Semiconductor Inspection Using Pulsed Light and Circuit Modeling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for inspecting semiconductor devices fail to detect defects related to time response such as capacitance and require a circuit model for quantitative evaluation of defects.
Innovation Solution
A charged particle beam device with a charged particle optical system, electron pulse generator, and detector, combined with a light irradiation system and contact probe, controlled by a device that measures and generates a circuit model to estimate circuit constants and defect structures based on secondary electron detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a method using electron beam and light irradiation is used to inspect defects based on current change, then resistance defects can be detected, but time response defects such as capacitance cannot be detected
Solution Approach 1:
The inspection system integrates multiple measurement functions into a single platform by combining voltage contrast imaging with time-resolved current measurement capabilities. The system can detect both resistance defects (through steady-state voltage contrast) and capacitance defects (through time-resolved current response), making it universally applicable to various electrical characteristic inspections without requiring separate specialized equipment.
Solution Approach 2:
The system measures electrical characteristics by changing the time parameter of measurement. By capturing current responses at multiple time points after light irradiation, the system can distinguish between resistance defects (which show immediate current change) and capacitance defects (which show time-dependent current decay), thereby expanding the range of detectable electrical characteristics through parameter variation.
2Measurement precision
If a circuit model is used to quantitatively evaluate defects, then defect position and type can be inspected, but the method becomes complex and requires pre-established reference models
Solution Approach 1:
The system performs self-characterization by automatically extracting circuit parameters (such as resistance and capacitance values) directly from the measured voltage contrast and time-resolved current data. Instead of requiring external circuit models to be pre-established, the system generates its own reference data from the actual device under test, eliminating the need for complex external modeling and simplifying the inspection process while maintaining quantitative evaluation accuracy.
3Measurement precision
If voltage contrast imaging is used to evaluate electrical resistance, then resistance defects can be detected, but the method lacks time resolution for capacitance measurement
Solution Approach 1:
The system employs periodic pulsed light irradiation combined with time-resolved current measurement to capture the temporal dynamics of electrical responses. By irradiating the device with periodic light pulses and measuring the current at specific time intervals after each pulse, the system can resolve time-dependent phenomena such as capacitance charging and discharging, thereby recovering time response information that would be lost in steady-state voltage contrast imaging alone.
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 the measurement of electrical characteristics that cannot be measured by existing methods, providing a quantitative evaluation of defects and circuit constants.
Implementation Method 1
a detector configured to detect secondary electrons generated by irradiating the sample to be inspected with the pulse-controlled charged particle beam
Implementation Method 2
a light irradiation system including a light source configured to irradiate the sample to be inspected with light having a predetermined wavelength
Data Source
AI summary
A control device controls a contact probe in synchronization with a pulse-controlled light having a predetermined wavelength, a measurement instrument measures a characteristic of a sample to be inspected or an analysis sample, and a circuit constant or a defect structure of the sample to be inspected is estimated based on a circuit model created by an electric characteristic analysis device configured to generate the circuit model based on a value measured by the measurement instrument and a detection signal of secondary electrons detected by the charged particle beam device.