Charged Particle Beam Aligner for Deep Hole Signal Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current scanning electron microscopes face challenges in accurately detecting signals from the bottom of deep holes and trenches due to interference from side wall electrons, leading to inefficient detection and difficulty in achieving high S/N ratios, especially when trying to unify signals from left and right detectors.
Innovation Solution
A charged particle beam apparatus with an aligner and control unit that selectively aligns and controls the trajectories of secondary electrons, allowing for efficient detection of signals in specified directions and improving the S/N ratio by emphasizing the brightness of signal waveforms, enabling precise measurement of pattern dimensions and edge information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple detectors are used to detect charged particles from different directions, then the detection coverage is improved, but the ability to detect signals from deep hole bottoms is worsened due to side wall interference
Solution Approach 1:
The detection process is segmented into two distinct stages: first detecting charged particles that pass through the passage opening, then detecting charged particles resulting from bombardment on another member. This segmentation allows separate optimization of detection angles and positions for each particle type, improving bottom signal detection while maintaining comprehensive detection coverage.
Solution Approach 2:
Another member is introduced as an intermediary element that charged particles bombard after passing through the passage opening. This intermediary converts the trajectory information of particles from deep hole bottoms into detectable signals, enabling differentiation between bottom-originated particles and side wall interference.
2Stability of the object's composition
If trajectories of discharged charged particles are aligned to unify detector outputs, then the uniformity of left and right edge brightness is improved, but the detection efficiency of edge information is worsened
Solution Approach 1:
The aligner dynamically adjusts the trajectories of discharged charged particles based on real-time detection needs. Rather than fixed alignment, the system can adaptively modify particle paths to optimize both uniformity and edge information detection, switching between alignment modes as required by different measurement objectives.
Solution Approach 2:
The aligner performs preliminary alignment of charged particle trajectories before they reach the detectors. By pre-adjusting particle paths, the system ensures that particles originate from specific regions (such as hole bottoms) reach the detectors in a controlled manner, improving both uniformity and edge detection efficiency.
3Measurement precision
If the focus is placed on detecting high angle electrons, then the image contrast of hole bottom is improved, but the detection of low angle electrons from side walls is worsened
Solution Approach 1:
The detection system segments charged particles based on their origin and trajectory: particles passing through the passage opening are detected separately from particles bombarding another member. This segmentation allows high angle electrons from hole bottoms to be detected with high contrast while side wall electrons are detected through a different channel, reducing mutual interference.
Solution Approach 2:
Another member serves as an intermediary that converts trajectory information into spatial separation. By having particles bombarding this intermediary at different locations based on their origin, the system can distinguish between high angle electrons from hole bottoms and low angle electrons from side walls, reducing harmful interference.
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 solution allows for high-accuracy detection of edge information at the bottom of deep structures and improves the identification of patterns difficult to judge through top/down images, enhancing the measurement accuracy in semiconductor manufacturing processes.
Implementation Method 1
an aligner for aligning the charged particles discharged from the sample and a control unit for controlling the aligner
Data Source
AI summary
The charged particle beam apparatus having an opening formation member formed with an opening for passage of a charged particle beam emitted from a charged particle source, and either a detector adapted to detect charged particles having passed through the passage opening or a detector adapted to detect charged particles resulting from bombardment on another member of the charged particles having passed through the opening, comprises an aligner for aligning charged particles discharged from the sample and a control unit for controlling the aligner, wherein the control unit controls the aligner to cause it to shift trajectories of the charged particles discharged from the sample so that length measurement may be executed on the basis of detection signals before and after the alignment by the aligner.