Electron Beam Layer Profiling for Buried Semiconductor Edges
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Solution Overview
Problem
Current examination methods struggle to accurately determine the properties of multiple layers within semiconductor wafers, particularly those buried beneath other layers, which is crucial for high-density and high-performance semiconductor fabrication.
Innovation Solution
An electron beam examination system scans semiconductor specimens with varying landing energies to generate distinct patterns of lateral edges for different layers, allowing for the differentiation and property determination of these layers based on differences in pattern widths, amplitudes, and slopes in the acquired signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional examination methods are used to measure dimensions of semiconductor specimens, then the measurement process is simple, but the measurement precision for buried layers is insufficient
Solution Approach 1:
The patent applies parameter changes by varying the landing energy of the electron beam to alter its penetration depth and interaction characteristics with different layers. By adjusting this parameter, the system generates distinct signal patterns for layers at different depths, enabling precise measurement of buried layers that conventional methods cannot resolve
Solution Approach 2:
The patent introduces a new dimension of analysis by utilizing the energy-depth relationship of electron beam interaction. Instead of relying solely on spatial positioning, the system measures signal patterns across different landing energies, creating an energy-dimensional space where buried layers can be distinguished and measured with high precision
2Loss of information
If electron beam with fixed landing energy is used to scan the specimen, then the examination process is straightforward, but the ability to differentiate between layers at different depths is lost
Solution Approach 1:
The patent applies preliminary action by performing a series of scans at different landing energies before final measurement. This preliminary exploration of the energy-response characteristics allows the system to establish the relationship between landing energy and layer-specific signal patterns, enabling subsequent precise differentiation of buried layers
Solution Approach 2:
The system utilizes feedback by analyzing the signal patterns generated at each landing energy level and adjusting the measurement strategy accordingly. The feedback loop identifies characteristic patterns for different layers and refines the energy selection to optimize depth differentiation, maintaining ease of operation while preventing information loss
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 precise identification of layer positions, widths, and compliance with design data, even in complex multi-material patterns, enhancing the accuracy of semiconductor fabrication processes.
Implementation Method 1
an electron beam examination system operative to scan the specimen with an electron beam associated with a landing energy
Data Source
AI summary
There are provided systems and methods comprising obtaining an acquisition signal informative of a semiconductor specimen comprising at least a first layer located at a first depth and a second layer located at a second depth, wherein the acquisition signal has been acquired by an electron beam examination system operative to scan the specimen with an electron beam associated with a landing energy enabling generating, in at least one of the acquisition signal or in a signal derived from the acquisition signal, a first pattern informative of a lateral edge of the first layer, and a second pattern informative of a lateral edge of the second layer, wherein the second pattern differs from the first pattern, and using at least one of the acquisition signal or the signal derived from the acquisition signal, to determine properties of at least one of the first layer or the second layer.