Concentric Toroid CMP Platen for Uniform Wafer Planarization

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Solution Overview

Problem

The semiconductor industry faces challenges in achieving uniform thickness profiles during the manufacturing of semiconductor devices due to non-uniform deposition processes, leading to variations in feature sizes and material removal rates, which affect the integration density and quality of electronic components.

Innovation Solution

A multi-zone chemical mechanical planarization (CMP) system with individually controlled concentric toroidal platen sections, allowing for precise control of pressure, rotation speed, temperature, and slurry distribution across different zones of the polishing pad to optimize material removal rates and achieve uniform wafer thickness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional single-zone CMP process is used, then the process is simple and easy to operate, but the wafer thickness uniformity is poor due to non-uniform deposition

Engineering Contradiction:

Improvewafer thickness uniformityVSAvoidCMP system complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The polishing pad is divided into multiple independently controllable zones (first zone, second zone, third zone, etc.), each capable of independent pressure application, rotation, and slurry delivery. This segmentation allows different regions of the wafer to receive customized polishing parameters, resolving the contradiction by enabling precise thickness uniformity control through zoned manipulation while maintaining a modular system architecture.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different zones of the polishing pad are assigned different operational parameters (pressure, rotation speed, slurry flow rate) tailored to specific regions of the wafer. The first zone applies higher pressure for areas requiring more material removal, while other zones apply reduced pressure, creating local quality variations that achieve overall wafer thickness uniformity without requiring complete system redesign.

Inventive Principle:

Principle #3Local quality

2Productivity

If non-uniform pressure is applied across polishing zones, then material removal rate is optimized, but polishing pad wear becomes non-uniform

Engineering Contradiction:

Improvematerial removal rateVSAvoidpolishing pad wear uniformity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system employs dynamic pressure control where each polishing zone can independently adjust its pressure application in real-time based on process requirements. The first zone can apply higher dynamic pressure for aggressive material removal where needed, while other zones apply reduced dynamic pressure, allowing the system to optimize material removal rate while managing pad wear through adaptive, zone-specific pressure modulation.

Inventive Principle:

Principle #15Dynamics

3Productivity

If higher pressure is applied to increase material removal rate, then productivity improves, but polishing pad lifespan decreases

Engineering Contradiction:

Improvematerial removal rateVSAvoidpolishing pad lifespan

Core Design Contradiction:

ProductivityVSDuration of action of stationary object

Solution Approach 1:

The polishing pad is segmented into multiple zones with independent pressure control, allowing the first zone to operate at higher pressure for increased material removal rate while other zones operate at reduced pressure to minimize wear. This spatial segmentation of pressure application enables the system to achieve high productivity in specific regions without sacrificing overall pad lifespan, as different zones experience different stress levels.

Inventive Principle:

Principle #1Segmentation

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 system improves the uniformity of wafer thickness, reduces polishing pad wear, and extends its lifespan, while enhancing the integration density and quality of semiconductor components by allowing for more precise control of the CMP process.

Implementation Method 1

chemical mechanical polishing (CMP) process uses an abrasive material and a reactive chemical slurry in conjunction with a polishing pad

Methodology Applied

Scientific EffectMechanical abrasion: Abrasion

Implementation Method 2

chemical mechanical polishing (CMP) process uses an abrasive material and a reactive chemical slurry

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentUS11772228B2Chemical mechanical polishing apparatus including a multi-zone platen

Publication Date: 2023.10.03 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A chemical mechanical planarization apparatus includes a multi-zone platen comprising a plurality of individually controlled concentric toroids. The rotation direction, rotation speed, applied force, relative height, and temperature of each concentric toroid is individually controlled. Concentric polishing pads are affixed to an upper surface of each of the individually controlled concentric toroids. The chemical mechanical planarization apparatus includes a single central slurry source or includes individual slurry sources for each individually controlled concentric toroid.