Segmentation Type CMP Polishing Head for Uniform Layer Thickness
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Solution Overview
Problem
Chemical mechanical polishing (CMP) processes often result in non-uniform layer thicknesses on semiconductor substrates due to uniform pressure application, leading to errors in subsequent processes.
Innovation Solution
A polishing head with a segmentation type head module that uses a distribution block, main actuator, and control module to apply localized pressures through a working fluid, allowing for independent control of pressure lines to ensure uniform thickness post-CMP process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If uniform pressure is applied to the semiconductor substrate during CMP, then the polishing process is simple and easy to control, but the layer thickness becomes non-uniform across different regions
Solution Approach 1:
The polishing head is divided into multiple independent pressure control regions, each capable of applying different pressures to different regions of the substrate. The head includes a body with multiple pressure control units that can be independently actuated, allowing localized pressure adjustment to achieve uniform layer thickness across the substrate surface.
Solution Approach 2:
The polishing head incorporates movable components including a movable retainer ring and adjustable pressure control units that can dynamically adjust their position and applied pressure during the polishing process. This dynamic adjustment capability allows the system to compensate for variations in substrate topography and achieve uniform polishing across different regions.
2Manufacturing precision
If localized pressure control is implemented on the substrate, then uniform layer thickness can be achieved, but the pressure control system becomes complex
Solution Approach 1:
Different regions of the polishing head are equipped with pressure control units having different characteristics and capabilities tailored to their specific functions. The retainer ring provides circumferential support while pressure control units at different locations can apply different pressure magnitudes and distributions, optimizing polishing uniformity without requiring a uniformly complex control system across the entire head.
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 enables precise application of desired pressures to substrate regions, ensuring uniform layer thickness and minimizing errors in subsequent processes.
Implementation Method 1
The segmentation type head module may be configured to locally pressurize the substrate using the working fluid provided through the plurality of pressure lines
Data Source
AI summary
A polishing head of a CMP apparatus may include a head block, a distribution block and a segmentation type head module. The head block may configured to be positioned over a substrate. The distribution block may be rotatably connected to a lower surface of the head block with respect to a vertical direction. A plurality of pressure lines may be connected to the distribution block and configured to flow a working fluid therethrough. The segmentation type head module may be connected to the lower surface of the distribution block. The segmentation type head module may be configured to rotate with respect to the vertical direction together with the distribution block. The segmentation type head module may be configured to locally pressurize the substrate using the working fluid provided through the pressure lines.