Semiconductor Process Simulation With RNN Step Profile Prediction

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Solution Overview

Problem

Current semiconductor process simulation technologies are limited in generating profiles for intermediate process steps, making it difficult to trace faults and optimize process conditions, as they primarily produce final profiles and lack the capability to accurately predict profiles for each step.

Innovation Solution

A simulation method using a recurrent neural network (RNN) with process emulation cells, which receives previous output profiles, target profiles, and process condition information to generate accurate profiles for each process step by incorporating prior knowledge of time series causal relationships.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional process simulation is used, then final profile can be obtained, but intermediate step profiles cannot be obtained

Engineering Contradiction:
Improveprofile estimation accuracyVSAvoidintermediate step profile information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent segments the semiconductor manufacturing process into multiple discrete process steps, with each step represented by a dedicated process emulation cell in the RNN architecture. This segmentation allows the system to generate and analyze profiles for each intermediate step independently, rather than only producing the final profile. The segmented approach enables detailed inspection and fault tracing at each process stage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs preliminary action by using the RNN model to predict and generate intermediate step profiles before actual manufacturing occurs. The system performs preliminary simulation of each process step to estimate profiles, allowing for pre-identification of potential faults and optimization opportunities before committing to the actual manufacturing process.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If multiple profiles for multiple process steps are checked, then process optimization is improved, but cost and technology limitations prevent this

Engineering Contradiction:
Improveprocess optimizationVSAvoidsimulation system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex physical measurement and inspection systems with a computational RNN-based simulation system. Instead of using expensive and complex experimental methods to obtain profiles at each process step, the system uses machine learning models to substitute for physical measurement, significantly reducing both cost and technological complexity while maintaining the ability to generate multiple process step profiles.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes parameter changes by training the RNN model on historical process data with various parameters (process conditions, equipment settings, etc.) and then using the trained model to predict profiles under different parameter combinations. This allows for efficient process optimization by simulating how changes in parameters affect intermediate profiles without requiring actual experimental trials for each parameter combination.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If only final profile is obtained through simulation, then simulation simplicity is maintained, but fault tracing becomes difficult

Engineering Contradiction:
Improvesimulation simplicityVSAvoidfault detection capability
Core Design Contradiction:
Ease of operationVSDifficulty of detecting and measuring

Solution Approach 1:

The patent introduces intermediate process step profiles as mediators between the initial process conditions and the final profile. These intermediate profiles serve as diagnostic checkpoints that help trace faults back to their source process steps. The RNN architecture generates these intermediate profiles automatically, maintaining simulation simplicity while enhancing fault detection capability through the addition of these intermediary diagnostic data points.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS11574095B2Simulation system for semiconductor process and simulation method thereof
Publication Date: 2023.02.07 SAMSUNG ELECTRONICS CO LTD
  • US11574095B2 patent drawing
  • US11574095B2 patent drawing
  • US11574095B2 patent drawing

AI summary

Provided is a simulation method performed by a process simulator, implemented with a recurrent neural network (RNN) including a plurality of process emulation cells, which are arranged in time series and configured to train and predict, based on a final target profile, a profile of each process step included in a semiconductor manufacturing process. The simulation method includes: receiving, at a first process emulation cell, a previous output profile provided at a previous process step, a target profile and process condition information of a current process step; and generating, at the first process emulation cell, a current output profile corresponding to the current process step, based on the target profile, the process condition information, and prior knowledge information, the prior knowledge information defining a time series causal relationship between the previous process step and the current process step.