Automated Inline Defect Characterization for Semiconductor Yield

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Solution Overview

Problem

Current semiconductor manufacturing processes face challenges in identifying and characterizing defects inline during fabrication, leading to increased complexity and reduced efficiency in defect classification and yield improvement, especially as critical dimensions become smaller.

Innovation Solution

An automated method for inline defect characterization using a computer-implemented system that imports semiconductor circuit layouts and netlists, detects defects with optical or scanning electron microscopes, performs electrical analysis, and filters out insignificant defects based on critical dimensions and volumes, enabling classification and ranking of defects by their impact on circuit operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If automated inline defect characterization is implemented, then productivity and yield enhancement are improved, but device complexity increases due to integration of multiple analysis tools

Engineering Contradiction:
Improveproduction outputVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent combines multiple defect analysis tools (optical inspection, SEM, TEM, FIB, electrical testing) into a single integrated automated characterization system. This merging allows simultaneous execution of multiple analysis techniques on the same defect, eliminating the need for separate manual inspection steps and thereby improving productivity while managing system complexity through unified control.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The automated characterization system is designed to perform multiple functions: visual defect detection, dimensional measurement, material analysis, and electrical impact assessment. This multi-functionality allows a single system to replace multiple specialized tools, improving production throughput by handling diverse defect types without requiring separate inspection lines for each analysis type.

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

2Measurement precision

If comprehensive defect analysis is performed on all defects, then measurement precision is improved, but loss of time increases due to inspection of insignificant defects

Engineering Contradiction:
Improvedefect characterization accuracyVSAvoidinspection time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system applies different levels of analysis depth to different defects based on their characteristics and location. Critical defects in sensitive circuit areas receive comprehensive multi-tool analysis, while minor defects in non-critical areas receive simplified characterization. This localized quality approach ensures high measurement precision for important defects while minimizing inspection time for insignificant ones.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The automated system performs preliminary rapid screening of all defects using optical inspection, then selectively applies more time-consuming advanced analyses (SEM, TEM, electrical testing) only to defects that exceed certain criteria. This partial action approach ensures thorough characterization of critical defects while avoiding unnecessary analysis of minor defects, thereby reducing overall inspection time.

Inventive Principle:
Principle #16Partial or excessive action

3Manufacturing precision

If smaller critical dimensions are used in lithography, then manufacturing precision is improved, but object-affected harmful factors increase due to greater impact of smaller defects

Engineering Contradiction:
Improvefeature size precisionVSAvoiddefect impact
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The system performs comprehensive defect characterization inline during fabrication, before subsequent processing steps. By identifying and analyzing defects early in the manufacturing process, the system can predict which defects will become harmful after additional fabrication steps, allowing for preventive actions such as targeted rework or selective device disposal before the defects cause actual circuit failures.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The automated characterization system provides real-time feedback about defect characteristics and their potential impact on circuit functionality. This feedback loop allows the manufacturing process to be adjusted dynamically, with critical defects triggering alerts that can lead to process corrections, additional inspection of similar areas, or selective device handling to prevent defective chips from proceeding to later stages where defects would have greater harmful impact.

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach allows for real-time defect identification and classification, reducing the number of defects requiring inspection, increasing production output, and enhancing yield by accurately determining the impact of defects on semiconductor circuits, particularly for technology nodes below 45 nanometers.

Implementation Method 1

The defect may be detected using one of a group comprising an optical microscope and a scanning electronic microscope

Methodology Applied
Scientific EffectOptical microscopy:

Implementation Method 2

The defect may be detected using one of a group comprising an optical microscope and a scanning electronic microscope

Methodology Applied
Scientific EffectElectron beam imaging: Electron Beam

Implementation Method 3

The defect may be emphasized using voltage contrast

Methodology Applied
Scientific EffectVoltage contrast:

Data Source

PatentUS8826209B2Automated inline defect characterization
Publication Date: 2014.09.02 SYNOPSYS INC
  • US8826209B2 patent drawing
  • US8826209B2 patent drawing
  • US8826209B2 patent drawing

AI summary

Defect characterization is a useful tool for analyzing and improving fabrication for semiconductor chips. By using layout and netlist in combination with images of semiconductors, defects can be identified and analyzed. Electrical simulation can be performed on the netlist, based on the presence of the defect that was detected. Layout geometries where the defect was detected can be binned and a search can be performed of the remainder of the layout for similar groupings of layout geometries. Various representations of the semiconductor can be cross mapped, including layout, schematic, and netlist. The presence of certain defects can be correlated to yield, performance, and other characteristics.