High-Dimensional Variable Selection for Semiconductor Tool Parameter Analysis

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Solution Overview

Problem

Current semiconductor manufacturing processes face challenges in efficiently identifying critical parameters that affect tool performance due to the complexity of inspection tools, which have tens of thousands of measurable parameters, making it cumbersome for field service engineers to determine the correct parameters to adjust for matching and root-cause analysis.

Innovation Solution

A high-dimensional variable selection system and method that uses models like elastic net, forward-stagewise regression, or least angle regression to analyze sensor data and parametric tool measurements, identifying a list of critical parameters that significantly impact tool performance, allowing for efficient navigation through massive parameter sets and reducing the need for subjective parameter selection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If tens of thousands of parameters are tracked in inspection tools, then tool functionality and flexibility are improved, but parameter review complexity and analysis time increase significantly

Engineering Contradiction:
Improvetool functionalityVSAvoidparameter review complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts and identifies a small subset of critical parameters from the tens of thousands of measurable parameters. This subset serves as a fingerprint that captures most tool variations, allowing engineers to focus on only the most important parameters rather than reviewing all parameters manually.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an automated parameter selection system that acts as an intermediary between the complex tool parameters and the engineer's decision-making process. This system automatically identifies critical parameters and their interactions, eliminating the need for manual review of all parameters.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If one parameter at a time is correlated to Match Factor, then parameter analysis is simplified, but critical parameters may be overlooked and parameter interactions are missed

Engineering Contradiction:
Improveparameter analysis simplicityVSAvoidparameter selection accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent employs a comprehensive parameter selection framework that simultaneously evaluates multiple parameters and their interactions. This multi-functional approach identifies not only individual critical parameters but also parameter interactions, ensuring no critical factors are overlooked while maintaining systematic analysis.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system incorporates feedback mechanisms that continuously evaluate parameter importance and adjust the critical parameter subset accordingly. This ensures that the most relevant parameters are identified while accounting for parameter interactions and correlations.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If thousands of tool parameters are measured, then comprehensive tool characterization is achieved, but it is impractical to develop specifications for all parameters

Engineering Contradiction:
Improvetool characterization completenessVSAvoidspecification development efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent extracts a minimal subset of critical parameters that serve as a fingerprint for the tool. This subset captures most tool variations and is sufficient for developing specifications, making the specification development process practical and efficient while maintaining comprehensive tool characterization.

Inventive Principle:
Principle #2Taking out (Extraction)

4Productivity

If maintenance schedules are limited to one day, then service time is reduced, but thorough parameter analysis and tool matching become extremely cumbersome

Engineering Contradiction:
Improveservice speedVSAvoidparameter analysis ease
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent extracts a small subset of critical parameters that can be analyzed quickly during the one-day maintenance window. This subset captures the essential tool variations and enables efficient tool matching without requiring extensive parameter review.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system implements automated parameter selection and analysis that reduces the burden on field service engineers. The automated system identifies critical parameters and evaluates their impacts, allowing engineers to focus on decision-making rather than manual parameter analysis.

Inventive Principle:
Principle #25Self-service

Data Source

PatentUS11456194B2Determining critical parameters using a high-dimensional variable selection model
Publication Date: 2022.09.27 KLA CORP
  • US11456194B2 patent drawing
  • US11456194B2 patent drawing
  • US11456194B2 patent drawing

AI summary

A high-dimensional variable selection unit determines a list of critical parameters from sensor data and parametric tool measurements from a semiconductor manufacturing tool, such as a semiconductor inspection tool or other types of semiconductor manufacturing tools. The high-dimensional variable selection model can be, for example, elastic net, forward-stagewise regression, or least angle regression. The list of critical parameters may be used to design a next generation semiconductor manufacturing tool, to bring the semiconductor manufacturing tool back to a normal status, to match a semiconductor manufacturing tool's results with that of another semiconductor manufacturing tool, or to develop a specification for the semiconductor manufacturing tool.