Patterning CD Control Using Feedforward and Feedback Sequencing

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Solution Overview

Problem

Current semiconductor fabrication processes face inefficiencies in controlling critical dimensions and uniformity across wafers due to manual trial and error methods, which struggle to account for variations in incoming substrates and process changes, leading to increased variability and non-uniformity in feature dimensions.

Innovation Solution

Implementing automated feedforward and feedback control systems to manage variability in double patterning processes, using sensitivity factors and mathematical frameworks to minimize variations and correct for incoming pattern non-uniformities, allowing for localized fine tuning and process adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual trial and error process is used to control critical dimensions, then process flexibility is maintained, but manufacturing precision and productivity deteriorate due to inefficiency and time consumption

Engineering Contradiction:

Improveprocess flexibilityVSAvoidcritical dimension control

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent implements automated feedback control systems that measure critical dimensions and automatically adjust process parameters for subsequent wafers, replacing manual trial-and-error with closed-loop control that continuously improves precision while maintaining operational flexibility

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs preliminary measurements on incoming substrates and calculates required process adjustments before actual processing begins, allowing proactive compensation for variations rather than reactive manual adjustments

Inventive Principle:

Principle #10Preliminary action

2Device complexity

If manual trial and error process is used, then device complexity remains low, but productivity and manufacturing precision worsen due to inability to handle in-process variations

Engineering Contradiction:

Improvecontrol system complexityVSAvoidprocess efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The control system performs self-adjustment by automatically calculating and applying process parameter modifications based on measured variations, eliminating the need for manual intervention and significantly improving productivity without proportionally increasing complexity

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system dynamically changes process parameters based on measured variations in incoming substrates and previous process results, enabling automated adaptation to in-process variations that manual methods cannot handle efficiently

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If manual trial and error process is used, then ease of operation is maintained, but manufacturing precision deteriorates due to difficulty in accounting for substrate variations and process changes

Engineering Contradiction:

Improveoperational simplicityVSAvoidfeature dimension uniformity

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The system performs preliminary measurements and calculations on incoming substrates before processing, automatically determining the adjustments needed to compensate for variations, thereby maintaining operational simplicity while dramatically improving dimension uniformity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Automated feedback loops continuously measure critical dimensions and adjust process parameters to compensate for substrate variations and process drift, maintaining ease of operation while achieving consistent manufacturing precision across varying conditions

Inventive Principle:

Principle #23Feedback

4Manufacturing precision

If multiple patterning steps are used to achieve smaller features, then manufacturing precision improves, but device complexity and productivity worsen due to increased process steps and variability

Engineering Contradiction:

Improvefeature size controlVSAvoidnumber of process steps

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements feedback control across multiple patterning steps that measures intermediate results and adjusts subsequent process parameters to compensate for accumulated variations, maintaining precision while managing the complexity of multi-step processes

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts process parameters at each patterning step based on measured variations from previous steps, enabling precise control of final feature dimensions despite the increased number of process steps involved

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12531220B2Automated feedforward and feedback sequence for patterning CD control

Publication Date: 2026.01.20 LAM RES CORP

AI summary

A method for performing a feedback sequence for patterning CD control. The method including performing a series of process steps on a wafer to obtain a plurality of features, wherein a process step is performed under a process condition. The method including measuring a dimension of the plurality of features after performing the series of process steps. The method including determining a difference between the dimension that is measured and a target dimension for the plurality of features. The method including modifying the process condition for the process step based on the difference and a sensitivity factor for the plurality of features relating change in dimension and change in process condition.