Electrodeless Electron Mobility Measurement in Nano Materials
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for analyzing vertical movement characteristics of charges in nano-electronic materials often damage the samples due to electrode interaction, and existing technologies struggle to measure these characteristics effectively without distorting physical properties, especially in thin-film structures and 3D integration scenarios.
Innovation Solution
A method that eliminates the need for electrodes by using an electron gun or photon supply unit to irradiate the sample, measuring sample current, calculating secondary electron current, and defining an effective incident current to determine electron or hole mobility through equations like JEP(μ)=−1/(1−δEP)×μKBT∇q/e, allowing for electrodeless analysis of vertical movement characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional electrode patterning method is used to measure vertical movement characteristics of charges, then measurement capability is achieved, but physical properties of the sample are damaged due to electrode interaction
Solution Approach 1:
The invention extracts and removes the metal electrode component from the measurement system. Instead of using conventional electrode patterning methods that require metal electrodes to be deposited on the sample surface, the patent employs a scanning electron microscope with a floating gate structure that eliminates direct electrode-sample contact. This extraction of the harmful electrode element resolves the contradiction by enabling measurement without the damaging interaction.
Solution Approach 2:
The invention introduces a floating gate structure as an intermediary between the measurement system and the sample. The floating gate, which is not directly connected to external electrodes, serves as a mediator that allows charge measurement through capacitive coupling without physical contact. This intermediary structure enables the measurement of vertical charge movement while preventing the sample damage that would result from direct electrode interaction.
2Reliability
If metal electrodes are used for charge measurement in nanometer-thick films, then electrical contact is established, but physical properties are distorted due to electrode formation
Solution Approach 1:
The invention removes metal electrodes from the measurement configuration. By eliminating the electrode formation process entirely, the method avoids distorting the physical properties of nanometer-thick films while still achieving reliable electrical contact through the floating gate's capacitive coupling mechanism. This extraction resolves the contradiction by decoupling electrical measurement capability from the harmful electrode formation process.
Solution Approach 2:
The invention replaces the mechanical/electrical contact system (metal electrodes physically touching the sample) with a field-based measurement system. The floating gate structure utilizes electric field coupling and capacitive effects to establish electrical contact without physical contact. This substitution maintains measurement reliability while preserving the stability of the sample's physical properties by eliminating the mechanical intrusion of electrode formation.
3Object-affected harmful factors
If electrodeless measurement method is used to avoid sample damage, then sample integrity is preserved, but measurement capability must be developed without conventional electrodes
Solution Approach 1:
The invention makes the scanning electron microscope perform multiple functions by utilizing its existing electron beam generation capability for both imaging and charge measurement. The floating gate structure, integrated into the SEM, serves dual purposes: it maintains the electron beam path for imaging while simultaneously enabling electrodeless charge measurement through capacitive coupling. This multi-functionality reduces device complexity by leveraging existing SEM capabilities rather than requiring a completely new measurement apparatus.
Solution Approach 2:
The floating gate structure serves itself by utilizing the electron beam from the SEM to generate the measurement signal. The same electron beam that would normally be used for imaging also charges the floating gate, creating the signal needed for measurement. This self-service approach eliminates the need for separate electrode structures or additional measurement devices, thereby reducing overall system complexity while maintaining sample integrity.
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 approach reduces material development costs and time, enables real-time measurement of material properties, and provides accurate information on charge movement mechanics without physical damage, facilitating the design and development of customized electronic structures.
Implementation Method 1
an electron irradiation step of irradiating the metal sample with electrons using the electron gun
Implementation Method 2
a secondary electron current calculation step of calculating a secondary electron current through the measured sample current
Implementation Method 3
a sample current measurement step of applying a voltage to the metal sample to measure a sample current according to the applied voltage on the metal sample
Implementation Method 4
measuring electron mobility in the metal sample using a value of the defined effective incident current
Implementation Method 5
photon supply unit provided in the chamber, and a metal sample provided in the sealed space to face the photon supply unit, the method including an electron irradiation step of irradiating the metal sample with photons through the photon supply unit
Data Source
AI summary
A method for measuring electron mobility according to the present invention, which is performed by an apparatus comprising a chamber forming a sealed space, an electron gun provided in the chamber, and a metal sample disposed opposite to the electron gun in the sealed space, comprises: an electron irradiation step of irradiating the metal sample with electrons by the electron gun; a sample current measurement step of applying a voltage to the metal sample to measure a sample current obtained in the metal sample according to the applied voltage; a secondary electron current calculation step of calculating a secondary electron current through the measured sample current; and an effective incident current definition step of defining the sum of the measured sample current and the calculated secondary electron current as an effective incident current.