Processing Condition Learning Using Pseudo States in Vacuum Control

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Solution Overview

Problem

In semiconductor manufacturing, optimizing processing procedures with numerous control parameters is challenging due to the difficulty in analyzing correlations between inputs and outputs, and direct observation of sample states is often impossible, especially in vacuum environments like etching chambers.

Innovation Solution

A system utilizing reinforcement learning with a pseudo state calculated from physical quantities correlating with the sample state, allowing for the determination of appropriate processing conditions for each step without direct measurement of the sample state, using a computer-based learning unit that performs value function analysis and adjusts processing conditions based on evaluated pseudo states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If reinforcement learning is applied to optimize processing procedures with numerous control parameters, then optimization efficiency is improved, but the complexity of analyzing correlations between inputs and outputs increases

Engineering Contradiction:
Improveoptimization efficiencyVSAvoidcomplexity of analyzing correlations
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces a pseudo-state as an intermediary representation that bridges the gap between complex processing conditions and sample states. Instead of directly analyzing the complex correlations between numerous control parameters and sample states, the system calculates a pseudo-state from physical quantities that serve as a mediator, simplifying the reinforcement learning process while maintaining optimization efficiency

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct observation and measurement of sample states with a computational model that calculates pseudo-states from physical quantities. This substitution eliminates the need for direct mechanical intervention or complex measurement systems, using information processing instead to achieve the same optimization goal

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

2Measurement precision

If direct measurement of sample state is performed to achieve accurate control, then control precision is improved, but the ability to operate in vacuum environments without breaking vacuum is deteriorated

Engineering Contradiction:
Improvecontrol precisionVSAvoidability to operate in vacuum environments
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent uses physical quantities as intermediaries to infer sample states without direct measurement. By measuring physical quantities that can be obtained in vacuum environments and calculating pseudo-states from these measurements, the system achieves control precision while maintaining vacuum integrity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct mechanical measurement of sample states with a computational inference system. Instead of physically accessing or touching the sample to measure its state, the system uses a calculation model that derives sample state information from physical quantity measurements, enabling operation in vacuum environments

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

3Manufacturing precision

If the number of control parameters is increased to achieve fine and complicated processing, then processing capability is improved, but the time required for process development increases

Engineering Contradiction:
Improveprocessing capabilityVSAvoidtime required for process development
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent enables the system to automatically optimize processing procedures through reinforcement learning without requiring extensive manual experimentation. The system serves itself by using the calculated pseudo-states and value functions to autonomously determine optimal control parameters, significantly reducing the time required for process development while maintaining fine and complicated processing capability

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements a feedback mechanism where the results of processing are used to update the value function, which in turn guides future processing condition selections. This closed-loop feedback system allows the system to learn from past experiences and continuously improve processing capability over time, reducing the need for extensive preliminary experimentation

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS11112775B2System and method of determining processing condition
Publication Date: 2021.09.07 HITACHI LTD
  • US11112775B2 patent drawing
  • US11112775B2 patent drawing
  • US11112775B2 patent drawing

AI summary

A system for determining a processing procedure including a plurality of processes for controlling an object, the system includes a learning unit for performing a learning process for determining a processing condition of each of a plurality of processes, and the learning unit acquires a physical quantity correlating with a state of the object on which a process has been performed under a predetermined processing condition, from a device for controlling the object on the basis of the processing procedure, calculates a pseudo state corresponding to the state of the object on the basis of the physical quantity, performs a learning process using a value function, and determines a processing condition of each of the plurality of processes to achieve a target state of the object.