Pulse Electron Microscopy for Partial Disconnection Detection
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Solution Overview
Problem
Conventional electron beam-based inspection methods in semiconductor manufacturing can only detect defects that produce strong signals, such as complete disconnections, failing to identify defects with partial disconnections, which hampers yield improvement and production efficiency.
Innovation Solution
A pulse electron microscope device utilizing a photocathode and two laser pulses with controlled time intervals between them, enabling high-speed inspection by adjusting the pulse repetition rate and scan rate to detect defects without speed reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional electron beam inspection methods are used, then inspection speed is maintained, but only defects producing strong signals (complete disconnections) can be detected
Solution Approach 1:
The patent applies periodic action by using two laser pulses with a controlled time interval to generate electron pulses that sequentially irradiate the sample. The first laser pulse creates an initial electron pulse, and the second laser pulse creates a second electron pulse after a predetermined time interval. This periodic pulsing enables detection of voltage contrast changes over time, allowing detection of partial disconnections that conventional continuous electron beam methods miss, while maintaining high inspection speed through optimized pulse timing.
2Productivity
If the time interval between laser pulses is reduced to increase inspection speed, then productivity improves, but measurement precision of voltage contrast changes deteriorates
Solution Approach 1:
The patent applies parameter changes by optimizing the time interval between the first and second laser pulses to a predetermined value that balances inspection speed and detection accuracy. By carefully controlling this time interval parameter, the system captures voltage contrast changes at their maximum amplitude while maintaining high inspection throughput. The pulse width, repetition rate, and interval are all tuned as parameters to achieve both speed and precision.
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
The device enhances defect detection efficiency by identifying all defects, including partial disconnections, without speed reduction, thereby improving semiconductor production yield and inspection speed.
Implementation Method 1
a column part including a photocathode, the photocathode configured to convert the first laser pulse into a first electron pulse and convert the second-1 laser pulse into a second electron pulse
Data Source
AI summary
An embodiment of the present disclosure provides a pulse electron microscope device including: a pulse generator configured to emit a laser pulse; a first beam splitter configured to split the laser pulse into a first laser pulse and a second laser pulse; a second beam splitter configured to split the second laser pulse and to reflect a second-1 laser pulse; an interval controller configured to control a time interval between the first laser pulse and the second-1 laser pulse by controlling an optical path length of the first laser pulse; a column part including a photocathode, the photocathode configured to convert the first laser pulse into a first electron pulse and convert the second-1 laser pulse into a second electron pulse; and an inspection module configured to inspect electrical defects in the sample by detecting a change in potential occurring on a surface of the sample.