CMP Pad Conditioner with CVD Diamond Protrusions
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Solution Overview
Problem
Existing CMP pad conditioners face issues with high friction during conditioning, leading to reduced polishing pad lifespan, uneven slurry distribution, and decreased workpiece quality due to irregular diamond particle distribution and varying sizes, which cause vibrations and difficulty in dispersing slurry particles.
Innovation Solution
A pad conditioner with a substrate featuring protrusions of different heights, forming a plane parallel to the surface, and a diamond layer applied on these protrusions, which reduces friction and ensures uniform slurry distribution by altering the cutting tip structure to include multiple height groups and varying separation distances, and using CVD to deposit a (1,0,0) plane diamond layer for reduced friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If diamond particles are electroplated or brazed onto the conditioner surface, then the conditioner can cut the polishing pad, but the diamond particles are irregularly distributed and have different sizes, causing non-uniform surface height and roughening the polishing pad surface
Solution Approach 1:
The patent replaces the mechanical electroplating or brazing process with a chemical CVD (chemical vapor deposition) process to deposit diamond particles. This substitution allows for more uniform distribution and size control of diamond particles on the conditioner surface, resolving the contradiction between ease of manufacture and manufacturing precision.
Solution Approach 2:
The patent changes the deposition method parameters by using CVD with controlled gas flow, temperature, and pressure conditions. This enables precise control over diamond particle size and distribution uniformity, achieving smooth surface height while maintaining manufacturability.
2Ease of operation
If the substrate surface applies a predetermined load to the rotating pad, then the substrate rotates according to the pad rotation, but this increases friction between the conditioner and polishing pad, causing vibrations
Solution Approach 1:
The patent modifies the substrate surface geometry by creating protrusions with specific curvature profiles instead of flat surfaces. This curvature design reduces the contact area and preload between the conditioner and rotating pad, thereby reducing friction and vibrations while maintaining operational effectiveness.
Solution Approach 2:
The patent applies different surface properties to different regions of the substrate by creating protrusions with varying heights and distributions. This local variation in surface quality allows certain areas to have reduced friction characteristics while maintaining cutting capability in other areas, resolving the contradiction between ease of operation and reduction of harmful friction.
3Device complexity
If the cutting tip uses widely separated truncated polypyramids, then the structure is simple, but the distance between polypyramids is too wide to uniformly disperse slurry particles
Solution Approach 1:
The patent segments the cutting tip surface into multiple protrusions with optimized spacing and height distribution. This segmentation creates numerous smaller contact points that are closely spaced, enabling uniform slurry particle dispersion while maintaining structural simplicity through repetitive modular patterns.
Solution Approach 2:
The patent transitions from a two-dimensional flat surface to a three-dimensional structured surface with protrusions of varying heights. This dimensional change allows for increased surface area and more uniform slurry distribution without significantly increasing device complexity, as the protrusions follow a systematic pattern.
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 significantly reduces friction, prolongs polishing pad lifespan, improves slurry distribution, and enhances workpiece quality by maintaining surface uniformity, while increasing dimensional reproducibility and productivity in the manufacturing process.
Implementation Method 1
a diamond layer which is applied on the plurality of protrusions or on the entire surface having the protrusions
Data Source
AI summary
This invention relates to a conditioner for a chemical mechanical planarization pad, which is necessary for global planarization of a wafer in order to increase the degree of integration of a semiconductor device, and more particularly to a pad conditioner having a structure able to reduce friction with a pad so as to solve the problems caused by a lot of friction being generated upon conditioning, and to a method of manufacturing the same.