Magnetic Coupling for CMP Pad Conditioner Rotation
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Solution Overview
Problem
The chemical mechanical polishing (CMP) process for semiconductor wafers faces challenges in maintaining consistent pad condition and wafer-to-wafer process uniformity due to the smoothing of the polishing pad, which affects the polishing result.
Innovation Solution
A conditioner module with a coarse surface, equipped with particles like diamond pellets, is used to recondition the pad by adjusting its roughness, and a magnetic coupling system allows for efficient detachment and reattachment of the conditioner module to different surfaces, extending its lifespan and maintaining uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the polishing pad is used continuously for CMP process, then the polishing area is maintained, but the pad surface becomes smoother and polishing uniformity deteriorates
Solution Approach 1:
The conditioner module is divided into multiple independent conditioning surfaces (first conditioning surface, second conditioning surface, third conditioning surface) that can be sequentially engaged with the pad. This segmentation allows the pad to be reconditioned on different surfaces without replacing the entire conditioner module, thereby extending pad service life while maintaining polishing uniformity.
Solution Approach 2:
Instead of discarding the conditioner module after one conditioning surface is worn, the system recovers unused conditioning surfaces by rotating the conditioner module to engage a fresh surface with the pad. This extends the conditioner module's service life and maintains consistent pad reconditioning capability throughout its operational life.
2Duration of action of moving object
If the conditioner module is designed with single surface, then the structure is simple, but the conditioner lifespan is limited
Solution Approach 1:
The conditioner module is designed with multiple conditioning surfaces that can all perform the same reconditioning function. The rotation mechanism allows any of these surfaces to be engaged with the pad, making the conditioner module multi-functional and extendable without fundamentally changing its basic structure.
Solution Approach 2:
The conditioner module incorporates a rotation mechanism that dynamically switches between multiple conditioning surfaces. This dynamic capability allows the system to extend the conditioner's operational life by bringing different surfaces into contact with the pad as needed, without requiring a completely static multi-surface design.
3Manufacturing precision
If the pad surface is reconditioned frequently, then the polishing uniformity is maintained, but the process time increases
Solution Approach 1:
The multiple conditioning surfaces allow for continuous reconditioning capability. As one surface is used, the system can quickly rotate to the next surface without removing the conditioner module or interrupting the CMP process significantly, thereby maintaining continuous useful action of pad reconditioning.
Solution Approach 2:
The conditioner module prepares multiple conditioning surfaces in advance, so when one surface becomes worn, another fresh surface is already available for immediate use. This preliminary preparation eliminates the need for time-consuming module replacement or extended reconditioning cycles.
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 solution effectively maintains the pad's roughness, ensuring consistent polishing results and extending the conditioner module's lifespan by allowing multiple surfaces to be used for reconditioning, thereby improving the CMP process's uniformity and efficiency.
Implementation Method 1
an electromagnetic module configured to generate a magnetic field to detachably couple the conditioner module to the arm
Implementation Method 2
A conditioner module with a coarse surface, equipped with particles like diamond pellets, is used to recondition the pad by adjusting its roughness
Data Source
AI summary
An apparatus for chemically mechanically polishing includes an arm configured to move a conditioner module. The conditioner module is configured to contact a pad so as to change a degree of roughness of the pad. The pad is configured to contact and polish a semiconductor wafer. The arm has a first end and a second end opposite to the first end. The first end has an electromagnetic module. The conditioner module is detachably magnetically coupled to the arm by means of the electromagnetic module. The second end is coupled to a knob and configured to pivot at the knob. The arm moves the conditioner module through the pivoting of the second end at the knob. The conditioner module is disconnected from the arm when a magnetic polarity at the electromagnetic module is changed.