Substitute Sample Modeling for Semiconductor Process Parameter Tuning

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Solution Overview

Problem

In semiconductor processing, optimizing control parameters is costly and time-consuming due to the need for extensive learning data and the expense and time required for processing tests using actual product samples, which are difficult to measure efficiently.

Innovation Solution

A computer-based system that uses a substitute sample to correlate processing outputs with control parameters, allowing for the calculation of target control parameters for actual samples based on a model indicating the correlation between substitute and actual sample outputs, reducing the need for extensive learning data and costly actual sample measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a large amount of learning data is used to optimize processing conditions through machine learning, then the accuracy of control parameter optimization is improved, but the process development cost and time increase due to the need for extensive processing tests using expensive actual product samples

Engineering Contradiction:
Improveaccuracy of control parameter optimizationVSAvoidprocess development time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent creates a substitute sample that copies the essential structural characteristics of the actual product sample but uses inexpensive materials. This substitute sample serves as a replica for measurement purposes, allowing the acquisition of learning data without using expensive actual product samples, thereby reducing both cost and time while maintaining measurement accuracy

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent introduces a substitute sample made from inexpensive materials that can be used for multiple measurements without degrading. This substitute sample replaces expensive actual product samples in the measurement process, enabling the collection of large amounts of learning data at low cost and allowing rapid iteration for optimization

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Reliability

If actual product samples are used for processing tests to acquire learning data, then the reliability of optimization results is improved, but the measurement efficiency decreases due to the complexity and cost of actual samples

Engineering Contradiction:
Improvereliability of optimization resultsVSAvoidmeasurement efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The substitute sample is designed to copy the critical structural features and measurement characteristics of the actual product sample while using simple, inexpensive materials. This allows measurements to be performed rapidly and efficiently on the substitute sample, which then translates to reliable optimization results when applied to the actual product

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent changes the material parameters of the sample from expensive actual product materials to inexpensive substitute materials, while maintaining the structural and geometric parameters that are relevant to the measurement. This parameter substitution enables efficient measurement without sacrificing the reliability of the optimization results

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS11287782B2Computer, method for determining processing control parameter, substitute sample, measurement system, and measurement method
Publication Date: 2022.03.29 HITACHI LTD
  • US11287782B2 patent drawing
  • US11287782B2 patent drawing
  • US11287782B2 patent drawing

AI summary

A computer for determining a control parameter of processing to be performed on a sample includes: a memory unit configured to store a first model indicating a correlation between a first processing output obtained by measuring a first sample used for manufacturing, on which the processing is performed and a second processing output obtained by measuring a second sample that is easier to measure than the first sample and on which the processing is performed, and a second model indicating a correlation between a control parameter of the processing performed on the second sample and the second processing output; and an analysis unit configured to calculate a target control parameter of the processing performed on the first sample based on a target processing output as the target first processing output, the first model, and the second model.