Wafer Particle Defect Activation for Raman Spectroscopy

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Solution Overview

Problem

Current semiconductor wafer inspection systems face challenges in detecting and identifying particle defects on wafer surfaces without transferring the wafer to separate tools, as many defect particles are spectroscopically inactive and require additional analysis tools like SEM and EDX, which is time-consuming and inefficient.

Innovation Solution

A scanning surface inspection system that detects particle defects and transforms them into spectroscopically active states using chemical, thermal, or photochemical treatments, allowing for simultaneous defect detection and composition analysis using Raman spectroscopy without the need for additional tools.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If separate SEM and EDX tools are used to analyze particle defects, then composition identification accuracy is improved, but inspection time and process complexity increase

Engineering Contradiction:
Improvecomposition identification accuracyVSAvoidinspection time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent combines multiple analysis functions (Raman spectroscopy, SEM, and EDX) into a single integrated inspection tool. This merging allows the system to perform composition analysis, imaging, and elemental detection simultaneously on the same wafer without transferring between separate tools, thereby maintaining measurement precision while reducing inspection time and process complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The inspection tool is designed with multi-functionality, capable of performing Raman spectroscopy for composition identification, SEM for imaging, and EDX for elemental analysis. This universal tool eliminates the need for multiple specialized devices, reducing wafer transfer operations and accelerating the overall inspection process while maintaining accurate composition identification.

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

2Loss of information

If wafer is transferred between multiple tools for analysis, then comprehensive defect characterization is improved, but throughput and efficiency deteriorate

Engineering Contradiction:
Improvedefect characterization completenessVSAvoidthroughput
Core Design Contradiction:
Loss of informationVSProductivity

Solution Approach 1:

The patent integrates Raman spectroscopy, SEM, and EDX capabilities into a single inspection system. This merging enables comprehensive defect characterization including composition, morphology, and elemental analysis to be performed on the same wafer without transfer operations, thereby maintaining complete information gathering while significantly improving throughput and manufacturing efficiency.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If Raman spectroscopy is used to detect particle composition, then analysis speed is improved, but detectability of spectroscopically inactive particles deteriorates

Engineering Contradiction:
Improveanalysis speedVSAvoidparticle detectability
Core Design Contradiction:
ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies preliminary chemical treatment to particles before Raman spectroscopy analysis. This preliminary action modifies the particle surface or composition to enhance its Raman scattering signal, making spectroscopically inactive particles detectable. The treatment is performed in advance of the spectroscopic measurement, enabling both fast analysis and improved particle detectability.

Inventive Principle:
Principle #10Preliminary action

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

Enables rapid detection and identification of particle defects on semiconductor wafers by activating observable Raman bands, improving the signal-to-noise ratio and reducing the time and cost associated with transferring wafers for analysis, thereby enhancing the efficiency of semiconductor manufacturing processes.

Implementation Method 1

activates observable Raman bands in one or more of the detected particles by chemical treatment, thermal treatment, or photochemical treatment

Methodology Applied
Scientific EffectPhotochemical treatment: Photo-oxidation

Implementation Method 2

activates observable Raman bands in one or more of the detected particles by chemical treatment, thermal treatment, or photochemical treatment

Methodology Applied
Scientific EffectThermal treatment: Heating

Implementation Method 3

A spectrometer is employed to resolve solid-state vibrational modes in the inelastic light, revealing composition information

Methodology Applied
Scientific EffectRaman scattering: Brillouin Scattering

Data Source

PatentEP3549160B1Activation of wafer particle defects for spectroscopic composition analysis
Publication Date: 2022.01.05 KLA CORP
  • EP3549160B1 patent drawingFigure 1
  • EP3549160B1 patent drawingFigure 2
  • EP3549160B1 patent drawingFigure 3

AI summary

Methods and systems for detecting a particle defect on a wafer surface, transforming the particle to a spectroscopically active state, and identifying a material composition of the activated particle by a spectroscopic technique are described herein. Particle defects are transformed by chemical treatment, thermal treatment, photochemical treatment, or a combination thereof, such that an activated particle exhibits atomic vibrational bands that can be observed spectroscopically. In one embodiment, a surface inspection system detects the presence of a particle defect on a wafer surface, activates observable Raman bands in one or more of the detected particles, and identifies the material composition of the activated particle by a spectroscopic technique. By performing both defect detection and composition analysis on the same inspection tool, it is not necessary to transfer a wafer to a different review tool, or combination of tools, to perform composition analysis of particle defects deposited on semiconductor wafers.