CMP Recipe Generation via Localized Thickness Metrology

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Solution Overview

Problem

Conventional bulk chemical mechanical polishing processes fail to adequately planarize substrates due to localized high spots, making it challenging to create effective polishing recipes for small pad CMP systems, which often result in over or under polishing and undesirable polishing of adjacent areas.

Innovation Solution

A method and apparatus that utilize a metrology station to premeasure thickness at selected locations on a substrate, providing thickness corrections to a controller for a polishing module, which calculates polishing parameters for each die location to create a customized polishing recipe for precise material removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional bulk chemical mechanical polishing is used, then the polishing process is simple and fast, but the substrate cannot be sufficiently planarized due to localized high spots

Engineering Contradiction:

Improveplanarization qualityVSAvoidpolishing system complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The polishing process is segmented into multiple localized polishing operations, each targeting specific die locations with high spots. The controller divides the substrate into discrete polishing zones and applies customized polishing parameters to each zone, transforming a single bulk polishing operation into multiple targeted operations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system applies different polishing parameters (pressure, speed, duration) to different locations on the substrate based on locally measured thickness variations. Each die location receives customized polishing treatment tailored to its specific topography, enabling precise removal of localized high spots while preserving adjacent areas.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If a small polishing pad is used to target specific die locations, then localized polishing capability is improved, but creating polishing recipes becomes challenging and time-consuming

Engineering Contradiction:

Improvelocalized polishing accuracyVSAvoidrecipe creation time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The system performs preliminary thickness measurements on the substrate before polishing using a metrology station. This pre-characterization of the substrate topography enables the controller to automatically generate appropriate polishing recipes without manual intervention, eliminating the time-consuming recipe creation process while maintaining precise localized polishing capability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The polishing system automatically generates its own polishing recipes by processing metrology data through the controller. The system self-adjusts polishing parameters based on measured substrate characteristics, eliminating the need for operator intervention in recipe creation and enabling automatic adaptation to different substrates.

Inventive Principle:

Principle #25Self-service

3Manufacturing precision

If manual polishing recipe creation is used for small pad CMP, then flexibility to adjust parameters is high, but over or under polishing occurs and adjacent areas are undesirably polished

Engineering Contradiction:

Improvepolishing control accuracyVSAvoidpolishing process control

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The system uses feedback from metrology measurements to automatically adjust polishing parameters for each die location. The controller receives thickness data from the metrology station and uses this feedback to calculate precise polishing parameters, ensuring accurate material removal without over or under polishing, and preventing unwanted polishing of adjacent areas.

Inventive Principle:

Principle #23Feedback

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 approach allows for accurate and efficient removal of material from local areas on substrates, improving planarization and reducing errors in polishing, with the ability to remove material thicknesses of 20 Angstroms to 200 Angstroms with high accuracy (+/−5 Angstroms), suitable for both R&D and manufacturing environments.

Implementation Method 1

Material is removed globally across the surface of the feature side of the substrate that is in contact with the polishing pad through a combination of chemical and mechanical activity

Methodology Applied

Scientific EffectChemical mechanical polishing:

Data Source

PatentUS10256111B2Chemical mechanical polishing automated recipe generation

Publication Date: 2019.04.09 APPLIED MATERIALS INC

AI summary

A method for polishing dies locations on a substrate with a polishing module. A thickness at selected locations on the substrate is premeasured at a metrology station, each location corresponding to a location of a single die. The thickness obtained by the metrology station for the selected locations of the substrate is provided to a controller of a polishing module. The thickness corrections for each selected location on the substrate are determined. A polishing step in a polishing recipe is formed from the thickness correction for each selected location. A polishing parameter for each die location is calculated for the recipe.