Polishing Head with Elastic Holder for Film Thickness Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional chemical mechanical polishing (CMP) methods struggle to control film thickness profiles on semiconductor wafers with high precision, particularly in the circumferential direction, due to limitations in pressure chamber dimensions and actuator expansion/contraction capabilities, leading to insufficient pressing force and accuracy issues.
Innovation Solution
A polishing head with pressure actuators arranged along both radial and circumferential directions, supported by an elastic holder and actuator operation controller, which uses a bag-shaped airbag and linear guide member to maintain close proximity to the polishing surface, allowing for precise control of film thickness through adjustable pressure and reduced actuator stretching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If actuators with small expansion and contraction rates are used, then the device complexity is reduced, but stroke errors occur due to surface accuracy, inclination, and installation errors
Solution Approach 1:
An elastic holder is introduced as an intermediary component between the actuator and the wafer. This elastic holder compensates for stroke errors caused by surface accuracy, inclination, and installation errors by providing flexible support and adjustment capability, allowing the actuator to maintain proper contact with the wafer surface despite minor misalignments.
Solution Approach 2:
The system changes the operational parameters of the actuator by operating it at a position close to the polishing surface rather than at its full extension. This parameter change allows the actuator to function effectively despite its limited expansion and contraction rate, as the elastic holder compensates for the reduced stroke.
2Manufacturing precision
If the actuator is expanded and contracted to correct stroke error, then the manufacturing precision is improved, but the amount of expansion and contraction becomes insufficient
Solution Approach 1:
The elastic holder serves as a mediator that amplifies the actuator's limited expansion and contraction capability. By providing elastic support and flexible positioning, the holder enables the actuator to achieve sufficient pressing force on the wafer despite its small expansion amount, effectively compensating for the insufficient stroke.
Solution Approach 2:
The system introduces dynamic flexibility through the elastic holder, which can deform and adapt during operation. This dynamic capability allows the actuator to compensate for its limited expansion range by using the elastic holder's deformability to achieve the necessary contact pressure and positioning accuracy.
3Device complexity
If pressure chambers are arranged concentrically, then the device complexity is reduced, but it is not possible to control pressing force along the circumferential direction
Solution Approach 1:
The pressure control system is segmented into multiple independent pressure actuators arranged in a grid pattern, with each actuator capable of independent control. This segmentation allows precise control of pressing force in both radial and circumferential directions, enabling accurate control of the film thickness profile across the wafer surface.
Solution Approach 2:
The system transitions from conventional concentric pressure chamber arrangement to a two-dimensional grid arrangement of pressure actuators. This dimensional change enables independent control of pressing force in both radial and circumferential directions, providing comprehensive control over the film thickness profile across the entire wafer surface.
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 configuration enables accurate control of film thickness profiles across the wafer surface, eliminating stroke errors and ensuring sufficient pressing force, thereby supporting miniaturization and multi-layering in semiconductor manufacturing.
Implementation Method 1
an elastic holder configured to hold the actuator support portion
Implementation Method 2
pressure actuators configured to independently press a specific portion of a substrate; an actuator operation controller configured to control an operation of each of the pressure actuators
Data Source
AI summary
A polishing head capable of accurately controlling a thickness profile of a wafer is disclosed. The polishing head includes a plurality of pressure actuators, an actuator operation controller, an actuator support portion, and an clastic holder. The actuator operation controller is mounted on a head main body.