end point in time of the polishing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single end point detector is used to check the polishing end point, then the device complexity is low, but the measurement precision is insufficient due to variations in polishing speed across different regions
Solution Approach 1:
The polishing object is divided into multiple regions, and multiple temperature sensors are arranged at different radial positions to measure temperatures of different regions separately. This segmentation allows for region-specific temperature monitoring, capturing local variations in polishing speed and enabling more precise end point detection for each region.
Solution Approach 2:
The temperature sensors are arranged not only in the radial direction but also at different heights (vertical dimension) from the polishing pad. This three-dimensional arrangement (radial position + height) provides comprehensive temperature coverage across different regions and depths of the polishing object, enhancing measurement precision without excessive complexity.
2Measurement precision
If multiple temperature sensors are arranged to measure different regions, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
The support structure serves multiple functions: it holds multiple temperature sensors at specific positions, provides thermal insulation, and maintains the spatial arrangement of sensors. This multi-functional design reduces the need for separate components, thereby improving measurement precision while controlling device complexity.
Solution Approach 2:
A support structure acts as an intermediary between the temperature sensors and the polishing object. This intermediary component facilitates the mounting of sensors at optimal positions while providing thermal insulation and structural support, simplifying the overall system architecture despite the presence of multiple sensors.
3Measurement precision
If temperature sensors are placed close to the polishing pad, then the temperature measurement accuracy improves, but the sensors may be affected by harmful factors such as mechanical stress and thermal shock
Solution Approach 1:
The support structure serves as an intermediary that positions temperature sensors at an optimized distance from the polishing pad. This intermediary arrangement allows sensors to be close enough for accurate temperature detection while maintaining sufficient distance to avoid direct mechanical stress and thermal shock from the polishing interface.
Solution Approach 2:
The support structure provides beforehand cushioning by positioning sensors at a protected distance from the harsh polishing environment. This prior protection prevents mechanical stress and thermal shock from directly affecting the sensors, while still enabling accurate temperature measurement through the support structure's thermal conduction properties.
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 solution enables precise determination of the end point in time, ensuring that the polishing process is completed to the desired thickness, thereby improving the reliability and accuracy of the polishing process.
Implementation Method 1
a plurality of temperature sensors mounted on the carrier... measure temperatures respectively corresponding to a plurality of regions into which a polishing object is divided
Implementation Method 2
a polishing pad disposed on a lower portion of the carrier... polishing process
Implementation Method 3
a polishing process corresponds to a process of forming a desired thickness by entirely or partially removing a target layer
Data Source
AI summary
A polishing process apparatus includes a carrier including a polishing head on which a polishing object is provided, a polishing pad on a lower portion of the carrier, a plurality of temperature sensors on the carrier, and a controller configured to control the carrier, the polishing pad, and the plurality of temperature sensors. The plurality of temperature sensors are in a row in a radial direction, parallel to an upper surface of the polishing head and extending outwardly from a rotation axis of the polishing head. The controller is configured to derive an end point in time of a polishing process using the plurality of temperature sensors and to precisely manage a thickness of the polishing object to be polished, thereby improving reliability of the polishing process apparatus.