Charged Particle Beam Inspection for Thin Device Defects
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Solution Overview
Problem
Conventional SEM inspection tools fail to reliably detect defects in thin device structures due to their time-dependent electrical characteristics, as they typically capture only a single image, which may not capture the defect if the electrical characteristics change over time.
Innovation Solution
A charged particle beam inspection system that directs charged particles onto a wafer over multiple time sequences, producing multiple images of the same area to detect changes in electrical characteristics and identify defects in thin device structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single image is captured by conventional SEM inspection tools, then the inspection process is fast and simple, but defects in thin device structures with time-dependent electrical characteristics cannot be reliably detected
Solution Approach 1:
The inspection system performs multiple image captures of the same area at different time points, creating a time-series inspection process. This periodic sampling allows detection of defects that manifest transiently in thin device structures with time-dependent electrical characteristics, resolving the contradiction between detection reliability and process complexity by systematically repeating the measurement.
Solution Approach 2:
The system transitions from a static single-image capture approach to a dynamic multi-temporal inspection method. By capturing images at multiple time points and analyzing temporal changes in electrical characteristics, the system adapts to the dynamic nature of defects in thin device structures, improving reliability while managing complexity through automated temporal analysis.
2Measurement precision
If multiple images are captured over time sequences to detect transient changes, then defect detection reliability improves, but inspection time and processing complexity increase
Solution Approach 1:
The system captures a series of images over time sequences, using partial temporal sampling rather than continuous monitoring. This approach achieves sufficient measurement precision for detecting transient defects while limiting the total inspection time by selecting strategic time points for image capture, balancing precision requirements with time constraints.
Solution Approach 2:
The system performs preliminary image captures at multiple time points to establish temporal baselines before final defect analysis. This preliminary temporal sampling allows the system to identify time-dependent patterns and prepare for efficient defect detection, reducing the time required for final analysis by pre-processing temporal information.
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 reliable detection of defects in thin device structures by capturing transient changes in electrical surface potential, improving defect identification and reducing false negatives in advanced semiconductor manufacturing.
Implementation Method 1
a beam of primary electrons having a relatively high energy is decelerated to land on a sample at a relatively low landing energy and is focused to form a probe spot thereon. Due to this focused probe spot of primary electrons, secondary electrons will be generated from the surface.
Implementation Method 2
The secondary electrons may comprise backscattered electrons, secondary electrons, or Auger electrons, resulting from the interactions of the primary electrons with the wafer.
Implementation Method 3
The secondary electrons may comprise backscattered electrons, secondary electrons, or Auger electrons, resulting from the interactions of the primary electrons with the wafer.
Data Source
AI summary
An improved charged particle beam inspection apparatus, and more particularly, a particle beam inspection apparatus for detecting a thin device structure defect is disclosed. An improved charged particle beam inspection apparatus may include a charged particle beam source to direct charged particles to a location of a wafer under inspection over a time sequence. The improved charged particle beam apparatus may further include a controller configured to sample multiple images of the area of the wafer at difference times over the time sequence. The multiple images may be compared to detect a voltage contrast difference or changes to identify a thin device structure defect.