CMP Polishing Pad Radial Grooves Fluid Residence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional chemical mechanical polishing (CMP) pads with concentric circular groove patterns face limitations in improving polishing performance, increasing removal rate, reducing slurry usage, and minimizing defects, while also struggling with global uniformity and slurry efficiency.
Innovation Solution
The introduction of a polishing pad with radial feeder grooves and biased grooves that direct polishing fluid either inward or outward, adjusting residence time and fluid distribution to enhance polishing efficiency, uniformity, and debris removal, allowing for higher downforce and reduced slurry usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If concentric circular groove patterns are used, then polishing uniformity is improved, but removal rate is limited
Solution Approach 1:
The polishing pad surface is segmented into multiple polishing regions separated by radial feeder grooves. Each region contains multiple biased grooves that direct slurry flow in specific directions. This segmentation allows different regions to have optimized slurry distribution patterns, improving both uniformity and removal rate simultaneously
Solution Approach 2:
Different regions of the polishing pad are given different groove configurations to optimize local polishing performance. The biased grooves in each region are angled to direct slurry flow locally toward the wafer contact area, creating optimal polishing conditions in each specific zone while maintaining global uniformity
2Productivity
If radial feeder grooves are added to increase removal rate, then productivity is improved, but slurry usage increases substantially
Solution Approach 1:
The biased grooves function as hydraulic channels that direct slurry flow efficiently to where it is needed most - the wafer contact region. By controlling the angle and orientation of grooves, the system optimizes slurry distribution and reduces waste, allowing higher removal rates with reduced slurry consumption
3Productivity
If radial feeder grooves are added to improve polishing performance, then removal rate increases, but pad life decreases due to reduced landing area
Solution Approach 1:
The polishing pad is divided into multiple regions with biased grooves distributed across the surface. This segmentation ensures that wear is distributed evenly across multiple landing zones rather than concentrated in a single area, extending pad life while maintaining high removal rates through optimized slurry delivery to active polishing regions
4Ease of manufacture
If conventional groove patterns are used, then manufacturing is simple, but polishing uniformity and defect reduction are limited
Solution Approach 1:
The biased groove configuration provides localized optimization of slurry flow without requiring complex manufacturing processes. Each groove is angled at a specific bias to direct flow locally, achieving superior polishing uniformity and defect reduction while maintaining compatibility with standard groove fabrication methods
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 groove pattern design improves polishing uniformity, increases removal rate, reduces defects, and extends pad life by optimizing fluid distribution and debris removal, enabling efficient polishing with reduced slurry consumption and improved edge profile consistency.
Implementation Method 1
both the inward and outward biased grooves moving polishing fluid toward the outer edge of the polishing pad
Implementation Method 2
The polishing pad and wafer typically rotate relative to one another to polish a substrate. As the polishing pad rotates beneath the wafer, the wafer sweeps out a typically annular polishing track
Implementation Method 3
The wafer surface is polished and made planar by chemical and mechanical action of the polishing layer and polishing medium on the surface
Implementation Method 4
distributing polishing fluid onto the rotating polishing pad and into the radial feeder grooves and the series of biased grooves
Data Source
AI summary
The invention provides a method for polishing or planarizing a wafer of at least one of semiconductor, optical and magnetic substrates. The method includes rotating a polishing pad, the rotating polishing pad having radial feeder grooves in the polishing layer separating the polishing layer into polishing regions. The polishing regions are circular sectors defined by two adjacent radial feeder grooves. The radial feeder grooves extend from a location adjacent the center to a location adjacent the outer edge. Each polishing region includes a series of biased grooves connecting a pair of adjacent radial feeder grooves. Pressing and rotating the wafer against the rotating polishing pad for multiple rotations of the polishing pad adjusts polishing by either increasing or decreasing residence time of the polishing fluid under the wafer.