Wafer Polishing Device Cooling Channel for Uniform Temperature

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Solution Overview

Problem

Conventional chemical-mechanical wafer polishing devices inadequately cool the central area of wafers, leading to uneven polishing rates and instability in maintaining wafer flatness due to partial cooling of the peripheral area.

Innovation Solution

A chemical-mechanical wafer polishing device with a membrane having a cooling channel portion and a cooling fluid supply system that evenly distributes cooling fluid across the wafer, including a cooling channel on the action plate portion's upper and bottom surfaces, ensuring uniform cooling of both the peripheral and central areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling gas is supplied to the peripheral area of the wafer, then the peripheral area is cooled, but the central area is not properly cooled leading to uneven polishing

Engineering Contradiction:

Improvecooling of peripheral areaVSAvoidwafer flatness

Core Design Contradiction:

TemperatureVSManufacturing precision

Solution Approach 1:

The cooling function is segmented into two distinct systems: a cooling gas supply system for the peripheral area and a cooling fluid supply system for the central area. This segmentation allows independent control of cooling in different regions, resolving the contradiction by ensuring both peripheral and central areas are adequately cooled without interfering with each other

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different cooling methods are applied to different regions of the wafer: cooling gas is supplied to the peripheral area while cooling fluid is supplied to the central area through the action plate. This local differentiation of cooling quality ensures uniform temperature distribution across the entire wafer surface, maintaining polishing precision

Inventive Principle:

Principle #3Local quality

2Productivity

If friction occurs between wafer and polishing pad, then polishing action is generated, but frictional heat increases surface temperature causing temperature deviation

Engineering Contradiction:

Improvepolishing actionVSAvoidsurface temperature

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The frictional heat generated during polishing, which is normally a harmful effect causing temperature deviation, is converted into a beneficial cooling opportunity. By actively supplying cooling gas to the peripheral area and cooling fluid to the central area, the system transforms the heat generation problem into a controlled thermal management solution that maintains uniform polishing conditions

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

Cooling gas and cooling fluid act as intermediary substances that mediate between the frictional heat generation at the polishing interface and the wafer substrate. These intermediaries absorb and remove the frictional heat, preventing temperature deviation while allowing the polishing action to continue

Inventive Principle:

Principle #24Intermediary (Mediator)

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 solution allows for even cooling of the wafer, ensuring consistent polishing rates across the entire surface, thereby stabilizing the flatness of the wafer during the polishing process.

Implementation Method 1

a cooling channel portion (45), which has an action plate upper surface section (45a) formed on an upper surface of the action plate portion (41), and an action plate bottom surface section (45b) formed on a bottom surface of the action plate portion (41)

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a chamber pressure adjustment portion (113), which adjusts a pressure inside the chamber (144), to generate a drawing force, which draws the bottom surface of the membrane (140) towards the polishing head (120)

Methodology Applied

Scientific EffectNegative pressure adhesion: Pressure Drop

Implementation Method 3

frictional heat is generated during the polishing process, and the frictional heat increases the surface temperature of the wafer

Methodology Applied

Scientific EffectFrictional heating: Friction

Data Source

PatentUS10131031B2Chemical-mechanical wafer polishing device

Publication Date: 2018.11.20 THE SPACESHIP COMPANY

AI summary

Disclosed is a chemical-mechanical wafer polishing device having an elastic membrane including a circular action plate portion, a membrane circumferential wall portion extending from a circumferential edge of the action plate portion along a direction perpendicular to a plate surface, and a chamber formed between the action plate portion and the membrane circumferential wall portion. The membrane includes a cooling channel portion having an action plate bottom surface section, and a supply penetration section penetrating the action plate portion such that one end is connected to the action plate bottom surface section and the other end is exposed to the upper side of the action plate portion. The chemical-mechanical wafer polishing device includes a cooling fluid supply portion having a cooling fluid supply tube connected to a free end of the supply penetration section, and providing a cooling fluid to the cooling channel portion.