Charged-Particle Beam Focusing for Stage Vibration Compensation
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Solution Overview
Problem
Existing charged-particle beam inspection systems face limitations in high precision stage motion control mechanisms, which affect imaging resolution and throughput in semiconductor manufacturing, particularly for small feature sizes and 3D structures.
Innovation Solution
A charged-particle beam system with a stage that is movable in X-Y and Z axes, equipped with a position sensing system and controller to dynamically adjust beam deflection and focus signals to compensate for lateral and vertical displacements, using piezoelectric motors and sensors for precise stage leveling and focus control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high precision stage motion control mechanisms are used, then imaging resolution is improved, but device complexity increases
Solution Approach 1:
The system employs vibration sensors to detect stage vibrations and uses feedback control to generate compensation signals that are applied to beam deflectors and focus adjusters, creating a closed-loop system that actively counteracts vibrations to maintain imaging resolution without requiring overly complex mechanical stage control
Solution Approach 2:
Instead of directly controlling stage position with high precision mechanisms, the patent introduces an intermediary compensation system that senses vibrations and applies corrective signals to the beam path, effectively decoupling the imaging quality from direct stage control complexity
2Measurement precision
If stage vibration compensation is implemented, then imaging precision is improved, but device complexity increases
Solution Approach 1:
The system uses the stage's own vibration characteristics detected by mounted sensors to generate self-compensation signals, allowing the system to correct its own vibrations without requiring external complex compensation mechanisms
Solution Approach 2:
Vibration sensors continuously monitor stage vibrations and feed this information back to the control system, which generates real-time compensation signals applied to beam deflectors and focus elements, creating an adaptive closed-loop vibration cancellation system
3Productivity
If dynamic beam deflection and focus adjustment are applied, then throughput is improved, but device complexity increases
Solution Approach 1:
The system dynamically adjusts beam deflection and focus parameters in real-time based on detected stage vibrations, allowing the inspection process to continue at high speed while adaptively compensating for motion errors, thereby maintaining high throughput without requiring static high-precision mechanical control
Solution Approach 2:
The patent replaces complex high-precision mechanical stage control with an electromagnetic field-based compensation approach, where beam deflectors and focus adjusters controlled by electrical signals compensate for mechanical vibrations, substituting mechanical precision requirements with controllable electromagnetic field adjustments
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
Enhances imaging precision and throughput by compensating for stage vibrations and displacements, enabling high-resolution 3D imaging of semiconductor components, improving defect detection and alignment accuracy.
Implementation Method 1
using piezoelectric motors and sensors for precise stage leveling and focus control
Implementation Method 2
a position sensing system to determine a lateral and vertical displacement of the stage
Implementation Method 3
apply a first signal to deflect a primary charged-particle beam incident on the sample to at least partly compensate for the lateral displacement of the stage
Implementation Method 4
apply a second signal to adjust a focus of a deflected charged-particle beam incident on the sample to at least partly compensate for the vertical displacement of the stage
Data Source
AI summary
Systems and methods for irradiating a sample with a charged-particle beam are disclosed. The charged-particle beam system may comprise a stage configured to hold a sample and is movable in at least one of X-Y-Z axes. The charged-particle beam system may further comprise a position sensing system to determine a lateral and vertical displacement of the stage, and a beam deflection controller configured to apply a first signal to deflect a primary charged-particle beam incident on the sample to at least partly compensate for the lateral displacement, and to apply a second signal to adjust a focus of the deflected charged-particle beam incident on the sample to at least partly compensate for the vertical displacement of the stage. The first and second signals may comprise an electrical signal having a high bandwidth in a range of 10 kHz to 50 kHz, and 50 kHz to 200 kHz, respectively.