SEM：Scanning Electron Microscopy
Features
SEM is a method for imaging the surface morphology and compositional differences of the sample based on the information of electrons generated from the sample by electron beam irradiation. Features include:
- Up to 500,000x magnification
- Images from secondary electrons (SE), backscattered electrons (BSE), and transmitted electrons (TE)
- 0.1 to 30 kV acceleration voltage
- Up to 6-inch circular samples
- Optional measurements provide additional information
- Elemental analysis with attached EDX detector
- Evaluation of junction positions and shapes of semiconductor devices by electronbeam-induced current (EBIC)
- Crystalline data from electron backscattering diffraction (EBSD)
- Steric structural information by in situ repeated focused ion beam etching (FIB), also known as "slice & view".
- Real-time monitoring and control of chamber atmosphere and sample temperature
Application Examples
- Surface observation
- Cross-sectional observation
- Failure analysis
- Film thickness measurement
- Particle size measurement
Principle
Electrons are accelerated by a static electric field and impinge on the sample. Images are then created from either secondary electron emission, reflection, or transmission (requires a flake sample similarly to TEM).
The angle, depth, and type of the electron scattering depend on the material and the accelerating voltage, so it is necessary to select the optimum acceleration voltage according to the purpose of the measurement. Fig. 2 shows the calculated scattering depth of Si and Cu for two acceleration voltages and Fig. 3 shows the various processes resulting from the electron bombardment.
Data examples
Secondary electron image: Potato starch
- Excellent surface morphology information
- High resolution
- Excellent contrast
Backscattered electron image: W/Cr multilayer film
- Excellent composition information
- Low impact by surface morphology on image contrast
- Less susceptible to charge-up
SEM-STEM image: Organic electroluminescent device
- Identification of density and composition differences from high-contrast imaging.
Backscattered electron image: Frozen cosmetic foundation liquid
- Evaluation of liquids and gel samples
Data delivery format
Specifications
Items for enquiries
- Purpose and content of measurement
- Sample information
- Number of samples, and availability of preliminary samples
- Shape, composition, and availability of cutting and/or coating the sample
- Layer structure and film thickness (for cross-sectional observation)
- Handling instructions
- Details on delivery
- Preferred due date for preliminary analysis report
- Due date for delivery of final report
- Any other issues
Caution
The following materials may adversely affect the evaluation:
- Magnetic materials
- Samples with a low melting point and vaporization
- Insulating material (may be observable by conductive treatment such as Pt or C)
［SEM］走査電子顕微鏡法の分析事例はこちらからご覧ください。