TEM Sample Preparation via Bilateral Electron Beam Deposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In TEM sample preparation, thin film portions tend to curve due to internal stress as their thickness decreases, and existing methods to form deposition films to prevent curvature are inadequate for extremely thin films, as they can introduce tension.
Innovation Solution
A method involving the use of an ion beam to process a sample into a thin film portion, followed by simultaneous deposition of films on both surfaces of the thin film portion using an electron beam and deposition gas, thereby applying tension evenly and preventing curvature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the thickness of the thin film portion is reduced to achieve higher resolution TEM observation, then the observation precision is improved, but the thin film portion curves due to internal stress
Solution Approach 1:
The patent applies counterweight principle by forming deposition films on both the front surface and rear surface of the thin film portion. The deposition films act as counterbalancing weights that offset the internal stress causing curvature, allowing the ultra-thin film to maintain flatness while achieving the required thickness for high-resolution TEM observation.
Solution Approach 2:
The patent uses composite materials by combining the original thin film portion with deposition films formed on both surfaces. This composite structure integrates the ultra-thin film (for observation quality) with the deposition films (for mechanical stability), resolving the contradiction between thickness reduction and curvature prevention.
2Stability of the object's composition
If a deposition film is formed on the thin film portion to prevent curvature, then the shape stability is improved, but the thin film portion may be curved by tension of the deposition film when extremely thin
Solution Approach 1:
The patent applies asymmetry principle by forming deposition films on both surfaces of the thin film portion rather than just one surface. This symmetric deposition approach ensures that tensile forces are distributed evenly on both sides, preventing the deposition film itself from inducing curvature while still providing the necessary shape stability.
Solution Approach 2:
The deposition film on the rear surface acts as a counterbalance to the tensile force of the deposition film on the front surface. This counterweight effect neutralizes the tension-induced curvature, allowing the use of deposition films for shape stabilization even in extremely thin film portions.
3Device complexity
If conventional deposition methods are used to form reinforcement layers, then the device complexity is reduced, but the manufacturing precision deteriorates due to inability to form films on both surfaces simultaneously
Solution Approach 1:
The patent applies multi-functionality principle by using a single electron beam deposition system to perform multiple functions: forming the deposition film on the front surface, transmitting through the thin film portion, and forming the deposition film on the rear surface. This unified approach simplifies the device while achieving precise bilateral film formation.
Solution Approach 2:
The patent utilizes the transmission property of electron beams through ultra-thin films to deposit material on both surfaces simultaneously. By leveraging the third dimension (beam transmission through the film thickness), the process achieves bilateral deposition without requiring separate deposition chambers or complex positioning mechanisms.
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 effectively prevents curvature of the thin film portion by forming deposition films on both surfaces, allowing for accurate sample preparation without distortion, even at extremely small thicknesses.
Implementation Method 1
processing a sample piece by an ion beam, thereby forming a thin film portion
Implementation Method 2
irradiating the thin film portion with the electron beam, thereby forming a first deposition film on a first surface of the thin film portion and a second deposition film on a second surface
Data Source
AI summary
A sample preparation method includes processing a sample by an ion beam to form a thin film portion having a thickness that allows an electron beam to transmit therethrough; supplying deposition gas to the thin film portion; and irradiating the thin film portion with an electron beam to simultaneously form a deposition film on a front surface of the thin film portion and a deposition film on a rear surface of the thin film portion opposed to the front surface. The electron beam transmits through the thin film portion, generating secondary electrons from both the front and rear surfaces that decompose the deposition gas to form the deposition films.