Auger Electron Spectrometry Charging Mitigation via Voltage Differential

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional methods for analyzing integrated circuits using Auger Electron Spectrometry face challenges such as charging effects due to non-conductive passivation materials, leading to distorted spectra and reduced accuracy in identifying particulate contamination and residues, which affect device yields and reliability.

Innovation Solution

A method involving the use of a blocking material, such as a platinum film and aluminum foil, to protect the pad area during sample preparation, followed by applying a voltage differential to draw away charged particles and minimize charging effects, allowing for accurate spectrometer analysis without damaging the surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional Auger Electron Spectrometry is used to analyze integrated circuits, then device analysis can be performed, but charging effects occur due to non-conductive passivation materials causing distorted spectra and reduced measurement accuracy

Engineering Contradiction:

Improvespectra accuracyVSAvoidcharging effects

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The sample surface is segmented into different regions: a charged region with non-conductive passivation material and a reference region with conductive material. This segmentation allows the reference region to provide a stable electrical potential while the charged region undergoes analysis, enabling accurate measurement despite charging effects in the passivation material region

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A conductive reference material (such as aluminum foil or conductive paste) is introduced as an intermediary element on the sample surface. This reference material serves as a mediator that provides a stable electrical potential, allowing the spectrometer to differentiate between charging effects and actual sample characteristics, thereby improving measurement accuracy

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If blocking materials are used to protect pad areas during sample preparation, then surface damage is prevented, but additional processing steps are required

Engineering Contradiction:

Improvesurface integrityVSAvoidprocessing steps

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The conductive reference material is applied to the sample surface in advance during sample preparation, before the Auger electron spectrometry analysis. This preliminary action ensures that the reference region is already in place to counteract charging effects during analysis, and the pad areas are protected with blocking materials, streamlining the overall process

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The conductive reference material serves multiple functions: it provides a stable electrical potential for accurate measurement, acts as a charge neutralization source during analysis, and can serve as a reference for both quantitative and qualitative analysis. This multi-functionality reduces the need for separate reference samples or additional processing steps

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 enhances the accuracy of Auger Electron Spectrometry by reducing charging influences, improving device yields, and maintaining cost-effectiveness without substantial modifications to existing equipment or processes, thereby identifying contamination and residues effectively.

Implementation Method 1

charging effects due to non-conductive passivation materials, leading to distorted spectra

Methodology Applied

Scientific EffectCharging effects: Electrostatics

Implementation Method 2

Auger Electronic Spectrometer (AES)

Methodology Applied

Scientific EffectAuger electron spectroscopy: Auger Effect

Data Source

PatentUS7927893B2Method for treatment of samples for auger electronic spectrometer (AES) in the manufacture of integrated circuits

Publication Date: 2011.04.19 SEMICON MFG INT (SHANGHAI) CORP

AI summary

A method for analyzing a sample for the manufacture of integrated circuits, e.g. MOS transistors, application specific integrated circuits, memory devices, microprocessors, system on a chip. The method includes providing an integrated circuit chip, which has a surface area with at least one region of interest, e.g., bond pad. The method includes covering a first portion of the surface area including the region of interest using a blocking material. The method also forms a metal layer on a second portion of the surface area, while the blocking material protects the first portion. The method removes the blocking material to expose the first portion of the surface area including the region of interest. The method also subjects the metal layer to a voltage differential to draw away one or more charged particles from the first portion of the surface area. The method also subjects the surface area including the region of interest to spectrometer analysis.